Mechanical Engineering Ph.D. Thesis EXERGY EVOLUTION OF THE MINERAL CAPITAL ON EARTH By Alicia Valero Delgado July 2008 Directed by: Antonio Valero Capilla, Ph.D. Department of Mechanical Engineering Centro Politécnico Superior University of Zaragoza Exergy evolution of the mineral capital on earth Alicia Valero Delgado Thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy University of Zaragoza, Spain Abstract The 20th century has been characterized by the economic growth of many industrialized countries. This growth was mainly sustained by the massive extraction and use of the earth’s mineral resources. The tendency observed worldwide in the present, is that consumption will continue increasing, especially due to the rapid development of Asia, the desire for a higher living standard of the developing world and the technological progress. But the physical limitations of our planet might seriously restrain world economies. In fact, many mineral commodities such as oil or copper are already showing signs of scarcity problems, and consequently their prices are increasing sharply. Our society is based on an inefficient use of energy and materials, since there is a lack of awareness of the limit. If resources are limited, their management must be carefully planned. But it is impossible to manage efficiently the resources on earth, if we do not know what is available and at which rate it is being depleted. Therefore, the aim of this PhD has been the assessment of the physical stock on earth and the degradation velocity of our mineral resources due to human action. This has been accomplished through the exergy analysis under the exergoecological approach. This way, the resources are physically assessed as the energy required to replace them from a complete degraded state to the conditions in which they are currently presented in nature. The main advantage of its use with respect to other physical indicators is that in a single property, all the physical features of a resource are accounted for. Furthermore, exergy has the capability of aggregating heterogeneous energy and material assets. Unlike standard economic valuations, the exergy analysis gives objective information since it is not subject to monetary policy, or currency speculation. i Accordingly, in this work three imperative activities were carried out: • A systematic analysis of the main chemical components and the mineral resources on earth has been accomplished. Furthermore, the first composition in terms of minerals of the upper continental crust has been developed, through a procedure that assures chemical coherence between species and elements. The integration of all these data has provided a global overview of the geochemistry of our planet with special attention to the substances that compose the earth’s outer spheres and to that part of the substances useful to man: the mineral resources. • The thermodynamic tools required for the physical assessment of natural resources and particularly for minerals have been provided. This way, the standard thermodynamic properties of the earth and its constituents (enthalpy, Gibbs free energy and exergy) have been calculated. Additionally, the exergy of the mineral resources of the earth (of fuel and non-fuel origin) has been obtained and compared to that of other energy resources. • With the help of different scarcity indicators developed in this PhD, an analysis of the state of our mineral resources has been accomplished. For that purpose the mineral exergy degradation throughout the 20th century has been studied. This has allowed to estimate when the peak of production of the main mineral commodities is reached. Additionally, an outlook of the scarcity degree of our mineral capital in the 21st century has been undertaken. The results of this study reveal that the exergy analysis of minerals could constitute a universal and transparent prediction tool for assessing the degradation degree of non-renewable resources, with dramatic consequences for the future management of the earth’s physical stock. ii To my beloved grandfather iii ‘‘In the end we will conserve only what we love; we will love only what we understand; we will understand only what we have been taught” Baba Dioum. Senegalese Environmentalist v Acknowledgements The work with this dissertation has been exciting, instructive, and fun, although moments of hardship and frustration have also existed. Without help, support, and encouragement from a great number persons, I would never have been able to finish this PhD. In this long ride of almost 5 years, I have had the opportunity to meet exceptional people around the world. In the scientific field, many researchers have unselfishly supported me. I should start to acknowledge the Russian geochemist N.A. Grigor’ev, that I discovered by chance investigating the literature about the geochemistry of the earth. Through a quite complicated communication procedure (via ordinary post and in Russian language), Grigor’ev generously shared with me his not yet published results about the mineralogical composition of the earth’s crust. Thanks to the translations of the Russian teacher in the University of Zaragoza Helena Moradell, Grigor’ev’s exceptional and pioneer work has been the base of the model of continental crust developed in this PhD. A deep debt of thanks is also owed to Gavin Mudd from the Institute for Sustainable Water Resources in Monash University (Australia), who kindly made available and prior to publication, his excellent and also pioneer study about average mineral ore grades in his country. Thanks to Mudd’s work, a comprehensive case study of the mineral exergy degradation of a nation was possible. This thesis has required a high level of geological and geochemical knowledge. Therefore, my chemical engineering background had to be reinforced with earth science’s fundamentals. Of essential help was the continued support of Javier Gómez, from the department of petrology in the University of Zaragoza. From the very beginning, he became my unofficial advisor in the geological field and his point of view has been very valued for this work. I should also thank the “Instituto Geológico y Minero de España - IGME”, and in particular Miguel Ángel Zapatero, for making available IGME’s information and mineral statistics. Decisive for the accomplishment of this PhD, was my 3-month stay at the British Geological Survey (BGS), one of the most renowned geological institutions in Europe. Not only the exceptional library and data bases of BGS were crucial for this work, but also the good advice of many of its premium researchers. I would like to express my deepest gratitude to the BGS’s director, John Ludden, who immediately accepted me in the organization and gave me access with no exception to all BGS available information. Thanks go also to Andrew Bloodworth, head of the Mineral’s UK department and to all his team, for their warm welcome and for treating me as one more of the group. I cannot forget Tim Colman, who was always willing to help me and from which I learnt so many things. I have met at BGS many good friends that surely will remain in the future. vii The thermochemistry part of this PhD was strongly reinforced with the reviews of Philippe Vieillard, probably the best European expert in the field of geothermochemistry, from the University of Poitiers. In these few lines, I want to express my gratitude for the many hours that Vieillard spent in teaching me patiently the different estimation methods for the calculation of the thermodynamic properties of minerals and in reviewing the results obtained. I would like to thank prof. Jan Szargut and Wojciech Stanek from the Institute of Thermal Technology in the Silesian University of Technology. It has been an honor to interact and discuss with my Polish friends the different exergy approaches used. Very useful were also the advices of the Spanish renowned economist José Manuel Naredo. He has been and is being a fundamental piece in the integration of the exergoecological approach used and further developed in this PhD, into the economic thinking. I should not forget Juan Ignacio Pardo, from the department of physical chemistry and Ma Cruz López de Silanes, from the department of applied mathematics, both in the University of Zaragoza, who were always willing to help me. If Javier Gómez was my geology advisor, César Torres, expert of thermoeconomics and collaborator of the CIRCE Foundation, was doubtless my mathematics and LATEX advisor. When I got stuck in a mathematical problem, he was the one in finding the best solution. In the same way, he has solved most of my numerous doubts with LATEX. In fact, he is the author of the layout of this PhD. Thank you very much indeed for your invaluable help and time. I wish to acknowledge the CIRCE Foundation for its financial support and for the excellent working environment. All its members, starting from the administration staff, teachers, students and researchers make the work very pleasant. Special thanks are owed to my managers and fellows Javier Uche, Luis Miguel Romeo and Inmaculada Arauzo, who have giving me every facility in the accomplishment of this PhD. Thanks to their generosity and that of my CIRCE friends Amaya Martínez and Francisco Barrio, I could dedicate most of my time in the last year in finishing this work. I would also like to thank all my friends from Zaragoza, and from other parts of Spain for the great moments that I have shared with them. viii This PhD is dedicated to my beloved grandfather, who has always believed in me and has supported and encouraged me. As you see I finally finished the work that you were impatiently waiting for. In the same way, I want to deeply thank my grandmother, for her endless care and affection. And of course I cannot forget my uncles, aunts and cousins, which all constitute an important part of my life. I am totally indebted to Stefan, who left family, friends and work in Germany for living with me in Spain. Probably I will never be able to reward the huge sacrifice you have made for me. I just hope that in some way, it has been worth. Thanks for your love, patience and understanding. Thanks also for helping me in the programming of the calculation tools used in this PhD, which has resulted in the first scientific web portal devoted to exergoecology. The great success of the "Exergoecology Portal", which every day gains supporters around the world, is due to your effort and your well-doing. You are not only a good professional, but an excellent person and I am very lucky to have you by my side. My beloved mother, your wise advise, love and care are an essential support in my personal and professional life. Your firm and sincere personality has affected me to be steadfast and never bend to difficulty. You have taught me many indispensable things of life that have helped me to face fearlessly important challenges and decisions in my life. I reserve my most grateful thanks to my father and supervisor Antonio Valero. To be honest, at the beginning I was not sure whether this combination would work. Today I am sure that it was worth and that you have been the best PhD director that I could ever had. Obviously you have been very demanding with me, probably more than with other of your students. But you have also been there many evenings, week-ends and holidays, motivating me to work harder and to do my best. You are an inspiration for me as a scientist, teacher, entrepreneur and most importantly as a father. It has been a great pleasure to work with you. When the next one? ix Contents Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Starting point, objectives and scope . . . . . . . . . . . . . . . . . 1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 Economic growth and the consumption of natural resources 1.3 Scarcity indicators . . . . . . . . . . . . . . . . . . . . . . . . . . 1.4 Exergy and the assessment of natural resources . . . . . . . . 1.5 The Exergoecology approach . . . . . . . . . . . . . . . . . . . . 1.6 Scope, objectives and structure of this PhD . . . . . . . . . . . 1.7 Scientific papers derived from this PhD . . . . . . . . . . . . . I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The earth and its resources x 1 1 1 4 7 9 12 14 17 2 The geochemistry of the earth. Known facts . . . . . . . . . . . . . . 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 The bulk earth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2.1 The composition of the earth . . . . . . . . . . . . . . . . . 2.3 The atmosphere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.3.1 The composition of the atmosphere . . . . . . . . . . . . . 2.4 The hydrosphere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4.1 Seawater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.4.1.1 The composition of the sea . . . . . . . . . . . . 2.4.2 Renewable water resources: surface and ground waters 2.4.2.1 Stream, river and lake waters . . . . . . . . . . 2.4.2.2 Ground waters . . . . . . . . . . . . . . . . . . . . 2.4.3 Ice caps, ice sheets and glaciers . . . . . . . . . . . . . . . 2.4.3.1 The composition of glacial runoff . . . . . . . . 2.5 The continental crust . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.5.1 The chemical composition of the upper continental crust 2.6 Summary of the chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 19 19 19 20 22 23 25 26 30 30 33 33 35 37 37 41 3 The mineralogical composition of the upper continental crust . . . . 43 x . . . . . . . . . . . . . . . . . 3.1 3.2 3.3 3.4 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The classification of minerals . . . . . . . . . . . . . . . . . . . . . . . . 3.2.1 The silica minerals . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.2 The feldspar group . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.3 The pyroxene group . . . . . . . . . . . . . . . . . . . . . . . . 3.2.4 The amphibole group . . . . . . . . . . . . . . . . . . . . . . . . 3.2.5 The olivine group . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.6 The mica group . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.2.7 The chlorite group . . . . . . . . . . . . . . . . . . . . . . . . . Grigor’ev’s mineralogical composition of the crust . . . . . . . . . . . A new model of the mineralogical composition of the earth’s crust . 3.4.1 The mass balance . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.2 The mass balance applied to the continental crust . . . . . . 3.4.3 Aluminium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.4 Antimony . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.5 Arsenic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.6 Barium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.7 Beryllium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.8 Bismuth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.9 Boron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.10 Bromine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.11 Cadmium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.12 Calcium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.13 Carbon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.14 Cerium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.15 Cesium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.16 Chlorine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.17 Chromium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.18 Cobalt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.19 Copper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.20 Dysprosium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.21 Erbium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.22 Europium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.23 Fluorine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.24 Gadolinium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.25 Gallium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.26 Germanium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.27 Gold . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.28 Hafnium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.29 Holmium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.30 Indium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.31 Iodine . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.32 Iridium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.4.33 Iron . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xi 43 43 44 44 45 45 45 46 46 46 54 54 55 58 59 59 60 60 61 61 62 62 62 63 63 64 64 65 65 66 66 66 66 66 67 67 67 68 68 68 69 69 69 69 3.4.34 3.4.35 3.4.36 3.4.37 3.4.38 3.4.39 3.4.40 3.4.41 3.4.42 3.4.43 3.4.44 3.4.45 3.4.46 3.4.47 3.4.48 3.4.49 3.4.50 3.4.51 3.4.52 3.4.53 3.4.54 3.4.55 3.4.56 3.4.57 3.4.58 3.4.59 3.4.60 3.4.61 3.4.62 3.4.63 3.4.64 3.4.65 3.4.66 3.4.67 3.4.68 3.4.69 3.4.70 3.4.71 3.4.72 3.4.73 3.4.74 3.4.75 Lanthanum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lead . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lithium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lutetium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Magnesium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Manganese . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mercury . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Molybdenum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Neodymium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nickel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Niobium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Osmium and Iridium . . . . . . . . . . . . . . . . . . . . . . . . Palladium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Phosphorous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Platinum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Potassium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Praseodymium . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rare Earth Elements: Praseodymium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium and Lutetium . . . . . . . . . . . . . . . . . . . Rhenium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rhodium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rubidium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ruthenium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Samarium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scandium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Selenium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Silicon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Silver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sodium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Strontium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Sulfur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tantalum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tellurium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Terbium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thallium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thorium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thulium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Tin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Titanium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Uranium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vanadium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Wolfram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xii 70 70 71 71 71 72 72 73 73 73 74 74 75 75 76 76 77 77 77 78 78 79 79 79 79 80 80 81 81 81 82 82 83 83 83 84 84 84 84 85 85 86 . . . . . . . . . . . . . . . . . . . . . . 86 86 87 87 88 91 99 100 101 102 103 4 The resources of the earth . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2 Natural resources: definition, classification and early assessment 4.3 The energy balance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 Energy from the solid earth . . . . . . . . . . . . . . . . . . . . . . . . 4.4.1 The Geothermal energy . . . . . . . . . . . . . . . . . . . . . 4.4.2 Nuclear energy . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Tidal energy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6 Energy from the sun . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6.1 Solar power . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6.2 Water power . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6.3 Wind power . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6.4 Ocean power . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6.4.1 Ocean thermal gradient . . . . . . . . . . . . . . . 4.6.4.2 Ocean Waves . . . . . . . . . . . . . . . . . . . . . . 4.6.5 Biomass . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6.6 Fossil fuels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6.6.1 Coal . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.6.6.2 Oil and natural gas . . . . . . . . . . . . . . . . . . 4.6.6.3 Unconventional fossil fuels . . . . . . . . . . . . . 4.7 Summary of the results of energy resources . . . . . . . . . . . . . . 4.8 Non-fuel mineral resources . . . . . . . . . . . . . . . . . . . . . . . . 4.8.1 The economic classification of minerals . . . . . . . . . . . 4.8.2 Mineral’s average ore grades . . . . . . . . . . . . . . . . . . 4.8.3 Mineral’s abundance . . . . . . . . . . . . . . . . . . . . . . . 4.9 Summary of the chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 105 105 106 107 108 109 111 112 112 113 114 115 116 117 118 119 119 121 124 127 127 129 130 136 138 3.5 3.6 3.7 3.4.76 Ytterbium . . . . . . . . . . . . . . . . . . . . 3.4.77 Yttrium . . . . . . . . . . . . . . . . . . . . . 3.4.78 Zinc . . . . . . . . . . . . . . . . . . . . . . . 3.4.79 Zirconium . . . . . . . . . . . . . . . . . . . . Mathematical representation . . . . . . . . . . . . . Results . . . . . . . . . . . . . . . . . . . . . . . . . . 3.6.1 Discussion of the most abundant minerals 3.6.2 Discussion of the most relevant minerals . 3.6.3 Discussion of the aggregated composition 3.6.4 Drawbacks of the model . . . . . . . . . . . Summary of the chapter . . . . . . . . . . . . . . . . xiii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . II The thermodynamic properties of the earth and its exergy evolution 5 Thermodynamic models for the exergy assessment of natural resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.2 The reference environment . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.1 Selection of the best suitable reference environment . . . . 5.2.1.1 Partial reference environments . . . . . . . . . . . . 5.2.1.2 Comprehensive reference environments . . . . . . 5.2.1.3 Abundance criterion . . . . . . . . . . . . . . . . . . 5.2.2 Calculation methodology: standard chemical exergy of the chemical elements . . . . . . . . . . . . . . . . . . . . . . . . . 5.2.2.1 Standard chemical exergy of chemical compounds 5.2.2.2 Gaseous reference substances . . . . . . . . . . . . 5.2.2.3 Solid reference substances . . . . . . . . . . . . . . 5.2.2.4 Reference substances dissolved in seawater . . . . 5.2.3 Update of Szargut’s R.E. . . . . . . . . . . . . . . . . . . . . . . 5.2.3.1 Update of the standard chemical exergy of chemical compounds . . . . . . . . . . . . . . . . . . . . . . 5.2.3.2 Update of the gaseous reference substances . . . . 5.2.3.3 Update of the solid reference substances . . . . . . 5.2.3.4 Update of the liquid reference substances . . . . . 5.2.3.5 The updated reference environment. Results . . . 5.2.4 Drawbacks of Szargut’s R.E. methodology . . . . . . . . . . . 5.3 The exergy of mineral resources . . . . . . . . . . . . . . . . . . . . . . 5.3.1 The energy involved in the process of formation of a mineral deposit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.3.2 The exergy of non-fuel mineral resources . . . . . . . . . . . 5.3.3 The chemical energy and exergy of fossil fuels . . . . . . . . 5.3.4 The exergy costs . . . . . . . . . . . . . . . . . . . . . . . . . . . 5.4 Prediction of Enthalpy and Gibbs free energy of formation of minerals 5.4.1 Calculation of ∆H 0f or ∆G 0f from s0 . . . . . . . . . . . . . . . 5.4.2 The ideal mixing model . . . . . . . . . . . . . . . . . . . . . . 5.4.3 Assuming ∆G r and ∆H r constant . . . . . . . . . . . . . . . . 5.4.3.1 Thermochemical approximations for sulfosalts and complex oxides . . . . . . . . . . . . . . . . . . . . . 5.4.3.2 The method of corresponding states . . . . . . . . 5.4.4 The method of Chermak and Rimstidt for silicate minerals . 5.4.5 The ∆O−2 method . . . . . . . . . . . . . . . . . . . . . . . . . 5.4.5.1 The ∆O−2 method for hydrated clay minerals and for phyllosilicates . . . . . . . . . . . . . . . . . . . . 5.4.5.2 The ∆O−2 method for different compounds with the same cations . . . . . . . . . . . . . . . . . . . . xiv 139 141 141 141 142 142 143 146 146 146 147 147 148 150 150 150 150 152 153 156 157 157 159 160 168 172 172 173 174 174 176 177 178 180 181 Assuming ∆S r zero . . . . . . . . . . . . . . . . . . . . . Assuming ∆G r and ∆H r zero . . . . . . . . . . . . . . . 5.4.7.1 The element substitution method . . . . . . 5.4.7.2 The addition method for hydrated minerals 5.4.7.3 The decomposition method . . . . . . . . . . 5.4.8 Summary of the methodologies . . . . . . . . . . . . . Summary of the chapter . . . . . . . . . . . . . . . . . . . . . . . 5.4.6 5.4.7 5.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 181 181 182 183 184 185 6 The thermodynamic properties of the earth and its mineral resources 6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 The properties of the earth . . . . . . . . . . . . . . . . . . . . . . . . . 6.2.1 The thermodynamic properties of the atmosphere . . . . . . 6.2.2 The thermodynamic properties of the hydrosphere . . . . . 6.2.3 The thermodynamic properties of the upper continental crust 6.2.4 The chemical exergy of the earth . . . . . . . . . . . . . . . . 6.3 An approach to the chemical composition of the crepuscular earth . 6.4 The exergy of the mineral resources . . . . . . . . . . . . . . . . . . . 6.4.1 The exergy contained in fossil fuels . . . . . . . . . . . . . . . 6.4.1.1 Coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4.1.2 Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.4.1.3 Natural gas . . . . . . . . . . . . . . . . . . . . . . . . 6.4.2 The exergy of non-fuel mineral resources . . . . . . . . . . . 6.4.3 The exergy of the natural resources on earth . . . . . . . . . 6.5 Summary of the chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 187 187 188 190 195 205 205 207 207 208 212 215 218 221 225 7 The time factor in the exergy assessment of mineral resources . . . . 7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 The exergy distance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.3 The tons of mineral equivalent . . . . . . . . . . . . . . . . . . . . . . . 7.4 The R/P ratio applied to exergy . . . . . . . . . . . . . . . . . . . . . . 7.5 The Hubbert peak applied to exergy . . . . . . . . . . . . . . . . . . . 7.6 The exergy loss of mineral deposits due to mineral extraction. The case of copper in the US . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.1 Copper mining features . . . . . . . . . . . . . . . . . . . . . . 7.6.2 Chemical exergy . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.3 Concentration exergy . . . . . . . . . . . . . . . . . . . . . . . . 7.6.4 Total exergy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.5 Exergy costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.6.6 The R/P ratio and the depletion degree of the deposits . . . 7.6.7 The Hubbert peak model . . . . . . . . . . . . . . . . . . . . . 7.6.8 Summary of the results . . . . . . . . . . . . . . . . . . . . . . 7.7 The exergy loss of a country due to mineral extraction. The case of Australia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.7.1 Non-fuel minerals . . . . . . . . . . . . . . . . . . . . . . . . . . 227 227 227 230 232 232 xv 235 235 237 238 240 241 242 242 244 245 246 . . . . . . . . . . . . . . 247 249 252 254 255 259 261 262 263 264 267 267 275 277 8 The exergy evolution of planet earth . . . . . . . . . . . . . . . . . . . . . 8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2 The exergy loss of world’s mineral reserves in the 20th century . . . 8.2.1 Non-fuel minerals . . . . . . . . . . . . . . . . . . . . . . . . . . 8.2.2 Fuel minerals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3 The exergy loss of world’s fossil fuel reserves due to the greenhouse effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3.1 The carbon cycle and the greenhouse effect . . . . . . . . . . 8.3.2 Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.3.3 The fossil fuel exergy decrease . . . . . . . . . . . . . . . . . . 8.4 A prediction of the exergy loss of world’s mineral reserves in the 21st century . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4.1 Hubbert scenario . . . . . . . . . . . . . . . . . . . . . . . . . . 8.4.2 The IPCC’s B1 scenario . . . . . . . . . . . . . . . . . . . . . . . 8.4.3 The IPCC’s A1T scenario . . . . . . . . . . . . . . . . . . . . . . 8.4.4 The IPCC’s B2 scenario . . . . . . . . . . . . . . . . . . . . . . . 8.4.5 The IPCC’s A1B scenario . . . . . . . . . . . . . . . . . . . . . . 8.4.6 The IPCC’s A2 scenario . . . . . . . . . . . . . . . . . . . . . . . 8.4.7 The IPCC’s A1FI scenario . . . . . . . . . . . . . . . . . . . . . 8.4.8 Summary of the scenarios . . . . . . . . . . . . . . . . . . . . . 8.5 Final reflections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.5.1 The Limits to Growth to be reconsidered? . . . . . . . . . . . 8.5.2 The need for global agreements on the extraction and use of natural resources . . . . . . . . . . . . . . . . . . . . . . . . . 8.5.3 The need for an accountability theory of mineral resources. The Physical Geonomics . . . . . . . . . . . . . . . . . . . . . . 8.6 Summary of the chapter . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 281 281 282 291 9 Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 7.8 7.9 7.7.1.1 Gold . . . . . . . . . . . . . . . . 7.7.1.2 Copper . . . . . . . . . . . . . . 7.7.1.3 Nickel . . . . . . . . . . . . . . . 7.7.1.4 Silver . . . . . . . . . . . . . . . 7.7.1.5 Lead . . . . . . . . . . . . . . . . 7.7.1.6 Zinc . . . . . . . . . . . . . . . . 7.7.1.7 Iron . . . . . . . . . . . . . . . . 7.7.2 Fuel minerals . . . . . . . . . . . . . . . . . 7.7.2.1 Coal . . . . . . . . . . . . . . . . 7.7.2.2 Oil . . . . . . . . . . . . . . . . . 7.7.2.3 Natural gas . . . . . . . . . . . . 7.7.3 Summary and discussion of the results . Conversion of exergy costs into monetary costs Summary of the chapter . . . . . . . . . . . . . . . xvi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 297 298 302 307 307 309 310 311 314 315 315 317 320 320 322 325 327 9.1 9.2 9.3 9.4 Introduction . . . . . . . . . . . . . . Synthesis of the PhD . . . . . . . . . Scientific contributions of the PhD Perspectives . . . . . . . . . . . . . . . . . . 331 331 340 346 A Additional calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.1 Input data. Mineralogical composition of the earth’s crust . . . . . . A.2 Calculation of average mineral ore grades . . . . . . . . . . . . . . . . A.3 Calculation of the R.E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.4 Calculation of the chemical exergy of gaseous fuels . . . . . . . . . . A.5 Estimation of the thermodynamic properties of minerals . . . . . . . A.5.1 Chermak’s methodology . . . . . . . . . . . . . . . . . . . . . . A.5.2 Vieillard’s methodology for hydrated clay minerals . . . . . A.5.3 Estimated values of the enthalpy and Gibbs free energy of minerals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.6 Exergy calculation of the mineral resources . . . . . . . . . . . . . . . A.7 Australian fossil fuel production . . . . . . . . . . . . . . . . . . . . . . A.7.1 Coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.7.2 Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.7.3 Natural gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.8 World’s fuel production . . . . . . . . . . . . . . . . . . . . . . . . . . . A.8.1 Uranium . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.8.2 Coal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.8.3 Oil . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.8.4 Natural gas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.9 The Hubbert peak applied to world production of the main non-fuel minerals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.10 Fuel consumption in the 21st century . . . . . . . . . . . . . . . . . . 351 351 376 384 386 386 386 387 Nomenclature, Figures, Tables and References 413 Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 415 List of Figures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421 List of Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 xvii . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 397 402 402 403 404 404 404 405 406 407 408 410 Chapter 1 Starting point, objectives and scope 1.1 Introduction The aim of this first introductory chapter is to provide an overview of the fundamentals on which this PhD is based and to outline the main objectives and scope of the study. Since this work is focused on the assessment of earth’s resources, the most relevant studies concerned with the depletion of natural resources are reviewed. The former studies reveal the urgent need for information about our natural capital and for appropriate indicators for its assessment. Accordingly, the most common scarcity indicators are outlined and compared to the indicator used in this PhD: the exergy indicator, based on the second law of thermodynamics. Subsequently, an overview of the different existing approaches connecting the entropy law with the consumption of resources is provided. The latter are compared to the exergoecology approach, which is the methodology applied in this PhD for the assessment of mineral resources. Finally, the specific questions that this work tries to answer are outlined, together with its scope. 1.2 Economic growth and the consumption of natural resources The earth’s continental crust is the source of the main goods essential for industrial civilization. Fuels, metals and non-metallic minerals are the fundamental basis for the technological development of any country. As Dunham [78] states, although the whole continental crust is composed by rocks as solid solutions of minerals, these 1 2 STARTING POINT, OBJECTIVES AND SCOPE are not in practice recoverable. Only when a combination of natural processes has worked together to produce an enrichment, is an ore to be found. And these complex processes operate very slowly when compared with the whole life-span of our species so far. Hence, it is clear the non-renewable nature of mineral resources, at least from a human perspective. The 20 th century was marked by great technological innovations leading to the consumption and further dispersion of huge amounts of mineral resources previously concentrated in natural deposits. This fact pushed up the economies of industrialized countries, but also raised the concern about resources scarcity. Probably, the possibility of running out of energy resources has provoked the most worries, especially due to the sharp rise of fuel prices. However non-fuel resources are also being exhausted very rapidly, as shown by Morse [230]: only in the US, over the span of the last century, the demand for metals grew from a little over 160 million tons to about 3,3 billion tons. The general attitude that has governed in the past was that the earth is nothing more than resources to be used. Adam Smith’s invisible hand [321] has been a guiding principle for those who believe that free trade or market will ultimately lead to a natural order of things. Nevertheless, in the early seventies the first Arab oil embargo, the peaking of oil production, together with the studies of the Club of Rome (Forrester [96] and Meadows et al. [218]), started the alarm bells ringing regarding resources scarcity as the limit to economic growth [221]. In fact, the theory that economic growth is irrevocably constrained by the finiteness of natural resources came at least1 a century before with the British economist Thomas Malthus [206]. The theory of Malthus was that the efforts of an expanding population to produce food on a limited land base would suffer diminishing returns, and if reproduction was not checked through moral restraint it would be checked by famine, war and pestilence. Malthus contemporary David Ricardo relativized the Malthusian’s absolute scarcity of land. He showed that an expanding competitive economy could always turn to lower-quality land, thereby increasing the required labor to produce food and driving up its cost [302]. But classical economists were mainly focused on land and did not really faced the problem of depletion of minerals and other non-renewable resources. It was not until the beginning of the 20 th century, that the US conservation movement feared that progress would end because the rapacious present generation would consume the next of its needed natural resources. In the 1930s, Harold Hotelling [145] put numbers to the not very rigorous statements of the conservationists. According to Hotelling, resources would be depleted at a declining rate, and their price would rise at a rate equal to their owners’ opportunity rate of interest. In the seventies, the Club of Rome came into being and the first attempt at a global model by J. Forrester was pubilshed in World Dynamics [96]. The limits to Growth 1 The French physiocrats came to the conclusion in the XVIII century that land is the source of all wealth. Economic growth and the consumption of natural resources 3 by Meadows et al. [218] followed in 1972, receiving great publicity. The works of Meadows et al. in 1972 and later updates in 1993 [217] and 2004 [219], argue that the current exponential growth cannot longer be supported as natural goods become depleted. Through the World3 computer model, different scenarios of resources consumption, pollution, population, policy, etc. were developed. The study claimed that if no immediate actions are undertaken, an economical collapse is foreseeable in the near future. The truth is that even if the consumption of natural capital has increased dramatically, evidence until to date has not really supported the idea that natural resources depletion has stopped economic growth. Some authors such as Barnett and Morse [20] or Scott and Pearse [302] appealed to the role of technological progress in improving the efficiency of extractive processes and redefining available resources. They stated that there is no evidence for the hypothesis that natural resources will lead to reduction of economic growth. Solow [326] argued that substitution of capital goods of natural resources in production processes reduces resource requirements and, in general, technical change may overcome limits imposed on economic activities in the environment. On the contrary, Costanza and Daly [65], Ayres and Nair [17] or Cleveland and Ruth [59], believe that technology will not overcome resource scarcity and environmental degradation, since human capital ultimately is derived from and sustained by energy, materials and ecological services. Until now, natural capital has been treated as a free good, but nowadays it is becoming the limiting factor in development. Champan and Roberts [53] argue also that resource substitution might be valid in the short term, but will fail in the long term when there is equal resource scarcity on all substitutable materials. Some attempts have been made to measure the economic costs of depletion and degradation and use them to correct standard measures of economic welfare such as GDP (see for instance Ahmad, El Serafy and Lutz [2]; Daly and Cobb [70]; Costanza [64]; Van Dieren [75]). Although the debate on how national accounting should be extended towards environmental accounting is still open, all approaches reflect that when depletions of natural capital, pollution costs, and income distribution effects are accounted for, the improving of the economy is seriously questioned. As we face the new century, the question of whether resource scarcity will constrain economy is still in the air. But the rapid economic development of Asia and the desire for a higher living standard in the developing world demands an even greater consumption of natural resources together with rapid technological progress to prevent increasing scarcity of the different commodities. Our society is based on an inefficient use of energy and materials, since there is a lack of awareness of the limit. If resources are limited, their management must be carefully planned in order to be consistent with the sustainability doctrine. But for that purpose, we need to know how many resources are available on earth and at which rate they are being consumed. A responsible management can only be based thus on a comprehensive 4 STARTING POINT, OBJECTIVES AND SCOPE information source. As Faber [91] claimed, the true intertemporal scarcity of environmental goods must be analyzed and appropriate indicators for the scarcity of these goods must be found. In this PhD, we have dived in data bases of many different institutions, organizations, universities and journals, searching for global numbers of the mineral capital on earth. For someone that never faced that task, it is surprising the lack of existing information about our resources not only in the past, but also in the present. This is a clear indicator of the little importance that humankind has placed in investigating the resources that nature gives us for free. Generally, the institutions owning information about resources do not interpret the compiled values. And ironically, many studies claiming the end of natural resources are rarely based on the physical statistics provided by the formers. More resources data bases, better global statistics, the opening of global information channels and impartial and serious interpretations of the information are key factors for transformation to sustainability. And the data interpretation must be undertaken with the help of appropriate indicators. This PhD has tried to fill with physical content some of the sociological messages about resource scarcity published elsewhere. This has been accomplished by making a rigorous analysis of the global minerals on earth through an indicator based on the second law of thermodynamics. The next section provides an overview of the different available scarcity indicators with its capabilities and drawbacks, so as to compare them to the indicator chosen in this PhD. 1.3 Scarcity indicators Consideration of scarcity and its measurement requires clarification of what we mean by scarcity. As Zwartendyk et al. [414] argue, physical scarcity refers to the relative rarity of an element or mineral substance in nature; it has nothing to do with human effort. Economic scarcity has very much to do with the interests and needs of humans. It reflects that work is required to obtain mineral products and that we are willing to pay a price for them. Generally, the greater the physical scarcity of a mineral, the costlier it will be to obtain, so its economic scarcity may be greater as well. The scientific community has already started to study this issue and some physical and economic indicators have been proposed. In the renowned work Scarcity and Growth2 (1963) of Barnet and Morse [20], extraction costs were used as scarcity indicators. Extraction cost is computed as the amount of labor and capital required to produce a unit of output. The same indicator 2 Scarcity and Growth was the first systematic empirical examination of historical trends. Scarcity indicators 5 was used until the update of that work: Scarcity and Growth Reconsidered [325]. This measure is founded on the classical economics view that with diminishing marginal returns and finite natural resources, the cost of natural resource extraction should increase as demand increases and depletion occurs. Krautkraemer [188] argued in Scarcity and Growth Reconsidered that extraction cost is an inherently static measure; it does not capture future effects that are important for indicating natural resource scarcity. In addition, extraction cost captures information about only the supply side of the market. If demand is growing more rapidly than extraction cost is declining, then extraction cost will give a false indication of decreasing scarcity (the opposite is also possible). Probably the most used indicator nowadays is price. Price incorporates information about the demand for the resource and possible expectations about future demand and availability. According to Fisher [95], the resource price would “summarize the sacrifices, direct and indirect, made to obtain a unit of the resource”. Naredo [237] claims though that standard economy is only concerned with what being directly useful to man, is also acquirable, valuable and produce-able. For this reason, most of the natural resources, remain outside the object of analysis of the economic system. And the price-fixing mechanisms, rarely take into account the concrete physical characteristics which make them valuable. Ruth [294] states that for prices to subsume all required information to make an intertemporally optimal choice about material and energy and the level of production, markets must be efficient, and preferences of current and future generations have to be anticipated. Additionally, current and future technologies must be fully described. In contrast, prices rather reflect the incomplete description of current technologies, preferences of present generations, and current institutional settings. Though non renewable resources are becoming more and more scarce, prices have not followed the same trend. According to Hotelling [145], prices should raise with scarcity, since low cost resources normally would be used first and quantities of extraction normally would decrease over time. On the contrary, historical statistics show that costs of extraction and prices have mostly decreased over time [313]. This apparent contradiction is due to technological innovation but also to the lack of information about scarcity. Reynolds [277] states that true scarcity is only revealed through prices towards the end of exhaustion. Physical indicators are usually based either on mass or energy. Generally, all energy resources are assessed in terms of its energy content, what allows a direct comparison between them. On the other hand, non-fuel minerals are usually physically and individually assessed in terms of tonnage and grade. It is obvious that mineral resources evaluated in that way cannot be easily compared, and a global number for the mineral’s capital on earth cannot be given, as mass and grade are not additive. Furthermore, assimilating such a great amount of information for each resource is not always easy and not very useful for decision makers. 6 STARTING POINT, OBJECTIVES AND SCOPE Odum [245], [246] proposed an original physical unit of measure for assessing resources and products based on the solar emergy joule (sej). Emergy analysis is a technique of quantitative analysis which determines the values of resources, services and commodities in common units of the solar energy it took to make them. One of its fundamental organizing principles is the maximum empower principle. It is stated as “systems that will prevail in competition with others, develop the most useful work with inflowing emergy sources by reinforcing productive processes and overcoming limitations through system organization”. To derive solar emergy of a resource or commodity, it is necessary to trace back through all the resources and energy that are used to produce it and express them in the amount of solar energy that went into their production [42]. The solar emergy per unit product or output flow is called “solar transformity”, with units of seJ/J. Solar transformities have to be obtained for each commodity. Most transformities cannot be considered as universal, as the processes involved in the formation of the commodities differ, depending on the period of time and place considered. The emergy analysis owns two fundamental capabilities that we think are required to be used as a scarcity indicator: 1) it is based on the physical characteristics of the resource and 2) all resources are measured with a single unit. Generally, the emergy analysis can be successfully applied for renewable resources. However it is very questioned the applicability of this approach for mineral resources, where the sun has not played a central role in their creation. No matter how much solar energy is received from the sun, the quantity of gold or iron for instance on earth, will not change. Consequently, the rigorousness of the transformities for mineral resource assessment is doubtful. Hence, the emergy analysis is not suitable for the purpose of this PhD, which is the assessment of mineral resources. The physical features that make mineral resources valuable are: a particular composition which differentiates them from the surrounding environment, and a distribution which places them in a specific concentration. And these intrinsic properties can be in fact evaluated from a second law of thermodynamics point of view in terms of a single property: exergy. As it happens to emergy and unlike standard economic valuations, the exergy analysis gives objective information since it is not subject to monetary policy, or currency speculation. Furthermore, all natural resources can be assessed in terms of exergy and can be summed up. Exergy is a property of the resource and as such, the calculation methods are physically and mathematically supported, as opposed to emergy. As explained in the next section, exergy is based on the notion of a reference environment, in which the quality and quantity of substances is fixed. Hence the analysis places value to resources depending on the level of departure from the defined reference environment. And, as opposed to the emergy analysis, whether the substances in it were created through the energy of the sun or through other processes is irrelevant and does not affect the final results. Exergy and the assessment of natural resources 7 The exergy method is chosen in this PhD for assessing the evolution of mineral scarcity. In the next section, an overview of the different existing approaches connecting the entropy law with the consumption of resources is provided. 1.4 Exergy and the assessment of natural resources A fundamental law of nature (the first law of thermodynamics), tells us that energy and matter can be neither created nor destroyed. The second law places additional limits on energy transformations and reflects qualitative characteristics. It states that energy can only be transformed by the consumption of quality. Locally, the quality can be improved, but this can only occur at the expense of a greater deterioration of the quality elsewhere. The level of quality deterioration or disorder is measured through the property entropy. Hence, the second law of thermodynamics can be formulated as follows. In all real processes of energy transformation the total entropy of all involved bodies can only be increased or, in an ideal case, unchanged. Beyond these conditions, the process is impossible even if the first law is fulfilled [39]. The combination of both laws indicates that it is not a question of the existent amount of mass or energy, but on the quality of that mass or energy, or in other words on its exergy content. Technically, exergy is defined as the maximum amount of work that may theoretically be performed by bringing a resource into equilibrium with its surroundings by a sequence of reversible processes. The exergy of a system gives an idea of its evolution potential for not being in thermodynamic equilibrium with the environment. Unlike mass and energy, exergy is not a conserved property. It is an extensive property, with the same unit as energy. In all physical transformations of matter or energy, it is always exergy that is lost. Exergy analysis is a powerful tool for improving the efficiency of processes and systems. This leads to less resources to be used and the emission of less wastes to the environment. However it is a much more useful concept, and can be applied for resource accounting. All materials have a definable and calculable exergy content, with respect to a defined external environment. The consumption of natural resources implies destruction of organized systems and pollution dispersion, which is in fact generation of entropy or exergy destruction. Furthermore, exergy has the capability of aggregating heterogeneous energy and material assets. This is why the exergy analysis can describe perfectly the degradation of natural capital. For that reason, an increasing number of scientists, such as Szargut and coworkers [344], [338], [339], Brodianski [39], Wall [393], [394], [395], Rosen [289], [290], Dincer [76], Sciubba [299] or Ayres et al. [14] believe that exergy provides useful information within resource accounting and can adequately address certain environmental concerns. Additionally, different renowned studies have shown up the connection between economic scarcity and the entropy law. Some notable examples are briefly outlined next. 8 STARTING POINT, OBJECTIVES AND SCOPE Georgescu-Roegen was one of the first authors in realizing the links between the economic process and the second law of thermodynamics. In his seminal work The Entropy Law and the Economic Process [111], he states that “the entropy law itself emerges as the most economic in nature of all natural laws [...] and this law is the basis of the economy of life at all levels”. Georgescu-Roegen stresses the importance of the variable time in economic activity, which is clearly shown in the irreversibility of the exploitation of resources. This author even postulated the Fourth Law of Thermodynamics, the entropy law of matter. According to this law, matter and not energy is the limiting factor in economic growth. Georgescu-Roegen’s Fourth Law has been criticized by a number of analysts in economics and physical sciences. It has been pointed out that on a fundamental physical level, there is no such law. In principle, it is always possible to use high quality energy to trace, collect and reassemble the dissipated elements [59]. The theoretical flaws of the Fourth Law, have lead some to dismiss Georgescu-Roegen’s ideas or deny their significance. Faber et al. [92] developed a model integrating thermodynamic considerations into a model of optimal resource use and environmental management. They analyzed the relationship among resource use in the economic system, capital formation, resource concentration and entropy production. Ayres and Nair [17] state that the second law of thermodynamics has certain consequences for the production process which are not adequately reflected in the standard economic model. Among these consequences are that the exergy of the total output of a sector must be less than the exergy of the inputs and overall entropy is increased through the production of waste materials and heat. Ayres and Miller [16] developed a model that treats natural resources, physical capital and knowledge (measured in terms of negative entropy or negentropy) as mutually substitutable inputs into the production process. In 1988, Ayres [13] used the model for the calculation of optimal investment policies and simulation of optimal time paths and substitution pattern for the world primary energy sources from the year 1869 to 2050. Recently, Ayres [15], calculated the exergy performed in the US economy during the twentieth century. One of the conclusions of his study was that growth in exergy consumption have had an enormous impact on past economic growth. The increasing efficiency of the production in primary work tended to result in lower costs, which triggered increasing demand that often resulted in greater exergy consumption. This fact is known as “Jevons paradox”. Ruth [294] stated that use in economic production processes must consider thermodynamic limits on material and energy use in order to be optimal in the long-run. And economic decisions must consider the finiteness of the resources available, the interconnectedness of the economic system with other ecosystem components, the time preference of consumers and producers and the technologies with which materials and energy are transformed in the production process. He developed a model of nonrenewable resource use. As an example, Ruth determined the optimal extraction path and production of iron ore at each period of time, taking into account thermodynamic limits on material and energy efficiency, the treatment of endoge- The Exergoecology approach 9 nous technical change through the theory of learning curves and the evaluation of alternative time paths from an economic and thermodynamic perspective. In this PhD thesis, exergy has been used as a global scarcity indicator from the point of view of the exergoecology paradigm. In the next section, exergoecology will be explained in detail, and compared to other approaches, where exergy is also used as an accounting tool. 1.5 The Exergoecology approach Generally, the studies based on exergy and natural resources are focused on calculating the amount of exergy required for the production of a certain good. Probably, the better known one is the thermo-ecological cost analysis proposed by Szargut and coworkers [341], [344], [328]. The thermo-ecological cost analysis accounts for the cumulative consumption of non-renewable exergy connected with the fabrication of a particular product including the additional exergy consumption needed for the compensation of environmental losses caused by the disposal of harmful substances to the environment. A similar approach is also used by Ayres and coworkers. For example, in [14], Ayres et al. applied the exergy concept for accounting for the materials and energy use and waste residuals of five basic metal industries in the US. This allowed to compare systems on a common basis, to identify major loss streams that may correspond to inefficiencies and to provide a first evaluation of their environmental burden. Other exergy-based approaches are for instance those from Sciubba [300], Connely and Koshland [61] or Cornelissen and Hirs [63]. Sciubba [300] extended Szargut’s theory, including non-energetic quantities like capital, labor and environmetal impact on the calculation. Connely and Koshland [61], discussed the ties between exergy and industrial ecology and proposed exergy-based definitions and methods for addressing resource depletion. Cornelissen and Hirs [63] applied the exergy analysis to the Life Cycle Assessment (LCA) methodology and proposed the exergetic life cycle assessment, which should account for the depletion of natural resources. All these approaches provide very useful information for the optimization of processes, as they obtain the exergy costs of production, allowing a reduction in energy, materials and harmful emissions. The Exergoecology method proposed by Valero [365], which derives from the general theory of exergy cost developed by the same author [370], uses also the property exergy as an accounting tool, but differs radically from the approaches explained above in the point of how resources are assessed. Exergoecology is defined as the exergy assessment of natural resources, from a defined R.E. It allows to value these resources, according to the physical cost that would require to obtain them from the materials contained in a hypothetical earth that has reached the maximum level 10 STARTING POINT, OBJECTIVES AND SCOPE of deterioration. In other words, it quantifies the physical cost of replacing natural resources from a degraded state in the so called reference environment to the conditions in which they are currently presented in nature. Its aim is to determine the physical stock available in the current continental crust, how that stock is being degraded and dispersed by mankind and at which rate. As Naredo [238] states, if life came up and evolved from a primitive soup, human species pushes now strongly towards a sort of crepuscular planet, whose composition would be hypothetically equivalent to the R.E. This methodology allows to quantify the loss of the natural resource’s potential as the human effect pushes it towards that sort of entropic planet. One of the questions that opens the exergoecology paradigm is the determination of the degraded planet (or entropic planet) towards which civilization is moving. The entropic planet could be assimilated to a dead planet where all materials have reacted, dispersed and mixed and are in a hypothetical chemical equilibrium. A degraded earth would still have an atmosphere, hydrosphere and continental crust. Nevertheless, there would not be any mineral deposits, all fossil fuels would have been burned and consequently, the CO2 concentration in the atmosphere would be much higher than it now is. Similarly, all water available in the hydrosphere would be in the form of salt-water, due to the mixing processes. So far, the assessment of mineral resources has been carried out from R.E. models designed for the optimization of industrial processes. It is open to question whether these kinds of models fit the characteristics of the degraded planet that we are searching for. This topic will be addressed in chapter 5 of this report. Note the difference between extraction costs and replacement costs. The former assesses the resource from the mine to market. However, the latter assesses the resource from the entropic planet to the mine. As Carpintero [50] and Naredo [238] argue, economy puts value to natural goods considering its extraction costs and not its replacement costs. Therefore, extraction and not recovery or recycling is promoted, thus enhancing the efficiency of the extraction processes rather than saving those resources for future generations. Moreover, extraction implies more emissions and more degradation. The exergoecological approach quantifies the physical costs, both in minimum exergy terms and in actual exergy terms, required to replace the resources with the best available technology. Thereby the anthropogenic view of the value of resources is shifted to the nature’s point of view. This way, the earth is not consider as an infinite reservoir of minerals. On the contrary, it is seen as a warehouse with a finite number of exergy resources, whose extraction implies the use of other exergy resources. Furthermore, as the warehouse becomes depleted, the quantity of exergy resources required to extract more goods increases following an exponential behavior. In exergoecology, conservation rather than efficiency is the point. Exergoecology has been developed so far for its application to inorganic substances, focusing mainly on the mineral capital. Nevertheless, Jorgensen [176], [175] applies similar concepts for ecosystems, and introduces the term Eco-exergy. According to this author, eco-exergy is defined as “the exergy of an ecosystem but with the same The Exergoecology approach 11 THERMO-ECOLOGICAL COST Solar energy Exergy Resources NATURE Exergy Services of products Emissions Technological abatement process Life cycle of the product Zero Exergy Wastes, effluents and emissions Residues Reference Environment Exergy distance Technological process of replacement of materials from the Reference Environment Exergy EXERGOECOLOGICAL COST Figure 1.1. Conceptual diagram of the terms exergoecology and thermo-ecology system at the same temperature and pressure but consisting of dead inorganic material as reference”. Eco-exergy becomes then a measure of how far the ecosystem is from thermodynamic equilibrium, or how developed the ecosystem is. Let us outline the difference between the exergoecological method and the other exergy approaches (leaded by the thermo-ecological method) through an example. In the production of copper from a deposit, Szargut’s thermo-ecological analysis would account for the exergy input of all industrial processes involved in the production of pure copper from the mine, including the abatement processes of the emissions and wastes (see Fig. 1.1). The exergoecology approach closes the cycle of Fig. 1.1, because it is concerned about the exergy needed to return the copper from the depleted state of the R.E. to the conditions of the mine where it was found. The exergy distance between the R.E. and the mine increases with the mine’s quality. This means that as the mineral deposits become exhausted, the exergy difference between the R.E. and the mine becomes lower. In the limit, when all natural resources have been extracted and dispersed, this distance is equal to zero or, what is the same, the planet has lost all its natural exergy. The exergoecology paradigm and its ideas were developed by Valero in the book of Naredo and Valero [239] “Desarrollo económico y deterioro ecológico” (Economical development and ecological degradation). In that book, the basis for a general theory of the physical cost of economic processes is proposed, and some examples of the exergy replacement costs of minerals are provided. 12 STARTING POINT, OBJECTIVES AND SCOPE Additionally, two PhD thesis accomplished in the CIRCE institute of the University of Zaragoza and directed by Antonio Valero, have applied and have further developed the exergoecology approach. The first one entitled “Análisis De Los Costes Exergéticos De La Riqueza Mineral Terrestre. Su Aplicación Para La Gestión De La Sostenibilidad” [276] (Exergy cost analysis of the mineral wealth on earth. Applicaton for the management of sustainability), was carried out by Lidia Ranz in 1999. The second one was written by Edgar Botero one year later: “Valoración Exergética De Recursos Naturales, Minerales, Agua y Combustibles Fósiles” [34] (Exergy assessment of natural resources, minerals, water and fossil fuels). Ranz developed an approximation of the R.E., based on the methodology proposed by Szargut [336] and calculated the chemical exergy of some important mineral commodities. Her reference environment was chosen according to the abundance criterion, i.e. the components of the R.E. should be the most abundant ones found currently in nature. For that purpose, she carried out a comprehensive and systematic analysis of the most abundant minerals on earth for each chemical element. An important message of her study was that exergoecology is irrevocably connected to geology. A problem with Ranz’s proposed R.E. is that if we assign zero exergy to the most abundant substances, we are decreasing arbitrarily the natural capital, because many abundant minerals like sulfides naturally evolute to the most stable species. Botero extended the exergy analysis to other natural resources such as water and fossil fuels. In his PhD, the concept of exergy replacement costs was further developed, and the exergy abatement costs, were firstly applied. The exergy replacement cost was first calculated as the exergy required for replacing a resource from the R.E. to the current conditions found in nature, with the best available technology. The exergy abatement cost was proposed as a physical way to measure the exergy cost for avoiding the environmental externalities associated to the use of fossil fuels, with the best available technology. Both PhD thesis, the book of Naredo and Valero [239], and the first paper describing the exergoecological method (Valero [365]), constitute the basis and starting point of the present study. The fundamental concepts described in the previous works are used in this thesis and are further developed. 1.6 Scope, objectives and structure of this PhD The aim of this PhD is the analysis of the state of the mineral’s exergy on earth and its degradation velocity, due to the human action. As opposed to Botero’s and Ranz’s PhDs, where the exergoecological analysis was applied in a static way, in this thesis the time factor constitutes a fundamental variable. For that purpose, an exhaustive analysis of the geochemistry of our planet and its past, current and future declining resources needs to be carried out. Scope, objectives and structure of this PhD 13 Although an exergy analysis of the entropic earth remains outside the scope of this PhD, a previous step for modeling it, is the assessment of the composition of the atmosphere, hydrosphere and continental crust. While the atmosphere and hydrosphere are well studied and its main components are reasonably known, the composition of the continental crust in terms of minerals has been barely studied. In fact, only the chemical composition of it in terms of elements is approximately known, and nowadays it is still being improved and updated. Therefore, an important milestone of this PhD, is to develop a model of the mineralogical composition of the upper continental crust. With the upper crust’s model, an approach to the chemical composition of the crepuscular earth can be provided. Once the composition of the main components of the earth is known, a closer look can be taken at its resources useful to man. The aim is to make a thorough analysis of the abundance and physical characteristics of renewable and non renewable resources on earth, stressing the mineral capital. The whole physical stock on earth will be later assessed with a single unit of measure in terms of exergy. The use of exergy as an accounting tool, requires the thermodynamic properties of the substances under analysis. We have dealt with more than 330 substances, for which a little more than 50% empirical thermodynamic values are available from the literature. Therefore, another milestone of this thesis is the semi-theoretical estimation of the lacking properties. With this information, the enthalpy, Gibbs free energy and exergy of each of the components included in the three outer layers of the earth will be obtained for the first time. In the same way, the exergy of the main mineral resources of fuel and non-fuel origin will be calculated and compared to the other physical resources on earth. The accomplishment of a dynamic analysis of the resources on earth, requires the time factor to be introduced. The final aim is to analyze the degradation of mineral resources due to the human action, from the beginning of the industrialization period to nowadays. For that purpose, a comprehensive review of historical statistics of fuel and non-fuel mineral extraction from different institutions needs to be carried out. Additionally, with the help of scenarios, the possible degradation of mineral resources in the future can be provided. The representation of the exergy degradation throughout history, will allows us to introduce new concepts and to apply degradation models for assessing global mineral scarcity. An example of that is the application of the Hubbert peak model, for determining the peak of production of all kinds of minerals. The objectives of this PhD cannot be accomplished only with a thermodynamic perspective. We have stated throughout this work, that other disciplines such as geology, geochemistry and economy are also crucial. Hence, for the completion of the studies, interaction with experts from different knowledge areas was required. In the geological field, the interaction with experts from the British Geological Survey and the department of Petrology in the University of Zaragoza were decisive. In 14 STARTING POINT, OBJECTIVES AND SCOPE the same way, the geochemistry part of this PhD was reinforced with the reviews of Dr. Vieillard, from the “Laboratoire d’Hydrogéologie, Argiles, Sols et Altérations” in the University of Poitiers. In the economic field, the point of view of the Spanish economist J.M. Naredo was especially taken into account. This PhD is structured into two differentiated parts. Part 1, which includes chapters 2, 3 and 4, describes the geochemistry of the earth and its resources. Part 2 contains chapters 5, 6, 7, and 8 and is focused on calculating the thermodynamic properties of the earth and its exergy evolution. Summarizing, this PhD tries to answer the following questions: • Chapter 2: What is the chemical composition of the layers of the earth? • Chapter 3: What is the average mineralogical composition of the continental crust? • Chapter 4: What are the available, potential and currently in use energy resources of the earth? What are the non-fuel mineral resources on earth and which is their average ore grade? • Chapter 5: Which is the R.E. and the thermodynamic models required for the calculation of the thermodynamic properties of the earth? • Chapter 6: What is the enthalpy, Gibbs free energy and exergy of the planet and its resources? What is the exergy replacement cost of the mineral resources on earth? • Chapter 7: How can we measure the level and the velocity of degradation of mineral resources? How are these concepts applied to a specific nation? • Chapter 8: How fast is humankind degrading the mineral exergy resources of the earth? Have we reached the peak of production of minerals? In short, the aim of this PhD is to improve the knowledge of the earth and its resources, from the exergoecological point of view. Because, as stated before, it is impossible to manage efficiently the resources on earth, if we do not know what is available and at which rate it is being depleted. 1.7 Scientific papers derived from this PhD Some of the results obtained in this PhD have been presented in different conferences and published in international journals. Here is a list of the papers developed from the work carried out in this PhD ([343], [368],[377], [378], [375], [376], [374], [373]). Scientific papers derived from this PhD 15 1. J. Szargut, A. Valero, W. Stanek, and A. Valero D. Towards an international legal reference environment. In Proceedings of ECOS 2005, pages 409–420, Trondheim, Norway, June 2005. 2. A. Valero, E. Botero, and A. Valero D. Exergy accounting of natural resources. Exergy, Energy System Analysis, and Optimization., from Encyclopedia of Life Support Systems (EOLSS), Developed under the Auspices of the UNESCO Eolss Publishers, Oxford, UK; Online encyclopedia: http://www.eolss.net, Retrieved May 19, 2005. 3. A. Valero D., A. Valero, and A. Martinez. Exergy evaluation of the mineral capital on Earth. Influence of the reference environment. In Proceedings of IMECE 2005, Orlando, USA, 5-11 November 2005. ASME. 4. A. Valero D., A. Valero, A. Martínez, and G. Mudd. A physical way to assess the decrease of mineral capital through exergy. The Australian case. In Proceedings of ISEE 2006, New Delhi, India, 15-18 December 2006. Ninth Biennial Conference on the International Society for Ecological Economics (ISEE). “Ecological Sustainability and Human Well-being”. 5. A. Valero D., A. Valero, and I. Arauzo. Exergy as an indicator for resources scarcity. The exergy loss of Australian mineral capital, a case study. In Proceedings of IMECE2006, Chicago, USA, 5-10 November 2006. ASME. 6. A. Valero D., A. Valero, and I. Arauzo. Evolution of the decrease in mineral exergy throughout the 20th century. The case of copper in the US. Energy, 33(2):107–115, 2008. 7. A. Valero D. Assessing world mineral deposits through the second law of thermodynamics. In Inproceedings of the Mineral Deposit Studies Group (MDSG) conference, Nottingham (UK), 2-4 January 2008. 8. A. Valero, A. Valero D., and C. Torres. Exergy and the Hubbert peak. An extended analysis for the assessment of the scarcity of minerals on earth. In Proceedings of IMECE 2008, Boston, USA, 31 October - 6 November 2008. ASME. Part I The earth and its resources 17 Chapter 2 The geochemistry of the earth. Known facts 2.1 Introduction In this chapter a comprehensive analysis of the geochemistry of the earth is undertaken as the starting point for assessing its thermodynamic properties. The geochemical features of each layer of the earth are described: the atmosphere; hydrosphere with the oceans, surface and ground waters as well as ice sheets; and the crust, focusing mainly on the upper part of it. 2.2 The bulk earth The earth is an approximately spherical body, 12.756 km of diameter and 5, 98×1024 kg [23]. Its physical and chemical peculiarities have allowed the existence of life on earth. The solid earth is divided into the crust (continental and oceanic), mantle and core. The external layers above the crust are the hydrosphere and the atmosphere. From all layers, the mantle and core are the largest, accounting for 67 and 33% of the total mass of the earth [169]. The crust, hydrosphere and atmosphere together make up less than 1% by mass. Only that small fraction of the mass of the earth is available for direct study and analysis, and so it is necessary to use indirect methods to estimate the earth’s inner composition. The continental crust, in concert with the atmosphere and hydrosphere provides the nurturing and nourishing habitat in which our species lives. 2.2.1 The composition of the earth The earth can be considered as a closed system with a finite number of substances in it, except for the very occasional and insignificant matter contribution of mete- 19 20 THE GEOCHEMISTRY OF THE EARTH . KNOWN FACTS orites [209]. The spheres are large reservoirs and between the reservoirs there are flows of materials that balance out and keep the reservoir compositions nearly constant. Hence the composition of the atmosphere, hydrosphere and continental crust is practically constant. Table 2.1 shows the composition of the main layers on earth based on Javoy’s [169] study. Only four elements constitute nearly 95% of the earth’s mass. In order of abundance, these are O, Fe, M g and Si. The relative importance of M g relies on the geochemistry of the mantle, rather than on the other layers of the solid earth, where Si and Fe predominate in the upper crust and core, respectively. Other estimations were done by Mason [209], Ringwood [280], Ganapathy and Anders [105] and Smith [322]. As Javoy [169] states, the only significant discrepancy between chemical models of the earth lies in the lower mantle. All primary upper mantle compositions agree to within a few percent relative for major and minor elements. For the core, the composition is not so strictly defined but the dominant agreement is on Fe − N i − C o − C r − M n − Si − O − S combinations. If we only take into account the outer layers of the earth, i.e. the continental crust, hydrosphere and atmosphere, these constitute 92,87%, 3,15% and 0,0712% by volume, respectively. In the next sections, the geochemistry of the atmosphere, hydrosphere and upper continental crust are explained in detail. 2.3 The atmosphere The atmosphere is the colorless, odorless and tasteless gaseous layer surrounding the earth and retained by it through the earth’s gravity. Its relative mass compared to the other spheres of the earth is minuscule (see table 2.1). Nevertheless, it is a crucial geochemical reservoir, providing conditions essential for sustaining life, such as supplying O2 , CO2 , moisture and many nutrients. The atmosphere plays also a very direct role in controlling the earth’s climate via the absorption and scattering of sunlight and infrared radiation and reducing temperature extremes between day and night. The atmosphere is made up of several layers with different qualities [359], [182] [331] (see figure 2.1): • The troposphere is the lowest atmospheric layer. It begins at the surface and extends between 7 to 17 km. It contains over 75% of all the atmospheric gases and vast quantities of water and dust. Almost all phenomena of weather and climate that physically affect man take place within the troposphere, caused by the churning of its mass. The troposphere is the region in which the infrared radiation is absorbed mainly by water vapor to raise the surface temperature. The atmosphere 21 Table 2.1. Composition of the main envelopes derived from direct sampling or from a chemical translation of a direct measurement (density), in the case of the core, and the corresponding whole earth composition [169]. Mantle % vol % mass O Si Mg Al Ca Fe Ni Ti Cr Mn Na S K U Th Cl Br B C N Rare gases 81,89 67 44,12 20,89 25,09 1,24 1,49 6,53 0,17 0,058 0,169 0,081 0,14 0,01 0,03 5E-12 1,2E-11 Oceanic crust 0,085 0,072 44,33 23,1 4,66 8,47 8,07 8,17 0,3 0,9 0,2 0,11 2,08 Continental crust 0,44 0,36 47,25 27,58 2,65 8,36 4,57 5,13 Core Oceans Atmosphere 17,56 32,54 3 7 0,033 0,023 88,889 1,48E-08 0,842 ppm 23,16 0,0053 0,0412 80 4,65 0,42 0,09 2,37 0,77 0,57 4 0,12 2E-11 4,4E-11 1,58 1,00E-06 3,50E-06 1,0764 0,0902 0,0398 1,9383 0,04 0,0005 0,0028 75,56 1,28 Whole earth 100 100 30,76 16,39 16,82 0,87 1,02 30,43 1,63 0,04 0,36 0,24 0,10 1,31 2,59E-02 6,96E-12 2,07E-11 4,46E-04 1,15E-07 2,68E-02 6,36E-08 1,08E-09 • The stratosphere extends from the troposphere to about 50 km. In this thin layer, there is 19% of the atmospheric gases and a small quantity of water vapor. Temperature increases with height because of the absorption of ultraviolet light by ozone. The ozone layer is contained in the stratosphere. • The mesosphere extends from about 50 km to the range of 80 to 85 km. The gases in the mesosphere are too thin to absorb much of the sun’s radiation, but the air is thick enough to slow down meteorites. In this case, the temperature decreases with height. • The thermosphere ranges from 80-85 km to more than 640 km.The gases of this sphere are even thinner than in the mesosphere, but they absorb ultraviolet light from the sun and as a consequence, temperature increases with height. • The ionosphere is part of the thermosphere and is made of electrically charged gas particles ionized by solar radiation. It plays an important role since it 22 THE GEOCHEMISTRY OF THE EARTH . KNOWN FACTS Figure 2.1. The atmospheric layers. Source: http://www.atmosphere.mpg.de (Max Plank Institute) influences radio propagation to distant places on earth. Furthermore, it is responsible for auras. • And finally the exosphere, it is the outermost layer of the atmosphere and extends from 500 to 1000 km up to 10.000 km. It is composed of free-moving particles that may migrate into and out of the magnetosphere. In this layer, gases get thinner and thinner and drift off into space. The stability of the physical and geochemical conditions of the atmosphere is being altered by the action of man through air pollution. The greatest source of emissions are the burning of fossil fuels, emitting huge quantities of carbon dioxide, methane and fluorocarbons, believed to contribute to global warming. Another man-made consequence of the use of chlorofluorocarbons is the stratospheric ozone depletion, which lowers the effectiveness of the atmosphere to protect us against UV radiation. 2.3.1 The composition of the atmosphere In terms of its constituent gases, the atmosphere presents a notably uniform chemical composition to heights of about 100 km [100], except for water which varies with location and season as well as with elevation. Above this altitude, the atmosphere becomes layered and non uniform in chemical composition. The hydrosphere 23 The atmosphere is composed roughly by (volume content) 78% of usually inert nitrogen1 , around 21% of oxygen, 0,93% argon, 380 ppm of carbon dioxide, a variable amount of water vapor (average around 1%) and trace amounts of other gases. That mixture of gases is commonly known as air. The latest atmospheric geochemical advances are compiled in Keeling [181]. Next, the main components of the troposphere and their origin are explained basing on the information provided by Turekian [359]. Nitrogen in the presence of oxygen at the surface of the oceans combines to form nitrate in solution as the stable form. Both nitrogen and oxygen are maintained at their levels by biological processes. Oxygen is more biologically controlled than nitrogen but both are dependent on the chemical actions of life. The argon in the atmosphere is believed to have been produced by the radioactive decay of potassium-40 in the earth and released to the atmosphere by degassing of the earth. It is not certain whether most of the argon was supplied from the argon produced in the earth by potassium-40 decay at some major degassing epoch in the earth’s early history or by the continuously generated argon in the earth’s crust and mantle. Methane and carbon dioxide are closely tied to biological activity. Methane oxidized carbon dioxide and its presence is directly sustained by production by bacteria and animals. Man-made impurities such as sulphur dioxide and carbon monoxide, which are responsible for the physical discomforts of smog, are also sometimes highly concentrated in urban areas. A summary of the composition of the atmosphere at the start of the twenty-first century done by Prinn [272], from Brasseur et al. [36] and Prinn et al. [271] is given in table 2.2. 2.4 The hydrosphere The hydrosphere is the liquid water component of the earth. It includes oceans, seas, lakes, rivers, rain, underground water, ice and atmospheric water vapor as in clouds. It covers about 70% of the surface of the earth and is the home for many plants and animals. The hydrosphere is in continuous motion through the hydrologic cycle, which is a conceptual model that describes the storage and movement of water between the biosphere, atmosphere, lithosphere and the hydrosphere (see section 4.6.2 for more details). 1 Normally inert except upon electrolysis by lightning and in certain biochemical processes of nitrogen fixation. 24 THE GEOCHEMISTRY OF THE EARTH . KNOWN FACTS Table 2.2. Gaseous chemical composition of the atmosphere [272]. Substance Mole fraction in dry air Major sources Nitrogen Oxygen Argon Carbon dioxide Chemical formula N2 O2 Ar CO2 78,084 20,948 0,934 360 % % % ppm Neon Helium Methane Hydrogen Ne He C H4 H2 18,18 5,24 1,7 0,55 ppm ppm ppm ppm Nitrous oxide Carbon monoxide N2 O CO 0,31 50-200 ppm ppb Ozone (troposphere) Ozone (stratosphere) NMHC Chlorofluorocarbon 12 Chlorofluorocarbon 11 Methylchloroform Carbon tetrachloride Nitrogen oxides O3 O3 Cx H y C F2 Cl2 C F C l3 C H3 C C l3 C C l4 N Ox 10-500 0,5-10 5,0-20 540 265 65 98 0,01-1 ppb ppm ppb ppt ppt ppt ppt ppm Ammonia Hydroxyl radical Hydroperoxyl radical Hydrogen peroxide Formaldehyde Sulfur dioxide N H3 OH HO2 H2 O2 C H2 O SO2 0,01-1 0,05 2 0,1-10 0,1-1 0,01-1 ppb ppt ppt ppb ppb ppb Dimethyl sulfide Carbon disulfide Carbonyl sulfide C H3 SC H3 C S2 OC S 10-100 1-300 500 ppt ppt ppt Hydrogen sulfide H2 S 5-500 ppt Biological Biological Inert Combustion, ocean, biosphere Inert Inert Biogenic, anthropogenic Biogenic, anthropogenic, photochemical Biogenic, anthropogenic Photochemical, anthropogenic Photochemical Photochemical Biogenic, anthropogenic Anthropogenic Anthropogenic Anthropogenic Anthropogenic Soils, lightning, anthropogenic Biogenic Photochemical Photochemical Photochemical Photochemical Photochemical, volcanic, anthropogenic Biogenic Biogenic, anthropogenic Biogenic, volcanic, anthropogenic Biogenic, volcanic The hydrosphere 25 Table 2.3. Inventory of water at the earth’s surface [263]. Reservoir Oceans Ice Caps and Glaciers Groundwater Lakes Soil Moisture Atmosphere Streams and Rivers Biosphere Sum Volume, M km3 1370 29 9,5 0,125 0,065 0,013 0,0017 0,0006 1408,71 % 97,25 2,05 0,68 0,01 0,005 0,001 0,0001 0,00004 100,00 The planetary water supply is dominated by the oceans (see table 2.3). Approximately 97% of all water on the earth is the oceans. The other 3% is held as freshwater in glaciers and icecaps, groundwater, lakes, soil, the atmosphere and biosphere [263]. The greater portion of the fresh water (75%) is in the shape of ice and permanent snow cover in the Antarctic, Arctic and mountainous regions. Next 25% are fresh and ground waters. Only 0,33% of the total amount of fresh waters on the earth are concentrated in lakes, reservoirs and river systems (surface waters), which are most accessible for economic needs and very important for water ecosystems. Considered as a whole, the earth has a comparatively stable water budget. The major problem is that most of it is overwhelmingly salty. Additionally, fresh water is not evenly distributed over the lands. Furthermore, industrialization and unsustainable land uses are increasing dramatically water pollution and thereby threatening world water supply. Next, the main water reservoirs of the earth are analyzed, stressing out their abundances, economic uses and chemical compositions. 2.4.1 Seawater The oceans account for a little over 70% of the earth’s surface and comprise more than 97% of the hydrosphere. The volume of ocean water is about 1, 37 · 109 km3 [263]. The Pacific ocean is by far the biggest in the world, followed by the Atlantic and the Indian oceans (see table 2.4). Oceans represent a relatively well-mixed system of considerable mass and potential economic use. The prime functions of the oceans are those related to atmospheric behavior. The oceans constitute the only major source of atmospheric moisture for the lands, and they serve as gigantic “energy cells” for the receipt, storage, and release of the radiant sun energy that fuels the earth’s climatic and weather systems. Besides of being a huge food reservoir, they have other uses such as pure water 26 THE GEOCHEMISTRY OF THE EARTH . KNOWN FACTS Table 2.4. Volume of Oceans and Seas. Adapted from [85] Name Atlantic Ocean without marginal seas with marginal seas Pacific Ocean without marginal seas with marginal seas Indian Ocean without marginal seas with marginal seas Arctic Ocean Mediterranean Sea and Black Sea Gulf of Mexico and Caribbean Sea Australasian Central Sea Hudson Bay Baltic Sea North Sea English Channel Irish Sea Sea of Okhotsk Bering Sea The world ocean Volume, M km3 324,6 354,7 707,6 723,7 291 291,9 17 4,2 9,6 9,9 0,16 0,02 0,05 0,004 0,006 1,3 3,33 1.370 sources after the process of desalination and as chlorine and bromine sources2 . Nevertheless, its salinity avoids seawater to have more economic uses than the other types of water reservoirs mentioned before. In fact it is frequently considered to be a drain rather than a resource. 2.4.1.1 The composition of the sea Despite their overall size, the oceans are sufficiently uniform to make description of their chemical nature relatively straightforward. Studies have shown that the relative compositions of major components: N a+ , M g 2+ , C a2+ , K + , C l − , SO4−2 , − S r 2+ , H BO3− , CO32− , B(OH)3 , B(OH)− of seawater were constant [69], [37], 4, F [264] and [224]. The first six ions make up 99,4% of the dissolved salts (see table 2.5). Most of the chemicals in the ocean are brought from the water of rivers, which in turn receive them from rocks of the crust that have suffered the process of weathering. An average composition of river waters given by Livingstone [197] is listed in table 2.8. It is remarkable the difference between river and ocean chemical compositions. The explanation of that relies on the residence time of the ions. Most abundant ions found in seawater have residence times of above one million years [137]. The salinity of ocean water is about 35 parts per thousand by mass, but 2 See sections 3.4.16 and 3.4.10 for more details. The hydrosphere 27 Table 2.5. The composition of average seawater. Adapted from [224] Substance C l− N a+ M g 2+ SO42− C a2+ K+ H CO3− Br − S r 2+ CO32− B(OH)− 4 F− B(OH)3 Sum Concentration, mg/g 19,351 10,784 1,284 2,713 0,412 0,399 0,107 0,067 0,008 0,048 0,003 0,013 0,009 35,198 variations from about 33 to 38 parts per thousand are observed in the open oceans. The variation in salinity results from a number of physical processes that control the salt content of seawater such as temperature, rainfall, ice melting or land runoff. But not all seawater substances have a crustal origin. In fact, the sea is a huge reservoir for many atmospheric substances such as carbon dioxide, a major contributor to climate change. Through the air-sea interaction processes, all the components of air can be expected to find their way into the ocean. Additionally, there are other sources and mechanisms producing gases within the ocean that supplement those supplied from the atmosphere. The dissolved gases in seawater are classified into four general groups [148]. The first group contains the inert gases: nitrogen, argon, helium, neon, xenon, and krypton. These gases enter the oceans through the air-sea interface or through the introduction of aerated water by land runoff. The second group is composed by solely oxygen, coming from the same sources than the other group plus from photosynthesis by the plants that exist in the ocean. The third group also contains only one member, carbon dioxide. This gas is introduced into the sea through the large chemical equilibrium system. Specific sources of carbon dioxide include the atmosphere, land runoff and the ocean floor. The fourth group is simply the collection of all the remaining gaseous ingredients found in seawater, and its sources are air pollution, usually from industry, and chemical reactions other than photosynthesis. Hydrogen sulfide resulting from the reduction of sulfate in the absence of oxygen is one member of this fourth group. Wilhelm Dittmar’s complete analysis of the seventy-seven seawater samples collected in 1884 stood for almost a century. Nowadays, one of the most accepted composition of minor species in seawater is the compilation of Quinby-Hunt and Turekian [273], listed in table 2.6. 28 THE GEOCHEMISTRY OF THE EARTH . KNOWN Table 2.6: Predicted Mean Oceanic Concentrations. Adapted from [273]. Element Hydrogen Helium Lithium Beryllium Boron Carbon Nitrogen Oxygen Fluorine Neon Sodium Magnesium Aluminum Silicon Phosphorous Sulfur Chlorine Argon Potassium Calcium Scandium Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton Rubidium Strontium Yttrium Zirconium Niobium Molybdenum Species H2 Concentration Inorganic Boron ΣCO2 N2 N O3 Dissolved O2 Silicate Reactive Phosphate Sulfate Chloride < < < C r (tot) Dissolved M n < As (V) Dimethylarsenate Se (tot) Se (IV) Se (VI) Bromide 1,9 178 0,2 4,4 2200 590 30 150 1,3 8 10,781 1,28 1 110 2 2,712 19,353 15,6 399 415 412 1 1 1 330 330 250 10 40 2 480 120 390 10 <> 20 5 2 nmol/kg µg/kg ng/kg mg/kg µg/kg µg/kg µg/kg µg/kg mg/kg nmol/kg g/kg g/kg µg/kg µmole/kg µmole/kg g/kg g/kg µmole/kg mg/kg mg/kg mg/kg ng/kg ng/kg µg/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg µg/kg 170 ng/kg < 67 3,7 124 7,8 7,7 13 ' 1 < 1 11 Continued on next page . . . mg/kg nmol/kg mug/kg mg/kg mg/kg ng/kg µg/kg ng/kg µg/kg FACTS The hydrosphere 29 Table 2.6: Predicted Mean Oceanic Concentrations. Adapted from [273]. – continued from previous page. Element Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon Cesium Barium Lanthanum Cerium Praeseodymium Neodymium Promethium Samarium Europeum Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury Thallium Lead Bismuth Polonium Radon Radium Actinium Thorium Proactinium Uranium Species Concentration 0,5 End of the table ng/kg 3 70 0,5 0,5 0,2 ng/kg ng/kg ng/kg ng/kg µg/kg 59 60 0,5 0,3 11,7 4 4 0,6 4 µg/kg µg/kg nmol/kg ng/kg µg/kg ng/kg ng/kg ng/kg ng/kg 0,6 0,1 0,8 0,1 1 0,2 0,9 0,2 0,9 0,2 8 2,5 1 4 ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg ng/kg 11 6 12 1 10 ng/kg ng/kg ng/kg ng/kg ng/kg 0,7 ng/kg 3,2 µg/kg 30 2.4.2 THE GEOCHEMISTRY OF THE EARTH . KNOWN FACTS Renewable water resources: surface and ground waters The renewable water resources are the total amount of a country’s water resources, both surface water and ground water, which are generated through the hydrological cycle. It is mainly the river runoff estimated in the volume referred to a unit of time (as for instance km3 /year) and formed in the region at issue or incoming from outside, including the ground water inflow to the river network. This kind of water resources includes also the yearly renewable upper aquifer ground water not drained by the river systems. Despite of their relative low abundance, renewable water resources on earth (see table 2.3) in forms of lakes, streams3 , rivers and ground water play an important role for life and especially for human-beings, since they are the main sources of freshwater. They are also an important source of water for agricultural and industrial consumption. Rivers and flows are comparatively small but essential source of energy. Many rivers are avenues of transportation. They have also a great scenic and recreational value. The mean renewable global water resources are estimated at 42.785 km3 /year, and they are very variable with space and time. Table 2.7 presents the distribution of water resources and availability by the earth’s continents. This information is based on a water balance approach by Shiklomanov [311], who provided country data for 51 countries on available water resources. Other comprehensive world renewable publications are the early work of L’vovich [204], Gleick [115] and the World Resources Institute [410]. By an absolute value the largest water resources are characteristic of Asia and South America. The smallest are typical for Europe and Australia with Oceania. Due to rapid earth’s population, growth since 1970 to 1994, the potential water availability of earth’s population decreased form 12,9 to 7,6 km3 per year and person. 2.4.2.1 Stream, river and lake waters The nature of aqueous solutions that are produced or modified by the processes of weathering is determined by several factors, including chemical controls such as reaction rate, solubility and interface reactions, as well as environmental controls such as climate, geology and the hydrologic cycle. The solutions from weathering may mix with other waters that effectively have not been involved in a weathering process. In turn, the mixed waters may be modified by further reactions such as by some cation exchange with clay or other mineral phases, or by the activities of man. 3 Stream is defined as a body of water that carries rock particles and dissolved substances, and flows down a slope along a clearly defined path. The hydrosphere 31 Table 2.7. Renewable water resources and potential water availability by continents [311]. Continent Europe North America Africa Asia South America Australia and Oceania World Area, M km2 Population, Millions 1995 Water resources, km3 /year Water availability, 1000m3 /year Average Max. Min. per km2 10,46 24,3 685 453 2900 7890 3410 8917 2254 6895 277 324 per capita 4,23 17,4 30,1 43,5 17,9 708 3445 315 4050 13510 12030 5082 15008 14350 3073 11800 10320 134 311 672 5,72 3,92 38,2 8,95 28,7 2404 2880 1891 269 83,7 135 5633 42785 44751 39775 317 7,6 There is therefore a great variation in the concentrations of dissolved materials in lake, stream and river water. Nonetheless an extensive amount of available data allowed Livingstone [197] to estimate the mean composition of world river water (see table 2.8). Table 2.8. Mean chemical contents of world river water [197] Substance H CO3− SO42− C l− N O3− C a2+ M g 2+ N a+ K+ Fe2+ SiO2 Sum Concentration µg/g 58,4 11,2 7,8 1 15 4,1 6,3 2,3 0,67 13,1 120 Different compilations of the average concentration of the main trace elements found in rivers were later done by Li [196] and Gaillardet et al. [102]. The composition of Li is lited in table 2.9. Lake waters also vary greatly in composition, not only from lake to lake but often within a lake where marked temperature and compositional stratifications can occur. Reducing conditions often exist in the lower, more saline level of stratified lakes and 32 THE GEOCHEMISTRY OF THE EARTH . KNOWN FACTS Table 2.9. The average concentrations of elements in filtered river water. Concentration in ppb. Adapted from Li [196]. Element Li Be B F Na Mg Al Si P S Cl K Ca Sc Ti V Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Rb Sr Y Zr Nb Concentration 3 0,01 10 100 6300 4100 50 6500 20 3700 7800 2300 15000 0,004 3 0,9 1 7 40 0,1 0,3 7 20 0,09 0,005 2 0,06 20 1 70 Element Mo Ag Cd In Sn Sb I Cs Ba La Ce Pr Nd Sm Eu Gd Tb Ho Er Tm Yb Lu Hf Ta W Re Au Hg Tl Pb Bi Th U Concentration 0,6 0,3 0,01 0,04 0,07 7 0,02 20 0,05 0,08 0,007 0,04 0,008 0,001 0,008 0,001 0,001 0,004 0,001 0,004 0,001 0,03 0,002 0,07 1 0,1 0,04 The hydrosphere 33 these give rise to relatively high concentrations of nitrite ammonia and Fe2+ in the water. The reducing conditions may also lead to the production of hydrogen sulphide gas and the precipitation of some metal sulphides (including iron sulphides). Silica and phosphorous may be released from the sediments. The thermocline zone, which separates the upper and lower levels of a lake by a large change in temperature, prevents the diffusion of atmospheric oxygen to go into the reduction layer [137]. 2.4.2.2 Ground waters As seen from table 2.3, less than 1% of the water on earth is ground water. Although the total volume of ground water is small, it is about 35 times greater than the volume of water lying in fresh-water lakes of flowing in streams on the earth’s surface. Nearly all the earth’s groundwater has its origin in rainfall. It is always slowly moving on its way back to the ocean, either directly through the ground or by flowing out onto the surface and joining stream. The hydrogeochemistry of ground waters reflects the source of the water, the lithology of the aquifer and the local chemical conditions such as temperature, pressure and redox potential. White et al. [405] classified the source of ground waters as: • magmatic, • meteoric (e.g. precipitated and surface water), • connate (i.e. water trapped in the pore spaced of a sediment at the time of deposition), • oceanic. Extensive compilations of ground water compositions were recorded by White et al. [405]. Table 2.10 shows examples of constituents of ground waters in Maryland and New York from different rock types. 2.4.3 Ice caps, ice sheets and glaciers Glaciers, ice sheets and ice caps are huge masses of ice, formed on land by the compaction and re-crystallization of snow, that move very slowly down slopes or move outward due to their own weight. If the rate of melting is greater than the rate of accumulation, the glacier recedes; if it is less, the glacier advances. Many recent studies on glacier runoff around the world have shown that the first tendency is rather happening presumably due to climate change. Around 10% of the earth’s surface is covered by glaciers (∼ 15, 9 × 106 km2 glacierized vs 148, 8 × 106 of total land surface [185]). Approximately 91% of the earth’s land ice covers Antarctica, 8% Greenland and glaciers in other regions contribute 34 THE GEOCHEMISTRY OF THE EARTH . KNOWN FACTS Table 2.10. Constituents of ground waters from different rock types. Concentrations in µg/g [405]. Substance Cations or oxide SiO2 Al Fe Ca Mg Na K Anions H CO3 CO3 SO4 Cl F N O3 PO4 Granite Serpentinite Shale 39 9 1,6 27 6,2 9,5 1,4 31 0,2 0,06 9,5 51 4 2,2 5,5 0 3,5 227 29 12 2,7 93 0 32 5,2 0 7,5 0 276 0 2,6 12 0 6,8 0 288 0 439 24 0 0,9 0 to around 1% (see table 2.11). Current annual global glacial runoff range from 0,3×103 km3 to 1×103 km3 [173]. Glaciers are estimated to contribute to 0,6 to 1% to the global annual runoff. There are two types of glaciers, those that are unconstrained by topography and blanket the topography, including ice sheets and ice caps, and those that are constrained by topography, mainly valley glaciers. Ice sheets cover areas which are typically > 5 × 104 km2 (mostly found in Antarctica and Greenland), whereas ice caps cover smaller areas < 5×104 km2 . Ice masses constrained by topography cover areas between 1 and 100 km2 . Most research on the geochemical weathering of glaciers has been conducted mainly on valley glaciers. Fortunately it seems that to a first approximation, the biochemical processes inferred from the small systems are similar to those occurring in large systems [357]. Glaciers are very important to the stability of the environment. Changes in heat and atmosphere can cause glaciers to melt, change shape and move more rapidly and as a consequence, more land is reformed in its movement. Glaciers exert a direct influence on the hydrologic cycle by slowing the passage of water through the cycle. Like ground water, glaciers are considered to be key natural reservoirs of freshwater. They are therefore extremely important sources of water for human consumption, irrigation, electric power and other industrial uses, especially during the summer, when the highest rate of melting is reached and precipitation is more scarce. The hydrosphere 35 Table 2.11. Area of land surface covered by glaciers in different regions of the world, together with estimates of volume and the equivalent sea level rise that the volume implies [185]. 2.4.3.1 Region Area, km2 Volume, km3 Antarctica Greenland North America Asia Europe South America Australasia Africa Total 13600000 1730000 276000 185000 54000 25900 860 10 15900000 25600000 2600000 Sea level equivalent, m 64 6 200000 0,5 28400000 70,5 The composition of glacial runoff The main source of water in most glacier systems is snow and/or ice melt. Some water is also derived from rain, and a little is derived from geothermal melting and internal deformation [257]. Table 2.12 shows the chemical composition of glacial runoff compiled by Brown [43] for different regions of the world. It also includes an estimation on the average composition of glaciers on earth, which is the weighted sum of the average compositions in each region. Glacial runoff is a dilute solution containing ions C a2+ , H CO3− , SO42− , with variable N a+ and C l − . Glacial runoff is usually more dilute than global mean river4 . 4 See table 2.8 for comparisons between river and glacier compositions. Region Greenland Antarctica Iceland Alaska Canadian high Arctic Canadian rockies Cascades European alps Himalayas Norway Svalbard Average C a2+ 2,60-3,40 1,44-26,01 2,20-7,00 11,00 5,20-52,01 19,20-22,0 0,70-1,60 0,40-12,8 1,50-11,8 0,18-12,5 2,40-20,0 12,69 M g 2+ 0,82-1,19 1,45-4,07 0,36-1,45 0,44 0,25-7,75 3,51-3,75 0,10-0,24 0,07-1,69 0,08-2,78 0,02-0,80 1,20-6,54 2,59 N a+ 1,79-2,53 8,28-32,2 0,69-11,0 0,57 0,02-4,37 0,09-0,83 0,06-0,39 0,11-2,11 0,57-1,49 0,19-4,83 2,53-6,21 18,44 K+ 0,20-0,35 0,03-4,30 0,11-0,47 2,39 0,0039-1,53 0,23-0,36 0,38-1,45 0,23-1,29 0,86-1,99 0,04-1,13 0,20-1,60 1,98 H CO3− 13,42-20,74 5,55-97,62 11,59-34,78 26,24 12,81-42,1 54,3-56,13 5,06-6,10 0,67-24,41 12,20-44,54 0,09-41,49 6,71-57,35 48,15 SO42− 4,32-9,60 1,63-57,61 1,25-6,24 12,48 2,83-187,2 18,24-24,96 0,38-1,39 0,48-11,52 7,68-19,68 0,34-6,72 4,61-36,49 27,38 0,02-1,56 0,02-0,37 0,02-3,23 0,09-5,27 7,71 THE 0,03-0,43 C l− 0,27-0,51 0,01-17,01 0,51 0,03 Table 2.12. The concentration of major ions in glacial runoff from different regions of the world. Concentrations are reported in mg/l. Adapted from [43] 36 GEOCHEMISTRY OF THE EARTH . KNOWN FACTS The continental crust 2.5 37 The continental crust The solid earth is composed by several layers. These can be classified into: core, mantle and crust. Figure 2.2 shows an earth cutaway with its different layers. The inner part of the earth is the core and is about 2900 km below the earth’s surface. The core is further divided into the inner and outer core. The inner core, or center of the earth is solid and about 1250 km thick. The outer core (approx. 2200 km thick) is composed of high-density molten metals, highly concentrated in iron [403]. The core is surrounded by a solid mantle of iron-magnesium silicates and oxides. It contains the inner mantle (between 300 and 2890 km below the earth’s surface) and the outer mantle (between 10 and 300 km below the earth’s surface). The outer shell covering the mantle is called the crust. According to Rudnick [291], it constitutes only 0,6% of the silicate earth and is covered by geological rock formations and the oceans. It is made up of the oceanic and continental crust. The oceanic crust is 7 km on average thick and is composed of relatively rock types such as basalt. The continental crust is about 40 km thick and contains virtually every rock type known on earth. The structure of the continental crust is defined to consist of upper-, middle- and lower crustal layers. The deep continental crust is composed of granulite-facies rocks and begins at 23 km depth on average. The middle crust extends from 8 to 17 km depth. Estimates indicate that it is composed of rocks in the amphibolite facies. The upper continental crust is the reservoir of the main minerals and other natural resources useful for mankind. Therefore, it will be our object of study. Furthermore, being the most accessible part of our planet, the upper crust has long been the target of geochemical investigations. According to Yoder [411], the mass of the upper continental crust is about half the mass of the total crust, this corresponds to a volume of 6, 55 × 1020 cm3 and thus a sphere with a radius of about 54±4 km as an upper limit. 2.5.1 The chemical composition of the upper continental crust There are two basic methods employed to determine the composition of the upper crust [291]: • establishing weighted averages of the compositions of rocks exposed at the surface and, • determining averages of the composition of insoluble elements in fine-grained clastic sedimentary rocks or glacial deposits and using these to infer uppercrust composition. The determination of the major-element composition of the upper continental crust relies on the first method. It has been used by a variety of authors starting with 38 THE GEOCHEMISTRY OF THE EARTH . KNOWN FACTS Figure 2.2. Earth’s cutaway. Source: USGS [397] Clarke et al. in 1889 [58] and continuing with Ronov and Yaroshevsky [287], Shaw et al. [306], [308], Eade and Fahring [80], Condie [60] and Gao et al. [106]. The results of these independent studies show a very similar composition for most majorelement averages, but not insignificant differences for rare earth elements (REEs). Estimates of the trace-element composition of the upper crust rely on the natural sampling processes of sedimentation and glaciation. This method was suggested by Goldschmidt [116], [117], using the idea that glacial clays are compositionally representative of the crust from which they were derived. Elements that are insoluble during weathering are transported from the site of weathering/glacial erosion to deposition and their concentrations in sedimentary rocks may provide robust estimates of the average composition of their source regions. Relevant studies of the composition of the crust through these methods are: Taylor and McLennan [353], [354], Plank and Langmuir [267] and the recent work of McLennan [215]. Table 2.13 shows average upper crustal compositions from the compilation works done by Wedepohl [404], McLennan [215] and the latest recommended composition of Rudnick et al. [292]. Rudnick et al. presented their best estimate for the chemical composition of the upper continental crust based mainly on averages of the different surface-exposure studies such as Shaw et al. [306], Fahring and Eade [93], Plank and Langmuir [267], Taylor and McLennan [353], McLennan [215], Sims et al. [314], Gao et al. [106], Teng et al. [355] or Newson et al. [243]. In the upper crust, only eight elements account for 99% of the weight; the most prominent among these is O, accounting for almost 50% of the weight. The continental crust Table 2.13: Average composition of the upper continental crust according to different studies. Elements in g/g. Element O Si Al Fe Ca Na Mg K Ti C P Mn S Ba F Cl Sr Zr Cr V Rb Zn Ce N Ni La Nd Cu Co Y Nb Li Sc Ga Pb B Th Pr Sm Hf Gd Dy Cs Be Wedepohl [404] McLennan [215] Rudnick et. al. [292] 4,72E-01 4,72E-01 2,88E-01 3,08E-01 3,09E-01 7,96E-02 8,04E-02 8,15E-02 4,32E-02 3,50E-02 3,92E-02 3,85E-02 3,00E-02 2,57E-02 2,36E-02 2,89E-02 2,73E-02 2,20E-02 1,33E-02 1,50E-02 2,14E-02 2,80E-02 2,32E-02 4,01E-03 4,10E-03 3,84E-03 1,99E-03 7,57E-04 7,00E-04 6,55E-04 7,16E-04 6,00E-04 7,74E-04 6,97E-04 6,20E-05 5,84E-04 5,50E-04 6,28E-04 5,25E-04 5,57E-04 4,72E-04 3,70E-04 3,33E-04 3,50E-04 3,20E-04 2,03E-04 1,90E-04 1,93E-04 1,26E-04 8,30E-05 9,20E-05 9,80E-05 1,07E-04 9,70E-05 7,80E-05 1,12E-04 8,40E-05 6,50E-05 7,10E-05 6,70E-05 6,00E-05 6,40E-05 6,30E-05 6,00E-05 8,30E-05 5,60E-05 4,40E-05 4,70E-05 3,00E-05 3,00E-05 3,10E-05 2,70E-05 2,60E-05 2,70E-05 2,50E-05 2,50E-05 2,80E-05 2,40E-05 1,70E-05 1,73E-05 2,40E-05 2,20E-05 2,10E-05 1,90E-05 1,20E-05 1,20E-05 1,80E-05 2,00E-05 2,40E-05 1,60E-05 1,36E-05 1,40E-05 1,50E-05 1,70E-05 1,75E-05 1,48E-05 1,70E-05 1,70E-05 1,10E-05 1,50E-05 1,70E-05 8,50E-06 1,07E-05 1,05E-05 6,70E-06 7,10E-06 7,10E-06 5,30E-06 4,50E-06 4,70E-06 4,90E-06 5,80E-06 5,30E-06 4,00E-06 3,80E-06 4,00E-06 3,80E-06 3,50E-06 3,90E-06 3,40E-06 4,60E-06 4,90E-06 2,40E-06 3,00E-06 2,10E-06 Continued on next page . . . 39 40 THE GEOCHEMISTRY OF THE EARTH . KNOWN FACTS Table 2.13: Average composition of the upper continental crust according to different studies. Elements in g/g. – continued from previous page. Element Sn Er Yb As U Ge Eu Mo Ta Br W Ho I Tb Tl Lu Sb Tm Se Cd Bi Ag In Hg Te Au Pd Pt Re Ru Rh Ir Os Wedepohl [404] 2,30E-06 2,10E-06 2,00E-06 1,70E-06 1,70E-06 1,40E-06 1,30E-06 1,10E-06 1,10E-06 1,00E-06 1,00E-06 8,00E-07 8,00E-07 6,50E-07 5,20E-07 3,50E-07 3,00E-07 3,00E-07 1,20E-07 1,00E-07 8,50E-08 7,00E-08 5,00E-08 4,00E-08 5,00E-09 2,50E-09 4,00E-10 4,00E-10 4,00E-10 1,00E-10 6,00E-11 5,00E-11 5,00E-11 McLennan [215] 5,50E-06 2,30E-06 2,20E-06 1,50E-06 2,80E-06 1,60E-06 8,80E-07 1,50E-06 1,00E-06 2,00E-06 8,00E-07 6,40E-07 7,50E-07 3,20E-07 2,00E-07 3,30E-07 5,00E-05 9,80E-08 1,27E-07 5,00E-08 5,00E-08 1,80E-09 5,00E-10 4,00E-10 2,00E-11 5,00E-11 End of the table Rudnick et. al. [292] 2,10E-06 2,30E-06 1,96E-06 4,80E-06 2,70E-06 1,40E-06 1,00E-06 1,10E-06 9,00E-07 1,60E-06 1,90E-06 8,30E-07 1,40E-06 7,00E-07 9,00E-07 3,10E-07 4,00E-07 3,00E-07 9,00E-08 9,00E-08 1,60E-07 5,30E-08 5,60E-08 5,00E-08 1,50E-09 5,20E-10 5,00E-10 1,98E-10 3,40E-10 2,20E-11 3,10E-11 Although a lot of effort has been placed in determining the chemical composition of the upper continental crust, the mineralogical composition of it has been barely studied. This is due mainly to the complexity and heterogeneity of the earth’s crust. The thermodynamic properties of the earth are related to the species contained in it and not to their elements, as we will see in later chapters. Therefore, a model of the Summary of the chapter 41 mineralogical composition of the crust needs to be developed. This will be the aim of chapter 3. 2.6 Summary of the chapter In order to determine the thermodynamic properties of the earth, the geochemistry of it must be analyzed in detail. For that purpose, the composition of each layer: atmosphere, hydrosphere and continental crust has to be studied in terms of substances. A comprehensive analysis of the physical and geochemical properties of the earth has been undertaken in this chapter. First, a coarse composition of the bulk earth with the relative mass proportions of each sphere has been presented. This overview has given way to the more detailed explanation of the geochemistry of the atmosphere, hydrosphere and upper continental crust. The atmosphere is the gaseous layer surrounding the earth. It is further divided into different parts. The troposphere, being the lowest of all, is the layer with which human beings have more interaction. The chemical composition of the atmosphere is rather uniform to heights up to 100 km. Apart from the natural occurring gases, there are traces of anthropogenic substances in the atmosphere that may alter the conditions on earth. The hydrosphere is the liquid water component of the earth and includes seas (constituting over 97% of it); renewable water resources (rivers, lakes and underground water); ice; and atmospheric water. The continuous motion of the hydrosphere is governed by the hydrological cycle. The composition of seawater is, as it happened to the atmosphere, quite uniform. Many components of the sea have a crustal origin. Nevertheless, it contains dissolved atmospheric gases such as CO2 , what makes oceans to be huge and crucial reservoirs of GhG gases. Although the relative small weight proportion, renewable water resources are essential for life on earth, as they are the main sources of freshwater. No uniform composition can be applied to them, but some examples and averages have been provided. Glaciers, ice sheets and ice caps are huge amounts of frozen freshwater, and as a consequence they are important water suppliers for human beings. The composition of glacial runoff from the different regions of the world has been presented. The solid earth is composed by the core, mantle and crust. The crust is further divided into the lower, middle and upper crust. The upper crust is the reservoir of the main minerals and other natural resources for mankind and being the most accessible, it is the best well studied part. Its chemical composition in terms of elements is well known. However, the mineralogical composition has been barely studied. 42 THE GEOCHEMISTRY OF THE EARTH . KNOWN FACTS In the next chapter, the only unknown composition of the earth’s outer spheres, the upper continental crust, will be analyzed in detail and a new methodology for obtaining its mineralogical composition will be developed. Chapter 3 The mineralogical composition of the upper continental crust 3.1 Introduction In this chapter, a model of the mineralogical composition of the earth’s crust is developed. The starting point of the model is the composition given by the Russian geochemist Grigor’ev. The new mineralogical composition is constrained by the conservation of mass statement, which must be satisfied not only in the crust, but in the entire earth. Additionally, the model is given geological consistence, by introducing a series of assumptions based on geological observations. This information, will allow to obtain in further chapters, the thermodynamic properties of the earth’s upper crust and to propose an approximation of the entropic planet. 3.2 The classification of minerals Minerals can be defined as natural occurring inorganic solids that possess an orderly internal structure and a definite chemical composition, whereas rocks are indefinite mixtures of naturally occurring substances, mainly minerals. According to the International Mineralogical Association1 there are more than 4000 known minerals. Of these, around 150 can be called “common”, 50 are occasional and the rest are “rare” or “extremely rare”. Minerals can be classified according to different criteria including hardness, crystal structure, specific gravity, color, luster or cleavage. Table 3.1 shows one of the most commonly used mineral classifications based on the chemical composition. The most 1 The International Mineralogical Association (IMA) is responsible for the approval of and naming of new mineral species found in nature. 43 44 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Table 3.1. Mineral classification based on Dana’s New Mineralogy [103] I II III IV V VI VII VIII IX Native Elements Sulfides Oxides Hydroxides Halides Carbonates Nitrates Borates Sulfates Chromates Phosphates Arsenates Vanadates Tungstates Molybdates Silicates: - Nesosilicates - Sorosilicates - Cyclosilicates - Ionosilicates - Phyllosilicates - Tectosilicates Organic Minerals common minerals are the silicates, accounting for more than 90% of the earth’s crust, whereas the most common non-silicates are carbonates, oxides and sulfides. Minerals can be further classified into groups. Some of the main groups found in nature are now briefly discussed, indicating the principal minerals included in each group. The information has been primarily extracted from Mason [209]. 3.2.1 The silica minerals Silica (SiO2 ) occurs in nature as five different minerals: quartz (including chalcedony), tridymite, cristobalite, opal and lechatelierite or silica glass. Of these, quartz is very common, tridymite and cristobalite are widely distributed in volcanic rocks and can hardly be called rare; opal is not uncommon and lechatelierite is very rare. 3.2.2 The feldspar group The feldspar are the most common of all minerals. They are closely related in form and physical properties, but they fall into two groups: the potassium and barium feldspars, which are monoclinic or very nearly monoclinic in symmetry, and the The classification of minerals 45 sodium and calcium feldspars (plagioclases), which are triclinic. The general formula of feldspars can be stated as X Al(Al, Si)Si2 O8 , being X elements N a, K, C a, and Ba. The barium-containing feldspars are very rare and of no importance as rockforming minerals. The main K-feldspars are orthoclase, sanidine and microcline. In the plagioclase subgroup, albite, oligoclase, andesine, labradorite, bytownite and anorthite are the most important minerals. 3.2.3 The pyroxene group The pyroxenes are a group of minerals closely related in crystallographic and other principal properties, as well as in chemical composition, although they crystallize in two different systems, orthorhombic and monoclinic. Pyroxenes have the general formula X Y (Si, Al)2 O6 (where X represents C a, N a, Fe+2 and M g and more rarely Z n, M n and Li and Y represents ions of smaller size, such as C r, Al, Fe+3 , M g, M n, Sc, T i, V and even Fe+2 ). On the basis of chemical composition and crystal structure, the following species are recognized: enstatite and hyperstene (both orthorhombic), augite, clinoenstatite, clinohypersthene, aegirine, diopside, pegeonite, jadeite, spodumene, pigeonite or hedenbergite (all monoclinic). 3.2.4 The amphibole group The amphibole group comprises a number of species, which, although falling both in the orthorhombic and monoclinic systems, are closely related in crystallographic and other physical properties, as well as in chemical composition. They form isomorphous series, and extensive replacement of one ion by others of similar size can take place, giving rise to very complex chemical compositions. The difference in chemical composition between compounds of the amphibole type and corresponding compounds of the pyroxene type is not great. A general formula for all members of the amphibole group can be written (W, X , Y )7−8 (Z4 O11 )2 (O, OH, F )2 , in which symbols W, X, Y, Z indicate elements having similar ionic radii and capable of replacing each other. W stands for C a, N a and K; X stands for M g and Fe+3 (sometimes M n); Y for T i, Al and Fe+3 ; and Z for Si and Al. The main amphibole minerals are tremolite, actinolite, cummingtonite, hornblende, glaucophane, arfvedsonite or riebeckite. 3.2.5 The olivine group The minerals of the olivine group are silicates of bivalent metals and crystallize in the orthorhombic system. The composition of olivine generally corresponds closely to (M g, Fe)2 SiO4 , there being little replacement by other elements. Minerals included in the olivine group are: forsterite, fayalite, olivine, tephroite, monticellite, glaucochroite and larsenite. 46 3.2.6 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST The mica group The minerals of the mica group have in common the perfect basal cleavage easily recognizable. The composition of individual specimens may be very complex, but a general formula of the type W (X , Y )2−3 Z4 O10 (OH, F )2 can be written for the group as a whole. In this formula W is generally K or N a, X and Y represent Al, Li, M g, Fe2+ , and Fe3+ ; Z represents Si and Al, the Si:Al ratio being generally about 3:1. Some of the main mica minerals are biotite, muscovite, paragonite, phologipte and lepidolite. 3.2.7 The chlorite group The chlorites are a group of phyllosilicate minerals. Chlorites can be described by the following four endmembers based on their chemistry via substitution of M g, Fe, N i, and M n in the silicate lattice: clinochlore (M g5 Al)(AlSi3 )O10 (OH)8 , chamosite (Fe5 Al)(AlSi3 )O10 (OH)8 , nimite (N i5 Al)(AlSi3 )O10 (OH)8 and pennantite (M n, Al)6 (Si, Al)4 O10 (OH)8 . The formula that emphasizes the group is (M g, Fe)3 (Si, Al)4 O10 (OH)2 · (M g, Fe)3 (OH)6 . And the main chlorite minerals are besides of the ones mentioned above, clinochlore, ripidolite, pennantite, orthochamosite, thuringite or penninite. 3.3 Grigor’ev’s mineralogical composition of the crust As explained in the previous chapter, a lot of effort has been placed in determining the chemical composition of the upper continental crust. The composition has been refined and improved with the studies of many different authors throughout the last century. Nevertheless, the mineralogical composition of it has been barely studied, because of the complexity and heterogeneity of the earth’s crust. A very general average mineralogical composition of the crust was obtained by Wedepohl2 [402], [403], and Nesbitt and Young [242] (table 3.2). According to these studies, only ten types of minerals are the main constituents of the upper crust. A more comprehensive study of the mineralogical composition of the upper crust was recently carried out by Grigor’ev [127]. He calculated the average contents of rock forming and accessory minerals in the upper part of the continental crust through the model of Ronov et al. [288]. The average composition of 208 minerals in the rocks of the upper crust was already calculated by the same author for the first time in year 2000 [124]. The calculations were based on the quantitatively analysis published in the literature of more than 3000 rock samples published mainly 2 The mineralogical composition of the crust given by Wedepohl was calculated using the mineral composition of magmatic rocks. Grigor’ev’s mineralogical composition of the crust 47 Table 3.2. Crustal abundance of minerals. Data in percent volume. Mineral Quartz Plagioclase Orthoclase Biotite Muscovite Chlorite Amphiboles Pyroxenes Olivines Oxides Others Wedepohl [402] 21,0 41,0 21,0 4,0 6,0 4,0 0,6 2,0 0,5 Nesbitt and Young [242] 23,2 39,9 12,9 8,7 5,0 2,2 2,1 1,4 0,2 1,6 3,0 in the USSR and USA. In Grigor’ev’s 2007 [127] publication, additional data was considered. The average content in rocks of 265 minerals, their varieties and their non-mineral materials were calculated. The content of 80 fundamental minerals of the list was corrected, in order to ensure the mass balance with the chemical composition of the elements in the rocks. The output is the result of a partiallyquantitative mineralogical analysis. His main bibliographical sources were [38], [119], [126], [228] and [301]. Table 3.3: Average mineralogical composition of the upper continental crust according to Grigor’ev [127]. Results are given in mass percentage. Mineral Native Elements Copper Silver Gold Lead Polixene I-Platinum Zinc Bismuth Tin Graphite Moissonite Sulphur Sulphides Tetradymite Chalcocite Bornite Acanthite Argentite Pentlandite Sphalerite Abundance, mass % 4,10E-07 1,20E-07 1,80E-08 1,80E-07 3,00E-10 3,00E-10 4,70E-08 4,90E-08 4,40E-08 1,20E-01 7,00E-07 9,00E-05 1,60E-08 1,80E-07 2,20E-06 3,90E-08 7,10E-08 8,40E-05 4,60E-05 Continued on next page . . . 48 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Table 3.3: Average mineralogical composition of the upper continental crust according to Grigor’ev [127]. Results are given in mass percentage. – continued from previous page. Mineral Metacinnabar Chalcopyrite Tetrahedrite Freibergite Fahlerz Group Cubanite Pyrrhotite Troilite Nickeline Galena Cinnabar Covellite Cooperite Antimonite/ Stibnite Bismuthinite Stephanite Samsonite Boulangerite Pyrargirite Violarite Pyrite Marcasite Vaesite Cobaltite Gersdorffite Lollingite Arsenopyrite Molybdenite Realgar Orpiment Halides Halite Chlorargyrite Sylvite Fluorite Bischofite Carnallite Oxides Periclase Spinel Pleonaste Magnetite Ulvöspinel Jacobsite Chromite Iotsite Corundum Hematite Abundance, mass % 7,60E-10 1,10E-04 5,70E-08 3,90E-08 6,00E-06 2,90E-02 2,00E-07 5,10E-06 1,90E-05 5,90E-08 3,60E-06 3,00E-10 4,40E-09 9,20E-08 3,50E-08 2,80E-09 4,00E-10 7,40E-08 7,60E-06 6,30E-02 1,20E-03 7,60E-06 8,40E-07 3,00E-06 5,00E-10 8,80E-06 1,20E-05 2,80E-08 8,50E-07 1,90E-01 4,50E-09 6,60E-04 2,20E-03 2,60E-05 1,30E-04 2,40E-08 2,40E-03 1,10E-05 6,50E-01 6,60E-02 3,00E-04 1,90E-04 1,40E-06 3,80E-03 7,90E-02 Continued on next page . . . Grigor’ev’s mineralogical composition of the crust Table 3.3: Average mineralogical composition of the upper continental crust according to Grigor’ev [127]. Results are given in mass percentage. – continued from previous page. Mineral Abundance, mass % Ilmenite 1,90E-01 Perovskite 2,80E-05 Loparite 1,00E-06 Pyrochlore 1,00E-06 Microlite 7,60E-09 Quarz 2,40E+01 Tridymite 6,60E-05 Cristobalite 1,30E-03 Opal 1,30E+00 Pyrolusite 5,40E-04 Rutile 1,10E-02 Cassiterite 2,50E-06 Hollandite 6,40E-04 Ilmenorutile 2,50E-05 Cryptomelane 2,50E-04 Psilomelane 3,10E-04 Todorokite 8,60E-05 Vernadite 2,60E-05 Anatase 1,80E-03 Brookite 1,70E-05 Columbite 6,60E-06 Ferrotantalite 2,60E-07 Delorenzite/ Tanteuxenite 6,60E-09 Polycrase 4,00E-11 Euxenite 6,60E-06 Blomstrandite/ Betafite 9,00E-07 Fergusonite 2,40E-06 Baddeleyite 3,10E-07 Thorianite 3,40E-08 Uraninite 6,60E-06 Hydroxides Hydragillite/ Gibbsite 4,30E-02 Diaspore 5,50E-02 Brucite 2,50E-04 Goethite 8,50E-02 Manganite 1,50E-04 Boehmite 1,80E-02 Carbonates Magnesite 1,50E-02 Smithsonite 3,70E-08 Siderite 1,20E-01 Mg-Siderite 5,90E-03 Rhodochrosite 1,20E-03 Calcite 3,98E+00 Dolomite 7,00E-01 Ankerite 3,10E-02 Aragonite 3,80E-02 Strontianite 2,00E-07 Continued on next page . . . 49 50 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Table 3.3: Average mineralogical composition of the upper continental crust according to Grigor’ev [127]. Results are given in mass percentage. – continued from previous page. Mineral Abundance, mass % Cerussite 6,30E-07 Azurite 2,50E-06 Malachite 2,00E-06 Dawsonite 1,80E-04 Bastnasite 3,20E-04 Bismutite 1,10E-07 Sulphates Anhydrite 4,50E-02 Celestine 1,70E-04 Anglesite 3,30E-07 Barite 7,30E-04 Alunite 7,60E-09 Jarosite 4,00E-04 Kieserite 6,70E-04 Gypsum 2,40E-02 Wolframates Wolframite 7,80E-07 Powellite 4,00E-08 Scheelite 6,50E-06 Wulfenite 4,00E-09 Phosphates Xenotime 3,70E-05 Monazite 1,30E-03 Rhabdophane 3,30E-07 Amblygonite 4,90E-08 Apatite 1,30E-01 Francolite 8,30E-03 Britholite 2,10E-06 Vivianite 1,30E-07 Weinschenkite/ Churchite 3,70E-08 Metatorbenite 7,40E-09 Nesosilicates (single tetrahedrons) Phenakite 4,00E-06 Forsterite 1,10E-02 Olivine 3,70E-02 Fayalite 3,90E-03 Tephroite 1,40E-03 Almandine 8,50E-01 Spessartine 2,60E-03 Grossular 2,50E-03 Andradite 1,20E-03 Zircon 1,00E-02 Naegite 3,30E-08 Tsirtolite 1,90E-06 Thorite 5,70E-05 Uranium-Thorite 8,60E-08 Sillimanite 3,10E-01 Continued on next page . . . Grigor’ev’s mineralogical composition of the crust Table 3.3: Average mineralogical composition of the upper continental crust according to Grigor’ev [127]. Results are given in mass percentage. – continued from previous page. Mineral Abundance, mass % Andalusite 6,30E-02 Distene/ Kyanite 2,20E-02 Topaz 4,60E-04 Staurolite 5,10E-02 Sapphirine 2,20E-03 Kornerupine 6,00E-04 Chondrodite 2,20E-05 Humite 1,00E-03 Clinohumite 1,50E-03 Braunite 2,70E-03 Gadolinite 4,00E-06 Titanite 1,80E-01 Leucoxene 1,50E-02 Murmanite 1,70E-05 Dumortierit 7,60E-09 Thortveitite 7,60E-09 Yttrialite 1,60E-05 Wohlerite 1,30E-11 Lovenite/ Lavenite 2,50E-07 Rinkolite/ Mosandrite 5,30E-09 Lamprophyllite 5,00E-06 Bertrandite 4,00E-06 Lawsonite 2,40E-01 Clinozoisite 4,10E-02 Epidote 1,17E+00 Zoisite 3,10E-02 Orthite/ Allanite 4,80E-03 Chevkinite 4,20E-07 Pumpellyite 1,50E-02 Vesubianite/ Idocrase 2,70E-02 Prehnite 1,70E-01 Cyclosilicates Eudialyte 1,10E-05 Neptunite 2,50E-06 Axinite -Fe 1,10E-05 Beryl 1,60E-04 Nordite 5,50E-08 Cordierite 8,80E-03 Tourmaline 4,30E-03 Chrysocolla 2,70E-09 Inosilicates (single and double chains) Pigeonite 6,90E-02 Diopside 4,80E-01 Hedenbergite 8,20E-03 Ferrosilite 5,00E-02 Spodumene 9,60E-07 Jadeite 2,90E-03 Aegirine 9,00E-02 Continued on next page . . . 51 52 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Table 3.3: Average mineralogical composition of the upper continental crust according to Grigor’ev [127]. Results are given in mass percentage. – continued from previous page. Mineral Abundance, mass % Omphacite 2,50E-04 Augite 1,21E+00 Enstatite 4,40E-02 Bronzite 6,50E-02 Hypersthene 4,30E-01 Cummingtonite 4,60E-01 Tremolite 5,50E-02 Actinolite 3,90E-01 Riebeckite 1,70E-01 Arfvedsonite 3,10E-03 Glaucophane 1,50E-03 Crossite 5,10E-02 Hastingsite 3,10E-01 Hornblende 3,16E+00 Anthophyllite 3,30E-03 Gedrite 5,10E-03 Aenigmatite 1,10E-04 Wollastonite 5,70E-04 Rhodonite 3,30E-04 Miserite 1,80E-07 Ramsayite/ Lorenzenite 5,00E-06 Phyllosilicates (sheets) Talc 4,60E-02 Pyrophyllite 1,00E-03 Paragonite 5,60E-01 Muscovite 1,99E+00 Glaukonite 1,30E-01 Phengite 3,90E-02 Phlogopite 1,30E-02 Biotite 7,49E+00 Lepidomelane/ Annite 7,60E-02 Hydromuscovite/ Illite 2,51E+00 Hydrobiotite 4,80E-01 Stilpnomelane 2,80E-02 Montmorillonite 4,30E-01 Beidellite 1,60E-01 Nontronite 5,70E-01 Vermiculite 5,40E-02 Pennine 2,70E-01 Clinochlore 6,90E-01 Ripidolite/ Cinochlore 1,89E+00 Sepiolite 5,50E-01 Thuringite/ Chamosite 1,20E-01 Clementite 4,00E-03 Chloritoid 3,30E-04 Kaolinite 2,60E-01 Serpentine/ Clinochrysotile 7,20E-02 Garnierite/ Falcondoite 1,30E-05 Continued on next page . . . Grigor’ev’s mineralogical composition of the crust 53 Table 3.3: Average mineralogical composition of the upper continental crust according to Grigor’ev [127]. Results are given in mass percentage. – continued from previous page. Mineral Hisingerite Palygorskite Tectosilicates (framework) Nepheline Analcime Anorthite Bytownite Labradorite Andesine Oligoclase Albite Orthoclase Sanidine Cancrinite Sodalite Hydrosodalite Nosean Helvine/ Helvite Scapolite Natrolite Thomsonite Palagonite Basic Crystal Acid Crystal C org Sum Abundance, mass % 1,80E-04 1,80E-04 6,20E-03 6,60E-03 3,30E-02 3,00E-01 3,02E+00 6,56E+00 1,43E+01 4,00E+00 9,81E+00 6,10E-02 2,20E-05 6,40E-05 2,50E-05 2,50E-04 4,00E-06 1,80E-02 8,80E-02 6,00E-02 1,70E-02 3,10E-01 3,10E-02 1,10E-01 99,51 End of the table According to Grigor’ev’s composition, the molecular weight of the earth’s upper crust is 142,1 g/mole3 . This value is important, because it will be required for the calculation of the chemical exergy of the elements, discussed in chapter 5. Grigor’ev’s mineralogical composition, although comprehensive, does not satisfy the mass balance of the earth. In the next section, a methodology for obtaining the average composition of the earth’s crust is developed, assuring that all species comprising the analysis are mathematically, chemically and geologically consistent. 3 The calculation of the average molecular weight of the crust is carried out through the weighted sum of the molecular weights of each mineral considered. The chemical composition and molecular weights of the substances listed in table 3.3 are given in table 3.5. 54 THE 3.4 MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST A new model of the mineralogical composition of the earth’s crust 3.4.1 The mass balance As explained in section 2.2, the earth can be assumed to be a closed system, with a fixed number of substances contained in it. Hence, it will always be true that the total mass of the earth is constant. As an example, let us consider a very simplified earth containing ξi species (CO2 , H2 O, O2 , N2 , C aSO4 · 2H2 O and C aCO3 ), composed by ε j chemical elements (C, H, O, N , S, C a), where ξi and ε j are expressed in moles of the substance per gram of earth (mole/g). Then, the system of equations defined in Eq. 3.1 has to be satisfied [369]: Σr j,i · ξi = ε j (3.1) being R the stoichiometric coefficient matrix of the species of dimensions [ j × i], as in the next table. i→ R[ j × i] = 1 CO2 1 0 4 0 0 0 2 H2 O 0 2 1 0 0 0 3 O2 0 0 2 0 0 0 4 N2 0 0 0 2 0 0 5 C aSO4 · 2H2 O 0 4 6 0 1 1 6 C aCO3 1 0 1 1 0 0 C H O N S Ca j ↓ 1 2 3 4 5 6 The resolution of the system of equations for vector ξ gives the general expression of ξi = ε j · r −1 j,i . In our particular case, this is: (i=1) (i=2) (i=3) (i=4) (i=5) (i=6) CO2 H2 O O2 N2 C aSO4 · 2H2 O C aCO3 ξ1 = C + S − C a ξ2 = H/2 − 2S ξ3 = −C + O/2 − H/4 − 3S/2 − C a/2 ξ4 = N /2 ξ5 = S ξ6 = C a − S As it happens to the entire earth, the substances contained in each sphere of our planet can be considered to be constant. Therefore, the same methodology is applied for the components of the atmosphere, hydrosphere and continental crust. A new model of the mineralogical composition of the earth’s crust 3.4.2 55 The mass balance applied to the continental crust If the continental crust is assumed to be a closed system, the elements contained in the minerals of the crust, must be equal to the chemical composition of the crust. If we assume to be correct the chemical composition defined by Rudnick et al. [292] given in table 2.13, the application of Eq. 3.1 to Grigor’ev’s analysis, should give as result Rudnick’s values. However, the output of the mass balance between species and elements for Grigorev’s analysis does not correspond to the chemical composition of the upper earth’s crust determined by Rudnick et al. [292], i.e. ε̂ j 6= ε j (see table 3.4)4 . Additionally, not all the elements compiled in the chemical composition are taken into account in the minerals of Grigor’ev’s analysis (Grigor’ev accounts for 56 elements, as opposed to the 78 included in Rudnick et al. study). The reason for which many elements are missing in Grigor’ev’s analysis is because many of them are minor elements not appearing with enough concentration in the crust in order to form by themselves mineral phases. They usually replace major elements in crystal structures. The ability of certain different elements to exist in place of each other in certain points of a space lattice is called Diadochy. Table 3.4: Comparison of Rudnick and Gao’s [292] chemical composition of the upper earth’s crust and the one generated by Grigor’ev [127] according to Eq. 3.1. Element O Si Al Fe Na Ca K Mg Ti C Mn P Ba S F Cl Sr Zr 4 Rudnick and Gao [292] From Grigorev [127] ε̂ j · M W j , g/g ε j · M W j , g/g 4,72E-01 4,76E-01 3,09E-01 2,86E-01 8,15E-02 7,02E-02 3,92E-02 3,58E-02 2,73E-02 1,99E-02 2,57E-02 3,86E-02 2,32E-02 2,43E-02 1,50E-02 2,25E-02 3,84E-03 1,50E-03 1,99E-03 8,22E-03 7,74E-04 6,02E-05 6,55E-04 2,53E-04 6,28E-04 5,84E-06 6,20E-04 6,13E-04 5,57E-04 1,09E-03 3,70E-04 1,19E-03 3,20E-04 8,13E-07 1,93E-04 4,98E-05 Continued on next page . . . Difference (ε̂ j -ε j )/ε̂ j , % -0,76 7,18 13,86 8,59 27,08 -50,54 -4,68 -50,18 60,95 -313,26 92,22 61,43 99,07 1,19 -95,46 -222,54 99,75 74,18 In table 3.4, the values are expressed in g of substance per g of crust, since this is the usual way found in the literature of expressing the chemical composition of the crust. This means that ε j is multiplied by the molecular weight of the substance M W j . 56 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Table 3.4: Comparison of Rudnick and Gao’s [292] chemical composition of the upper earth’s crust and the one generated by Grigor’ev [127] according to Eq. 3.1. – continued from previous page. Element V Cr Rb N Zn Ce Ni La Cu Nd Li Y Ga Co B Pb Sc Nb Th Pr Hf Cs As Sm Gd Dy U Er Be Sn Yb W Br Ge I Mo Eu Ta Tl Ho Tb Sb Lu Tm Bi Se Cd Rudnick and Gao [292] From Grigorev [127] ε̂ j · M W j , g/g ε j · M W j , g/g 9,70E-05 9,20E-05 8,83E-07 8,40E-05 8,30E-05 6,70E-05 3,11E-07 6,30E-05 8,18E-06 4,70E-05 4,07E-07 3,10E-05 3,91E-06 2,80E-05 4,64E-07 2,70E-05 1,57E-06 2,40E-05 5,66E-10 2,10E-05 9,98E-07 1,75E-05 1,73E-05 2,98E-09 1,70E-05 1,45E-06 1,70E-05 4,84E-07 1,40E-05 1,83E-11 1,20E-05 1,19E-07 1,05E-05 1,09E-06 7,10E-06 5,30E-06 4,90E-06 4,80E-06 9,24E-08 4,70E-06 1,22E-09 4,00E-06 3,90E-06 2,70E-06 5,97E-08 2,30E-06 2,10E-06 9,64E-08 2,10E-06 2,01E-08 1,96E-06 2,39E-07 1,90E-06 4,63E-08 1,60E-06 1,40E-06 1,40E-06 1,10E-06 7,22E-08 1,00E-06 9,00E-07 1,60E-08 9,00E-07 8,30E-07 7,00E-07 4,00E-07 5,04E-10 3,10E-07 3,00E-07 1,60E-07 2,23E-09 9,00E-08 9,00E-08 Continued on next page . . . Difference (ε̂ j -ε j )/ε̂ j , % 99,04 100,00 99,54 87,01 99,13 87,39 98,34 94,20 100,00 95,25 99,98 91,48 97,15 99,01 89,66 98,07 99,97 97,79 95,41 99,04 87,82 97,56 93,44 98,22 99,87 98,60 A new model of the mineralogical composition of the earth’s crust 57 Table 3.4: Comparison of Rudnick and Gao’s [292] chemical composition of the upper earth’s crust and the one generated by Grigor’ev [127] according to Eq. 3.1. – continued from previous page. Element In Ag Hg Te Au Pd Pt Ru Re Rh Os Ir SUM Rudnick and Gao [292] From Grigorev [127] ε̂ j · M W j , g/g ε j · M W j , g/g 5,60E-08 5,30E-08 3,04E-09 5,00E-08 5,16E-10 5,00E-09 5,79E-11 1,50E-09 1,80E-10 5,20E-10 5,14E-13 5,00E-10 4,89E-12 3,40E-10 1,98E-10 6,00E-11 3,10E-11 2,20E-11 1,00 0,98 End of the table Difference (ε̂ j -ε j )/ε̂ j , % 94,26 98,97 98,84 88,00 99,90 99,02 Assuming that the average chemical composition of Rudnick and Gao [292] is correct, if the difference between the mass content of a specific element given by Rudnick (ε̂ j ) and that included in the mineralogical composition of the crust given by Grigor’ev (ε j ) is positive, i.e. ε̂ j − ε j > 0, then it can be due to two factors: 1. The quantity of one or more minerals containing the specific element under consideration is greater than the assumption done by Grigor’ev. 2. There are other minerals not included in Grigorev’s analysis or ores containing not insignificant quantities of the element under consideration. On the other hand, if the difference is negative (ε̂ j −ε j < 0), it is clear that Grigor’ev overestimated the quantity of the mineral or minerals containing the element under consideration. Basing on Grigorev’s analysis, a new mineralogical composition of the upper conPm tinental crust i=1 ξ̂i will be calculated. The model will be optimized so that it complies with the following requirements: 1. The mass balance between species and elements must be satisfied. P j r j,i · ξ̂i = ε̂ j , being ε̂ j the chemical composition of the upper crust determined by Rudnick et al. [292]. 2. The mass content of every mineral in the crust must be always greater than zero, i.e. ξ̂i > 0. 58 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST 3. Generally, the relative proportions of the minerals in Grigorev’s model will be kept if constraints 1 and 2 are satisfied. 4. If an important5 mineral of a certain element is not considered in Grigor’ev analysis, it will be included in our model, making reasonable assumptions on its abundance based on the literature. Next, the minerals of each element found in the upper continental crust will be briefly described, stressing out their main uses, terrestrial abundance and distribution. The specific optimization method for each element will be also outlined6 . The information about uses and main minerals and ores of the different elements has been extracted mainly from geochemical books: Wedepohl [402], [403] and Greenwood and Earnshaw [122]; mineral books and databases: Hey [140], Duda [77], the Geochemical Earth Reference Model [329], [114], Jolyon [172] and Barthelmy [21]; and from commodity databases: US Geological Survey (USGS) [363] and British Geological Survey (BGS) [28]. The descriptive procedure for obtaining the mineralogical composition shown next, is represented in a mathematical way in section 3.5. 3.4.3 Aluminium Aluminium is a light, malleable, ductile, easily machined and strong metal used for many different applications. It has excellent corrosion resistance and durability. Some of the many uses for aluminium are in transportation (automobiles, aircraft, trucks railcars, marine vessels, etc.), packaging (cans, foil, etc.), transmission lines, machinery, mirrors, cooking utensils, water treatment, etc. Aluminium is the most abundant metal in the earth’s crust. It is a major constituent of many common igneous minerals, including feldspars and micas. Aluminim is a very reactive metal and it requires a lot of energy to extract it from its ore bauxite, which is composed mainly of the minerals gibbsite Al(OH)3 , diaspore AlO(OH) and boehmite AlO(OH). Therefore, recovery of this metal from scrap has become so important and about 50% of its production comes from recycled Al. In our model of continental crust, we have considered 84 Al-containing minerals, one more than in Grigorev’s analysis. Their abundance in the earth’s crust will be determined applying the constraints explained above. 5 A mineral is considered to be important here, especially when it constitutes an ore of a certain element. 6 Note that when we refer to percentages in the optimization process, they are always based on a volume basis. A new model of the mineralogical composition of the earth’s crust 3.4.4 59 Antimony Antimony is a semimetallic chemical element increasingly being used in the semiconductor industry. As an alloy, it increases lead’s durability and mechanical strength. Antimony compounds are used to make flame-proofing materials, paints, glass and pottery. Stibnite S b2 S3 is the most important ore of antimony and it occurs in large quantities in China, South Africa, Mexico, Bolivia and Chile. Other sulfide ores include ullmanite N iS bS, livingstonite H gS b4 S8, boulangerite P b5 S b4 S11 or jamesonite FeP b4 S b6 S14 and small amounts of oxide minerals formed by weathering are also known. Considerable amounts of S b are also obtained as a byproduct in lead and copper refining, especially from galena. Grigorev’s S b minerals are stibnite, boulangerite, tetrahedrite and the silver minerals samsonite, freibergite, stephanite and pyrargirite. Since stibnite is by far the most important mineral of S b, the quantity of that mineral on earth should presumably account for a very important part of S b in the crust. The quantity of antimony in stibnite considered by Grigor’ev is about four orders of magnitude smaller than Rudnick’s S b estimations in the upper crust. Therefore, we will ignore Grigorev’s estimations about stibnite and assume that most S b comes at equal rates from stibnite and in solution with galena P bS. Grigorev’s estimation for boulangerite and tetrahedrite will be assumed to be correct. The quantity of the S b-Ag-containing minerals are fixed by their silver content. 3.4.5 Arsenic Arsenic is a semi-metallic poisonous element. Its compounds are used as insecticides of fruit trees, as wood preservatives, in making special types of glass and lately, in the semiconductor gallium arsenade, which has the ability to convert electric current to laser light. Many other arsenic compounds used in the past have fallen out of use due to their toxicity and reactivity. Arsenic minerals are widely distributed throughout the world and small amounts of the free element have also been found. Most arsenic is found in conjunction with sulphur such as realgar As4 S4 and orpiment As2 S3 , and the oxidized form arsenolite As2 O3 . But non is mined as such because it is produced as a byproduct of refining ores of other metals such as iron, copper, cobalt or nickel. The main economic source of As is arsenopyrite FeAsS. But it can be also recovered from loellingite FeAs2 , safflorite C oAs, nickeline N iAs, cobaltite C oAsS, gersdoffite N iAsS, enargite Cu3 AsS4 , etc. The arsenic-containing minerals considered by Grigor’ev are: the sulphides arsenopyrite, orpimnet, realgar, freibergite and the sulfosalt group “fahlerz group”, which will be assumed to be represented by the mineral tennantite Cu11 Fe2+ As4 S13 . 60 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Less abundant N i, Fe and C o arsenides recorded in his model are nickeline, gersdorffite, loellingite and cobaltite. In addition to the minerals considered by Grigor’ev, the cobalt arsenide smaltite7 is also included. Due to the importance of its oxidized form, arsenolite will be also taken into account, assuming that it is responsible for the same quantity of As on earth as realgar. The relative proportions given by Grigor’ev will be kept in our model. The abundance of cobaltite, smaltite and freibergite are fixed by their C o and Ag contents. 3.4.6 Barium Barium is an alkaline-earth metal that is chemically similar to calcium. Barium and its compounds have many industrial uses. For instance barite BaSO4 is extremely important for the petroleum industry, which accounts for more than 85% of the barite consumption in the world. It is used as a weighting agent in petroleum well-drilling mud. Barium-nickel alloys are used for spark-plug electrodes and in vacuum tubes as drying and oxygen-removing agents. Barium nitrate and chlorate give fireworks a green color. Other compounds of barium are used to make bricks, tiles, glass or rubber. Barium is rather abundant in the earth’s crust. The chief mined ore is barite. A subsidiary mineral is barium carbonate witherite, BaCO3 . Barium-containing minerals analyzed by Grigor’ev are barite, psilomenane, hollandite and lamprophyllite. We take into account in our model all four minerals given by Grigorev’s analysis and include additionally witherite, for being an important Ba ore. It will be assumed that witherite accounts for about 10% of the Ba content of all barite in the crust. The relative concentrations of the minerals in Grigor’ev model will be kept. Nevertheless, the quantity of lamprophyllite is fixed as a result of the strontium mass balance8 . 3.4.7 Beryllium Beryllium is a light alkaline-earth metal and has one of the highest melting points of any light metal. It is used as an alloying agent in the production of beryllium-copper. Thanks to their electrical and thermal conductivity, high strength and hardness, good stability over a wide temperature range, Be − Cu alloys are used in many applications. Some of them are in the defense and aerospace industries, in the field of X-ray detection diagnostic and in the manufacture of computer equipment. Beryllium is relatively unabundant in the earth’s crust. It occurs as bertrandite Be4 Si2 O7 (OH)2 , beryl Be3 Al2 Si6 O18 , chrysoberyl BeAl2 O4 and phenakite Be2 SiO4 . Precious forms of beryl are aquamarine and emerald. 7 8 See section 3.4.18 for details about the assumptions done for cobaltite and smaltite. See section 3.4.63 for details about the optimization procedure for lamprohyllite A new model of the mineralogical composition of the earth’s crust 61 Grigor’ev accounted in his model for beryl, phenakite, bertrandite and helvite M n4 Be3 (SiO4)3 . In addition to those minerals, chrysoberyl is included in our model, assuming that it has the same Be content as beryl. The relative proportions of the minerals given by Grigor’ev will be kept and the concentrations of each mineral will be obtained assuring that constraint 1 is satisfied. 3.4.8 Bismuth Bismuth is a metal used for metallurgical additives for castings and galvanizing, in the manufacture of low melting solders and fusible alloys as well as low toxicity bird shot and fishing sinkers. Additionally, it finds some application in the pharmaceutical industry. The most important ores of bismuth are bismuthinite Bi2 S3 , bismutite (BiO)2 CO3 and bismite B2 O3 . It occurs naturally also as the metal itself and is found as crystals in the sulphide ores of nickel, cobalt, silver and tin. The main commercial source of the element is as a byproduct from lead-zinc and copper plants. Grigor’ev takes into account four minerals containing bismuth: bismutite, bismuthinite, native bismuth and tetradymite. Because of its importance, we include in our model bismite as well, assuming that it accounts for the same quantity of Bi as bismuthinite. Nevertheless, the relative proportions of bismutite, bismuthinite and native bismuth as well as the quantity of tetradymite9 given by Grigor’ev will be kept in our model. 3.4.9 Boron Boron is a non metallic element and the only non-metal of the group 13 of the periodic table. The most economically important compound of boron is borax, used for insulating fiberglass and sodium perborate bleach. Boric acid is also an important compound used in textile products. Other uses of boron are in synthetic herbicides and fertilizers, porcelain enamels, detergents, soaps, cleaners and cosmetics, catalysts or corrosion control. More than 200 minerals contain boron, but only a few of commercial importance. Boron is usually found combined in tincal N a2 B4 O7 ·10H2 O (natural borax), sassolite H3 BO3 (natural boric acid), colemanite C a2 B6 O11 · 5H2 O, kernite N a2 B4 O7 · 4H2 O, ulexite N aC aB5 O9 · 8H2 O and boracite M g3 B7 O13 C l. Only four minerals make up almost 90% of the borates used by industry worldwide: borax, kernite, colemanite and ulexite. Non of these minerals are included in Grigorev’s model. However, boron element is present in his analysis as the borate silicates tourmaline, kornerupine, axinite 9 See section 3.4.66 for the derivation of the assumption for tetradymite. 62 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST and dumortierite. Nevertheless, we cannot forget the four most important boroncontaining minerals for industrial applications. Therefore, we keep in our model the concentrations of the borates given by Grigor’ev and assume that the rest quantity of boron in the crust is in form of borax, kernite, colemanite and ulexite having all of them the same boron content. 3.4.10 Bromine Bromine is a brownish-red liquid at ambient temperature and is used in industry to make organobromo compounds. These compounds find application as insecticides, fire extinguishers, water purification, flame retardants, pharmaceuticals, fumigants, dyes or photography. Like chlorine, the largest amount of bromine is the oceans. Salt lakes and brine wells are also rich sources of bromine, and these are usually richer in bromine than the oceans. It occurs in nature as bromide salts in very diffuse amounts in crustal rock, which are accumulated in sea water after leaching processes. Grigor’ev does not include any bromine-containing minerals. We will account for them in our model as “dispersed Br”. 3.4.11 Cadmium Cadmium is used as a protective coating for iron and steel, as a pigment, and as a stabilizer for plastics. But its main application (about three-fourths of its production) is used in Ni-Cd batteries. No cadmium ore is mined for the metal, because more than enough is produced as a byproduct of the smelting of zinc from its ore, sphalerite (Z nS), in which greenockite C dS is a significant impurity making up as much as 3%. No cadmium ores are recorded by Grigor’ev. We will assume in our model that greenockite is the only ore containing C d. 3.4.12 Calcium Calcium is a silvery white metal belonging to the alkaline earth group. The metal is used as a reducing agent in the extraction of other metals, as a deoxidizer, desulfurizer and decarbonizer in the manufacture of many steels, as separating material for gaseous mixtures, as an alloying agent used in the production of aluminium, beryllium, copper, lead and magnesium alloys as well as in the making of cements and mortars to be used in construction. Calcium compounds are used in a wide variety of applications such as insecticides, manufacture of plastics, as an additive in food and vitamin pills, as a disinfectant, as a fertilizer, in paints lights and X-rays, etc. A new model of the mineralogical composition of the earth’s crust 63 Calcium is the fifth most abundant element in the earth’s crust and the third most abundant metal after Al and Fe. Vast sedimentary deposits of C aCO3 , which represent the fossilized remains of earlier marine life, occur over large parts of the earth’s surface. Other important minerals are gypsum C aSO4 · 2H2 O, anhydrite C aSO4 , fluorite C aF2 and apatite C a5 (PO4 )3 F . Sixty-six minerals contain C a in our model. The mass balance between elements and species for carbon in Grigorev’s model gives a quantity of C a greater than the accepted value for C a in the earth’s crust in Rudnick et al. [292]. Probably, Grigor’ev overestimated the quantity of some calcium-containing minerals in the upper crust. 3.4.13 Carbon Carbon is a non metallic element that forms more chemical compounds than any other element except hydrogen. The major economic use of carbon not in living material or organisms is in the form of hydrocarbons. The free element has a lot of uses, including jewelry (as diamonds), as a black fume pigment in automobile’s rims, printer’s ink, for pencil tips, dry cell and arch electrodes and as a lubricant. Carbon compounds have also plenty of uses. Carbon dioxide is used in drinks, in fire extinguishers and in solid state, as a cooler. Carbon monoxide is used as a reduction agent in many metallurgic processes. Other carbon compounds are used as solvents, cooling systems, for welding and cutting materials. Carbon occurs both as the free element (graphite, diamond) and in combined form mainly as the carbonates of C a, M g, and other electropositive elements. It also occurs as CO2 , a minor but very important constituent of the atmosphere, because of its important contribution to the greenhouse effect. Additionally, carbon is widely distributed in the organic form of coal and petroleum. The carbon-containing substances included in Grigorev’s model are graphite, organic carbon, moissonite and the carbonates calcite, dolomite, siderite, aragonite, magnesite, dawsonite, cancrinite, strontianite, bismutite, bastnasite, smithsonite cerussite, azurite, malachite, ankerite and rhodocrossite. Additionally, we have included in our model the barium carbonate witherite, for being an important Ba ore. It must be pointed out, that the mass balance between elements and species for carbon in Grigorev’s model gives a quantity of C greater than the accepted value for C in the earth’s crust in Rudnick et al. [292]. Probably, Grigor’ev overestimated the quantity of some carbon-containing minerals in the upper crust. 3.4.14 Cerium Cerium is a silvery metallic element, belonging to the lanthanide group. The metal is used as a core for the carbon electrodes of arc lamps, in incandescent mantles for gas lighting, in aluminium and iron alloys, in stainless steel as a hardening agent and to make permanent magnets. 64 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Although cerium is part of the REE, it is not rare at all. In fact it is the most common rare earth and is more abundant than lead. It is commonly found in orthite, monazite, bastnaesite, rhabdophane or in zircon. Further Ce-containing minerals considered in Grigor’ev model are miserite, loparite, rhabdophane, chevkinite, tanteuxenite, euxenite rinkolite, polycrase, gadolinite, nordite britholite and fergusonite. In addition to those minerals, the cerium included in the crystal structure of other minerals such as zircon, gadolinite or bastnasite is accounted in our model as “diadochic C e”. The quantity of it will be calculated as the difference between the cerium content in the crust and the cerium content of the minerals included in the model. Except for miserite, which will be assumed to have the same concentration on earth than the one given by Grigor’ev, all other C e-containing minerals are fixed by their REE, U, Z r, Ba and Ta contents. 3.4.15 Cesium Cesium is the most electropositive and least abundant of the five naturally occurring alkali metals. The most important use for cesium has been in research and development, primarily in chemical and electrical applications. Cesium occurs as the hydrated aluminosilicate pollucite, Cs0.6 N a0.2 Rb0.04 Al0.9 Si2.1 O6 · (H2 O), but the world’s only commercial source is at Bernic Lake, Manitoba. Cesium is mainly obtained as a byproduct of the Li industry. Cesium is not included in any of the minerals given by Grigor’ev. We will account for it in our model in the form of pollucite, assuming that it is the only main Cs ore. 3.4.16 Chlorine Chlorine is the most common element of the halogens. In pure form, it is a greenyellow diatomic gas. Chlorine is very reactive and combines with nearly all other elements. It is used in water purification, disinfectants, in bleach and in mustard gas. Chlorine is also used extensively in the manufacture of many products directly or indirectly, i.e. in paper product production, antiseptics, food, insecticides, paints, petroleum products, plastics, medicines, etc. In nature it the upper continental crust it is found in the form of halite N aC l, but also in carnallite KC l and sylvite K M g C l3 · 6(H2 O). Nevertheless, it is so abundant in the ocean, that it is extracted mainly from the sea and underground brine deposits for commercial uses. In addition to the minerals mentioned above, Grigor’ev considers also the following C l-containing minerals: apatite, scapolite, sodalite, bischofite, eudialyte and chlorargirite. The mass balance between elements and species for chlorine in Grigorev’s model gives a quantity of C l grater than the accepted value for C l in the earth’s crust in Rudnick et al. [292]. Probably, Grigor’ev overestimated the quantity of halite. All A new model of the mineralogical composition of the earth’s crust 65 of them are included in our model keeping their relative proportions. The quantity of eudyalite and chlorargirite are however fixed by the Z r and Ag mass balance. 3.4.17 Chromium Chromium is a hard transition metal. In iron, steel and nonferrous alloys it imparts hardness and resistance to corrosion and oxidation. The use of chromium to produce stainless steel and nonferrous alloys are two of its more important applications. It finds also applications as dyes and paints to produce synthetic rubies, as a catalyst in dyeing and in the tanning of leather or to make molds for the firing bricks. The only ore of chromium of any commercial importance is chromite FeC r2 O4 . Other less plentiful sources are crocoite P bC rO4 and chrome ochre C r2 O3 , while the gemstones emerald and ruby owe their colors to traces of chromium. Like in Grigorev’s analysis, we include chromite as the main chromium-containing mineral, since the other C r ores can be assumed to be insignificant when compared to chromite. Dietzeite C a2 (IO3 )2 (C rO4 ) is the other C r-containing mineral considered but its concentration is fixed by its iodine content. It must be pointed out that there are big discrepancies between chromite concentration in Grigorev’s model and in our model. Nevertheless, we leave chromite as the sole chromium mineral for the reasons explained before. 3.4.18 Cobalt Cobalt is a hard ferromagnetic, silver-white transition metal. The largest use of cobalt is in superalloys, which are used to make parts of gas turbine aircraft engines. Cobalt is also used in corrosion resistant alloys, high-speed steels, cemented carbides, in magnets and magnetic recording media, as catalysts for the petroleum and chemical industries and as drying agent for paints and inks. More than 200 ores are known to contain cobalt but only a few are of commercial value. The more important are arsenides and sulfides such as smaltite, C oAs2 , cobaltite C oAsS and linnaeite C o3 S4 .These are invariably associated with nickel and also with copper and lead, so that C o is usually obtained as a byproduct or coproduct of these metals. The only cobalt-containing mineral considered in Grigorev’s analysis is cobaltite. In our model, we take also into account the other two minerals mentioned before, assuming that all three contribute with the same amount of C o to the cobalt content of the upper earth’s crust. Although important, only those three minerals are not responsible for the whole C o on earth10 . Therefore, we will assume that the concentration of cobaltite given by Grigor’ev is correct and will account for the rest C o in the earth crust as “dispersed C o”. 10 If cobaltite, smaltite and linnaeite would be assumed to be the only cobalt-carriers in the earth’s crust, the mass balance for arsenic would not be satisfied. 66 3.4.19 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Copper Copper is one of the coinage metals with gold and silver because of its former usage. It is an excellent conductor of heat and electricity and therefore is a key metal in the electric and electronic industry. Electrical uses of copper, including power transmission and generation, building wiring, telecommunication and electrical and electronic products account for about three quarters of total copper use. Further applications of copper are in construction, such as roofing and plumbing, industrial machinery such as heat exchangers. It is also commonly used in the manufacture of brass and other alloys with zinc, tin, nickel, lead aluminium, etc. Copper is found mainly as the sulfide, oxide or carbonate, its major ores being copper pyrite (chalcopyrite) CuFeS2 , which is estimated to account for about 50% of all Cu deposits; copper glance (chalcocite), Cu2 S; cuprite, Cu2 O, and malachite Cu2 CO3 (OH)2 . Bornite Cu5 FeS4 , azurite Cu3 (CO3 )2 (OH)2 , and covellite CuS are other minor ores of Cu. Native copper is found as well occasionally. In addition to the minerals explained above, other Cu-containing minerals in Grigorev’s model are chrysocolla, metatorbenite, tennantite, freibergite and tetrahedrite. No additional minerals will be taken into account in our model, since the most important are already gathered in Grigorev’s analysis. The quantities for metatorbenite and tennantite have been fixed by their uranium and arsenium content, while for freibergite and tetrahedrite by their silver content. For the rest substances, the relative proportions given by Grigor’ev will be maintained, assuring the compliance of constraint 1. 3.4.20 Dysprosium See section 3.4.52. 3.4.21 Erbium See section 3.4.52. 3.4.22 Europium See section 3.4.52. 3.4.23 Fluorine Fluorine is the lightest and most reactive element of the halogens. Atomic and molecular fluorine are used for plasma etching in semiconductor manufacturing, flat panel A new model of the mineralogical composition of the earth’s crust 67 display production and microelectromechanical systems fabrication. Sodium hexafluoroaluminate (cryolite), is used in the electrolysis of aluminium. It is indirectly used for the production of plastics such as teflon and halons such as freon. Fluorides are added to toothpaste to prevent dental cavities. Other components of fluorine are used in pharmaceuticals as antibiotics, antidepressants and for the prevention of infections. The three most important minerals of fluorine are fluorite C aF2 , cryolite N a3 Al F6 and flourapatite C a5 (PO4 )3 F . Of these, however, only fluorite is extensively the only commercial deposit. Cryolite is a rare mineral, the only commercial deposit being in Greenland, and most of it is used in the aluminium industry. But by far the largest amount of fluorine in the earth’s crust is in the form of of fluorapatite. Minor occurrences of fluorine are also in the rare elements topaz or bastanesite. The fluorine-containing minerals taken into account by Grigor’ev are: apatite, fluorite, topaz, bastnaesite, lamprophyllite, amblygonite, britholite, lavenite, rinkolite, wohlerite, microlite, apatite, bastnasite, francolite, pyrochlore, miserite, biotite, muscovite, hydrobiotite, phlogopite, clinohumite, fluorite, humite and chondrodite. In addition to those, we include in our model cryolite because of its industrial relevance, assuming that it contributes to the same F content to the earth than topaz. 3.4.24 Gadolinium See section 3.4.52 3.4.25 Gallium Gallium is a rare element and found little use until its properties as a semiconductor were discovered. Analog integrated circuits are the largest application for gallium with optoelectronic devices (mostly laser diodes and light-emitting diodes) as the second largest end use. The highest concentrations (0,1-1%) are found in the rare mineral germanite (Cu26 Fe4 Ge4 S32 ); concentrations in sphalerite (Z nS), bauxite or coal are a hundredfold less. It was formerly recovered from flue dusts emitted during sulfide roasting or coal burning (up to 1,5% Ga), but is now obtained as a byproduct of the Al industry. Grigor’ev does not explicitly include any mineral containing Ga. It will be included in our model as “dispersed Ga”. 3.4.26 Germanium Germanium is a semiconductor and was used for transistors, diodes and rectifiers until it was replaced by pure silicon in the early 1970’s. Meanwhile germanium 68 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST is used in fiber optics communication networks, infrared night vision systems and polymerization catalysts. Germanium minerals are extremely rare, but the element is widely distributed in trace amounts among the silicates of rocks, igneous as well as sedimentary and metamorphic ones. Recovery is achieved normally from the flue dusts of smelters processing Z n ores. Germanite is the only commercial mineral of Germanium (Cu26 Fe4 Ge4 S32 ), but it is not considered in Grigorev’s analysis. In order to account for Ge in our model, it will be included as “dispersed Ge”, which will represent all germanium included in the different ores where it is found. 3.4.27 Gold Gold is mostly used in the manufacture of jewelry. However, because of its superior electrical conductivity and resistance to corrosion, it has also emerged in the late 20th century as an essential industrial metal in computers, communication equipment, spacecraft, etc. Gold is widely but sparsely distributed both native and in tellurides. Grigo’ev considers native gold as the only carrier of Au in the upper crust. Since tellurides are also important ores for gold, we will include in our model the tellurides calaverite AuTe2 and sylvanite Au0.75 Ag0.25 Te2 , assuming that 15% in volume of Au in the upper continental crust comes from them at equal rates and the rest from native gold. 3.4.28 Hafnium Hafnium is a transition metal similar to zirconium. It resists corrosion and has a high melting point. Its major end uses are in nuclear control rods because of its excellent properties in absorbing neutrons, nickel-based superalloys, nozzles for plasma arc metal cutting and high-temperature ceramics. Hafnium ores are rare, but two are known: hafnon and alvite. However, H f is mostly found in quantities of about 2% of the Z r content in zirconium ores such as zircon Z rSiO4 and baddeleyite Z rO2 . H f will be considered in our model only as a diadochic element in zirconium ores, since Grigor’ev did not provide any information about the hafnium ores explained before. 3.4.29 Holmium See section 3.4.52. A new model of the mineralogical composition of the earth’s crust 3.4.30 69 Indium Indium is a rare metal used in low-melting fusible alloys, solders and electronics. Large-scale application for indium was also as a protective coating for bearings and other metal surfaces in high-performance aircraft engines. Nowadays, its main application is in the manufacture of indium-tin-oxide thin films for Liquid Crystal Displays (LCD). Indium tends to associate with the similarly sized Z n in its sulfide minerals, hence it is mainly produced from residues generated during zinc and lead sulfide ore processing, mainly from sphalerite Z nS. The indium metal indite Fe2+ I n2 S4 has been found in Siberia but it is very rare. We will include I n in our model as being in the crystal lattice of sphalerite (“diadochic I n in sphalerite”). 3.4.31 Iodine Iodine is the most electropositive halogen and is used in medical treatment as tincture and iodoform. It is employed in the preparation of certain drugs, and in the manufacture of printing inks and dyes. Silver iodine is used in photography and iodine is added to table salt and is used as a supplement to animal feed. It is also an ingredient of water purification tablets. Iodine is considerably less abundant than the lighter halogens. It can be found naturally in air, water and soil. But the most important sources are the oceans. It occurs but rarely as iodide minerals. Commercial deposits are usually iodates, e.g. lautarite C a(IO3 )2 and dietzeite C a2 (IO3 )2 (C rO4 ). None of these minerals or other iodine-containing minerals were considered by Grigor’ev. We will assume that the minerals above account for all I in the upper continental crust in the same proportion. 3.4.32 Iridium See section 3.4.46. 3.4.33 Iron Iron is the most used of all the metals, including 95% of all the metal tonnage produced worldwide. Thanks to the combination of low cost and high strength it is indispensable. Its applications go from food containers to cars, from screwdrivers to washing machines, from cargo ships to paper staples. Steel is the best known alloy of iron and some of the forms that iron takes include pig iron, cast iron, carbon steel, wrought iron, alloy steels and iron oxides. 70 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Iron is the most abundant element in the universe and on earth. widely distributed as oxides and carbonates, of which the chief ones are haematite Fe2 O3, magnetite Fe3 O4 and siderite FeCO3 . Eighty-two Fe-containing minerals are included in our model. 3.4.34 Lanthanum Lanthanum is a rare earth element (REE) and gives its name to the lanthanide group. It can be found in domestic equipment such as in color televisions, fluorescent and energy-saving lamps and optical glasses. If added in small amounts, it improves the malleability and resistance of steel. Lanthanum is also used as the core material in carbon arc electrodes and in zeolite catalysts for the petroleum industry. Lanthanum is one of the most abundant REE. Its major ores are minerals monazite and bastnasite, in percentages of up to 25 to 38 percent of the total lanthanide content. In addition to monazite and bastnasite, Grigor’ev considers in his analysis the Lacontaining minerals britholite, chevkinite, loparite, rhabdophane and nordite. All these minerals with their respective proportions are included in our model assuring the satisfaction of constraint number 1. The abundance of nordite is however fixed by its Ba content. 3.4.35 Lead Lead is a very corrosion-resistant, malleable and toxic bluish-white metal that has been known for at least 5000 years. Ancient romans used lead as drains from the baths. Nowadays lead is a major constituent of the lead-acid battery, it is used as a coloring element in ceramic glazes, as projectiles, as electrodes for electrolysis and in the glass of computer and television screens, shielding the viewer from radiation. Lead alloys include pewter and solder. The toxicity of lead leaded in the twentieth century to strong environmental regulations that significantly reduced or eliminated its use in nonbattery products including gasoline, paints, solders and water systems. Lead is the most abundant of the heavy elements. It can be found native, but its most important ore is the heavy black mineral galena P bS. Other important minerals are anglesite P bSO4 and cerussite P bCO3 . It is usually found in zinc, silver and copper ores and it is extracted together with these minerals. However, the largest current source of lead is recycling, primarily of automobile batteries. In addition to galena, anglesite and cerussite, Grigor’ev takes into account minerals boulangerite P b5 S b4 S11 , native lead P b and wulfenite P bM oO4 . All these are included in our model keeping the relative proportions of galena, cerussite, anglesite A new model of the mineralogical composition of the earth’s crust 71 and native lead given by Grigor’ev. The concentrations of wulfenite and boulangerite are fixed by their M o and S b contents respectively11 . 3.4.36 Lithium Lithium is an alkali metal of very high chemical reactivity. As a consequence, it takes part in a huge number of reactions. The carbonate can be used in the pottery industry and in medicine as antidepressant. Low-density alloys are used for armor plate and for aerospace components. The bromine and chloride both form concentrated brine, which have the property of absorbing humidity in a wide temperature range; these brines are also used for air conditioning systems. Lithium finds additional use in nuclear breeder reactors as a coolant and as a source for tritium. Other important uses for lithium are as lubricants, in porcelain glaze, as an additive to extend the life and performance of alkaline storage batteries and in welding. Lithium is a moderately abundant element. Its most important mineral commercially is spodumene LiAsSi2 O6 , followed by lepidolite K Li2 AlSi4 O1 0F (OH). It is commonly found in nature as silicates and phosphates. However it is usually recovered from brines. Grigor’ev has included in his model spodumene, the silicate neptunite and the phosphate amblygonite. Additionally, we will include lepidolite in our model because of its industrial importance, assuming that the Li quantity coming from it in the crust is 10% of that of spodumene. Our model keeps the relative proportions of the different lithium minerals considered by Grigor’ev, but assuring the satisfaction of the mass balance. 3.4.37 Lutetium See section 3.4.52. 3.4.38 Magnesium Magnesium is a light, chemically reactive metal, belonging to the alkaline earth group. It is known as the lighter structural metal in the industry, due to its low weight and its capability of forming mechanically resistant alloys. Magnesium alloys are used in beverage cans, as structural components of automobiles and machinery. Magnesium compounds, primarily magnesium oxide, are used mainly as refractory material in furnace linings for producing iron and steel, nonferrous metals, glass and cement. Magnesium oxide and other compounds are also used in agricultural, chemical and construction industries. 11 See sections 3.4.41 and 3.4.4 for details about the assumptions done for wulfenite and boulangerite, respectively. 72 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Magnesium is among the eight most abundant elements. It usually occurs in crustal rocks mainly as the insoluble carbonates and sulfates and less accessibly as silicates. Important magnesium-containing minerals are dolomite C aM g(CO3 )2 , magnesite M g CO3 , carnallite K2 M g C l4 · 6H2 O, olivine (M g, Fe)2 SiO4 , talc M g3 Si4 O10 (OH)2 or spinel M gAl2 O4 . Fifty-five magnesium-containing minerals have been considered in our model. 3.4.39 Manganese Manganese is a grey-white chemically active metal. It resembles iron and is essential in the iron and steel production by virtue of its sulfur-fixing, deoxidizing and alloying properties. It is also widely used in aluminium alloys. Further applications for manganese and its compounds are as additive in gasoline to boost octane rating, as a reagent in organic chemistry, as a colorizing and decolorizing agent for glass, as a paint, as a disinfectant and in batteries. Manganese is found over 300 different and widely distributed minerals of which about twelve are commercially important. It occurs in primary deposits as the silicate metal. Of more commercial importance are the secondary deposits of oxides and carbonates such as pyrolusite M nO2 and to a lesser extent as rhodochrosite M nCO3 . Vast quantities of manganese exist in manganese nodules (manganese, iron and other metal-containing agglomerates) of the ocean floor. But no economically viable methods of harvesting manganese nodules have been found yet. The M n-containing minerals included in Grigorev’s model are: rhodochrosite, pyrolusite, chloritoid, ankerite, todorokite, vernadite, spessartine, wolframite, jacobsite, cryptomelane, manganite, tephroite, braunite, rhodonite, samsonite, psilomelane, hollandite, neptunite, helvite, eudyalite, lavenite and nordite. The quantity of the nine latter minerals is fixed by their W , Ag, Ba, Li, Be, Z r and S r contents. The rest minerals are assumed to have in our model the relative proportions given by Grigor’ev. 3.4.40 Mercury Mercury is the only common metal which is liquid at ordinary temperatures. Because of its high density it is used in barometers and manometers. It is extensively used in thermometers thanks to its high rate of thermal expansion that is fairly constant over a wide temperature range. Amalgams of silver, gold and tin (alloys of mercury) are used in dentistry. Most mercury is used for the manufacture of industrial chemicals and form electrical and electronic applications. Cinnabar, H gS is the only important ore and source of mercury, being the deposits at Almaden in Spain the most famous and extensive ones. Grigor’ev records two minerals of mercury: cinnabar and metacinnabar. Both minerals will be kept in our model, maintaining their respective proportions. A new model of the mineralogical composition of the earth’s crust 3.4.41 73 Molybdenum Molybdenum is a refractory metal able to withstand extreme temperatures without significantly expanding or softening. Those properties make M o useful in applications that involve intense heat, including aircraft parts, electrical contacts and filaments. Molybdenum is used in alloys, mainly in steel, cast iron and superalloys. It is also used in electrodes, lubricants, pigments and catalysts. The most important ore of molybdenum is the sulphide molybdenite M oS2 , which can be found in tungsten and copper ores, being molybdenite a byproduct of W and Cu production. Less important ores are wulfenite P bM oO4 and powellite C aM oO4 . All three minerals are considered in Grigorev’s model and will be considered in our model, keeping Grigorev’s relative proportions. 3.4.42 Neodymium Neodymium is a member of the lanthanide series and hence has few properties which distinguish it from the other members of the series. Like lanthanum and other REE, it can be found in houses equipment such as televisions, lamps and glasses. Neodymium forms an important alloy (neodybium), found to produce very high magnetic field strengths with small masses. Neodymium is the second most abundant of the REE after cerium. It is found in minerals that include other lanthanide elements such as monazite and bastnasite. N d is included in the empirical formula of the minerals fergusonite, britholite and monazite given by Grigor’ev. In addition to those minerals, we include the rest of N d in the upper continental crust as “diadochic N d” in our model, which should account mainly for N d found as an ion solution in bastnaesite. 3.4.43 Nickel Nickel is a transition metal that belongs to the iron group. It is mainly used in the preparation of alloys, giving to them good strength, ductility and resistance to corrosion properties. About 65% of the nickel consumed in the western world is used to make stainless steel. The remaining is divided between alloy steels, rechargeable batteries, catalysts, coinage, foundry products and plating. The bulk of the nickel mined comes from two types of ore deposits. The first are laterites where the principal ore minerals are nickeliferous limonite12 and garnierite N i3 M gSi6 O15 (OH)2 · 6(H2 O). The second are magmatic sulfide deposits where the 2+ principal ore mineral is pentlandite Fe4.5 N i4.5 S8 . Arsenide ores such as nickeline 12 Nickeliferous limonite is the term used to describe poorly crystalline nickel-bearing ferric oxides of which the main constituent is goethite Fe3+ O · OH. 74 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST N iAs or gersdorffite N iAsS can be also found. N i appears as well in the crystalline structure of many other minerals including pyrrhotite, chalcopyrite, pyrite, ilmenite or magnetite. The laterites group is represented in Grigorev’s model by garnierite, while the second by pentlandite. Other arsenides and sulphides of N i considered are violarite Fe2+ N i23+ S4 , vaesite N iS2 , cooperite P t 0.6 P d0.3 N i0.1 S, nickeline and gersdorffite. Additionally to those, we will include in our model “diadochic N i”, which should account for the whole N i appearing in small quantities in the crystal lattice of the minerals mentioned before. It will be assumed that diadochic N i contributes to the same N i amount than pentlandite. The relative proportions given by Grigor’ev will be maintained, although cooperite13 , nickeline and gersdorffite14 are fixed by their P d, and As contents. 3.4.44 Niobium Niobium, sometimes called columbium, is a rare soft transition metal, used mainly for the production of high-temperature resistant alloys and special stainless steels. Small amounts of niobium impart greater strength to other metals. The applications of those alloys are in nuclear reactors, jets, missiles, cutting tools, pipelines, super magnets, surgical implants and welding rods. Niobium is additionally used as a superconductor when lowered to cryogenic temperatures. Niobium has been mainly mined as columbite FeN b2 O6 . Two other important N bcontaining minerals are euxenite (Y, C a, C e, U, T h)(N b, Ta, T i)2 O6 and pyrochlore N a1.5 C a0.5 N b2 O6 (OH)0.75 F0.25 the latter is now its most important ore. Due to its similarities to tantalum, minerals that contain niobium also contain tantalum, so that columbite gets the name of tantalite when tantalum preponderates. Besides of columbite, pyrochlore and tantalite, other N b-containing minerals included in Grigorev’s model are ilmenorutile, murmanite, loparite, tanteuxenite, lavenite rinkolite, wohlerite, polycrase, blomstrandite and fergusonite. No additional minerals will be included in our model. It will be assured the satisfaction of the mass balance, keeping the relative proportions of the different minerals given by Grigor’ev. 3.4.45 Nitrogen Nitrogen is a common inert gas and an essential element in most of the substances that make up living organisms, including proteins. Its main application is as a component in the manufacture of ammonia, subsequently used as fertilizer and to produce nitric acid. It can be used also as a refrigerant for freezing and transporting food products. 13 14 See section 3.4.47 for details about the optimization method used for cooperite. see section 3.4.5 for details about the optimization method used for nickeline and gersdorffite. A new model of the mineralogical composition of the earth’s crust 75 Despite its ready availability in the atmosphere, constituting 78% of the air by volume, nitrogen is relatively unabundant in the continental crust. The only major minerals are K N O3 (nitre, salpetre) and N aN O3 (sodanitre, nitratine). Both occur widespread. Grigor’ev did not consider any of both minerals. We will assume that they are the only carriers of Nitrogen in the upper continental crust at equal relative proportions. 3.4.46 Osmium and Iridium Osmium is a silvery metal of the platinum group metals. It has the distinction of being the most dense of all the naturally occurring elements. Its main application is as an alloy with other platinum metals. Iridium is a transition metal of the platinum family and it is notable for being the most corrosion resistant element known. Demand for iridium comes mainly from the electronic, automotive and chemical industry, where it is used to coat the electrodes in the chlor-alkali process and in catalysts. Osmium and iridum are very rare metals. Osmium is usually found in combination with iridium and ruthenium. The most important ores are iridosmine and osmiridium. The same main ores are found for iridium. Grigor’ev did not account for any of both substances. We will include both minerals in the proportions so that they comply with the mass balance for elements osmium and iridium. 3.4.47 Palladium Palladium is a silver-white metal belonging to the platinum group metals. Because of its corrosion resistance, a major use of palladium is in alloys used in low voltage electrical contacts. It is also used as a catalyst, replacing platinum for reducing car exhaust emissions and it is alloyed with certain metals in jewelry. Palladium is nowadays being more and more used in electrical appliances in the form of multilayer ceramic capacitors. Palladium is usually associated with the other platinum metals and occur either native or as sulfides or arsenides in N i, Cu and Fe sulfide ores. However, much of it is extracted as a by-product from copper-nickel ores such as chalcopyrite, pyrrhotite and pentlandite or chromite. The only mineral considered by Grigor’ev in his model is cooperite P t 0.6 P d0.3 N i0.1 S. The rest of palladium found in nature will be considered in our model to be included dispersed in the copper-nickel ores mentioned before. 76 3.4.48 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Phosphorous Phosphorous is a nonmetal of the nitrogen group. Concentrated acids are used in fertilizers for agriculture and farm production. Phosphates are used for special glasses, sodium lamps, in steel production, in military applications and in other applications such as pyrotechnics, pesticides, toothpaste or detergent. Phosphorous is an abundant mineral on earth. All its known terrestrial minerals are orthophosphates. Some 200 crystalline phosphate minerals have been described, but by far the major amount of P occurs in the family of apatites, and these are the only ones of industrial importance. Common members are fluorapatite C a5 (PO4 )3 F , chlorapatite C a5 (PO4 )3 C l and hydroxylapatite C a5 (PO4 )3 OH. In addition, there are vast deposits of amorphous phosphate rock phosphorite, which approximates in composition to fluoroapatite. The phosphates taken into account in Grigorev’s model are: apatite, xenotime, rhabdophane, amblygonite, metatorbernite, monazite, weinschenkite, francolite, vivianite. All three kinds of apatite are included in the general formula C a5 (PO4 )3 (OH)0.3333 F0.3333 C l0.3333 . No other minerals are taken into account in our model. Except for weinschenkite and vivianite, which are assumed to have the same concentration than the given by Grigor’ev, the quantity of all those minerals are fixed by the mass balance of C l,Y b, Li, U, Y , F and La. Additionally, the amorphous phosphate rock phosphorite is included in our model due to its abundance. It will be assumed to have the composition C a3 (PO4 )2 . 3.4.49 Platinum Platinum gives the name to the platinum-group metals (PGM), which comprise platinum, palladium, rhodium, ruthenium, iridium and osmium. It has outstanding catalytic properties and its resistance is well suited for making fine jewelry. Platinum and its alloys are used also in surgical tools, laboratory utensils, electrical resistance wires, etc. The glass industry uses platinum for optical fibers and liquid crystal display glass. Platinum occurs generally associated with the other platinum metals and occur also in native form or as sulfides or arsenides in N i, Cu and Fe sulfide ores. Three-quarters of the world’s platinum comes from South Africa, where it occurs as cooperite. It is also extracted as a by-product from copper-nickel ores such as chalcopyrite, pyrrhotite and pentlandite or with chromite. Platinum is included in three minerals of Grigorev’s model: cooperite, ferroplatinum and native platinum. We will maintain the concentrations given by Grigor’ev for the latter two and assume that the rest platinum in the upper crust is equally distributed in cooperite and in the copper-nickel ores mentioned before. A new model of the mineralogical composition of the earth’s crust 3.4.50 77 Potassium Potassium is a soft, silvery-white metal, member of the alkali group. Most potassium goes into fertilizers. Potassium carbonate is used in the glass manufacture for making televisions. Potassium hydroxide is used to make liquid soaps and detergents. Further application of other potassium compounds are in the pharmaceutical industry, photography and to make iodize salts. Potassium is a very abundant element on earth. Most of it occurs as minerals such as feldspars and clays. Potassium is leached from these by weathering, which explains why there is quite a lot of this element in the sea. Important ores for potassium are sylvite KC l, carnallite K M g C l3 · 6(H2 O) and alunite KAl3 (SO4 )2 (OH)6 . Potassium-containing minerals in Grigor’ev analysis are: orthoclase, hydromuscovite, glauconite, lepidomelane, nepheline, sanidine, stilpnomelane, jarosite, alunite, neptunite, sylvite, carnallite, miserite, biotite, muscovite, hydrobiotite, phlogopite, todoroskite and cryptomelane. In addition to those, niter, carnotite and lepidomelane are other potasium-containing minerals included in our model, because of its nitrogen, uranium and lithium contents15 . The quantity of the latter 9 minerals mentioned above of Grigorev’s analysis is fixed by their Li, U, C l, F and M n content. For the remaining minerals, their respective proportions given by Grigor’ev are kept in our model. It must be pointed out, that the mass balance between elements and species for potassium in Grigorev’s model gives a quantity of K greater than the accepted value for K in the earth’s crust in Rudnick et al. [292]. Probably, Grigor’ev overestimated the quantity of some potassium-containing minerals in the earth’s crust. 3.4.51 Praseodymium See section 3.4.52 3.4.52 Rare Earth Elements: Praseodymium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium and Lutetium All fourteen members of the lanthanide series have very similar geochemical properties. Many applications of rare earth elements (REE) are characterized by high specificity and high unit value. For example, europium is used for color cathoderay tubes and liquid crystal displays used in monitors and televisions. A major use of praseodymium is in misch metal, used in making cigarette lighters. Samarium is used as a catalyst in certain organic reactions. Erbium finds extensive use in 15 See sections 3.4.73, 3.4.36 and 3.4.39 for more details about the optimization process for uranium, lithium and manganese. 78 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST laser repeaters for fiber-optic telecommunication cables. Permanent magnet technology has been revolutionized by alloys containing gadolinium, dysprosium and other REE. Terbium, gadolinium or europium are used in new energy-efficient fluorescent lamps. Lutetium can be used as a catalyst in petroleum cracking in refineries and in alkylation, hydrogenation and polymerization applications. Holmium and thulium are being used in lasers for medical applications. There are over 100 minerals known to contain lanthanides but the only two of commercial importance are monazite, a mixed La, T h, Ln phosphate and bastnaesite, a La, Ln fluorocarbonate. Tamarium, terbium and erbium are also found in xenotime and euxenite, while gadolinite is also an important source for Holmium, Terbium and Thulium. Grigor’ev accounted for the mineral fergusonite in his model, which contains the REE Sm and traces of P r. We will keep in our model the same concentration of fergusonite on earth given by Grigor’ev. Not being specifically in the empirical formula of the minerals explained above, the REE Gd, T b, D y, H o, E r, T l and Lu will be considered in our model as diadochical elements. 3.4.53 Rhenium Rhenium was the last naturally-occurring element to be discovered. Its main applications in industry are found in the manufacture of tungsten-rhenium and molybdenum-rhenium alloys. Other important uses of rhenium are in platinumrhenium catalysts, used primarily in producing lead-free, high octane gasoline and in high-temperature superalloys used for jet engine components. The concentration of rhenium in the earth’s crust is extremely low and it is also very diffuse. Being chemically akin to molybdenum it is in molybdenites that its highest concentrations (0,2%) are found. No Re mineral is included in Grigorev’s model. We will account for it as “diodochic Re”. 3.4.54 Rhodium Rhodium is part of the platinum group metals. Most part of its production goes into catalytic converters for cars and in some industrial processes. It is used in alloys with platinum and iridium, giving improved high-temperature strength and oxidation resistance to furnace windings, high-temperature thermocouple and resistance wires, spark plugs, bearings, electrical contacts, etc. Rhodium occurs as rare deposits of the native element and in rare minerals associated with other metals of the platinum group. But usually, the commercially available metal comes as a by product of the refining of copper and nickel ores which contain up to 0,1% rhodium. A new model of the mineralogical composition of the earth’s crust 79 There is no rhodium mineral in Grigorev’s analysis. We will account for it as being included in the ores mentioned before. 3.4.55 Rubidium Rubidium is a silvery white, very active metal as are the other alkali metals. Rubidium and its salts have few commercial uses. The metal is used in the manufacture of photocells and in the removal of residual gases from vacuum tubes. Rubidium salts are used in glasses and ceramics and in fireworks to give them a purple color. Although very abundant, no purely Rb-containing mineral is known and much of the commercially available material is obtained as a byproduct of lepidolite processing for Li. It occurs also naturally in the minerals pollucite, lepodite, carnallite, zinnwaldite and leucite. All Rb on earth will be accounted in our model as “diadochic Rb”. 3.4.56 Ruthenium Ruthenium is one of the six platinum metals. It finds use in the electronic and chemical industry, with smaller amounts being used in alloying for increasing hardness and corrosion resistance. It is used in electrical contact alloys and filaments, in jewelry, in pen nibs and in instrument pivots. Like the other metals of its group, it is a versatile catalyst used in different industrial processes. Ruthenium is one of the rarest metals on earth. It is found native and sometimes associated with platinum, osmium and iridium. Like the other platinum metals, it is commercially extracted from nickel and copper deposits. In addition to osmiridium, we will assume that most part of ruthenium is found in nickel and copper ores. 3.4.57 Samarium See section 3.4.52 3.4.58 Scandium The transition metal scandium is mainly used in aluminium alloys for sporting equipment, metallurgical research, high-intensity metal halide lamps, analytical standards, electronics, oil well tracers and lacers. Scandium occurs in many ores in trace amounts, but has not been found in sufficient quantities to be considered as a reserve. Therefore, scandium has been produced 80 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST exclusively as a byproduct during processing of various ores or recovered from previously processed tailings or residues. Considerable amounts of scandium oxide Sc2 O3 can be obtained as a byproduct of the extraction of uranium. Its only rich mineral is the rare thortveitite Sc2 Si2 O7 . We will keep the value given by Grigor’ev for thortveitite, and assume that the rest of it is widely dispersed in other minerals. The latter is called in our model “Diodochic Sc”. 3.4.59 Selenium Selenium is a non metallic chemical element, resembling sulfur and tellurium in its chemical activity and physical properties. It has good photovoltaic and photoconductive properties, and it is used extensively in electronics, such as photocells, light meters and solar cells. The second largest use of selenium is the glass industry, used to remove color from glass. It finds also extensive application as animal feeds and food supplements. Additionally, it can be used in photocopying, in the toning of photographs, in metal alloys and to improve the abrasion resistance in vulcanized rubbers. Selenium is among the rarer elements on the earth’s crust. It is occasionally found native, but it is usually associated with sulfur, copper, zinc and lead, such as in the form of clausthalite CuSe or klockmanite P bSe. Selenium is recovered commercially as a byproduct of the electrolytic refining of copper where it accumulates in anode residues. There is no selenium mineral considered in Grigorev’s analysis. We will account for the element as being part of copper ores, since they are its main sources. 3.4.60 Silicon Silicon is a brittle steel-gray metalloid. It has many industrial uses. It is the main component of glass, cement, ceramics, most semiconductor devices and silicones. Silicon is also an important constituent of some steels and a major ingredient in bricks. It is also used as an alloy to provide resistance to aluminium, magnesium, copper and other metals. Metallurgic silicon is used as a raw material in the manufacture of organosilic and silicon resins, seals and oils. Silicon chips are used in integrated circuits and photovoltaic cells are made of thin cut slices of simple silicon crystals. Silicon is the most abundant element in the earth’s crust after oxygen. It never occurs free, it occurs invariably combined with oxygen and with trivial exceptions is always 4-coordinate in nature. Sand is used as a source of the silicon produced commercially. A few silicate minerals are mined, e.g. talc and mica. Other mined silicates are feldspars, nepheline, olivine, vermiculite, perlite, kaolinite, etc. Our model accounts for 136 Si-containing minerals. A new model of the mineralogical composition of the earth’s crust 3.4.61 81 Silver In addition to coinage, silver is used mainly in tableware, mirrors, electronic products, photography, jewelry and as a catalyst in oxidation reactions. Silver is widely distributed in sulfide ores of which argentite (Ag2 S) is the most important. Silver can be also found native in nature and associated to chlorine as Ag C l. Only about 10% of all silver mined is won from deposits primarily exploited for the metal; 90% or more represents a by-product of copper, lead, zinc and gold mining. Grigor’ev accounted in his model for the most important compounds of silver found in nature, namely native silver, argentite, acantithe, stephanite, pyrargirite, chlorargirite, freibergite and samsonite. In addition to those, we take into account the gold-silver telluride sylvanite. 3.4.62 Sodium Sodium is a white-silvery metal, belonging to the alkali group, and hence of high reactivity. Sodium in its metallic form is very important in making esters and in the manufacture of organic compounds. Sodium is also a component of sodium chloride N aC l, a very important compound found everywhere in the living environment. Other applications of sodium are: in alloys to improve their structure, in soap, to purify molten metals, in sodium vapor lamps, as a heat transfer fluid and as a desiccant for drying solvents. Sodium is a very abundant element in the earth’s crust. After chloride, sodium is also the second most abundant element dissolved in seawater. Sodium occurs as rock-salt (N aC l) and as the carbonate, nitrate, sulfate, borate, etc. Fifty N a-containing minerals have been considered in our model. 3.4.63 Strontium Strontium is a bright silvery alkaline-earth metal. Principal uses of strontium compounds are in pyrotechnics, vacuum tubes to remove the last traces of air and as the carbonate in special glass for television screens and visual display units. Further uses of strontium and its compounds are in toothpastes, in aerosol paint or for medical treatment of osteoporosis. Strontium commonly occurs in nature, averaging about 0,034% of all igneous rocks. It is found chiefly in the form of the sulfate mineral celestine S r CO4 and the carbonate strontianite S r CO3 . Grigorev’s strontium-containing minerals are celestine, strontianite and the rare minerals lamprophyllite and nordite. Our model will keep the relative proportions of 82 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST celestine and strontianite given by Grigor’ev, but assuring that they satisfy the mass balance for strontium in the upper crust. The abundance of nordite and lamprophyllite given by Grigor’ev is assumed to be correct. Although the S r content in Grigorev’s analysis does not fulfill constraint number 4 on page 57, no more strontiumcontaining minerals will be included in our model because celestine and strontianite are their most important ores should account for almost all Sn in the earth’s upper crust. 3.4.64 Sulfur Sulfur is a yellow solid nonmetal. Its main compound is sulfuric acid H2 SO4 , one of the most important substance in industrial and fertilizer complexes. In fact, the yearly consumption of sulfuric acid is an index of industrial development of a country. Sulfur is also used in batteries, detergents, fungicides, manufacture of fertilizers, gun power, matches and fireworks. It finds also application in the manufacture of corrosion-resistant concrete. Sulfur is widely distributed in nature. The three most important commercial sources are: 1) elemental sulfur in the caprock salt domes in the USA and Mexico and the sedimentary evaporite deposits in eastern Poland and western Asia; 2) as H2 S in sour natural gas and as organosulfur compounds in crude oil. They represent currently the main commercial source of the element. 3) from pyrites FeS2 and other metalsulfide minerals. Common naturally occurring sulfur compounds include the sulfide minerals cinnabar H gS, galena P bS, sphalerite Z nS, stibnite S b2 S3 and the sulfates gypsum C aSO4 · 2H2 O, alunite KAl3 (SO4 )2 (OH)6 and barite BaSO4 . Our model accounts for 47 S-containing minerals. 3.4.65 Tantalum Tantalum is a hard transition metal highly corrosion-resistant and a good conductor of heat and electricity. The major use for tantalum is in the manufacture of electronic components, mainly capacitors. Additionally, it is used in high-temperature applications such as aircraft engines and for handling corrosive chemicals. Tantalum occurs invariably together with niobium. The chief mineral for Ta is known as tantalite FeTa2 O6 . Deposits are widespread but rarely very concentrated. Microlite and euxenite are other minor ores for Ta. Grigor’ev accounts for Ta in minerals ferrotantalite, microlite, tanteuxenite and euxenite, as well as in polycrase and blomstrandite. The relative proportions of the four minerals given by Grigor’ev are kept in our model, while the quantities of the last two are fixed by the uranium mass balance16 . 16 dite. See section 3.4.73 for details about the optimization procedure used for polycrase and blomstran- A new model of the mineralogical composition of the earth’s crust 3.4.66 83 Tellurium Tellurium is a semiconductor. Its chemistry is similar to that of sulfur and has properties both of metals and non metals. It is used as an additive to steel and it is often alloyed to aluminium, copper, lead or tin. It can be used for cast iron, ceramics, blasting caps, solar panels or rubber. Tellurium is a relatively rare element. Commercial tellurium comes mainly as a byproduct of copper processing. Samples of tellurium can be found uncombined in nature, but they are extremely rare. There are some tellurium minerals such as calaverite, sylvanite or tellurite, but none is mined as a source of the element. The only mineral containing tellurium considered by Grigore’ev is tetradymite. We will keep the concentration given by Grigor’ev for tetradymite and include tellurite (assuming that it has the same Te concentration as sylvanite and calaverite) and “dispersed Te”, which should account for the rest of tellurium in the crust found mostly in copper ores. Remember that sylvanite and calaverite were already accounted for gold-containing minerals. 3.4.67 Terbium See section 3.4.52 3.4.68 Thallium Thallium is a soft and malleable heavy metal that is used in a wide variety of applications. Some of them are as a semiconductor material for selenium rectifiers, in gamma radiation detection equipment, in infrared radiation detection and transmission equipment, in crystalline filters for light diffraction, in medical diagnostic tests to detect heart diseases, etc. Although thallium is reasonable abundant in the crust, it exists mostly in association with potassium minerals such as sylvite and pollucite and is not generally considered to be commercially recoverable from those forms. Very rare minerals of thallium occur in nature as sulfide or selenide complexes with antimony, arsenic, copper, lead and silver such as hutchingsonite P bT lAs5 S9 , but they have no commercial importance as sources either. Thallium is commercially recovered as a byproduct from the flue dust and residues generated during the roasting and smelting of Z n and P b sulfide ores. No thallium mineral has been recorded by Grigor’ev. We will include T l in our model as “dispersed T l”, which should account for all T l in the crust in the forms of the sources mentioned above. 84 3.4.69 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Thorium Thorium is a silver-grey heavy metallic element of the actinide series. Thorium demand worldwide is relatively small. Some of its applications are as an alloying element in magnesium, as a coating for wolfram wire used in electronic equipment, to control grain size of plutonium used for electric lamps, as a catalyst, in the manufacture of refractory materials for the metallurgical industries, or as a fertile material for producing nuclear fuel. Thorium is very abundant in the earth’s crust (three times more abundant than uranium). Thorium occurs naturally in the minerals thorite, uranothorite, thorianite and is a major component of monazite, where it is usually commercially extracted as a byproduct. It is present also in significant amounts as diodochic element in the minerals zircon, titanite, gadolinite and blomstrandite. Grigor’ev records all the main thorium-containing minerals in his model explained above, as well as britholite, polycrase, yttrialite and chevkinite. They are all included in our model, maintaining the relative proportions provided by Grigor’ev. 3.4.70 Thulium See section 3.4.52. 3.4.71 Tin Tin is a silvery-white metal that finds extensive use as a protective layer for mild steel. Alloys of tin are used in many ways, such as solder for joining pipes or electronic circuits, bell and babbit metal, dental amalgams, etc. The principal alloys of tin are bronzite (tin and copper), soft solder (tin and lead), pewter (75% tin and 25% lead) and britannia metal (tin with small amounts of antimony and copper). There are few tin-containing minerals, but only one is of commercial significance and that is cassiterite SnO2 . Grigor’ev accounts for Sn in cassiterite as well as native tin. We keep the relative proportions of both minerals given by Grigor’ev in our model but assuring that they fulfill the mass balance of Sn on earth. No more tin-containing minerals will be included because cassiterite is its most important ore and should account for almost all Sn in the earth’s upper crust. 3.4.72 Titanium Titanium is a light, strong transition metal, well known for corrosion resistance and for its high strength-to-weight ratio. Most of it is consumed in the form of titanium A new model of the mineralogical composition of the earth’s crust 85 dioxide T iO2 , a white pigment in paints, paper and plastics. Titanium alloys are used in aircraft, pipes for power plants, armor plating, naval ships and missiles. In medicine, titanium is used to make hip and knee replacements, pace-makers, boneplates and screws. Titanium is an abundant element on earth and is found in minerals rutile T iO2 , brookite T iO2 , anatase T iO2 , illmenite Fe2+ T iO3 , leucoxene C aT iSiO5 and titanite C aT iSiO5 . The chief mined ore is ilmenite, but leucoxene and rutile are also important economic ores for titanium. Titanium-containing minerals considered by Grigor’ev are: ilmenite, leucoxene, rutile, brookite, titanite, augite, ulvöspinel, anatase, aenigmatite, perovskite, ramsayite, lamprophyllite, neptunite, blomstrandite, polycrase, lavenite, rinkolite, delorenzite, loparite, chevkinite, murmanite, ilmenorutile and euxenite. No additional minerals are included in our model. 3.4.73 Uranium Uranium is a silvery metallic radioactive element of the actinide group. It gained importance with the development of practical uses of nuclear energy. Depleted uranium is used as shielding to protect tanks and also in bullets and missiles. However, the main use of uranium is to fuel commercial nuclear power plants. Uranium is widely distributed, being the most important ores uraninite UO2 and carnotite K2 (UO2 )2 (V O4 )2 · 3H2 O. However, even these are usually dispersed so that typical ores contain only about 0,1%, and many of the more readily exploited deposits are nearing exhaustion. Significant concentrations of uranium occur in some minerals such as monazite sands or lignite. Grigor’ev considers five uranium-containing minerals: uraninite, betafite, metatorbenite and polycrase. In addition to those minerals, we include also carnotite in our model, assuming that it has the same U content as uraninite. The relative proportions of all minerals accounted by Grigor’ev are kept and their quantities are obtained by satisfying constraint 1. 3.4.74 Vanadium Vanadium is a transition metal and finds extensive use in the manufacture of special steels with exceptional strength and toughness. Steel alloys are used in axles, crankshafts, gears and other critical components. Mixed with aluminium in titanium alloys, it is used in jet engines and high speed air-frames. Vanadium is widely, though sparsely distributed; thus although more than 60 different minerals of vanadium have been characterized, there are few concentrated deposits and most of it is obtained as a byproduct of iron, uranium, phosphor, copper, lead, zinc or titanium ores. Most important vanadium minerals are patronite 86 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST V S4 , vanadinite P b5 (V O4 )3 C l and carnotite K2 (UO2 )2 (V O4 )2 · (H2 O). Vanadium is also found in some crude oils, coal, oil shale and tar sands. No vanadium-containing minerals are registered by Grigor’ev. We take into account in our model carnotite, for being an uranium important ore. The rest vanadium is assumed to come from dispersed sources. 3.4.75 Wolfram Wolfram, also known as Tungsten, is a transition metal, having the highest melting point of any metal. Hence, it is used in filaments in incandescent light bulbs, in electric contacts and arc-welding electrodes. It imparts great strength to alloys such as steel. Tungsten is also used in X-ray tubes and in microchip technology. Its most important application though is in the manufacture of cement carbide, since its main component is wolfram carbide (W C). There are several minerals of wolfram, the most important ones are scheelite and wolframite. Both minerals have been considered by Grigor’ev and will be taken into account in our model, keeping the relative proportions of Grigorev’s analysis. The quantity of both minerals in our model almost exceeds two orders of magnitude the values given by Grigorev. However, all references consulted coincide in giving most relevance only to those two substances. Therefore, no additional minerals are going to be considered. 3.4.76 Ytterbium Ytterbium is a rare earth element used in certain steels for improving the grain refinement, strength and other mechanical properties of stainless steel. Some ytterbium alloys have been used in dentistry. Like other REE, it can be used to dope phosphors, or for ceramic capacitors and other electronic devices. Ytterbium is found with other rare earth elements in several rare minerals as gadolinite, monazite and xenotime. It is most often recovered commercially from monazite sand. The latter minerals have been considered by Grigor’ev. We will assume that Grigorev’s quantity for xenotime is correct and will account for Y b in monazite as the difference between the contents in the earth’s crust and in xenotime. 3.4.77 Yttrium Yttrium is a silver-metallic rare earth metal. The largest use of the element is as its oxide yttria Y2 O3 , which is used in making red phosphors for color television picture A new model of the mineralogical composition of the earth’s crust 87 tubes. It is also used in small amounts to increase the strength of aluminium and magnesium alloys. Additional uses of yttrium are in camera lenses and to make superconductors. Yttrium, like lanthanum is invariably associated with lanthanide elements in minerals such as xenotime, monazite, fergusonite or gadolinite. Yttrium-containing minerals in Grigorev’s model are: fergusonite, thortveitite, polycrase, gadolinite, rinkolite, euxenite, tanteuxenite, ytriallite, orthite and weinschenkite. The concentration of all those minerals on earth, except for weinschenkite are fixed by their content in other elements in our model. For weinschenkite, we will assume that it has the concentration given by Grigor’ev. Additionally, “diodochic Y ” is included in our model in order to account for the Y found in the crystalline structure of other lanthanide minerals. 3.4.78 Zinc Zinc is a bluish-white transition metal. It is the fourth metal mostly consumed in the world. The main use of zinc is for the galvanizing of iron sheets or wires. Zinc is used in making alloys such as brass or bronze. Zinc oxide is used as a white pigment in plastics, cosmetics, paper, printing inks, etc. and as an activator in the rubber industry. The major ores of zinc are sphalerite Z nS and smithsonite Z nCO3 . Less impor2+ 3+ tant ores are franklinite Z n0.6 M n2+ 0.3 Fe0.1 M n0.5 O4 , hemimorphite Z n4 Si2 O7 (OH)2 2+ and wurtzite Z n0.9 Fe0.1 S. Grigorev’s Z n-containing minerals are sphalerite, smithsonite, nordite and native zinc. In our model we will assume that all those four minerals account for the majority of the zinc found in the upper crust and hence we will omit the less important ores mentioned above. The abundance of nordite is fixed by its S r content. 3.4.79 Zirconium Zirconium is a silver-gray metal with chemical and physical properties similar to those of titanium. It is extremely resistant to heat and corrosion. Zircon is its most used compound and is used in refractories, ceramic opacification and foundry sands. It is also considered as a semi-precious gemstone used in jewelry. Further uses for zirconium are in alloys such as zircaloy, which is used in nuclear applications since it does not absorb neutrons. It is also used in catalytic converters. Zirconium is not particularly a rare element and occurs in nature mainly as the silicate mineral zircon Z rSiO4 . Baddeleyite Z rO2 is also an important ore for Z r. Grigorev’s model includes eight different zirconium-containing minerals: zircon, naegite (a variety of zircon that contains U, T h, Y and other REE in its lattice), 88 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST sirtolite (a variety of zircon that contains T h and H f in its lattice), eudialyte, baddeleyite, lavenite, mosandrite and wohlerite. An interesting aspect about his analysis is that eudialyte is a more abundant mineral than baddeleyite, which is more common. All eight minerals are also included in our analysis. Grigorev’s relative proportions are kept, but assuring the satisfaction of the constraints described before. 3.5 Mathematical representation The problem described in a qualitatively way in the last section, can be represented mathematically according to Eq. 3.2. The objective is to minimize (M in) with a least squares Pprocedure the difference between the P mineralogical composition of our model ( ξ̂i ) and that of Grigor’ev’s analysis ( ξi ). This optimization must be constrained by physical and geological restrictions. The physical restrictions are constraints 1 and 2 defined in section 3.4, namely the satisfaction of the mass balance and the positiveness requirement for all minerals. The geological restrictions are based on reasonable assumptions and, as opposed to the physical ones, may change with new mineral discoveries and with the point of view of the analyst. Hence, the model that we have developed must not be considered as final and closed. On the contrary, it is the first step for obtaining a comprehensive, physically and geologically coherent mineralogical composition of the upper earth’s crust. Remember that the chemical composition of the crust has been improved throughout decades and is still under research. Vector ε̂ j , containing the elements that compose the minerals in our model are showed in table A.1 (page 351). Vector ξi , containing the minerals described by Grigor’ev’s analysis is represented in table A.2 (page 352). Finally, the matrix of coefficients R[ j × i] is showed in tables A.3 and A.417 (page 360). The objective function is showed in equation 3.2: M inkξ̂i − ξi k2 (3.2) The physical restrictions to be applied are: • Σr j,i · ξ̂i = ε̂ j • ξ̂i > 0 The geological restrictions based on reasonable assumptions and described in sections 3.4.3 through 3.4.79 for each substance are the following: 17 For the sake of a more flexible representation of matrix R[ j × i], its transposed is given R0 [i × j]. Mathematical representation 89 • Gold: ξ̂1 = ε̂1 · 0, 85/r1,1 • Calaverite: ξ̂2 = ε̂1 · 0, 075/r1,2 • Sylavanite: ξ̂3 = ε̂1 · 0, 075/r1,3 • Thortveitite: ξ̂6 = ξ6 • Lautarite: ξ̂22 = ε̂28 /(r28,22 + r28,23 ) • Dietzeite: ξ̂23 = ε̂28 /(r28,22 + r28,23 ) • Nitratine: ξ̂25 = ε̂31 /(r31,25 + r31,26 ) • Niter: ξ̂26 = ε̂31 /(r31,25 + r31,26 ) • Xenotime: ξ̂31 = ξ31 • Tetradymite: ξ̂35 = ξ35 • Tellurite: ξ̂36 = (r2,2 · ξ̂2 )/(r2,36 ) • Polixene: ξ̂40 = ξ40 • I-Platinum: ξ̂41 = ξ41 • Cooperite: ξ̂42 = (ε̂46 − r46,40 · ξ̂40 − r46,41 · ξ̂41 )/(2 · r46,42 ) • P t in N i-Cu ores ξ̂43 = (ε̂46 − r46,40 · ξ̂40 − r46,41 · ξ̂41 )/(2 · r46,43 ) • Fergusonite: ξ̂47 = ξ47 • Stibnite: ξ̂50 = (ε̂41 − r41,34 · ξ̂34 − r41,51 · ξ̂51 − r41,309 · ξ̂309 − r41,310 · ξ̂310 − r41,312 · ξ̂312 )/(2 · r41,50 ) • Boulangerite: ξ̂51 = ξ51 • S b in galena: ξ̂52 = (ε̂41 − r41,34 · ξ̂34 − r41,51 · ξ̂51 − r41,309 · ξ̂309 − r41,310 · ξ̂310 − r41,312 · ξ̂312 )/(2 · r41,52 ) • Lamprophyllite: ξ̂55 = ξ55 • Tourmaline: ξ̂58 = ξ58 • Kornerupine: ξ̂59 = ξ59 • Axinite - Fe: ξ̂60 = ξ60 • Dumortierite: ξ̂61 = ξ61 • Sassolite: ξ̂62 = (ε̂62 −r62,58 · ξ̂58 −r62,59 · ξ̂59 −r62,60 · ξ̂60 −r62,61 · ξ̂61 )/(4·r62,62 ) 90 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST • Colemanite: ξ̂63 = (ε̂62 − r62,58 · ξ̂58 − r62,59 · ξ̂59 − r62,60 · ξ̂60 − r62,61 · ξ̂61 )/(4 · r62,63 ) • Kernite: ξ̂64 = (ε̂62 − r62,58 · ξ̂58 − r62,59 · ξ̂59 − r62,60 · ξ̂60 − r62,61 · ξ̂61 )/(4· r62,64 ) • Ulexite: ξ̂65 = (ε̂62 − r62,58 · ξ̂58 − r62,59 · ξ̂59 − r62,60 · ξ̂60 − r62,61 · ξ̂61 )/(4· r62,65 ) • Witherite: ξ̂68 = 0, 1 · ξ̂67 • Bismutite: ξ̂72 = (r42,70 · ξ̂70 )/(r42,72 ) • Carnotite: ξ̂85 = (r66,81 · ξ̂81 )/(r66,85 ) • Chyroberyl: ξ̂90 = (r71,86 · ξ̂86 )/(r71,90 ) • Cobaltite: ξ̂125 = ξ125 • Smaltite: ξ̂126 = ξ̂125 • Linnaeite: ξ̂127 = (r76,125 · ξ̂125 )/(r76,127 ) • Arsenolite: ξ̂136 = (r77,131 · ξ̂131 )/(r77,136 ) • Diadochic N i: ξ̂141 = (r48,137 · ξ̂137 )/(r48,141 ) • Miserite: ξ̂151 = ξ151 • Weinschenkite: ξ̂153 = ξ153 • Vivianite: ξ̂155 = ξ155 • Cryotile: ξ̂165 = (r60,163 · ξ̂163 )/(r60,165 ) • Lepidolite: ξ̂179 = (r64,73 · ξ73 · 0, 1)/r64,179 • Tetrahedrite: ξ̂313 = ξ313 • Nordite: ξ̂314 = ξ314 The problem described above was not able to be solved with a mathematical software18 . The reasons for which the mathematical applications could not solve it might have been: • Matrix R [ j × i] is a sparce matrix, composed mainly by zeros. • There are differences between the orders of magnitude of the minerals of a factor of up to 1012 . 18 The problem was tried to be solved with the software Matlab 7.0. The function used was lsqlin with the constraints described previously. Results 91 • The orders of magnitude are very small (down to 10−15 ) and may be below the significant figures of the programmes. The resolution of the system through a mathematical application is open for further studies. Probably, more powerful software will be required. 3.6 Results Fortunately, the optimization problem was solved in a manual way through a trial and error procedure. For that purpose, the relative proportions of the minerals in Grigorev’s model were always tried to be kept. The fitting of the elements, i.e. assuring that ε̂ j −ε j = 0, was carried out gradually in increasing order of appearance in the minerals recorded by Grigor’ev. This way, element Au was the first to be fitted, since native gold is the only Au-containing mineral in Grigor’ev’s model. The last element to be adjusted was Si, since it is the element mostly contained in the minerals of the crust. It must be pointed out that elements O and H have been left free, i.e. without constraints. Table 3.5 shows the mineralogical composition of the earth’s crust obtained in order of abundance. The abundance of the minerals in mass terms, is calculated with Eq. 3.3. ξ̂i · M Wi Abund ance(%) = Pm · 100 i=1 (ξ̂i · M Wi ) (3.3) In table A.2 in page 352, the difference between our mineralogical composition and that of Grigor’ev is shown. It contains 324 species, 57 more than in Grigor’ev’s model19 . Of the 324 substances, 292 are minerals and the rest are mainly diadochic elements included in the crystal structure of other minerals. That is the case for elements C e, N d, N i, Y , Rb, C o, D y, E r, Eu, Ga, Gd, Ge, H o, Lu, Re, Sc, T b, T l, T m, V , H f , I n, P d, P r, P t, Rh, Ru, S b, Se, Sm, Te, Y b. The resulting molecular weight of the upper continental crust according to this model is 157,7 g/mole20 . Next, the results obtained are discussed, stressing out the differences for the most abundant and relevant minerals with Grigor’ev’s model. Additionally, the minerals are aggregated into the main groups explained in section 3.2 and are compared to the values given by Wedepohl [402], [403] and Nesbitt and Young [242]. Finally the drawbacks of the model are also explained. 19 20 The non-mineral materials of Grigor’ev’s model have not been taken into account. Remember that the molecular weight of the crust in Grigor’ev’s model was M Wcr = 142, 1 g/mole. 92 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Table 3.5: Mineralogical composition of the earth’s crust according to the calculations of this study Mineral Formula SiO2 N aAlSi3 O8 N a0.8 C a0.2 Al1.2 Si2.8 O8 KAlSi3 O8 N a0.6 C a0.4 Al1.4 Si2.6 O8 N aAl3 Si3 O10 (OH)2 2+ K M g2.5 Fe0.5 AlSi3 O10 (OH)1.75 F0.25 2+ K0.6 (H3 O)0.4 Al2 M g0.4 Fe0.1 Si3.5 O10 (OH)2 MW g/mole 60,08 263,02 265,42 278,33 268,62 800,00 433,53 392,65 Abundance mass, % 2,29E+01 1,35E+01 1,19E+01 1,18E+01 5,46E+00 3,96E+00 3,82E+00 3,03E+00 Quarz Albite Oligoclase Orthoclase Andesine Paragonite Biotite Hydromuscovite/ Illite Augite Hornblende (Fe) Labradorite Nontronite Opal Ripidolite Almandine Muscovite Sillimanite Epidote Kaolinite Calcite Magnetite Riebeckite Beidellite Ilmenite Titanite Clinochlore Sepiolite Aegirine Diopside Natrolite Cummingtonite Ankerite Phosphate rock Hypersthene Hastingsite Bytownite Actinolite Hydrobiotite Montmorillonite Andalusite Lawsenite Diaspore Pennine Glauconite Prehnite Dolomite 2+ C a0.9 N a0.1 M g0.9 Fe0.2 Al0.4 T i0.1 Si1.9 O6 2+ 3+ C a2 Fe4 Al0.75 Fe0.25 (Si7 AlO22 )(OH)2 236,35 947,32 3,00E+00 2,63E+00 N a0.5 C a0.5 Al1.5 Si2.5 O8 N a0.3 Fe23+ Si3.7 Al0.3 O10 (OH)2 · 4(H2 O) SiO2 · 1.5(H2 O) 2+ Si3 Al2 O10 (OH)8 M g3.75 Fe1.25 Fe32+ Al2 (SiO4 )3 KAl3 Si3 O10 (OH)1.8 F0.2 Al2 SiO5 C a2 Fe3+ Al2 (SiO4 )3 (OH) Al2 Si2 O5 (OH)4 C aCO3 Fe23+ Fe2+ O4 N a2 Fe32+ Fe23+ (Si8 O22 )(OH)2 N a0.33 Al2.33 Si3.67 O10 (OH)2 Fe2+ T iO3 C aT iSiO5 2+ M g3.75 Fe1.25 Si3 Al2 O10 (OH)8 M g4 Si6 O15 (OH)2 · 6(H2 O) N aFe3+ Si2 O6 C aM gSi2 O6 N a2 Al2 Si3 O10 · 2(H2 O) M g7 (Si8 O22 )(OH)2 2+ C aFe0.6 M g0.3 M n2+ (CO3 )2 0.1 C a3 (PO4 )2 M g Fe2+ Si2 O6 N aC a2 Fe42+ Fe3+ (Si6 Al2 O22 )(OH)2 N a0.2 C a0.8 Al1.8 Si2.2 O8 C a2 M g3 Si8 O22 (OH)2 Fe22+ 3+ M g2.3 Fe0.6 K0.3 C a0.1 Si2.8 Al1.3 O10 (OH)1.8 F0.2 · 3(H2 O) N a0.165 C a0.0835 Al2.33 Si3.67 O10 (OH)2 Al2 SiO5 C aAl2 Si2 O7 AlO(OH) 2+ M g3.75 Fe1.25 Si3 Al2 O10 (OH)8 3+ 2+ K0.6 N a0.05 Fe1.3 M g0.4 Fe0.2 Al0.3 Si3.8 O10 (OH)2 C a2 Al2 Si3 O10 (OH)2 C aM g(CO3 )2 Continued on next page . . . 270,21 496,67 87,11 595,22 497,75 398,71 162,05 483,23 258,16 100,09 231,54 935,90 367,54 151,73 196,04 595,22 613,82 231,00 216,55 380,22 780,82 206,39 310,00 232,32 990,86 275,01 875,45 463,51 367,09 162,05 314,24 59,99 595,22 426,93 395,38 184,40 2,50E+00 1,93E+00 1,24E+00 1,20E+00 1,04E+00 1,01E+00 9,97E-01 9,06E-01 8,36E-01 8,00E-01 7,95E-01 5,74E-01 5,10E-01 4,71E-01 4,46E-01 4,37E-01 3,48E-01 3,04E-01 3,04E-01 2,97E-01 2,91E-01 2,82E-01 2,79E-01 2,72E-01 2,58E-01 2,50E-01 2,47E-01 2,44E-01 2,39E-01 2,03E-01 2,00E-01 1,77E-01 1,71E-01 1,56E-01 1,41E-01 1,41E-01 Results 93 Table 3.5: Mineralogical composition of the earth’s crust according to the calculations of this study. – continued from previous page. Mineral Formula Al(OH)3 MW g/mole 78,00 Abundance mass, % 1,38E-01 Hydragillite/ Gibbsite Ulvöspinel Goethite Neptunite Hematite Lepidomelane/ Annite Sanidine Barite Distene/ Kyanite Celestine Staurolite Thuringite/ Chamosite Ferrosilite Halite Boehmite Thomsonite Serpentine/ Clinochrysotile Pigeonite Bronzite Apatite Zircon Stilpnomelane Spodumene Psilomelane Leucoxene Tremolite Clinozoisite Crossite Pyrite Niter Talc Vermiculite Enstatite Anorthite Rutile Zoisite Nitratine Braunite Siderite Graphite Spessartine Anhydrite Olivine T i Fe22+ O4 Fe3+ O(OH) 2+ K N a2 Li Fe1.5 M n2+ T i2 Si8 O24 0.5 Fe2 O3 2+ 3+ K Fe2.5 M g0.5 Fe0.75 Al0.25 Si3 O10 (OH)2 223,57 88,85 907,69 159,69 512,40 1,16E-01 1,04E-01 9,97E-02 9,66E-02 9,11E-02 K0.75 N a0.25 AlSi3 O8 BaSO4 Al2 SiO5 274,30 233,39 162,05 7,31E-02 7,09E-02 7,08E-02 S rSO4 Fe2+ Al9 Si4 O23 (OH) 3+ 3+ Fe32+ M g2 Al0.5 Fe0.5 Si3 AlO10 (OH)2 183,68 851,86 562,80 6,70E-02 6,54E-02 6,43E-02 Fe2+ M gSi2 O6 N aC l AlO(OH) N aC a2 Al5 Si5 O20 · 6(H2 O) M g3 Si2 O5 (OH)4 263,86 58,44 59,99 806,56 277,11 6,11E-02 5,89E-02 5,79E-02 4,99E-02 4,56E-02 219,70 232,32 509,12 183,31 1391,50 186,09 745,37 196,04 812,37 454,36 815,09 119,98 101,10 379,27 415,30 200,78 277,41 79,88 454,36 84,99 604,64 115,86 12,01 495,03 136,14 153,31 4,37E-02 4,11E-02 4,03E-02 3,88E-02 3,85E-02 3,83E-02 3,80E-02 3,72E-02 3,48E-02 3,41E-02 3,31E-02 3,30E-02 3,00E-02 2,91E-02 2,81E-02 2,78E-02 2,75E-02 2,73E-02 2,58E-02 2,52E-02 2,45E-02 2,41E-02 2,41E-02 2,36E-02 2,36E-02 2,34E-02 2+ C a0.1 Si2 O6 M g1.35 Fe0.55 M g Fe2+ Si2 O6 C a5 (PO4 )3 (OH)0.33 F0.33 C l0.33 Z rSiO4 K0.8 Fe82+ Al0.8 Si11.1 O21 (OH)8.6 · 6(H2 O) LiAlSi2 O6 Ba2 M n3+ O10 · H2 O 5 C aT iSiO5 C a2 M g5 Si8 O22 (OH)2 C a2 Al3 (SiO4 )3 (OH) N a2 M g2 Fe2+ Al2 (Si8 O22 )(OH)2 FeS?2 K N O3 M g3 Si4 O10 (OH)2 M g3 Si4 O10 (OH)2 · 2(H2 O) M g2 Si2 O6 C aAl2 Si2 O8 T iO2 C a2 Al3 Si3 O12 (OH) N aN O3 M n2+ M n3+ 6 SiO12 Fe2+ CO3 C M n2+ 3Al2(SiO4)3 C aSO4 2+ M g1.6 Fe0.4 (SiO4 ) Continued on next page . . . 94 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Table 3.5: Mineralogical composition of the earth’s crust according to the calculations of this study. – continued from previous page. Mineral Formula 3+ 2+ Ba0.8 P b0.2 N a0.125 M n4+ 6 Fe1.3 M n0.5 Al 0.2 Si0.1 O16 N aAlSi2O6 · (H2 O) C Fe2+ C r2 O4 C a10 M g2 Al4 (SiO4 )5 (Si2 O7 )2 (OH)4 MW g/mole 848,06 220,15 12,01 223,84 1422,09 Abundance mass, % 2,23E-02 2,23E-02 2,21E-02 1,98E-02 1,71E-02 Hollandite Analcime C org Chromite Vesuvianite/ Idocrase Pyrrhotite Tephroite Gypsum Corundum Rhodochrosite Arfvedsonite Monazite (Ce) Sphalerite Jadeite Dispersed V Pumpellyite Diodochic Rb Aragonite Nepheline Forsterite Hedenbergite Chalcopyrite Phlogopite Witherite Pentlandite Cordierite Pyrolusite Fayalite Anatase Francolite Tourmaline Orthite-Ce/ Allanite Lepidolite Gedrite Beryl Pyrophyllite Rhodonite Magnesite Chloritoid Ilmenorutile Ulexite Diadochic Ce Jacobsite Clementite Kernite Bastnaesite Fe2+ S M n2+ (SiO4 ) 2 C aSO4 · 2H2 O Al2 O3 M nCO3 N a3 Fe42+ Fe3+ (Si8 O22 )(OH)2 C e0.5 La0.25 N d0.2 T h0.05 (PO4 ) Z nS 3+ N aAl0.9 Fe0.1 (Si2 O6 ) V C a2 M gAl2 (SiO4 )(Si2 O7 )(OH)2 · (H2 O) Rb C aCO3 N a0.75 K0.25 Al(SiO4 ) M g2 SiO4 C aFe2+ Si2 O6 CuFeS2 K M g3 AlSi3 O10 F (OH) BaCO3 2+ N i4.5 S8 Fe4.5 M g2 Al4 Si5 O18 M nO2 Fe22+ SiO4 T iO2 C a5 (PO4 )2.63 (CO3 )0.5 F1.11 N aFe32+ Al6 (BO3 )3 Si6 O18 (OH)4 C a1.2 C e0.4 Y0.133 Al2 Fe3+ (Si3 O12 )(OH) 87,91 201,96 158,14 101,96 114,95 958,89 240,21 97,44 205,03 51,00 502,25 85,00 100,09 146,08 140,69 248,09 183,53 419,25 197,34 771,94 584,95 86,94 203,78 79,88 501,26 1053,38 519,03 1,57E-02 1,27E-02 1,26E-02 1,22E-02 1,09E-02 1,05E-02 1,03E-02 9,96E-03 9,80E-03 9,71E-03 9,49E-03 8,30E-03 7,64E-03 7,43E-03 6,96E-03 6,82E-03 6,64E-03 6,62E-03 5,99E-03 5,75E-03 5,57E-03 4,90E-03 4,77E-03 4,46E-03 4,35E-03 4,30E-03 4,05E-03 K Li2 AlSi4 O10 F (OH) M g5 Al2 (Si6 Al2 O22 )(OH)2 Be3 Al2 Si6 O18 Al2 Si4 O10 (OH)2 M n2+ SiO3 M g CO3 2+ Fe1.2 M g0.6 M n2+ Al Si O (OH)4 0.2 4 2 10 2+ T i0.7 N b0.15 Fe0.225 O2 N aC aB5 O9 · 8H2 O Ce 2+ 3+ 3+ M n2+ 0.6 Fe0.3 M g 0.1 Fe1.5 M n0.5 O4 2+ 3+ Fe3 M g1.5 Al Fe Si3 AlO12 (OH)6 N a2 B4 O7 · 4H2 O La(CO3 )F Continued on next page . . . 388,30 783,97 537,50 360,31 131,02 84,31 484,71 92,01 405,23 140,00 227,38 692,09 290,28 219,12 3,99E-03 3,23E-03 3,22E-03 3,22E-03 3,04E-03 3,02E-03 3,00E-03 2,96E-03 2,92E-03 2,83E-03 2,72E-03 2,64E-03 2,61E-03 2,54E-03 Results 95 Table 3.5: Mineralogical composition of the earth’s crust according to the calculations of this study. – continued from previous page. Mineral Formula C a2 B6 O11 · 5H2 O H3 BO3 MW g/mole 411,09 61,83 Abundance mass, % 2,46E-03 2,22E-03 Colemanite Sassolite (natural boric acid) Cryptomelane Murmanite Anthophyllite Grossular Diadochic Ni Amblygonite Diadochic Y Scapolite Pollucite Dispersed Ga Dispersed Co Spinel Diadochic Nd Sapphirine Dispersed Sc Manganite Cristobalite Fluorite Andradite Glaucophane Todorokite Ferrocolumbite Clinohumite Pr in Monazite and Bastnasite Thorite Galena Marcasite Kornerupine Hf in Zr ores Vaesite Violarite Humite Jarosite Wollastonite Arsenopyrite Sm in Monazite and Bastnasite Kieserite Garnierite Euxenite Dispersed Dy Cubanite Dispersed Gd Nickeline K M n4+ M n2+ O 7.5 0.5 16 N a4 T i3.6 N b0.4 (Si2 O7 )2 O4 · 4(H2 O) M g7 Si8 O22 (OH)2 C a3 Al2 (SiO4 )3 Ni Li0.75 N a0.25 Al(PO4 )F0.75 (OH)0.25 Y N a2 C a2 Al3 Si9 O24 C l Cs0.6 N a0.2 Rb0.1 Al0.9 Si2.1 O6 · (H2 O) Ga Co M gAl2 O4 Nd M g4 Al6.5 Si1.5 O20 Sc M nO(OH) SiO2 C aF2 C a3 Fe22+ (SiO4 )3 N a2 (M g3 Al2 )Si8 O22 (OH)2 O12 · 3(H2 O) M n3+ N a2 M n4+ 2 4 Fe2+ N b2 O6 2+ M g6.75 Fe2.25 (SiO4 )4 F1.5 (OH)0.5 Pr 707,12 773,84 780,82 450,45 59,00 151,41 89,00 287,93 290,16 70,00 59,00 142,27 144,00 689,23 45,00 87,94 60,08 78,07 508,18 783,54 621,65 337,66 695,05 141,00 2,19E-03 2,15E-03 2,09E-03 2,08E-03 1,98E-03 1,95E-03 1,86E-03 1,83E-03 1,78E-03 1,76E-03 1,73E-03 1,52E-03 1,46E-03 1,40E-03 1,40E-03 1,36E-03 1,24E-03 1,12E-03 9,99E-04 9,49E-04 8,33E-04 8,10E-04 7,64E-04 7,10E-04 T hSiO4 P bS FeS2 2+ M g3.5 Fe0.2 Al5.7 (SiO4 )3.7 (BO4 )0.3 O1.2 (OH) Hf N iS2 Fe2+ N i2 S4 2+ M g5.25 Fe1.75 (SiO4 )3 F1.5 (OH)0.5 3+ K Fe3 (SO4 )2 (OH)6 C aSiO3 FeAsS Sm 324,12 239,27 119,98 649,39 178,00 122,82 301,49 538,58 500,81 116,16 162,83 150,00 6,91E-04 6,67E-04 6,29E-04 6,00E-04 5,29E-04 5,20E-04 5,20E-04 5,09E-04 4,79E-04 4,74E-04 4,71E-04 4,69E-04 M gSO4 · (H2 O) N i2 M gSi2 O5 (OH)4 Y0.7 C a0.2 C e0.1 (Ta0.2 )2 (N b0.7 )2 (T i0.025 )O6 Dy CuFe2 S3 Gd N iAs Continued on next page . . . 138,38 345,92 385,10 163,00 271,44 157,00 133,61 4,24E-04 4,10E-04 3,93E-04 3,91E-04 3,62E-04 3,19E-04 2,73E-04 96 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Table 3.5: Mineralogical composition of the earth’s crust according to the calculations of this study. – continued from previous page. Mineral Formula Aenigmatite Scheelite Cassiterite Carnotite Vernadite Topaz Dispersed Er Chrysoberyl Hisingerite Covellite Sylvite Yttrialite Molybdenite Yb in monazite Gersdorffite Dispersed Br Omphacite Brucite Uraninite Azurite Dietzeite Sb in galena Dispersed Ge Bornite Nosean Pyrochlore Malachite Palygorskite Lautarite Dispersed Eu Dispersed Tl Hydrosodalite Dispersed Ho Gadolinite Phenakite Bertrandite Helvine/ Helvite Strontianite Dispersed Tb Perovskite Tridymite Cryolite Sulphur Orpiment Brookite Eudialyte Carnallite N a2 Fe52+ T iSi6 O20 C aW O4 SnO2 K2 (UO2 )2 (V O4 )2 · 3H2 O 3+ M n4+ 0.6 Fe0.2 C a0.2 N a0.1 O1.5 (OH)0.5 · 1.4(H 2 O) Al2 (SiO4 )F1.1 (OH)0.9 Er BeAl2 O4 Fe23+ Si2 O5 (OH)4 · 2(H2 O) CuS KC l Y1.5 T h0.5 Si2 O7 M oS2 Yb N iAsS Br 2+ C a0.6 N a0.4 M g0.6 Al0.3 Fe0.1 Si2 O6 M g(OH)2 UO2 Cu3 (CO3 )2 (OH)2 C a2 (IO3 )2 (C rO4 ) Sb Ge Cu5 FeS4 N a8 Al6 Si6 O24 (SO4 ) N a1.5 C a0.5 N b2 O6 (OH)0.75 F0.25 Cu2 (CO3 )(OH)2 M gAlSi4 O10 (OH) · 4(H2 O) C a(IO3 )2 Eu Tl N a8 (AlSiO4 )6 (OH)2 Ho Y2 Fe2+ Be2 (Si2 O10 ) Be2 SiO4 Be4 Si2 O7 (OH)2 M n4 Be3 (SiO4 )3 S S r CO3 Tb C aT iO3 SiO2 N a3 Al F6 S8 As2 S3 T iO2 2+ N a4 C a2 C e0.5 Fe0.7 M n2+ Y Z rSi8 O22 (OH)1.5 C l0.5 0.3 0.1 K M g C l3 · 6(H2 O) Continued on next page . . . MW g/mole 861,60 287,93 150,71 902,18 112,17 182,25 167,00 126,97 351,92 95,61 74,55 417,54 160,07 173,00 165,68 80,00 213,67 58,32 270,03 344,67 545,96 879,29 73,00 501,84 1012,38 362,38 221,12 412,69 389,88 152,00 204,00 932,00 165,00 569,31 110,11 238,23 555,10 Abundance mass, % 2,73E-04 2,67E-04 2,61E-04 2,52E-04 2,45E-04 2,34E-04 2,30E-04 2,28E-04 2,20E-04 2,17E-04 2,05E-04 1,94E-04 1,83E-04 1,72E-04 1,61E-04 1,60E-04 1,60E-04 1,58E-04 1,51E-04 1,51E-04 1,51E-04 1,42E-04 1,41E-04 1,33E-04 1,31E-04 1,26E-04 1,21E-04 1,14E-04 1,08E-04 1,00E-04 8,98E-05 8,44E-05 8,30E-05 8,05E-05 8,05E-05 8,05E-05 8,05E-05 147,63 159,00 135,96 60,08 209,94 256,53 246,04 79,88 938,82 277,85 7,88E-05 7,00E-05 6,94E-05 6,30E-05 4,95E-05 4,72E-05 4,55E-05 4,21E-05 4,04E-05 4,03E-05 Results 97 Table 3.5: Mineralogical composition of the earth’s crust according to the calculations of this study. – continued from previous page. Mineral Formula Y bPO4 N aAl(CO3 )(OH)2 2+ Fe0.5 M n2+ (W O4 ) 0.5 Lu Tm S b2 S3 Cu P bCO3 3+ U0.3 C a0.2 N b0.9 T i0.8 Al0.1 Fe0.1 Ta0.5 O6 (OH) MW g/mole 268,01 144,00 303,24 175,00 169,00 339,70 63,55 267,21 413,09 Abundance mass, % 3,70E-05 3,62E-05 3,21E-05 3,10E-05 3,00E-05 2,75E-05 2,48E-05 2,21E-05 2,05E-05 Xenotime Dawsonite Wolframite Dispersed Lu Dispersed Tm Stibnite Copper Cerussite Blomstrandite/ Betafite Sodalite Britholite Ferrotantalite Ramsayite/ Lorenzenite Anglesite Greenockite Chondrodite Axinite -Fe Chalcocite Zinc Se in copper ores Loparite (Ce) Bischofite Smithsonite Sirtolite Pleonaste/ Magnesioferrite Lead Bismutite Cinnabar In in ZnS Arsenolite Bismuthinite Bismite Tin Cancrinite Chevkinite Bismuth RhabdophaneCe Fergusonite Native silver Iotsite Realgar Pyrargirite Argentite N a8 Al6 Si6 O24 C l2 C a2.9 C e0.9 T h0.6 La0.4 N d0.2 Si2.7 P0.5 O12 (OH)1.8 F0.2 Fe2+ Ta2 O6 N a2 T i2 Si2 O9 969,21 783,69 513,74 341,91 1,98E-05 1,71E-05 1,58E-05 1,24E-05 P bSO4 C dS 2+ M g3.75 Fe1.25 (SiO4 )2 F1.5 (OH)0.5 2+ C a2 Fe Al2 BO3 Si4 O12 (OH) Cu2 S Zn Se 303,26 144,48 382,12 570,12 159,16 65,39 79,00 1,16E-05 1,16E-05 1,12E-05 1,10E-05 1,09E-05 1,01E-05 9,00E-06 N a0.6 C e0.22 La0.11 C a0.1 T i0.8 N b0.2 O3 M g C l2 · 6(H2 O) Z nCO3 Z rSiO4 M g Fe23+ O4 168,78 203,30 125,40 183,31 158,04 8,13E-06 8,06E-06 7,98E-06 7,37E-06 6,96E-06 Pb Bi2 (CO3 )O2 H gS In As2 O3 Bi2 S3 Bi 2O3 Sn N a6 C a2 Al6 Si6 O24 (CO3 )2 2+ 3+ C e1.7 La1.4 C a0.8 T h0.1 Fe1.8 M g0.5 T i2.5 Fe0.5 Si4 O22 Bi C e0.75 La0.25 (PO4 ) · (H2 O) 207,20 509,97 232,66 115,00 197,84 514,16 465,96 118,69 1052,50 1212,52 208,98 252,80 6,32E-06 6,09E-06 5,73E-06 5,61E-06 5,55E-06 5,10E-06 4,62E-06 4,59E-06 4,42E-06 3,35E-06 2,71E-06 2,62E-06 N d0.4 C e0.4 Sm0.1 Y0.1 N bO4 Ag FeO As4 S4 Ag3 S bS3 Ag2 S Continued on next page . . . 294,57 107,87 71,80 106,99 541,55 247,80 2,38E-06 2,09E-06 1,71E-06 1,50E-06 1,29E-06 1,24E-06 98 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST Table 3.5: Mineralogical composition of the earth’s crust according to the calculations of this study. – continued from previous page. Mineral Formula Baddeleyite Uranium- Thorite Lavenite Z rO2 T hSiO4 Cobaltite Acanthite Freibergite Smaltite Powellite Stephanite Linnaeite Microlite Lamprophyllite Te in Cu ores Thorianite Delorenzite/ Tanteuxenite Miserite Fahlerz Group: Tennantite Metatorbenite Moissanite Vivianite Naegite Gold Chrysocolla Troilite Chlorargirite Metacinnabar Wulfenite Tetrahedrite Nordite Samsonite Pd in Ni-Cu ores Cooperite Weinschenkite Ru in Ni-Cu ores Sylvanite Lollingite Calaverite Pt in Ni-Cu ores Rinkolite/ Mosandrite Dispersed Re Tellurite MW g/mole 123,22 327,12 Abundance mass, % 1,20E-06 1,04E-06 2+ N a0.5 C a0.5 M n2+ Fe0.5 Z r0.8 T i0.1 0.5 N b0.1 (Si2 O7 )O0.6 (OH)0.3 F0.1 C oAsS Ag2 S 2+ Ag7.2 Cu3.6 Fe1.2 S b3 AsS13 C oAs2 C aM oO4 Ag5 S bS4 C o3 S4 N a0.4 C a1.6 Ta2 O6.6 (OH)0.3 F0.1 N a2 S r BaT i3 Si4 O16 (OH)F Te T hO2 Y0.7 C a0.2 C e0.12 (Ta0.7 )2 (N b0.2 )2 (T i0.1 )O5.5 (OH)0.5 388,58 1,01E-06 165,92 247,80 1929,46 125,40 200,02 789,36 305,06 547,81 818,87 128,00 264,04 480,83 8,40E-07 6,79E-07 6,79E-07 6,35E-07 6,10E-07 6,09E-07 5,15E-07 4,77E-07 4,59E-07 4,47E-07 4,12E-07 4,00E-07 KC a2 C e3 Si8 O22 (OH)1.5 F0.5 Cu11 Fe2+ As4 S13 1151,28 1471,40 2,30E-07 1,82E-07 Cu(UO2 )2(PO4 )2 · 8(H2 O) SiC Fe33+ (PO4 )2 · 8(H2 O) Z rSiO4 Au Cu2 Si2 O6 · (H2 O)4 FeS Ag C l H gS P bM oO4 Cu9 Fe3 S b4 S13 N a2.8 M n2+ S r0.5 C a0.5 La0.33 C e0.6 Z n0.6 M g0.4 Si6 O17 0.2 Ag4 M nS b2 S6 Pd 937,67 40,10 501,61 183,31 196,97 351,32 87,91 143,32 232,66 367,14 1643,31 758,57 922,31 106,00 1,69E-07 1,41E-07 1,30E-07 1,28E-07 1,28E-07 1,25E-07 1,05E-07 7,83E-08 7,38E-08 6,10E-08 5,70E-08 5,46E-08 4,87E-08 4,51E-08 P t 0.6 P d0.3 N i0.1 S Y PO4 · 2(H2 O) Ru 186,91 219,91 101,00 3,95E-08 3,70E-08 3,37E-08 Au0,75 Ag0,25 Te2 FeAs2 AuTe2 Pt N a2 C a3 C e1.5 Y0.5 T i0.4 N b0.5 Z r0.1 (Si2 O7 )2 O1.5 F3.5 429,89 205,69 452,17 195,00 922,39 3,27E-08 2,68E-08 2,58E-08 2,47E-08 2,07E-08 Re TeO2 186,00 159,60 1,98E-08 1,82E-08 Continued on next page . . . Results 99 Table 3.5: Mineralogical composition of the earth’s crust according to the calculations of this study. – continued from previous page. Mineral Formula Bi2 Te2 S M gO KAl3 (SO4 )2(OH)6 Sc1.5 Y0.5 Si2 O7 Al6.9 (BO3 )(SiO4 )3 O2.5 (OH)0.5 Rh MW g/mole 705,23 40,30 414,21 280,05 569,73 103,00 Abundance mass, % 1,60E-08 1,52E-08 9,11E-09 7,60E-09 7,60E-09 6,01E-09 Tetradymite Periclase Alunite Thortveitite Dumortierite Rh in Ni-Cu ores Osmium Iridium Polycrase (Y) Boulangerite I-Platinum Polixene/ Tetraferroplatinum Wohlerite Sum Os0.75 I r0.25 I r0.5 Os0.3 Ru0.2 Y0.5 C a0.1 C e0.1 U0.1 T h0.1 T i1.2 N b0.6 Ta0.2 O6 P b5 S b4 S11 Pt P t Fe 190,71 173,39 354,85 1887,90 195,08 167,00 3,00E-09 2,61E-09 8,71E-10 4,00E-10 3,00E-10 2,00E-10 N aC a2 Z r0.6 N b0.4 Si2 O8.4 (OH)0.3 F0.3 396,41 155,2 5,05E-11 105,0 End of the table 3.6.1 Discussion of the most abundant minerals The 10 most abundant minerals according to our calculations are: quartz, albite, oligoclase, orthoclase, andensine, paragonite, biotite, hydromuscovite, augite, and hornblende. Grigor’ev’s 10 most abundant minerals are quartz, oligoclase, orthoclase, biotite, andesine, albite, calcite, hornblende, labradorite and hydromuscovite. From the top ten most abundant minerals in Grigor’ev’s model, calcite and labradorite do not appear in the 1 to 10 ranking of abundance in our model. They appear in positions 20 and 11, respectively. On the contrary, minerals paragonite and augite appearing in our model as most abundant, are in Grigor’ev’s composition in positions: 15 and 14. The difference for labradorite in both models is very small, around 17%. However, the significant difference between the concentration of calcite in both models (75%) is because its quantity is fixed by element C. The quantity of carbon generated by Grigor’ev’s model in the upper earth’s crust is much greater than the one given by Wedepohl21 [404] (see table 3.4). According to Grigor’ev’s composition, calcite would account for around 50% of all carbon in the earth’s crust, what seems to be very unlikely, due to the vast amount of other important substances containing that element22 . It could also be possible, that Wedepohl’s concentration Rudnick and Gao [292] or McLennan [215] did not provide any number for element C and hence, the value of Wedepohl [404] was considered. 22 For instance all carbonates. 21 100 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST for element C was underestimated. In that case, calcite would occupy a more relevant position in the ranking of abundance of minerals in the crust, according to our model. Paragonite and augite are about 2,5 and 1,5 times more abundant in our model than in Grigor’ev’s, respectively. This is due to the fact that their contents are fixed by elements N a and M g. The discrepancy between both models for M g and N acontaining minerals is explained in the next section. 3.6.2 Discussion of the most relevant minerals Next, the abundances of some of the most important minerals for industrial uses are discussed and compared to Grigor’ev’s analysis. Those are the minerals of gold, silver, copper, iron, aluminium, titanium, magnesium, calcium, sodium, sulfur, mercury, zinc, lead and uranium. The abundance of gold obtained in our model is around one order of magnitude greater than that of Grigor’ev’s. As explained in section 3.4.27, it is widely found as native gold and in the form of tellurides. The number given by Grigor’ev for gold, would imply that only 12% of Au comes from native gold, instead of the 85% that we assumed. It is believed that the main source of element Au is native gold and not tellurides, and therefore we keep the assumptions made. Grigorev’s silver mineral’s concentration are also about one order of magnitude greater than in our model. It is considered, that most important Ag-containing minerals are included in both models. Hence, the mass balance indicates that the concentration for them should be around one order of magnitude greater. We have assumed that the minerals for copper considered in Grigor’ev’s model are the most important and no additional substances were taken into account. The mass balance for Cu brought the result that the Cu-containing minerals in our model are around two orders of magnitude greater than in Grigor’ev’s analysis. A great amount of Fe-containing minerals was considered in both models. The differences between them are usually less than 25% for the oxides and the most important silicates, being the numbers given by Grigor’ev greater. For sulfates, Grigorev’s iron-containing minerals are around 50% greater. The most important Al-containing minerals show a difference between both models of around 220%, such as for sillimanite or boehmite. The concentration of T i-containing minerals in our model is about 1,5 times greater than in Grigor’ev’s composition. Since most important titanium minerals have been considered, the mass balance for T i indicates that the values estimated by Grigor’ev are slightly low. The difference between the main M g and C a-containing minerals in both models is around 37% and 17% respectively, being the concentrations of our study smaller Results 101 Table 3.6. Crustal abundance of minerals according to this and Grigor’ev’s model in mass % [127] Mineral Quartz Plagioclase Others Orthoclase Oxides Micas Pyroxene Amphibole Chlorite This study 56,7 18,9 6,5 6,3 4,3 3,7 2,5 0,6 0,5 Grigor’ev [127] 58,8 15,6 11,6 5,2 3,2 2,9 1,4 0,6 0,7 than in Grigor’ev’s model, since the latter overestimated the abundance of the magnesium and calcium minerals, as revealed by the value of ε j , greater than ε̂ j . Sodium-containing minerals in our model are around 2,5 times greater than in Grigor’ev’s analysis for minerals like albite, nontronite, riebeckite or aegirine, where the limiting element is N a, but are around 17% smaller for those minerals that also contain C a. That is the case for oligoclase, andesine or labradorite. The abundance of sulfur minerals in our model differ from Grigor’ev’s study in less than 50% for native sulfur, gypsum or pyrite, but in two orders of magnitude in others, such as cinnabar. The differences depend on the limiting element that contain the substance. For the case of cinnabar, the limiting element is H g and not S. The discrepancy for the latter mineral and that for metacinnabar is because only two H g-containing minerals were considered (the most important ones). Zinc-containing minerals in our model are more than two orders of magnitude greater than in Grigor’ev’s studies. This is due to the fact that only a few zinc minerals were considered: sphalerite, smithsonite, nordite and native zinc. Probably, other minerals of zinc should be taken into account, such as franklinite, hemimorphite or wurtzite. We have considered only 6 uranium and 6 lead-containing minerals and that might be the reason why their concentrations in our model are around one and two orders of magnitude greater than in Grigor’ev’s study, respectively. As in the case of zinc, other minerals of uranium and lead are likely to be taken into account. 3.6.3 Discussion of the aggregated composition A comparison between the aggregated composition of the minerals in the crust (as carried out by Wedepohl [402], [403] and Nesbitt and Young [242], table 3.2) obtained in this and in Grigor’ev’s study, is shown in table 3.6. 102 THE MINERALOGICAL COMPOSITION OF THE UPPER CONTINENTAL CRUST The most significant differences between these two new models and the older ones from Wedepohl and Nesbitt and Young are the abundances of quartz and plagioclase. According to the recent models, quartz accounts for nearly 60% of the minerals on the upper earth’s crust. Plagioclase occupies the second position in abundance (representing more than 15%) and not the first, like in the older models. All four studies agree in that orthoclase is the third group of importance, although the new calculated values are significantly lower than the older ones, especially between Wedepohl’s and Grigor’ev’s. The relative proportion of micas (including biotite and muscovite) are much lower than in the older analysis. The same thing happens to chlorites, amphiboles and olivine, the latter with imperceptible abundance. However oxides are more abundant in the recent models, while the abundance of pyroxenes is close to the analysis of Nesbitt and Young. 3.6.4 Drawbacks of the model The first thing to me noted in the composition of table 3.5 is that the total mass of the minerals contained in the upper crust is greater than 100%. As mentioned above, the oxygen and hydrogen quantities in the crust have been left free. In the chemical compositions of the crust given by Rudnick et al. [292], Wedepohl [404] or McLennan [215], no H or O values are provided. However the value for O can be determined from the first two authors, as some of the elements are given as the corresponding oxides. That is the case for SiO2 , T iO2 , Al2 O3 , FeO, M nO, M gO, C aO, N a2 O, K2 O and P2 O5 . The oxygen concentration resulting from those oxides gives in Rudnick’s and Wedepohl’s models of the crust 2, 95 × 10−2 mole/g. In the model developed in this PhD, the concentration of oxygen is 4,8% greater: 3, 10 × 10−2 mole/g, while in Grigor’ev’s 0,7% greater: 2, 97 × 10−2 mole/g. Hence, if the chemical composition of the crust is right, then there is an excess of oxygen in the minerals of our model and that of Grigor’ev. This oxygen could be in the form of molecules O2 or H2 O, which would be in the concentration of 1, 5 × 10−2 and 1, 1 × 10−3 mole/g, respectively. An excess of oxygen could be attributed to the fact that the minerals considered may not be electronegatively neutral. Nevertheless, we have assured the neutrality of the charges of every mineral considered. If the oxygen quantity is fixed in our model, then the Si content is significantly smaller than the one given by Rudnick: 1, 01×10−2 instead of 1, 10×10−2 g/mole. With the chemical composition of the minerals given in table 3.5, there is no possible solution to Eq. 3.2 if the concentration of oxygen is also fixed. Hence, it seems that the problem comes from the chemical formulae used. It must be pointed out, that many of the minerals given by Grigor’ev do not have a fixed chemical composition. They represent a variety of minerals with changing concentrations of certain elements. That is the case for biotite, apatite, phosphate rock, etc. We have tried to take into account an average chemical formula, given by the empirical formula recorded under [172], but assuring the neutrality of the charges and the general molecular structure of the Summary of the chapter 103 mineral. Nevertheless, many different formulas are possible. Therefore, this aspect should be checked in further developments of the model. Another aspect that should be taken into account, is that the chemical composition of the earth in terms of elements has been assumed to be correct and not the one generated by Grigor’ev. The decision to do so was because the first one has been subject of many research studies throughout history, while the last one has just begun to be analyzed. Nevertheless, in some cases the procedure developed in this PhD could serve as a tool for assuring the chemical composition of the crust. The low concentration of calcite obtained in our model for example, has set the alarms for the concentration value of C in the crust, which might have been underestimated by Wedepohl. 3.7 Summary of the chapter In this chapter, a revision of the studies concerning the mineralogical composition of the earth’s crust has been carried out. It has been verified, that the literature about this topic is very limited and inaccurate, due to the heterogeneity and complexity of the crust. Nevertheless, one single author, the Russian geochemist Grigor’ev has been very recently the first one in giving a comprehensive mineralogical composition of the upper crust. With the help of Eq. 3.1, we were able to check the satisfaction of the mass balance between the minerals proposed by Grigor’ev and the better known chemical composition in terms of elements of the crust. The no satisfaction of the mass balance, lead us to propose a new composition, based on the Grigor’ev’s semi-empirical analysis. The methodology used minimizes the difference between Grigor’ev’s and our proposed compositions under the constraint of assuring chemical coherence with the average chemical composition of the earth’s crust in terms of elements. We have made assumptions based on the literature for those important minerals not taken into account in Grigor’ev’s analysis, and included them in our model. As a result, we have obtained a mean mineralogical composition of the upper crust, consisting of the 292 most abundant minerals. This composition does not have to be taken as final and closed, since many assumptions had to be made. Nevertheless, it is the first step for obtaining a coherent mineralogical composition of the crust. In chapters 2 and 3, we have tried to describe the composition of the earth as a whole. From the global components of the earth, only a few are used by man. The next chapter is focused on describing that part of the earth useful to man: the natural resources. Chapter 4 The resources of the earth 4.1 Introduction In this chapter, a deeper look at the earth’s components useful to man is undertaken. For that purpose, a revision of energy and non-energy resources is carried out. The energy resources have been divided into energy coming from the solid earth, i.e. nuclear and geothermal energy; tidal energy; and energy coming from the sun, including solar, water, wind, ocean power and hydrocarbons. In addition to the energy resources, mineral resources are also studied, stressing out their abundance and average crustal concentration. 4.2 Natural resources: definition, classification and early assessment A natural resource can be defined as any form of matter or energy obtained from the environment that meets human needs. Therefore water, air, oil, biomass or minerals are classified as natural resources. On the other hand, Costanza [65], defines the natural capital as a stock that yields a flow of variable goods in the future. Natural resources are frequently classified as renewable or non-renewable. Renewable resources are defined as resources that are regenerated on a human time scale. Examples of renewable resources are water, biomass or the energy from the sun. Non-renewable resources can be considered as a stock that has a regeneration rate of zero over a relatively long period. That is the case for minerals [203]. Minerals can be further classified as fuel and non-fuel mineral resources. Fuel resources are those from which energy can be potentially extracted. That is the case for coal, fuel or uranium. The rest are non-fuel minerals, including construction materials, metals, etc. 105 106 THE RESOURCES OF THE EARTH Table 4.1. World energy use in 1984 [130] Fuel source Coal Oil Gas Uranium Tar sands+Oil shale Current (EJ/y) 97,6 127,3 63,1 12,6 - use Proven reserves (EJ) 21500 4300 3700 813 550+ Resources (EJ) 238000 10000 10000 1324 1600+ Approx. total Fluxes (EJ/year) 300,6 30850+ Practical Hydro 21,7 100 260900+ Ultimate potential 200 Biomass 47 80 720 Wind Photovoltaic v. small v. small 30 infinite 100 infinite Geothermal Approx. total Overall total 0,1 63,8 368,4 large 210 large 1020+ Resource uncertainty ±20% -30% + 60% -40% + 70% ±50 highly uncertain little uncertainty highly uncertain speculative rapidly reducing price An early assessment of the renewable and nonrenewable energy resources on earth was done by Hall et al. [130] and can be seen in table 4.1. The degree of knowledge about resources and technological development has improved notably since the eighties, what has lead to better estimations of the available resources on earth. In the next sections, the numbers given in table 4.1 are updated and new figures are provided for other types of resources. The results are summarized in section 4.7, table 4.8. 4.3 The energy balance The sun is the main source of energy sustaining life on earth. According to Skinner [317], [318] the sun sends around 17, 3 × 1016 W of power in form of shortwavelength solar radiation towards the earth. From this, approximately 30% is directly reflected by clouds and by the earth’s surface, but most rays pass through the atmosphere, heating the layers of the earth and causing winds, rains, snowfalls and ocean currents. These transformations lead to progressive depreciation of energy quality, and therefore, to exergy losses. The devaluated energy in form of heat is however sent back to space and the earth’s surface remains in thermal balance. One part of solar radiation is used for photosynthesis and is temporarily stored in the bio- Energy from the solid earth Short wavelength solar radiation 17,3x1016 W 107 Short wavelength radiation Long wavelength radiation Tidal energy 27,3x1012 Direct reflection Tides, tidal energy, currents, etc. 5,2x1016 W 2,7x1012 W Direct conversion to heat 8,1x1016 W Winds, ocean currents, waves, etc. Conduction 21x1012 W 0,035x1016 W Evaporation and precipitation 4x1016 W Photosynthesis 0,004x1016 W Plant storage bank Water storage bank Submarine volcanism 11x1012 W Volcanoes, hot springs on land 0,3x1012 W Decay Organic matter Earth’s thermal energy 32,3x1012 W Common sedimentary rocks 1026 J Recoverable fossil fuels 2,5x1023 J Thermal energy 1,3x1027J to 10 km depth GEOTHERMAL ENERGY Spontaneous nuclear decay Uranium and Thorium withing 1 km of surface 5x1029 J Figure 4.1. Energy flow sheet for the surface of the earth [317] sphere as organic matter and eventually as coal, oil and natural gas. Another small fraction of the solar-derived energy is stored in water reservoirs such as lakes and rivers. But the sun is not the solely source of energy on earth, geothermal energy is the second most powerful source of energy, at 23 TW or 0,013 % of the total. This energy reaches the surface in the form of volcanoes, hot springs or conduction and plays an important role in the rock cycle. The third and smallest source of energy on earth is the tidal energy produced by the interaction of gravitational potential energy of the moon and the earth’s rotation. The transfer of tidal energy accounts for about 3 TW or 0,002 % of the total energy budget. Figure 4.1 shows the energy cycle on earth according to Skinner [317], which was adapted in part from Hubbert [147]. 4.4 Energy from the solid earth Two different sources of energy come from the solid earth. The first one is geothermal energy, which is considered as a renewable resource, but it has found less applicability on a global scale. The second one is the non-renewable nuclear energy, coming from the mining of radioactive minerals found on earth, mainly from uranium isotopes. The latter, although socially and politically controversial constitutes 108 THE RESOURCES OF THE EARTH nowadays a key source of energy for many countries. Next, both sources of energy will be explained in detail. 4.4.1 The Geothermal energy The temperature of the earth’s interior increases with depth. The geothermal gradient varies in different parts of the world from 15 to 75o C/km. The geothermal gradient creates obviously a heat flow leading to a heat loss escaping the crust. The amount of heat that escapes through the earth’s surface is due to the superposition of four components [168]: Q = QC + Q L + QB + QT (4.1) where Q B is the heat input at the base of the lithosphere1 due to mantle convection, Q T is a long-term transient due to cooling after a major tectonic or magmatic perturbation, Q L is the radiogenic heat production in the mantle part of the lithosphere, and Q C is the radiogenic heat production of the crust. The radiogenic heat production is due to the decay of the radioactive elements 238 U, 235 U, 232 U and 40 K either in the crust or in the upper mantle. For geological provinces older than ∼100 million years, Q L , Q B and Q T are lumped together into a single parameter called mantle heat flow Q M . There are different ways to estimate the bulk crustal heat flow of the earth. Some estimates [251], [7], [104] are obtained by redistributing the heat producing elements in the bulk silicate earth between the continental crust and various reservoirs in the mantle. They require assumptions regarding the structure of the convecting mantle, the composition and the homogeneity of the reservoirs. Other estimates are based on measurements either from representative rock types and their proportions in crustal columns derived from geophysical profiles [129], [60], [404], [32] or on large-scale production data sets [81], [307] [106]. Jaupart [168] suggested to estimate the bulk crustal heat production directly from the heat flow data and local studies of crustal structure and estimating the mantle heat flow Q M with different ways. He obtained the values of heat production for three age groups: Archean, Proterozoic, and Phanerozoic (see table 4.2). The average of heat production was estimated to be between 0,79 and 0,95 µW m−3 and the crustal heat flow component ranges from 32 to 38 mW m−2 , considering an average crustal thickness of 40 km. According to these numbers, the continental crust contributes to 5,8 to 6,9 TW to the total energy budget of the earth2 . Active provinces and continental margins now represent 30% of the total volume of the crust; 50% error on their heat production would lead to a 15% error in the global budget. These 1 The lithosphere is the rigid strong outer layer of the earth, consisting of the crust and upper mantle, approximately 100 km thick. 2 For a total volume of the continental crust of 7,3×1018 m3 . Energy from the solid earth 109 Table 4.2. Estimates of bulk continental crust heat production from heat flow data [168]. Age group Archean Proterozoic Phanerozoic Total continents Range of heat production µW m−3 0,56-0,73 0,73-0,90 0,95-1,10 0,79-0,95 Range of crustal heat flow, mW m−2 23-30 30-37 37-43 32-38 Fraction of total continental surface, % 9 56 35 numbers differ from the values given by Skinner [317], in which the the flow is estimated to be 63 mW m−2 or 32,3 TW across the entire earth’s surface (not only the crust). It seems though that the numbers given by Jaupart are more updated and in consonance with the order of magnitude of the geothermal studies mentioned before. Extrapolating Jaupart’s values to the entire surface of the earth, would lead to an average geothermal energy contribution3 of 17,9 TW. Geothermal energy constitutes a renewable source of energy. However, its reserves represent only a tiny fraction of all geothermal heat. Besides, like tidal energy, geothermal energy can be important locally but will be minor on a global scale. According to the Renewables Global Status Report [208], the 2005 worldwide geothermal capacity was 28 GWth for direct thermal use and 9,3 GW for electricity production. The Geothermal Energy Association [109] reports that geothermal resources using today’s technology have the potential to support between 35.448 and 72.392 MW of electrical generation capacity. Using enhanced technology currently under development (permeability enhancement, drilling improvements), the geothermal resources could support between 65.576 and 138.131 MW of electrical generation capacity. Assuming a 90% availability factor, which is well within the range experienced by geothermal power plants, this electric capacity could produce as much as 1, 09 × 109 MWh of electricity annually (124 GW) (Table 4.8). Nevertheless, these values need to be taken with precaution, until the USGS submits its geothermal energy report updating these numbers. 4.4.2 Nuclear energy Nuclear energy derives from the huge binding force of the nucleus of elements. Theoretically, there are two kinds of processes that can release nuclear energy: fusion and fission. Fusion consists in binding light elements, such as hydrogen and lithium, and thereby forming heavier elements. This is the process that goes on in the sun. Fusion has not yet been achieved in the laboratory under conditions such that the energy produced 3 For a total surface of the earth of 5,12×1014 m2 110 THE RESOURCES OF THE EARTH exceeds the energy used. Nevertheless, many scientists believe that it might be the solution of future energy supply. Hermann [138] estimated the exergy reservoir for the fusion cycle between deuterium (coming from the ocean) and tritium (bred from an isotope of lithium) as around 74 Ttoe. Furthermore, if deuterium, the isotope of 1 in every 5000 hydrogen atoms, is fused with another deuterium nucleus at higher temperatures, the resulting resource contained in the ocean is on the order of magnitude of 10 million YJ. Fission nuclear energy is produced during controlled transformation of suitable radioactive isotopes, when neutrons are fired into the nucleus, making the atoms unstable and subject to spontaneous disintegration. Uranium is the crucial fission energy raw material due to the fact that as mined it contains 0,71% of 235 U (the only naturally occurring fissionable atom). Thorium, beryllium, lithium and zirconium are other low-demand raw materials with potential or specific uses in nuclear power production [71]. When 235 U undergoes fission, it releases heat and forms new elements and ejects some neutrons from its nucleus. These neutrons are then used to induce more 235 U to fission. According to Skinner [317], once separated 235 U from 238 U (an energy intensive process), the disintegration of a single atom releases 3, 2×10−11 J; because one gram of 235 U contains 2, 56×1021 atoms, fission of a gram of uranium produces 8, 19 × 1010 J (equivalent to the energy released when 2,7 metric tons of coal are burned). Eq. 4.2 shows a representative fission process of 235 U. 1 235 0 n +92 95 −11 U →137 J 37 Cs +37 Rb + 3n + 3, 2 × 10 (4.2) Estimated uranium resources in the continental crust amounted in year 1986 to 3.457 kton [317] (see table 4.3), representing an exergy reservoir of 2, 8×1014 GJ or 6.741 Gtoe. More recent estimations of uranium sources indicate that these amount to about 13 Mt according to Grubler [128] and 14,8 Mt according to the OECD [247], which represent an exergy reservoir of around 23.800 and 27.100 Gtoe, respectively. With current state of technology, which makes use of only 0,7% of the natural fuel in a “once-through” fuel cycle, the reserves would last only a few hundred years (174 Gtoe). With fast spectrum reactors operated in a “closed” fuel cycle by reprocessing the spent fuel and extracting the un-utilized uranium and plutonium produced, the reserves of natural uranium may exceed 5.200 Gtoe (Table 4.8). However, if advanced breeder reactors could be designed in the future to efficiently utilize recycled or depleted uranium and all actinides, then the reserves of natural uranium may be extended to several thousand years at current consumption levels [249]. Additionally, Hermann [138], estimated the exergy reserves of thorium as around 7.500 Gtoe and of seawater uranium as around 8.350 Ttoe. At the end of year of 2006, 6% of the world’s primary energy consumption was derived from nuclear power plants (see figure 4.4), and amounted to 635,5 Mtoe. In Tidal energy 111 Table 4.3. Estimated uranium resources in ores rich enough to be mined for use in 235 U power plants [317], together with estimated rates of production for 2005 according to the BGS [139]. Data reported as ktons of metal content. No distinctions are drawn between reserves and resources, and no data for resources are reported by the former URSS countries. Country Australia USA Rep. Of South Africa Canada Niger Namibia France Other Total Reasonably assured resources, kton 1357 758 332 199 136 113 47 516 3457 Production 2005, kton 9,516 1,034 0,674 11,627 3,093 3,08 12,876 42 rate in France, more than half of all the electrical power comes from nuclear plants and in other European countries and Japan, the fraction is high too. Nuclear power capacity forecasts out to 2030 vary between 279 - 740 GWe when proposed new plants and the decommissioning of old plants are both considered [163]. Nuclear energy has the advantage against fossil fuels that it does not emit greenhouse gases and its reserves are greater (see table 4.3). Some renowned scientists such as Lovelock [200] claim that: “there is no alternative but nuclear fission energy until fusion energy and sensible forms of renewable energy arrive as a truly long-term provider”. However, other problems are associated with nuclear energy. The isotopes used in power plants are the same used in atomic weapons, so a political problem exists. The possibility of a power plant failing in some unexpected way creates a safety problem as it happened in the Chernobyl disaster in 1986. Finally, the problem of safe burial of dangerous radioactive waste matter must be faced, since some of the waste matter will retain dangerous levels of radioactivity for thousand years. 4.5 Tidal energy Tidal energy is the smallest source of energy on earth. Tides result from the gravitational attraction exerted upon the earth by the moon and to a lesser extent by the sun [346]. As the earth spins on its axis, the bulges move and produce two high and two low tides everywhere each day. Tidal heights are not uniform everywhere. They rarely exceed a meter in the deep ocean, but over continental shelves, they may reach 20 meters. Movement of such vast masses of water requires a great deal of exergy, which is estimated to be 2,7 TW. Through a year, this amounts to 0, 85× 1020 J, according to Skinner [317]. 112 THE RESOURCES OF THE EARTH Tidal electricity generation involves the construction of a barrage across a delta, estuaries, beaches, or other places that are affected by the tides. Like in a hydraulic power plant, normal turbines will produce electricity as the water flows out. However, tidal stations differ from hydraulic ones in the two-dimensional flow. They are able to produce electricity when both water enters the basin and when it leaves [54]. Tidal energy provides a non-polluting and inexhaustible supply of energy and assures the regularity of power production from year to year with less than 5% annual variation. The specific tidal exergy is about 10 kJ for each m2 of reservoir and each meter of height difference, according to Hermann [138]. The high capital cost for construction and the limited number of potential sites (about 20) are its main drawbacks. Tidal heights of 5 meters or more and easily dammed bays or estuaries are needed in order for tidal plants to operate effectively. To date, relatively few tidal power plants have been constructed. Of these, the oldest and by far the largest is the La Rance 240 megawatt barrage located near St. Malo, in Brittany, Northern France. The worldwide tidal power production is about 300 MW [208]. Tidal projects worldwide have been estimated to have a potential energy output of around 166 GW, according to the World Energy Council. 4.6 Energy from the sun According to Skinner [317], solar radiation is the largest energy input of the earth, accounting for about 99,985 % of the total. From the 173.000 TW of incoming solar radiation, about 30% is directly reflected unchanged, back into space, by the clouds, sea, continents, and ice and snow. Around 350 TW are used for causing winds, ocean currents, waves, etc. Evaporation and precipitation use approximately 4.000 TW of sun’s energy, which will lead to the storage of water and ice. Only 40 TW are effectively used in the process of photosynthesis, leading to the production of biomass and eventually of fossil fuels. 4.6.1 Solar power The exergy flow of solar radiation heating the land and oceans amounts to 43.200 TW (Szargut [337]), that is about three thousand times more than the present power needs of the whole world: 14 TW in 2006 and 17 TW in 2010. Energy supplied by the sun in one minute is enough to meet the global power need for one year (Khan [184]). Unfortunately, technology is not developed enough to make use of this huge amount of energy provided directly by the sun. Solar power density at the earth’s surface is 125-375 W/m2 and an average photovoltaic panel, with 15% efficiency, may deliver 15-60 W/m2 . But solar cell conversion efficiency has increased from 6% in 1954 to 40% in 2006 and thus the size of solar power stations has exponentially increased form 500 kW in 1977 to more than 3 GW in 2005 [208]. Electricity generated directly by utilizing solar photons to Energy from the sun 113 create free electrons in a PV cell is estimated to have a technical potential of at least 450.000 TWh/year or around 51 TW [170], [297] (Table 4.8). In addition to the direct use of solar radiation through photovoltaic panels, solar heating collectors use the sun’s energy to heat water. Solar thermal power capacity was 88 GWth in 2005 [208] and is expected to increase dramatically due to new building regulations, especially in Europe4 . Additionally, promising experiences with concentrating solar thermal power plants (CSP) show that this technology could be an alternative way of producing clean electricity from the sun. In CSPs, the solar flux is concentrated by parabolic troughshaped mirror reflectors (30 - 100 suns concentration), central tower receivers requiring numerous heliostats (500 - 1000 suns), or parabolic dish-shaped reflectors (1000 - 10.000 suns) to heat a working fluid, which in turn transfers the heat to a thermal power conversion system. According to Philibert [261], 1 km2 of land sited at lower latitudes in areas receiving high levels of direct insolation, such as desserts is enough to generate around 125 GWh/year from a 50 MW plant at 10% conversion of solar energy to electricity. Thus about 1% of the world’s desert areas (240.000 km2 ), if linked to demand centers by high voltage DC cables, could in theory be sufficient to meet total global electricity demand as forecast out to 2030. Installed capacity is 354 MWe from nine plants in California. New projects totalling over 1400 MW are being constructed in different parts of the world [208]. Technical potential estimates for global CSP vary widely from 630 GWe installed by 2040 [10] to 4700 GWe by 2030 [149] (Table 4.8). 4.6.2 Water power About 23% of the incoming solar radiation (around 40 PW) is the driving force of the hydrologic cycle, which is a conceptual model that describes the storage and movement of water between the biosphere, atmosphere, lithosphere and the hydrosphere (see figure 4.2). About 320.000 km3 of water are evaporated each year form the oceans, while evaporation from the land (including lakes and streams) contributes to 60.000 km3 of water. Of this total, about 284.000 km3 fall back to the ocean and the remaining 96.000 km3 fall on the earth’s land surface. Since 60.000 km3 of water evaporate from the land, 36.000 km3 of water remain to erode the land during the journey back to the oceans [346]. According to Szargut [337], the exergy flow used for the evaporation of water is around 38.100 TW. This exergy is transformed into the potential exergy of clouds (300 TW) and only a small part (5 TW) is transformed into the potential exergy of rivers. Additionally, he calculated the chemical exergy of fresh water reaching the land with the rain and snow as about 6 TW. Hence, the total water power is 11 TW, if the potential and chemical exergy components are summed (Table 4.8). Valero et 4 See the Directive 2002/91/EC on the energy performance of buildings. 114 THE RESOURCES OF THE EARTH al. [371] calculated the exergy replacement costs of renewable water resources and world’s ice sheets5 considering their chemical and potential components as between 3.592 and 53.304 Mtoe/year for freshwater and 3, 84 × 108 and 7.210 × 109 Mtoe for ice sheets. Humans use only part of the renewable exergy of water. That is the potential exergy of rivers in form of hydropower. The chemical and thermal exergy of the freshwater in rivers or ice sheets cannot be transformed into useful energy yet, at least with the current state of technology. Hydropower is the most highly developed renewable energy resource. The power present in water that runs off continents was calculated in 1962 as 2,9 TW [317]. The International Water Power & Dam Construction (IWP&DC) classified and calculated more recently the world hydroelectric potentials according to the following criteria [166]: • Gross Hydroelectric Potential: the hydroelectric potential of a country if all its water flows were turbined until sea level or to the country borders (if the flow continues into other countries) under 100% system efficiency. It has been estimated as 4.200 GW. • Technically Useful Hydroelectric Potential: the hydroelectric energy obtained from all the exploitable or exploited places under existing technological limits, without taking into account environmental, economic or other restrictions. It has been estimated as 1.800 GW (Table 4.8). • Economically Exploitable Hydroelectric Potential: part of technically feasible potential that can be or that has been developed under the local economic conditions and in a competitive way with other energy supply sources. Some of the places that can be exploited economically can have restrictions from the environmental point of view. Nonetheless, this limitation is not taken into account when determining this potential. It has been estimated as around 1.200 GW. At the end of 2006, worldwide hydropower consumption was 688,1 Mtoe, accounting for about 6% of the total energy consumption [35]. 4.6.3 Wind power According to Skinner [317], around 350 TW of solar energy is used for driving winds and ocean waves. Wind is horizontal air movement arising from differences in air pressure created by the uneven heating of the atmosphere. It always flows from a 5 Exergy replacement costs are defined as the energy required by the best available technologies to return a resource to the same conditions as it was delivered by the ecosystem(s). Energy from the sun 115 Figure 4.2. The hydrologic cycle. Source: http://www.ec.gc.ca/water (Environment Canada) place of high pressure to one of low pressure. Wind’s speed and direction are also affected by the Coriolis effect6 and friction occurring between wind and solid objects of any kind such as the ground, trees, etc. Most places around the world have wind speeds that average between 10 and 30 km/h [318]. The average global wind speed at 50 m is 6,6 m/s (23,7 km/h) [240] and with an exergy content of about 336 W /m2 perpendicular to the wind direction, according to Hermann [138]. Estimates of the total global wind power are very large (on the order of 1015 W) but much of the power is in high altitude winds and is not recoverable by devices on the land surface [317]. Global wind power generated at locations with mean annual wind speeds ≥ 6,9 m/s at 80 m is found to be ∼ 72 TW [9]. A technical potential of 72 TW installed global capacity at 20% average capacity factor would generate 126.000 TWh/yr or around 14,5 TW (Table 4.8). In 2005, the existing exergy power capacity worldwide was 59 GW [208]. 4.6.4 Ocean power The sun is responsible for three effects occurring in the oceans: an ocean thermal gradient, from which thermal energy could be eventually extracted; the thermohaline circulation, which is in part caused by the thermal gradient and causing vast 6 The Coriolis effect is the deviation from a straight line in the path of a moving body due to the earth’s rotation. 116 THE RESOURCES OF THE EARTH volumes of water to move around the globe; and ocean waves, indirectly generated by the sun through blowing of winds. 4.6.4.1 Ocean thermal gradient The sun heats the surface of the ocean, generating a thermal gradient that varies from around 22◦ C to 2◦ C in the deep ocean. This temperature difference gives a specific exergy of about 800 J/kg seawater [138]. Considering the mass of the oceans equal to 1, 37 × 1023 kg, this gives an absolute exergy of 1, 13 × 108 Gtoe (Table 4.8). Theoretically, this thermal gradient could be used for drawing energy from the oceans. However, the small temperature difference involved makes ocean thermal power to be unpracticable with current technology and no commercial plant exists. However, if this source of energy would be used with an efficiency of less than 1%, the ocean’s thermal energy potential would exceed the potential of fossil fuels [317]. Another consequence of the thermal gradient of oceans is the so called thermohaline circulation (THC) or “the great ocean conveyor belt” [40]. This global ocean circulation is driven by density differences, which depend on temperature and salinity. The salinity and temperature differences arise from heating/cooling at the sea surface and from the surface freshwater fluxes (evaporation and sea ice formation enhance salinity; precipitation, runoff and ice-melt decrease salinity). It transports enormous volumes of cold, salty water from the North Atlantic to the Northern Pacific, and brings warmer, fresher water in return. In the North Atlantic warm and salty water that has been transported north from tropical regions is cooled, forming frozen water without salts, and thereby, increasing the salinity of the remaining, unfrozen water. The dense, saline waters drop to the floor of the ocean. This water begins a great circuit through the world’s oceans (see the path of this circuit in fig. 4.3). In the Pacific, the current mixes with warmer water, where it undergoes upwelling and warming once again. When this warmer, saltier water reaches again the high northern latitudes, it chills, and eventually becomes North Atlantic deep water, completing the circuit. The volume transport of the overturning circulation at 24 N has been estimated from hydrographic section data as around 17 × 1016 m3 /s [286], its heat transport as 1.200 TW. The heat transport was estimated as well by Munk et al. [235] as 2.000 TW. The corresponding exergy flow assuming a difference of 20 K is about 100 TW transferred to the thermal gradient [138]. Unfortunately, there is currently no energy-conversion technology of this nature. The climatic effect of the THC is still to some extent under discussion, and is due to the heat transport of this circulation [274]. This amount of heat transported into the northern North Atlantic (north of 24 N) should warm this region by around 5o C (the difference sea surface temperature in the North Atlantic as compared to the North Pacific at similar latitudes). Global surface air temperatures show that over the three Energy from the sun 117 Figure 4.3. A simplified summary of the path of the Thermohaline Ocean Circulation [274] main deep water formation regions of the world ocean, air temperatures are warmer by up to around 10o C compared to the latitudinal mean. The concerns about the possible collapse of the THC through the anthropogenic greenhouse effect have increased recently. When the strength of the haline forcing increases due to excess precipitation, runoff, or ice melt, the conveyor belt will weaken or even shut down. The variability in the strength of the conveyor belt will lead to climate change in Europe (decreasing the temperatures down to 9o C) and it could also influence other areas of the global ocean. 4.6.4.2 Ocean Waves Waves are another expression of solar energy. They are formed from winds blowing over the ocean, and their energy content is many thousands of times greater than that in tides. The momentum to currents and surface gravity waves transferred by the wind is estimated as 60 TW [396], but the wave breaking and internal friction reduces the wave exergy flow to 3 TW breaking on the world’s coast [138]. For example, a single wave that is 1,8 meters high and moving in water 9 meters deep generates around 10 kW for each meter of wave front [317]. Different wave energy conversion schemes have been developed, but none are currently in large-scale use. The only two commercial wave power projects total 750 kW [163]. 118 THE RESOURCES OF THE EARTH Table 4.4. Specific exergy on a dry basis of representative biomass samples [138] Biomass type Eucalyptus Poplar Corn stover Bagasse Water hyacinth Brown kelp Exergy MJ/kg 19,9 19,2 18,2 17,8 15,2 10,9 (dry), The best wave energy climates have deep water power densities of 60-70 kW/m but fall to about 20 kW/m at the foreshore. Around 2% of the world’s 800.000 km of coastline exceeds 30kW/m giving a technical potential of around 500 GW assuming off-shore wave energy devices have 40% efficiency [163]. 4.6.5 Biomass Plants depend on sunlight of photosynthesis and hence biomass is another expression of solar power. The radiation flow absorbed by the vegetation has an energy of about 40 TW according to Skinner [317] and an exergy about 37 TW, according to Szargut [337]. Biomass is a term used for plant and animal derived material and includes wood, energy crops, crop residues and animal dung. It consists mostly of cellulose, lignin, protein and ash. Specific exergy of biomass ranges form 15 to 20 MJ/kg on a dry basis depending on carbon and ash content. Woody biomass tends to have a higher carbon content, as opposed to marine biomass [138] (see table 4.4). The photosynthetic efficiency of converting solar energy into energy-rich organic compounds averages around 1%. And only 2,5 TW of energy and 2,9 TW of exergy is transformed into the chemical exergy of plants [337]. Estimates of the dry weight of all living plant matter on earth’s land surface vary but average about 2×1012 metric tons [317]. Considering a specific exergy of biomass of 17 MJ/kg, the exergy content of dry biomass on earth is around 810 Gtoe7 The theoretical biomass potential was estimated by Johansson [170] as around 92 TW, what implies an available exergy capacity of 70 Gtoe each year (Table 4.8). Humans own about 16 TW of the land productivity. From these, about 5 TW contributes to the consumption of 1,5 TW in the form of wood fuel and around 0,2 TW goes into the production of 20 GW of ethanol [138]. The world biomass production energy potential vary greatly depending on the assumptions taken into account. Fulton and Howes [98] compiled the different estimates of world biomass production. 7 This number represents the total exergy we could extract from biomass, if it were not renewable. Energy from the sun 119 The IPCC [161] estimates a raw biomass energy potential of 10,4 Gtoe/year (14 TW) and a liquid biofuels energy potential of 3,6 Gtoe/year (4,8 TW), while Moreira [229] 31,2 Gtoe/year (41,5 TW) and 10,8 Gtoe/year (14,4 TW), respectively (Table 4.8). 4.6.6 Fossil fuels Fossil fuels represent the remains of plants or animals that gathered their energy from the sun millions of years ago and constitute reservoirs of chemical exergy. Around 40 GW of biological matter are buried under sediments and will eventually form fossil fuels [26]. Like the other minerals, they are nonrenewable resources, since they cannot be replenished at least in our lifetime. The main commercial types of fossil fuels are coal, oil and natural gas. Other unconventional fossil fuels include tight gas sands, coal bed methane, clathrate hydrates, shale and heavy oil and tar sands, but no commercial way of extraction has been discovered yet. The specific exergies of fossil fuels vary with the carbon content and the percentage of inert components. Different authors such as Shieh and Fan [310] or Stepanov [330] have derived expressions for the exergy estimation of fuels. In many cases, especially for substances containing mainly C, H, O and N , the High Heating Value (HHV) is essentially identical to the specific exergy. Fossil fuels are by far the most important sources of energy nowadays, accounting for 87,8% of world energy consumption. Production of fossil fuels reached at the end of 2006 over 9.500 Mtoe [35]. The remaining 12% is distributed at almost equal rates into nuclear and hydroelectrical power. See figure 4.4 for the world distribution of energy consumption. 4.6.6.1 Coal Coal is a sedimentary and metamorphic rock. It is formed from plants that grew in ancient swamps. The remains of the plants accumulated in a nonoxidizing environment and were eventually buried by other sediments, usually sand or mud, which are now the sandstone and shale typically associated with coal beds. The coal deposits start off as organic materials made chiefly of carbon, oxygen and hydrogen. With rising the temperature and pressure, due to the burial of the deposits, the hydrogen and oxygen are gradually lost [195]. In addition to carbon, oxygen and hydrogen, coal contains many other elements in small amounts. Sulfur is one of its most common impurities, making coal a dangerous pollutant of air and water. Table 4.5 shows the ASTM D388 coal-rank classification according to the high heating value (HHV). Coal’s specific exergy varies from about 20 to 30 MJ/kg [138], although some low-carbon coals such as lignites may have specific exergies as low as 15 MJ/kg. 120 THE Coal; 3090,1; 28% Oil; 3889,8; 36% RESOURCES OF THE EARTH Nuclear Energy; 688,1; 6% Natural Gas; 2574,9; 24% Hydroelectric; 688,1; 6% Figure 4.4. Primary world energy consumption by fuel type at the end of 2006. Values in Mtoe [35]. Coal accounts for about 28% of the energy consumption in the world. World proved8 reserves of coal at the end of 2006 were estimated by British Petroleum [35] to be 909.064 millions of tons (see figure 4.5) and by the WEC [401], 847.488 Mt. Considering an average heating value of 25 MJ/kg, the world’s coal proven reserves are about 523 Gtoe, taking the average reserves given by BP and the WEC. The exact exergy of the coal reserves will be calculated later in chapter 6. The WEC [401] estimates additional resources amount in place as around 1770 Mtons or 1100 Gtoe. From these, additional recoverable reserves are estimated at 180 Mtons or 110 Gtoe. Unlike oil or natural gas, coal is more evenly distributed worldwide and consumption and production rates are rather equilibrated (see figure 4.6). At the end of 2006, world coal consumption was 3.090,1 Mtoe [35]. The demand for coal is expected to more than double by 2030 and the IEA has estimated that more than 4.500 GW of new power plants (half in developing countries) will be required in this period [150]. 8 Proved reserves of coal - Generally taken to be those quantities that geological and engineering information indicates with reasonable certainty can be recovered in the future from known deposits under existing economic and operating conditions. Energy from the sun 121 Table 4.5. Rank of coal according to the norm ASTM D388. Class rank Anthracite Anthracite Meta-anthracite Semianthracite Bituminous Low-volatile Medium volatile High-volatile A High-volatile B High-volatile C Subbituminous Subbituminous A Subbituminous B Subbituminous C Lignite Lignite A Lignite B Fix carbon limits ≥ < Volatile limits ≥ < 98 92 86 98 92 2 8 2 8 14 78 69 - 86 78 69 14 22 31 22 31 - HHV Limits, MJ/kg ≥ < 32,56 30,24 26,75 32,56 30,24 24,42 22,1 19,31 26,75 24,42 22,1 14,65 19,31 14,65 Another young form of coal, peat, (partially decayed plant matter together with minerals) has been used as a fuel for thousands of years and is still in use, particularly in Northern Europe. The reserves of peat have not been estimated but are very large. 4.6.6.2 Oil and natural gas Oil and natural gas have proved to be economical, efficient and relative clean fuels. As a result, by 1950, they had overtaken coal as the primary source of energy. Almost without exception, petroleum and natural gas are associated with sedimentary rocks of marine origin. Both are mixtures of hydrocarbon compounds (composed largely of hydrogen and carbon) with minor amounts of sulphur, nitrogen and oxygen. Hydrocarbon production takes place in two stages [195]. First, biological, chemical and physical processes begin to break down the organic matter into what is called kerogen, a precursor of oil and gas. The second stage is marked by the thermal alteration of kerogen to hydrocarbons as the deposit is buried deeper by younger, overlying sediments. The production of hydrocarbons begins at a temperature of about 50 to 60o C and a depth of 2 to 2,5 km. Hydrocarbon formation continues to depths of 6 to 7 km and temperatures of 200 to 250o C. Formation of oil dominates in the lower range of temperature and burial and gas in the higher range. The British standard BS2869:1998 classifies fuel oil into six classes according to its boiling temperature, composition and purpose. No. 1 and No. 2 are referred to as distillate fuel oils, while No. 4, No. 5 and No. 6 are labelled residual fuel oils. In 122 THE RESOURCES OF THE EARTH Figure 4.5. Coal proved reserves at the end 2006. Values in thousand millions tonnes (share of anthracite and bituminous coal in brackets) [35]. Table 4.6. Rank of oil according to the British standard BS2869:1998 Class rank Density (kg/l) Residual carbon (%) Sulphur (%) Oxygen and Nitrogen (%) Hydrogen (%) Carbon (%) Water and sediments (%) Ashes (%) HHV (kJ/kg) No. 1 0,824 Traces 0,1 0,2 13,2 86,5 Traces Traces 46.365 No. 2 0,864 Traces 0,4-0,7 0,2 12,7 86,4 Traces Traces 45.509 No. 4 0,927 2,5 0,4-1,5 0,48 11,9 86,1 0,5 max. 0,02 43.920 No .5 0,952 5 2,0 max. 0,7 11,7 85,55 1,0 max. 0,05 43.353 No. 6 1 12 2,8 max. 0,92 10,5 85,7 2,0 max. 0,08 42.467 a more commercial sense: No. 1 fuel oil is kerosene; No. 2 is diesel oil and No. 4, 5 and 6 are heavy fuel oils. Table 4.6 shows the chemical composition, density and high heating value of classes 1, 2, 4, 5 and 6. Low molecular weight petroleum has an exergy content between 40 to 46 MJ/kg. Higher molecular weight petroleum and the hydrocarbon portion of the inorganic mixtures have a chemical exergy close to 40 MJ/kg [138]. Natural gas consists primarily of methane but including significant quantities of ethane, butane, propane, carbon dioxide, nitrogen, helium and hydrogen sulfide. Energy from the sun 123 2000 Mtoe 1500 1000 500 0 Total North America Total S. & Cent. America Total Europe Total Middle Total Africa & Eurasia East Coal: Production Total Asia Pacific Coal: Consumption Figure 4.6. Coal production and consumption at the end of 2006. Elaborated from data included in [35]. Table 4.7. Physical properties of different compositions of natural gas [34] CO2 5,5 3,51 26,2 0,17 0,2 - N2 32 0,7 87,7 0,6 0,6 0,5 H2 S 7 0,5 - Composition C H4 C2 H6 77,7 5,5 52,5 3,7 59,2 13,9 10,5 1,6 99,2 79,4 21,8 C3 H8 2,4 2,2 20 77,7 C4 H10 1,18 2,02 - C5 H12 0,63 3,44 - Density kg/N m3 0,9 1,06 1,08 1,14 0,72 1,41 1,77 HHV kJ/N m3 kJ/kg 39.575 43.915 32.600 30.750 31.668 29.261 5.073 2.552 37.524 52.126 72.176 51.079 89.110 50.049 The main properties of natural gas are listed in table 4.7. The specific exergy of natural gas is around 50 MJ/kg [138]. Oil accounts for 36% of world energy consumption, while natural gas for about 24%. World proved reserves of oil and gas are much smaller than those of coal. At the end of 2006, they were estimated as 1.208,2 thousand million barrels or 164,8 Gtons and of gas 181,46 trillion of cubic meters or 163,4 Gtoe, considering the conversion factor given in the BP report [35] (see figures 4.7 and 4.9). 124 THE RESOURCES OF THE EARTH In terms of exploration, the oil industry is relatively mature and the quantity of additional reserves that remain to be discovered is unclear. The general and rather pessimistic believe concerning oil discoveries is that few new oil fields are being discovered, and that most of the increases in reserves results from revisions of underestimated existing reserves (Ivanhoe and Leckie [165], Laherre [190], Campbell [45] or Hatfield [133]). The optimistic views appeal to improvements in technology, such as 3D seismic surveys and extended reach (e.g. horizontal) drilling, that have improved recovery rates from existing reservoirs and made profitable the development of fields previously regarded as uneconomic (Smith and Robinson [324]). Masters et al. [211] reflect the current state of knowledge as to the uncertainties in future potentials for conventional oil resources. These estimates assess in addition to the conventional oil reserves a corresponding range of additionally recoverable resources between 38 and 141 Gtoe. Estimates of gas reserves and resources are being revised continuously. The International Gas Union (IGU) estimates that additional reserves, including gas yet to be discovered could be as high as 200 Gtoe [156]. Gregory and Rogner [123] suggest an optimistic estimate for ultimately recoverable reserves of additional 500 Gtoe . World major oil suppliers are by far middle-east countries. Except of them, south and central America and Africa, the rest of the world is a net importer of oil, even if some countries like north America produce considerable amounts of the resource as well (see figure 4.8). Oil world consumption at the end of 2006 was 3889,8 Mtons [35]. Major natural gas consumers in the world are Asian-Pacific countries, and most part of it has to be imported. The largest producers in the world are the Russian federation, followed by north America, Iran, Norway and Algeria (see figure 4.10). Natural gas world consumption at the end of 2006 was 2574,9 Mtoe [35]. 4.6.6.3 Unconventional fossil fuels Besides of the fossil fuels mentioned before, there is a great quantity and variety of unconventional fossil fuel resources, not on a large-scale commercially recoverable. Oil that requires extra processing such as from shales, heavy oils, and oil (tar) sands, is classified as unconventional. Together contributed around 3% of world oil production in 2005 (66 Mtoe) and could reach 110 Mtoe by 2020 [230] and up to 140 Mtoe by 2030 [151]. Resource estimates are uncertain but could have a potential of over 830 Gtoe [163]. Methane stored in a variety of geologically complex, unconventional reservoirs, such as tight gas sands, fractured shales, coal beds and hydrates, is even more abundant than conventional gas. Worldwide coal bed methane may be larger than 190,5 Gtoe but a scarcity of basic information on the gas content of coal resources makes this number highly speculative [163]. A similar quantity is estimated to be in the form of Energy from the sun 125 Figure 4.7. Oil proved reserves at the end 2006. Values in thousand millions of barrels [35]. 1400 Mtoe 1200 1000 800 600 400 200 0 Total North America Total S. & Cent. America Total Europe Total Middle Total Africa & Eurasia East Oil: Production Total Asia Pacific Oil: Consumption Figure 4.8. Oil production and consumption at the end of 2006. Elaborated from data included in [35]. 126 THE RESOURCES OF THE EARTH Figure 4.9. Natural gas proved reserves at the end 2006. Values in trillion cubic meters [35]. 2000 Mtoe 1500 1000 500 0 Total North America Total S. & Cent. America Total Europe Total Middle Total Africa & Eurasia East Natural Gas: Production Total Asia Pacific Natural Gas: Consumption Figure 4.10. Natural gas production and consumption at the end of 2006. Elaborated from data included in [35]. Summary of the results of energy resources 127 tight sands. Methane clathrate is a solid form of water that contains a large amount of methane within its crystal structure. It is usually found in vast quantities under sediments on the ocean floor. According to the IPCC [160], technologies to recover these resources economically could be developed in the future, if demand for natural gas continues to grow in the longer run, in which case gas resource availability would increase enormously. The reserves are estimated by the USGS [360] to be greater than 1.400 Gtoe. The great drawback of these kinds of unconventional fuels is the elevated quantity of energy required for their extraction. The refinement of oil shale for instance, needs two or three times more energy than the production of conventional fuel oil. Furthermore, the associated environmental footprint is huge, since usually vast forest areas need to be destroyed and the important amount of water used and emissions produced threatens the biodiversity of the surroundings. 4.7 Summary of the results of energy resources Table 4.8 summarizes the results discussed in the previous sections. It shows the available energy, potential energy use and current energy consumption of most important energy resources on earth. With potential energy, we mean probable energy capacity using advanced technology, not necessarily developed nowadays. Consumption values are referred to the end of 2006, except for geothermal, PV, wind, biomass and tidal energy, which are 2005 values. It must be pointed out that the data must be still considered as an approximation and in any case, it might increase, as technology allows to make a more efficient use of the resources and to exploit non currently recoverable fuels. The detailed analysis of the results will be carried out in chapter 6, when all resources, including non-fuel minerals are assessed with the same unit of measure. In the next section the remaining type of natural resources will be studied. Namely, the non-fuel mineral resources. 4.8 Non-fuel mineral resources In addition to energy resources, non-fuel minerals are the other kind of resources essential for civilization. The quantity of minerals on earth is finite and hence they are classified as non-renewable. The physical and chemical properties of minerals are directly influenced by the two major energy sources of the earth: the sun and the geothermal power. They are responsible for the movement of materials from the earth’s interior, to the crust, from these to the sea or to rivers through currents and from the sea to form rocks in the so called geochemical cycle. The resulting dynamic equilibrium is called the geochemical balance [68]. 128 THE RESOURCES OF THE EARTH Table 4.8. Available energy, potential energy use and current consumption of natural resources on earth. Resource Available energy Geothermal 17,9 TW Potential energy use 59 - 124 GWe Uranium - fission Thorium - fission Deutorium + Tritium (fusion) Tidal power Solar PV Solar thermal power Water power Wind power Ocean thermal gradient Ocean conveyor belt Ocean waves Biomass Coal Natural gas Oil Unconventional fuels 27.100 Gtoe 7.500 Gtoe 74 Ttoe 2,7 TW 43,2 PW 43,2 PW 11 TW 1000 TW 1, 4 × 108 Gtoe 1.200 - 2.000 TW 3 TW 92 TW 1615 Gtoe 365-665 Gtoe 200-300 Gton ∼ 2600 Gtoe 5.200 Gtoe 166 GW 51,4 TW 630 - 4700 GWe 1.800 GW 14,5 TW 500 GW 19 - 56 TW 523 Gtoe 163,4 Gtoe 164,8 Gton - Current energy consumption 9,3 GWe / 28 GWth 635,5 Mtoe 300 MW 3 GWe 354 MWe 688,1 Mtoe 59 GW 750 kW 1,7 TW 3090 Mtoe 2574,9 Mtoe 3889,8 Mton 66 Mtoe In chapter 3 we obtained an estimation of the average mineralogical composition of the crust. The figures given in table 3.3 show the relative abundance of the minerals on earth. Of course minerals are not found in the same concentration everywhere in the crust. Fortunately for mankind, nature provides us with areas accounting for high-concentrated deposits, that allow us to extract them in a relatively cost-effective way. Minerals become concentrated in five ways [318]: 1. Concentration by hot, aqueous solutions flowing through fractures and pore spaces in crustal rock to form hydrothermal mineral deposits. 2. Concentration by magmatic processes within a body of igneous rock to form magmatic mineral deposits. 3. Concentration by precipitation from lake water or seawater to form sedimentary mineral deposits. 4. Concentration by flowing surface water in streams or along the shore to form placers. 5. Concentration by weathering processes to form residual mineral deposits. Besides of the physical way of classifying mineral concentrations, there is an economical way of classifying them. This is explained in the following section. Non-fuel mineral resources 4.8.1 129 The economic classification of minerals Concentrations of minerals can be classified as resources, reserves and reserve base, depending on the different factors explained next. The US Bureau of Mines defines a resource as a concentration of naturally occurring solid, liquid, or gaseous material in or on the earth’s crust in such form and amount that economic extraction of a commodity from the concentration is currently or potentially feasible. Reserve base is defined as that part of an identified resource9 that meets specified minimum physical and chemical criteria related to current mining and production practices, including those for grade, quality, thickness, and depth. And reserves are that part of the reserve base which could be economically extracted or produced at the time of determination. Reserve base and reserves are subdivided in order of increasing confidence into demonstrated and inferred. The latter are estimates based on an assumed continuity beyond indicated resources, for which there is geologic evidence. There may be no samples or measurements. Demonstrated reserves are the sum of measured and indicated. If the quantity is computed from dimensions revealed in outcrops, trenches, workings or drill holes; grade and or quality are computed from the results of detailed sampling; the sites of inspection are spaced closely and the geologic character is so well defined that size, shape, depth and mineral content of the resource are well established, then we talk about measured resources. Indicated resources are those in which the grade and or quality are computed from information similar to that used for measured resources, but the sites for inspection, sampling, measurement are farther apart or are otherwise less adequately spaced. It is clear then, that all the classifications listed above are related to economy, especially reserves. Figure 4.11 shows the mineral resources and reserves classification after McKelvey [214]. Increasing geological information expands the amount of reserves. So do commodity prices and development of efficient technologies, as lower grades become economically profitable. Hence, neither reserve base, nor reserves are good indicators for assessing the earth’s mineral capital. In fact, total world reserves of most mineral commodities are larger now than at any time in the past [141] due to wider geological information, more efficient technologies and price changes. The best approximation of numbers compiling the mineral capital would be using resources data. However, for being indeed the most comprehensive classification, the information is often scarce, inaccurate and incomplete as it can be seen in table 4.10. Estimates of resources are necessarily dynamic. For example, the realization that it was economic to mine copper porphyry deposits for their ore in the early part of the 20th century increased the world’s known copper reserves, and therefore resources, by several hundred per cent [121]. Too little is known about the earth’s crust, since exploration costs are extremely high. 9 Identified resources: resources whose location, grade, quality and quantity are known or estimated from specific geologic evidence. 130 THE RESOURCES OF THE EARTH Figure 4.11. A classification of mineral resources and reserves [141]. Most of the deposits worked at present are close to the surface but the earth’s crust is on average 40 km thick and the deepest open-pit mine is less than 1 km deep, while the deepest underground mine goes down to 3,5 km to the surface and few exceed 2 km [29]. Thus only approximately the outer one-tenth of the continental crust is of present interest [78]. Besides, there are many minerals and metals such as bismuth, cesium, germanium, gallium, etc. that are just byproducts of other more demanded metals such as gold, copper, zinc, lead, etc. No exploration efforts will be undertaken for those specific minerals until demand significantly increases. 4.8.2 Mineral’s average ore grades For some time, many geologists have assumed that the amount of less common metals existing at different grades in the crust could be represented by lognormal or similar unimodal frequency distributions. This assumption was questioned by Skinner [316] for the metals that make up less than 0,1% of the earth’s crust. He suggested that for these scarce metals the distribution might be bimodal and that the small mode at higher grades would represent metal concentrations of nonsilicate minerals localized in mineral deposits [73] (see fig. 4.12). There are mathematical procedures that correlate the tonnage of the ore with its mean grade. Much of the original work on this problem was carried out by Lasky [193]. He argued that a linear relation is obtained if the logarithm of the tonnage of ore with grades above a specified value is plotted against grade. Cargill et al. [48] suggested that a linear relation was obtained if the logarithm of the tonnage Non-fuel mineral resources 131 Tonnage a. Unimodal Grade Tonnage b. Bimodal Grade Figure 4.12. Two possible relationships between ore grade and the metal, mineral, or energy content of the resource base [316]. was plotted against the logarithm of the grade. Later on, the fractal relationship, exhibited by a variety of natural processes, was proved to be better applicable to mineral deposits. Turcotte [358], showed that the tonnage of ore with a mean grade was proportional to the mean grade raised to a power for mercury, copper and uranium deposits in the US. This fractal relationship follows the expression of Eq. 4.3. x̄ m xc = Mc M F 3 (4.3) Where x̄ m is the average concentration in the deposit; x c the concentration in the earth’s crust; M the tonnage of the deposit; Mc the tonnage of the piece of land under consideration and F the fractal relationship to be determined. These theoretical methodologies have mainly the objective to determine the tonnage of ore with grades above a specified value, providing thus a basis for estimating ore reserves. But they require as input for estimating F , information about already existing deposits with ore grades and tonnage, which is what we are searching for. A comprehensive study of average ore grades was undertaken by Cox and Singer [66]. In their study, a compendium of geologic models was presented, includ- 132 THE RESOURCES OF THE EARTH ing 85 descriptive models identifying attributes of the deposit type and 60 gradetonnage models giving estimated pre-mining tonnage’s grades from over 3900 wellcharacterized deposits all over the world. We have calculated with Eq. 4.4 the weighted average grades (x̄ m ) of the different mineral models of Cox and Singer [66], considering the average tonnage (M ) and grade (x m ) of the different deposits containing the particular mineral (see section A.2 in the appendix). The minerals under consideration in Cox and Singer’s study were: rare earths, uranium oxide, zircon, niobium oxide, barite, alumina, phosphorous, potash, titanium, chromium, manganese, iron, cobalt, nickel, copper, molybdenum, wolfram, palladium, platinum, rhodium, iridium, ruthenium, osmium, silver, gold, zinc, mercury, tin, lead and antimony. Table 4.9 shows the final average grade obtained. RM xmd M x̄ m = 0R M dM 0 (4.4) Some of the values may appear to be quite low. Nevertheless, it must be pointed out that the figures are averages of mineral extraction of deposits. Most deposits extract many minerals as byproducts, with a relatively low grade which would not be cost-effective if they were to be extracted alone. Table 4.9: Summary statistics of grade-tonnage models. After [66] Deposit RE2 O5 (%) Monazite (%) U3 O8 (%) Zircon (% Z rO2 ) N b2 O5 (%) Barite (%) Al2 O3 (%) P (%) P2 O5 (%) Ilmenite (% T iO2 ) Rutile (% T iO2 ) Leucocite (% T iO2 ) C r2 O3 (%) M n (%) Fe (%) C o (%) N i (%) x̄ m 0,10 0,03 0,33 0,27 0,64 83,02 45,97 0,11 24,01 1,27 0,21 0,23 43,52 31,49 51,05 0,11 1,30 Deposit Cu (%) M o (%) W O3 (%) P d (ppb) P t (ppb) Rh (ppb) I r (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Z n (%) H g (%) Sn (%) P b (%) S b (%) x̄ m 0,58 0,03 0,72 158,51 802,39 12,92 20,62 220,02 82,22 4,27 0,22 4,06 0,38 0,48 2,05 3,78 Non-fuel mineral resources 133 No average numbers have been found in the literature for the rest of the minerals not included in Cox and Singer [66]. Most of those minerals are not mined as the principal product and are only commercially produced in the case they are found as reasonable byproducts of other important minerals. In those cases, values found in the literature (as in Carr [51]) of certain deposits have been taken as reference. We are aware that those figures cannot be considered as global mineral ore grades. Nevertheless, they are good enough for giving an order of magnitude. The following assumptions have been made in order to estimate the average mineral ore grades not included in Cox and Singer: • Arsenic: Northparkes copper-gold ore grade for arsenic is 0,11% [323]; Mt Piper Gold Project in Victoria (Australia) contains 3% [252]. We will assume an average grade of 1%. • Beryllium: ore grades range from 0,2 to 3,5 % of beryllium oxide [260]. We will assume an average grade of 1%. • Bismuth: Bonfim W-Au-Bi-Te Skarn deposit (Brazil) contains 475 to > 2000 ppm [327]. We assume the value of 2000 ppm. • Boron: According to the USGS [363], average grades of boron oxide mined all over the world range from 11 to 39%. We will assume an average grade of 20%. • Bromine: an important source of bromine is the Dead Sea. Its bromine concentration is around 5000 ppm [406]. • Cadmium: cadmium is usually found in zinc ores. According to the Mineral Information Institute10 , zinc ores around the world average about 1/400 th as much cadmium as zinc. Hence, if Z n average grade is 4,06%, C d grade is estimated to be around 100 ppm. • Cesium: it is usually found in the mineral pollucite. The world largest pollucite deposit is in a zoned pegmatite at Bernic Lake, Canada, grading 23,3% cesium oxide11 . • Feldspar: the major commercial feldspar deposits occur in pegmatites, granitic rocks, granitic rock types known as alaskite and aplite and certain river, dune and beach sands. The feldspar content of these deposits range from 15 to up to 75% of the different feldspar minerals [180]. We will assume an average of 45%. 10 11 Mineral Information Institute: http://www.mii.org/Minerals/photocad.html Source: Houston Lake Mining Inc. http://www.houstonlakemining.com 134 THE RESOURCES OF THE EARTH • Fluorite (fluorspar): The compilation of Fulton and Montgomery [99], gives averages for the different types of deposits where fluorite is found: fissure veins (from 25 to 80%), statiform deposits (from 15% upward), stockworks (about 14%), gangue mineral (from 10 to 20%), lake sediments (50 to 60% of the clayey parts and 15% of the sandy parts). Specific examples of fluorite deposits are for example in the southwestern United States, deposits often assay less than 10% fluorite [131] and in the Pöhrenk deposit of Turkey ore grades range from a few to more than 40% C aF2 [110]. We will assume an average fluorite grade of 25%. • Gallium: the most important ore in which gallium is found as a trace element is bauxite in an average of 50 ppm, according to the Mineral Information Institute. Assuming that the average grade of alumina alumina in laterite bauxite is 45,97% [66], gallium grade is estimated here as about 23 ppm. • Germanium: grades of a few tens to several hundred ppm Ge are known in sulphide deposits [142], [220]. We will assume an average grade of 50 ppm. • Graphite: economic deposits of graphite include five main geological types: flake graphite disseminated in metamorphosed (with an average deposit of 10 to 12%), silica-rich sedimentary rocks (1-10%), flake graphite disseminated in marble amorphous deposits formed by metamorphism of coal or carbon-rich sediments (50-95%), veins filling fractures (85-98%) and contact metasomatic or hydrothermal deposits in marble (irregular concentrated). We will assume an average grade of 50%. • Gypsum: it is usually found in very high grades, ranging from 45 to 95% [174]. We will assume an average grade of 80%. • Hafnium: it is always present in 1,5 to 3,0 % in zirconium compounds [315]. Assuming an average of zinc of 0,27% [66], the hafnium average grade ranges from 40,5 to 81 ppm. We will assume an average of 60 ppm. • Helium: it is recovered usually as a byproduct in natural gas production. Some natural gas deposits have as much as 7% helium, found in Texas, Russia, Poland, Algeria, China and Canada12 . • Indium: the average value in ore deposits varies drastically up to percent levels. In the Kuroko deposits of Japan, the I n-content of Cu-concentrates had been reported at about 10 ppm and in Z n concentrates is 100 ppm. Some skarn deposits and Pb-Zn veins have ranges of I n concentration similar to these. Atypical maximum concentrations of I n are up to 3000 ppm. We will assume an average content of 140 g/t which is reported for one of the most well known I n deposits in Japan, the Toyoha mine in Hokkaido [236]. 12 Source: Mineral Information Institute (http://www.mii.org/Minerals/photohelium.html Non-fuel mineral resources 135 • Iodine: iodine is primarily retrieved from underground brines. Dried seaweeds, particularly those of the Liminaria family, contain as much as 0,45% iodine. Japan is the largest iodine producing country. The maximum iodine content of the brines is about 160 ppm [171]. • Lithium: some lithium is recovered from the mineral spodumene with an Li grade of 1 to 4%. But most lithium is recovered from brine. Lithium grades in brine range from 0,015 to 0,06% [260]. We will assume an average grade of 0,04%. • Magnesium compounds: one of the most important magnesium minerals is magnesite, M g CO3 , which represents the world’s largest source of magnesia, M gO. The next most used sources for magnesia are magnesia-rich brines and seawater. Dolomite is another important source for industrial magnesium. The crude ore of magnesite contains typically around 45% of magnesia. • Potash: potash oxide grades in Canada, the most important producer in the world, range from 14 to 32% [407]. In Saskatchewan, ore grades range between 23 and 27%13 . We assume an average grade of K2 O of 25%. • Rhenium is a very rare element produced mainly as a byproduct in the processing of porphyry copper-molybdenum ores. The Re contents in the majority of the concentrates range from 6 to 460 ppm [27]. We assume an average of 233 ppm. • Selenium: it is widely distributed within the earth’s crust and does not occur in concentrations high enough to justify solely for their content. It is recovered as byproduct of nonferrous metal mining, mostly from the anode slimes associated with electrolytic refining copper. The economic concentration14 is 2,5% [34]. • Strontium: celestine and strontianite are the only S r-containing minerals having sufficient quantities to make its recoveral practical. From these, only celestine has been found to occur in deposits of sufficient size. Celestine is mined in many countries all over the world. Reported average ore grades of S rSO4 range from 54% in Cyprus to more than 90% in Iran [244]. We will assume an average grade of 70% of celestine or 34% of S r content. • Tantalum: it is recovered from tantalite and columbite ores. The average ore grades are similar to those of niobium, since it is recovered from the same ores. Therefore, we assume that the average grade of tantalum oxide is 0,64%, the same as the grade of niobium oxide recorded by Cox and Singer [66]. 13 14 Source: the Canadian Encyclopedia (http://thecanadianencyclopedia.com) Economic concentration: concentration at which a mineral is economically producible 136 THE RESOURCES OF THE EARTH • Tellurium: it is widely distributed within the earth’s crust and does not occur in concentrations high enough to justify solely for their content. It is recovered as byproduct of nonferrous metal mining, mostly from the anode slimes associated with electrolytic refining copper. The economic concentration is 1 ppm [34]. • Thorium: it has been mined at an average grade of nearly 3% of T hO2 in the Bokan Mountain in Alaska [356]. • Vanadium: average ore grades for vanadium range from 0,3 to 5% [260]. We will assume an average of 2%. 4.8.3 Mineral’s abundance Table 4.10 shows world reserves, reserve base, and resources of the main naturaloccurring non-fuel minerals of economic importance according to the USGS [362]. It shows also the average ore grades obtained in the previous section. The most abundant ores in the crust are those of iron, followed by phosphate rock, potash, manganese and aluminium. On the contrary, the ores of the platinum group metals, thallium, tellurium and rhenium are the scarcest in the world. Table 4.10: Mineral world reserves, reserve base and world resources in 2006 Production Reserves Reserve base Resource Aluminium Antimony Arsenic Barite Beryllium Bismuth Boron (as B2 O3 ) Bromine tons 3,37E+07 1,34E+05 5,98E+04 7,96E+06 1,79E+02 5,70E+03 4,26E+06 tons 4,55E+09 2,10E+06 1,20E+06 1,90E+08 N.A. 3,20E+05 1,70E+08 tons 5,82E+09 4,30E+06 1,20E+06 8,80E+08 N.A. 6,80E+05 4,10E+08 5,45E+05 Large Large Cadmium Cesium Chromium Cobalt Copper Feldspar Fluorspar Gallium Germanium 1,93E+04 N.A. 5,85E+06 6,75E+04 1,51E+07 1,54E+07 5,33E+06 7,30E+01 9,00E+01 4,90E+05 1,20E+06 7,00E+04 1,10E+05 N.A. N.A. 7,00E+06 1,30E+07 4,90E+08 9,40E+08 Large Large 2,40E+08 4,80E+08 N.A. N.A. N.A. N.A. Continued on next page . . . World resources tons 1,36E+10 N.A. > 11000000 2,00E+09 > 8E+04 N.A. N.A. Unlimited (dead sea contains 1 billion tons of bromine) 6,00E+06 N.A. 3,80E+09 1,50E+07 > 3,00E+09 Large 5,00E+08 1,00E+06 N.A. Ore grades % 45,97 3,78 1,00 83,02 1,00 0,50 20,00 0,50 100 ppm 23,30 43,52 0,11 0,58 45,00 25,00 23 ppm 50 ppm Non-fuel mineral resources 137 Table 4.10: Mineral world reserves, reserve base and world resources in 2006 – continued from previous page. Production (year 2006) tons 2,46E+03 1,03E+06 1,25E+08 N.A. Reserves Reserve base tons 4,20E+04 8,60E+07 Large 6,10E+05 tons 9,00E+04 2,10E+08 Large 1,10E+06 World resources tons N.A. > 8,00E+08 Large N.A. 2,81E+04 5,81E+02 2,50E+04 N.A. 8,66E+08 3,47E+06 3,33E+05 N.A. 1,10E+04 1,50E+07 N.A. 7,30E+10 7,90E+07 4,10E+06 6,47E+06 1,60E+04 2,70E+07 N.A. 1,60E+11 1,70E+08 1,10E+07 N.A. N.A. 3,40E+07 N.A. 2,30E+11 > 1,50E+09 >1,3E+07 Magnesium 6,89E+05 N.A. N.A. Manganese Mercury Molybdenum Nickel Niobium Osmium Palladium Phosphate rock Platinum group metals Platinum Potash Rare Earths 1,19E+07 1,48E+03 1,84E+05 1,58E+06 4,45E+04 N.A. 2,24E+02 1,42E+08 4,60E+08 4,60E+04 8,60E+06 6,70E+07 2,70E+06 N.A. N.A. 1,80E+10 5,20E+09 2,40E+05 1,90E+07 1,50E+08 3,00E+06 N.A. N.A. 5,00E+10 Large to unlimited Large 6,00E+05 1,30E+07 N.A. N.A. N.A. N.A. N.A. 5,18E+02 7,10E+04 8,00E+04 > 1,00E+05 2,21E+02 2,91E+07 1,23E+05 N.A. 8,30E+09 8,80E+07 N.A. 1,80E+10 1,50E+08 Rhenium Ruthenium Selenium Silicon Silver Strontium Tantalum Tellurium Thallium Thorium Tin 4,72E+01 N.A. 1,54E+03 3,87E+06 2,02E+04 5,85E+05 1,39E+03 1,32E+02 1,00E+01 N.A. 3,02E+05 2,50E+03 1,00E+04 N.A. N.A. 8,20E+04 1,70E+05 N.A. N.A. 2,70E+05 5,70E+05 6,80E+06 1,20E+07 1,30E+05 1,80E+05 2,10E+04 4,70E+04 3,80E+02 6,50E+02 1,05E+06 1,23E+06 6,10E+06 1,10E+07 Continued on next page . . . N.A. 2,50E+11 Undiscovered resources are thought to be very large relative to expected demand 1,10E+04 N.A. N.A. N.A. Large > 1,00E+09 N.A. N.A. 6,47E+05 N.A. N.A. Resource Gold Graphite Gypsum Hafnium H f O2 ) Helium Indium Iodine Iridium Iron ore Lead Lithium (as Ore grades % 0,22 g/t 50,00 80,00 60 ppm 7,00 140 g/t 160 ppm 20,6 ppb 51,05 2,05 0,04 (Lithium brines) 45 as MgO 31,49 0,38 0,03 1,30 0,64 82,2 ppb 158,5 ppb 0,11 See Pt, Pd, Rh, Ru, Ir and Os 802,4 ppb 25,00 0,10 223 ppm 220,0 ppb 2,50 N.A. 4,3 g/t 34,00 0,65 1 ppm N.A. 3,00 0,48 138 THE RESOURCES OF THE EARTH Table 4.10: Mineral world reserves, reserve base and world resources in 2006 – continued from previous page. Resource Titanium (as T iO2 ) Vanadium Wolfram Yttrium (as Y2 O3 ) Zinc Zirconium (as Z rO2 ) Production (year 2006) tons 5,80E+06 Reserves Reserve base tons 7,30E+08 tons 1,50E+09 World sources tons N.A. re- Ore grades 5,63E+04 9,08E+04 8,90E+03 1,30E+07 2,90E+06 5,40E+05 3,80E+07 6,30E+06 6,10E+05 > 6,30E+07 N.A. N.A. 2,00 0,72 N.A. 1,00E+07 1,18E+06 1,80E+08 3,80E+07 4,80E+08 7,20E+07 1,90E+09 N.A. 4,06 0,27 % 0,69 End of the table 4.9 Summary of the chapter This chapter closes the analysis of the earth’s components (Part I of this report), by undertaking a review of the different natural resources, useful to man. With the most updated information sources, the available energy, potential energy use and current energy consumption of all known renewable and non-renewable energy resources has been obtained. That is for geothermal, nuclear, tidal, solar, wind and ocean power, as well as for biomass, coal, natural gas, oil and unconventional fuels. In addition to energy resources, non-fuel minerals have been analyzed. As opposed to fossil fuels, the abundance of minerals is not important if these are dispersed throughout the crust. Hence, besides of the available resources registered, which are very uncertain, average ore grades for the main mineral resources have been provided. Both figures (abundance and concentration), will allow us to calculate the exergy of non-fuel minerals. With the next chapter, begins Part II of this report, whose aim is to assess the exergy of the earth and its resources. Chapter 5, provides the thermodynamic tools required for calculating the exergy of the earth, including the mineral resources (of fuel and non-fuel nature) just reviewed. Consequently, all resources will be able to be evaluated with a single unit of measure, allowing us to compare them and to analyze their scarcity. Part II The thermodynamic properties of the earth and its exergy evolution 139 Chapter 5 Thermodynamic models for the exergy assessment of natural resources 5.1 Introduction This aim of this chapter is to provide the thermodynamic tools for the exergy assessment of natural resources and particularly for minerals. The exergy of any substance or process is always fixed by the so called reference environment (R.E.). Therefore, for calculating the exergy of any natural resource, an appropriate R.E. should be defined. In section 5.2, the different reference environments proposed in the literature are reviewed and the best suitable R.E. so far, for assessing the natural capital is chosen. Once the R.E. is fixed, the exergy of mineral resources can be calculated with the help of the thermodynamic models provided in section 5.3. For that purpose, the energy involved in the process of formation of a mineral deposit is described. Next, the formulas for obtaining the exergy and exergy cost of mineral resources (including fossil fuels) are provided. And finally, 12 models for estimating the Gibbs free energy values of mineral resources, required for the calculations, is shown. 5.2 The reference environment The R.E. can be assumed as being a thermodynamically dead planet where all materials have reacted, dispersed and mixed. This R.E. must be determined by the natural environment and is fixed by its chemical composition. In past years, there 141 142 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES have been many contributions to the determination of the best suitable R.E. The divergences between standard chemical exergies of the elements obtained from different R.E. conceptions can be very significant. Each R.E. definition generate different exergies, what implies that the determination of the natural capital’s exergy is necessarily linked to the definition and thermodynamic properties of the R.E. In order to correctly evaluate the natural resources, it is necessary to know how does the modification of reference substances or physical variables of the R.E. change the exergy calculation of a system. Most of the contributions concerned with that topic deal with the exergy variation of processes according to physical parameters of the environment such as pressure or temperature (see for instance Brodianski et al. [304] [39]). Other authors have studied the influence of environment CO2 or temperature on the exergy of fossil fuels (Valero and Arauzo [366]) and hydrocarbons (Rivero et al. [282]). Nevertheless, it is crucial to analyze the influence of the reference environment’s chemical composition if the point is to evaluate the natural capital’s exergy. Next, the different models of reference environments are reviewed, and the best suitable R.E. is selected and improved for the evaluation of natural resources. 5.2.1 Selection of the best suitable reference environment The different R.E. conceptions can be divided into two main groups: • Partial reference environments • Comprehensive reference environments 5.2.1.1 Partial reference environments Some authors such as Bosjankovich [33], Gaggioli and Petit [101] and Sussman [332] established that the R.E. should be defined according to the specific characteristics of the analyzed process. This criterion is based on that being the exergy a parameter that quantifies the theoretical evolution of a system with respect to the R.E., some of the possible evolutions of the system, cannot be attained because of process limitations. Hence, only possibilities of evolution that the system can practically attain are analyzed. The conception of these R.E. are very far removed from the idea of degraded earth. For computing exergy changes of variable composition or chemically reactive steady flow processes, a Comprehensive reference environment is generally unnecessary. However, this is not the case when the point is to evaluate the natural capital on earth. In that case, there are no process limitations and the resources can follow an evolution process towards the dead state. Thus a comprehensive R.E. is required. The reference environment 5.2.1.2 143 Comprehensive reference environments Within the known Comprehensive reference environments, all authors agree in dividing the Reference Substances (R.S.) that compose the R.E. into gaseous components of the atmospheric air, solid components of the external layer of the earth’s crust, and molecular components of seawater. Nevertheless, there are also criterion differences between the different authors. They can be classified into environments based on: • Szargut’s criterion • Chemical equilibrium • Abundance Szargut’s R.E. could be considered as an environment based on partial abundance, even though Szargut itself regards his R.E. as based only on abundance. We will show next, that his R.E. is not only based on abundance, as opposed to the criterion taken by Ranz [276]. According to Szargut’s criterion, among a group of reasonable abundant substances, the most stable will be chosen if they also fulfill the “earth similarity criterion”. That is, if the stability of the possible different reference substances for a specific element (measured in terms of the formation Gibbs energy) is within a certain threshold, then the most abundant R.S. will be chosen. If the differences exceed this threshold, the most stable substance will be taken as R.S. as long as the “earth similarity criterion” is not contradicted. The stability threshold has not a fix value and depends on each element considered, since it is subject to geological uncertainties. Thus for example in the case of S b, the substance S b2 S3 is more abundant than S b2 O5 , nevertheless, according to Szargut’s criterion, S b2 O5 , which is much more stable, will be taken as reference substance. This happens also with the substances listed in table 5.1. Nevertheless nitrates such as C a(N O3 )2 , N aN O3 , K N O3 are discarded, because being most stable but not abundant in the natural environment, they would break the similarity criterion if they are taken as R.S. Therefore, Szargut’s [333] dead environment is similar to the real physical environment and should represent the products of an interaction between the components of the natural environment and the waste products of the processes. The most probable products of this interaction should be chosen as reference species. Section 5.2.2 explains purposively the well known Szargut’s methodology for obtaining the chemical exergy of the elements from the R.E. 144 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES Table 5.1: Exergy difference of selected elements considering either as reference species the most abundant or the most stable substances in the R.E. [367] Element Most abundant species Most stable species Sb As S Bi Cd Ce Zn Co Cu Mo Os Ag Pt Pb Re Ru U S b2 S3 FeAsS FeS2 Bi C dS C ePO4 Z nS C o 3 S4 CuFeS2 M oS2 Os Ag2 S Pt P bS ReS2 Ru UO2 S b2 O5 As2 O5 SO4−2 BiO+ C dC l2 C eO2 Z n+2 C o3 O4 Cu+2 M oO4−2 OsO4 AgC l2− P tO2 P bC l2 Re2 O7 RuO2 UO3 .H2 O Exergy difference between both R.E. (kJ/mole) 1235,58 1201,32 963,63 228,88 745,75 258,33 717,22 967,70 1423,18 1675,9 306,81 330,65 84,59 710,34 1556,65 254,82 127,49 Another group of authors derive the chemical exergy of the elements from the hypothetical chemical equilibrium that could be attained on earth in a very distant future. Ahrendts [3], [4] and Diederichsen [74] for example, stated that if the amount of different elements in the reference system is known and the temperature of the system is fixed, the quantity of each chemical compound and the value of each chemical potential is uniquely determined by the condition of chemical equilibrium. This criterion is thermodynamically consistent and thus does not generate any negative exergies as it happens with the other two comprehensive R.E. classifications. Ahrendt’s R.E. relied on the model of Ronov and Yaroshevsky [287] to ascertain 15 elements, making up more than 99% of the earth’s crust: H, C, N , O, N a, M g, Al, Si, P, S, C l, Ar, K, C a, T i, M n and Fe. These elements were allowed to react until chemical equilibrium was attained. The composition of this environment in chemical equilibrium, had as a variable parameter the thickness of the crust layer (between δ = 1 m and δ = 1000 m). The resulting equilibrium reference system based on an earth’s crust of δ = 1000 m, showed that the exergy of oxygen was even smaller than that of fuels. He found that the exergy of oxygen increased, when the considered thickness of the crust was smaller. In order to overcome this paradox, Ahrendts considered a crust layer on only 1 m. Szargut criticizes Ahrendt’s model, stressing that it is not possible to attain an equilibrium with the system being not in the state of internal equilibrium (and the natural The reference environment 145 environment is far removed from such equilibrium). Valero, Ranz and Botero [371], explained already why Ahrendt’s R.E. was not suitable to evaluate the natural capital on earth. Most of the metals cannot be evaluated because they form part of the 1% of the earth’s crust neglected by Ahrendts. His obtained R.E. is very different from the real environment and it is very unlikely an eventual evolution towards it, since some processes are kinetically, biologically and/or geologically blocked. Diederichsen updated and extended Ahrendt’s model with new geochemical data and obtained among others, a R.E. including 75 elements. Furthermore, he allowed the composition of this environment to change with two variable parameters: thickness of the earth’s crust and ocean’s depth. The final chosen environment should fulfill the “earth similarity criterion”. The similarity with the earth was measured with the equilibrium pressure, the oxygen and nitrogen content in the gas-phase and the equilibrium salt content in the oceans. Even though Diederichsen [74] added more elements than Ahrendts [4] and included a new variable parameter, the composition of his new reference environment was still too different from the real earth. According to the “earth similarity criterion”, the R.E. that best fits with the earth’s environment takes a crust thickness of only 0,1 m and an ocean’s depth of 100 m. Greater values would move further away the R.E. from the real earth, and would have among other features, reduced pressures and oxygen contents. As it happened with Ahrendt’s model before, Diederichsen obtained high exergy values for oxygen. This happens because nearly all the oxygen of the air is consumed basically by the formation of nitrates and only in the limit, for a crustal thickness of 0 m, the mean earth pressure matches with that of the model. It seems therefore that achieving a R.E. in chemical equilibrium is in disagreement with the “earth similarity criterion” and is not appropriate for the evaluation of natural capital on earth. This idea fully fits with Lovelock’s Gaia hypothesis [199]: “the earth is a life being and fights against thermodynamic stable equilibrium.” Van Gool’s methodology [379] assures as well a R.E. in which all the substances have positive exergy values. However as he discards the geological information of mineral abundance, his R.E. does not guarantee a good model for a dissipated earth, which is critical in our research. Kameyama et al. [177] proposed a reference environment with the criterion of chemical stability. The references are the most stable compounds among those with thermo-chemical data and can be integrated in the solid, liquid and gaseous environments. As Szargut stated in [336], some of the most stable compounds selected by Kameyama et al. like nitrates, compounds between rare elements (e.g. P t Br2 ) or compounds with F r as the reference species for the elements F , C l, Br or I should not be recommended, because the probability of their formation in the environment is very small. Therefore, Kameyama et al. R.E. is not very suitable either to evaluate the scarcity of the natural capital. 146 5.2.1.3 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES Abundance criterion According to Ranz [276], lots of minerals are compounds with the most common components of the upper continental crust, but are not very stable and do not represent the products of an interaction between the components of the natural environment and the waste products of industrial processes. Hence, Ranz [276] proposes a new R.E. very close to the real environment based on abundance and following Szargut’s methodology. The solid phase of this new R.E. reproduces accurately the earth’s upper continental crust, since the solid reference species that make up this environment are the same as the most abundant types found in the earth’s upper continental crust. A problem with Ranz’s proposed R.E. is that if we assign zero exergy to the most abundant substances, we are decreasing arbitrarily the natural capital, because many abundant minerals like sulfides naturally evolute to the most stable oxides. Therefore, as proposed by Valero, Ranz and Botero [371], we must return to Szargut’s criterion of using the most stable substance, within the limits fixed by the “earth similarity criterion”. Hence, our first goal is to obtain a reference state for evaluating the natural resources on earth, based on Szargut’s criterion and methodology and using the more precise data used by Ranz and other authors such as Rivero [281], as well as new geochemical updates. In the next section, Szargut’s methodology for obtaining the standard chemical exergy of the chemical elements is explained and the variables used are discussed. 5.2.2 5.2.2.1 Calculation methodology: standard chemical exergy of the chemical elements Standard chemical exergy of chemical compounds The chemical exergy expresses the exergy of a substance at ambient temperature and pressure. It is defined as the maximum work which can be obtained when the considered substance is brought in a reversible way to the state of reference substances present in the environment, using the environment as a source of heat and of reference substances necessary for the realization of the described process. Standard chemical exergy results from a conventional assumption of a standard ambient temperature and pressure and standard concentration of reference substances in the natural environment. The chemical exergy of any chemical compound (bch i ), can be calculated by means of the exergy balance of a reversible formation reaction;. bch i = ∆G f i + X j r j,i bch j (5.1) The reference environment where: ∆G f i r j,i bch j 147 Gibbs free energy of substance i amount of mole of element j per mole of substance i standard chemical exergy of element j contained in substance i. If the chemical element does not belong to the reference substances, its standard chemical exergy can also be calculated from Eq. 5.1. The standard chemical exergy of the reference substances are calculated prior to the standard chemical exergy of the element. 5.2.2.2 Gaseous reference substances Free chemical elements present in the atmospheric air (O2 , N2 , Ar, H e, N e, K r, X e) and the compounds H2 O, CO2 are assumed as reference substances. Their standard chemical exergy results from the conventional standard concentration in the atmosphere. P0 bch i = −R̄ T 0 ln i0 = −R̄ T 0 ln x i (5.2) P where: R̄ universal gas constant (8,314E-3 kJ/(mole K)), 0 T standard ambient temperature (298,15 K), Pi0 conventional mean ideal gas partial pressure in the atmosphere (kPa), P 0 standard pressure (101,325 kPa), xi molar fraction in the environment. The values of standard chemical exergy of gaseous reference substances O2 , H2 O, CO2 , N2 are calculated before other values because they are necessary in the calculation of standard chemical exergy of non-gaseous reference substances. 5.2.2.3 Solid reference substances For a prevailing part of chemical elements, solid R.S. commonly appearing in the external layer of the continental part of earth’s crust, are assumed. However, the earth’s crust is a very complicated mixture of solid solutions and an exact calculation of the chemical exergy of its components is impossible. We can only approximately evaluate that exergy, assuming that the reference species behave as components of an ideal solution. Hence, Eq. 5.2 can be applied also in this case. The evaluation of the standard molar concentration of solid R.S. in the external layer of the earth’s crust is difficult and as stated in chapter 3, there wasn’t any average mineralogical composition until the recent publications of Grigor’ev [124], [127] arrived. In past geochemical publications (such as Allègre [6], [8], Shan Gao [106], Rudnick [291], Condie [60], Javoy [169], McDonough [212], Taylor and 148 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES McLennan [353], [216], [215], or Wedepohl [404]) one can only find mean mass concentrations of particular chemical elements and the most common oxides found in the continental crust, namely SiO2 , T iO2 , Al2 O3 , FeO, M nO, M gO, C aO, N a2 O, K2 O and P2 O5 . Hence, the best considered way so far to obtain the standard molar concentration of R.S. in the solid environment, has been with the following equation suggested by Szargut in [336]. xi = where: εj lj cj M Wc r 1 lj ε j c j M Wcr (5.3) mean molar concentration of the j-th element in the continental part of the earth’s crust (mole/g), number of the atoms of j-th element in the molecule of the reference species, fraction of the j-th element appearing in the form of reference species, mean molecular weight of the upper continental crust (g/mole). The reference reactions of the elements having solid reference substances contain usually gaseous reference substances such as O for example. Sometimes there appear also solid or liquid reference species. In such case the standard chemical exergy of the appearing solid or liquid reference substance should be calculated prior to the calculation of the chemical exergy of the considered element. 5.2.2.4 Reference substances dissolved in seawater Assumption of ionic or molecular R.S. dissolved in seawater ensures in many cases more exact determination of standard chemical exergy of chemical elements when compared with solid R.S. The calculation methods of thermodynamic functions of monocharged and bicharged ions are relatively exact. This is the case also when the reference substance is dissolved in molecular form with a very small degree of ionization. The method of calculation of standard chemical exergy of elements with R.S. dissolved in seawater was developed by Morris [340]: bch j = −∆ G f i + 0, 5 z + bch H2 − X rk,i bch k − k 0 + − R̄ T [2, 303 z (pH) + ln mi γi ] (5.4) The reference environment where: ∆G f i z+ rk,i bch H2 , bch k mi γi pH 149 Gibbs free energy of the R.S., number of elementary positive charges of the reference ion, number of molecules of additional elements k present in the molecule of reference substance i, standard chemical exergy of hydrogen gas and of the k-th additional element. conventional standard molarity of the reference substance i in seawater, activity coefficient (molarity scale) of the reference substance in seawater, exponent of the concentration of hydrogen ion in seawater (=8,1) Eq. 5.4 should be multiplied by 2 for the diatomic elements Br2 , C l2 and I2 . The activity coefficient of a single ion can be calculated by means of the DebyeHuckel equation: p A1 (z + )2 I − log γi = (5.5) p 1 + ai A2 I where: A1 A2 ai I = 0,51 kg1/2 mole−1/2 for water at 25o C, = 3,287 * 109 kg1/2 m−1 mole−1/2 for water at 25o C, effective diameter of the ion, ionic strength of the electrolyte. The ionic strength of the electrolyte results from the following equation: I = 1X 2 mi (z + )2 (5.6) i where: mi molarity of the ion, mole/kg H2 O, z + number of elementary electric charges of the ion. The ion C l − prevails among the negative ions in seawater. Therefore, the data of chlorides can be assumed for activity coefficients of the positive ions N a+ and K + . The activity coefficients of the negative ions C l − and SO4−2 can be estimated in reference to the predominant positive ion N a+ . The positive ionic reference substances were assumed for the elements from the first column of the periodic system and for the monocharged and bicharged negative ions formed from acids. The elements from the second column of the periodic system appear in seawater in the form of positive bicharged ions, however, they are not recommended as R.S., because the so calculated standard chemical exergy of the elements leads to negative values of chemical exergy of some solid compounds common in the earth’s crust. 150 THERMODYNAMIC 5.2.3 Update of Szargut’s R.E. MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES Next, Szargut’s R.E. will be updated with the help of new geochemical data and the information provided by other authors such as Ranz [276] or Rivero [281]. 5.2.3.1 Update of the standard chemical exergy of chemical compounds The only variable included in Eq. 5.1 that is subject to be updated is ∆G f . The Gibbs free energy used by Szargut [336] was revised by Rivero [281] using [258], [391], [194], [19] and [399]. No substantial differences were found, except for sillimanite (Al2 SiO5 ), whose new value was ∆G f = 2440, 9 kJ/mole. The information source of Ranz [276] for obtaining ∆G f , was Faure [94], which is a compilation of the literature from several authors. This source corroborates Rivero’s revision and thus, it will be considered for the calculation of this particular R.E. 5.2.3.2 Update of the gaseous reference substances Rivero and Garfias [281] accepted the reference pressure of Eq. 5.2 according to the conventional unit “physical atmosphere”, thus 101,325 kPa. We are assuming the mean partial pressure calculated by Szargut and used by Ranz [276], which is the really appearing mean value and is equal to 99,31 kPa. 5.2.3.3 Update of the solid reference substances The mean molar concentration of the elements in the upper continental crust ε j of Eq. 5.3 used in Szargut [336], was the recommended by Polanski and Smulikowski [268]. Ranz [276] used updated values mainly from Taylor and McLennan [354], [353]. For the elements: Br, C, C l, F , S, P t, Pu, Ra, Rh, Ru, Te, I, H g and N , Taylor and McLennan did not provide any information, therefore, Ranz used the values given by Wedepohl [404] for S, Br, C, F , I, H g, N and for the remaining elements, the values used by Szargut [336]. Some authors like Plank and Langmuir [267] basing on their studies on marine sediments, suggested already in 1998 some revisions of the estimated values by Taylor and McLennan [354], [353] for N b, Cs,T i, Ta. As a consequence, McLennan [215] published in year 2001 new mean molar concentrations of the upper continental crust for the elements: Sc, T i, V , C o, N i, N b, Cs, P b, Ta. The most recent data about the chemical composition of the upper continental crust has been published by Rudnick and Gao [292], taking into account the studies published so far. The recent values provided by Rudnick and Gao will be used for the update of Szargut’s R.E. Nevertheless, values for Pu and Ra that are not provided in their tables, will be assumed to be the ones given by Polanski [268]. The reference environment 151 As explained in chapter 3, Grigor’ev published in year 2000 [125] the average mineral content of the upper continental crust obtained through a great number of quantitative mineralogical analysis of important rocks. In 2007, Grigor’ev updated this information; the new analysis comprises 265 minerals, their varieties and their non-mineral materials, corresponding to 99,13% of the total mineral content of the upper continental crust. With this valuable information, we have been able to propose a new model of the continental crust, based on Grigor’ev’s composition, but assuring the mass balance of the earth. This information allows to obtain directly the standard molar concentration of the following 14 reference substances in the solid environment without using Eq. 5.3: Al2 SiO5 , BaSO4 , Be2 SiO4 , C aCO3 , Au, Fe2 O3 , M g3 Si4 O10 (OH)2 , M nO2 , SiO2 , S r CO3 , T hO2 , SnO2 , T iO2 , Z rSiO4 . For the rest substances, Eq. 5.3 must be used, taking ε j from the latest geochemical publications explained before. For the fraction of the j-th element appearing in the form of reference species (coefficient c j ), Szargut [335] associates values comprised between 0,5 for more abundant substances and 0,001 for less frequent substances from geochemical data given by Polanski and Smulikowski [268]. Ranz [276] obtained more accurate c j coefficients for solid R.S. containing the most abundant elements in the upper continental crust. For this purpose, she used the mineralogical composition of the earth’s upper layer obtained with the CIPW norm before and updated geochemical information, mainly from Taylor and McLennan [354]. For minority elements, due to the lack of information, Szargut’s [335] values were used. As long as a better mineralogical composition of the earth’s crust is not developed and the c j coefficients are recalculated with this information, we will assume the c j values obtained by Ranz [276]. The mean molecular mass of the upper layer of the continental part of the earth’s crust, was first estimated by Szargut [334]. The obtained value was M Wcr = 135,5 kg/kmole, applying the following estimation method: according to the geochemical data, the mean concentration values (in mole/kg) of particular chemical groups or elements in the external layer of the continental earth’s crust and the chemical compound formed from these groups were assumed. The first considered group was CO2 , which appears in the earth’s crust mainly as the carbonates of C a, M g and Fe. Per 1 mole of (C aO + M gO + FeO) 0,035 mole of CO2 is present. The group CO2 was partitioned between the mentioned groups and elements Z n, Cu, P b and C d, appearing also in the form of carbonates. The group SO3 was partitioned between C aO and M gO forming sulphates. It was assumed that a prevailing part of metals (Sn, C o, M n, Fe, N i) appears in the form of different oxides (C o2 O3 , C o3 O4 , Fe2 O3 , Fe3 O4 ). It was also assumed that 8% of Fe appears in the form of the free oxide Fe2 O3 . The remaining part appears in the form of FeT iO3 , FeC r2 O3 and silicates. For example, the following silicates were assumed: N aAlSi3 O8 , KAlSi3 O8 , N aFeSi2 O6 , M gSiO3 , C aO.Al2 Si2 O7 . Because of the large content of SiO2 , a considerable part of it was assumed in the free form. After estimating the composition of a mean sample of the lithosphere, its molecular mass was calculated. 152 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES Ranz [276] updated the molecular mass of the upper continental crust using more recent geochemical information and adopting not only a geochemical approach, but also a geological one. The methodology used was as follows: the international accepted norm CIPW [262] was applied to the mass fractions of the principal oxide groups obtained by Carmichael [49] for the cratonic and sedimentary layers, in order to redistribute the chemical components from the oxides to the mineral molecules that are representative in real minerals appearing in a rock. Next, the minerals of the norm and their respective relative masses were modified to adjust them to the real volumes of the principal groups of each rock. Finally, their molar fractions were calculated and the mean molecular mass of the whole was obtained. The resulting M Wc r was equal to 145,5 g/mole. Even though this methodology used better geochemical values than the ones in Szargut [334], and included the geological approach, we cannot forget that the CIPW norm is an artificial way to obtain the possible minerals that can appear in a rock. It is therefore only an approximation as well. In the light of Grigor’ev’s analysis, a more accurate molecular weight of the upper continental crust, based on experimental results rather than assumptions, can be easily obtained. The new calculated value is M Wcr = 142,1 g/mole, which is very close to the estimation done by Ranz. Our model threw up a mean molecular weight of the upper crust of M Wc r =155,2 g/mole. 5.2.3.4 Update of the liquid reference substances Rivero and Garfias [281] have found the influence of salinity of seawater on the calculated values of standard chemical exergy of elements calculated by means of reference substances dissolved in seawater. However, an increased salinity (greater than 35 per thousand) appears seldom (Red Sea), and the deviations are not large (usually less than 1,6%). Every introduction of solid reference substances can decrease the accuracy of calculations. Therefore we are assuming the solid reference substances only for the elements from the second column of the periodic system. Following ionic and molecular reference substances dissolved in seawater have been accepted in the recent publication of Szargut [338] and will be used for this proposal: C l − , Ag C l2− , B(OH)3 (aq), BiO+ , Br − , C d C l2 (aq), Cs+ , Cu+2 , H PO4−2 , HAsO4−2 , H g C l4−2 , IO3− , K + , Li + , M oO4−2 , N a+ , N i +2 , P bC l2 (aq), Rb+ , SO4−2 , SeO4−2 , W O4−2 , Z n+2 . Major ions in seawater are ions with fractions greater than 1 ppm. The seawater reference environment taken into account in this proposal comprises the following major ions: N a+ , K + , HAsO4−2 , BiO+ , C l − , SO4−2 , Br − , B(OH)3 . Values of the activity coefficients and molarity of these species basing on information presented in Millero [224], [225], Pilson [264] and Mottl [231] were reviewed and compared with those which Ranz and Rivero took into account. The reference environment 5.2.3.5 153 The updated reference environment. Results Table 5.4 shows the results obtained in this study for the chemical exergy of the elements with the geochemical information of the crust (M Wcr and z0i ) obtained in this PhD (This study 1) and the one provided by Grigor’ev [127] (This study 2). The solid R.S. assumed are those taken by Szargut [336], basing on the Szargut’s criterion mentioned before. Additionally, the values are compared to those given by Szargut [336], Valero, Ranz and Botero [371] and Rivero and Garfias [281]. The different reference substances divided into liquid, gaseous and solid R.S. and the values required for the calculations are shown in tables A.13, A.14 and A.15 in the appendix, page 384. The average difference between our study (1) and Szargut’s values is around 0,66% on average, while between study (2) with Grigor’ev’s model and Szarguts’, about 0,93%. Hence, in both cases, the average differences are very small. Nevertheless, small differences multiplied by huge numbers, such as the quantity of all minerals on earth, make these discrepancies to be not so insignificant. Next, each of the three subsystems (gaseous, liquid and solid R.S.) is analyzed, stressing the biggest differences found in the different models. The obtained values for gaseous R.S. are the same of those obtained by Szargut [336] and Valero, Ranz and Botero [371], since the methodology and the values used for this R.E. have been the same. The differences between this study (1) and (2) and that of Rivero and Garfias [281] are due to the different partial pressures in the atmosphere assumed. The new chemical exergies obtained differ in 0,5% in average for study (1) and 1% for study (2) with respect to the values obtained by Szargut in [336] for solid reference substances. Taking the empirical standard molar concentration of solid R.S. from our model instead of obtaining it with Eq. 5.3, implies a difference in the element chemical exergy of about 0,2% except for Au (9,5%) and F (6,7%). For the latter elements, the greater difference is due to the greater sensitivity of Au to x i (since its ∆G f is equal to zero) and the great proportion of atoms of C a in the reference substance of F (C aF2 ), respectively. It must be stressed that choosing a certain c j or another a 100 times greater, throws less differences in the chemical exergy of the elements than choosing another R.S., as can be seen in the models of Valero et al. [371] and Rivero et al. [281], when other R.S. are considered. The same thing happens with the molecular weight of the earth’s crust. An M Wcr of 142,1 or 155,2 only modifies the chemical exergy of the elements in 0,03%, and hence that parameter is not crucial at all. For the liquid R.S., with the exception of SO4−2 the differences are negligible from the point of view of the influence on the final exergy of the considered element. In the case of SO4− , Szargut and Valero et al. assumed a value of mSO−2 = 1,17E-2, and 4 Rivero mSO−2 = 1,24E-2. The molarity calculated basing on the three independent 4 sources [225], [264] and [231] is estimated as mSO−2 = 2,93E-2 and is almost 2,5 4 154 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES times greater. This difference decreases the chemical exergy of sulfur only about 2 kJ/mole. The rest of the obtained results are very similar to previous investigations and the differences are negligible. Table 5.4: Standard chemical exergies of the elements Element Ag Al Ar As Au B Ba Be Bi Br2 C Ca Cd Ce C l2 Co Cr Cs Cu Dy Er Eu F2 Fe Ga Gd Ge H2 He Hf Hg Ho Standard chemical exergy of the elements, bch j (kJ/mole) This study This study Szargut Valero et al. Rivero et al. 1 2 [336] [371] [281] 69,7 69,7 70,2 70,3 R.S.=AgC l 99,3 794,3 795,8 888,2 R.S. =Al2 O3 795,7 796,7 11,7 11,7 11,7 11,7 11,6 494,1 494,1 494,6 R.S.=As2 O5 492,6 411,5 51,5 56,4 50,5 53,4 50,6 628,6 628,6 628,5 628,5 628,1 765,5 777,2 775,1 774,3 775,4 602,6 606,4 604,4 R.S.=BeO 604,3 615,6 274,8 274,8 274,5 274,6 274,8 101,1 101,1 101,2 101,3 101,0 410,3 410,3 410,3 410,3 410,3 723,8 719,9 729,1 R.S.=C a2+ 729,1 712,4 293,2 293,2 293,8 293,8 R.S.=C dCO3 298,4 1054,2 1054,5 1054,6 1054,4 1054,7 124,2 124,2 123,6 123,7 123,7 308,9 308,6 312,0 R.S.=C o3 O4 313,4 270,4 584,4 584,5 584,3 R.S.=C r2 O3 584,4 559,1 404,5 404,5 404,4 404,6 404,6 134,0 134,0 134,2 134,2 R.S.=CuCO3 132,6 974,9 975,1 975,9 975,3 976,0 973,0 973,2 972,8 973,1 972,8 1003,9 1004,1 1003,8 1004,4 1003,8 556,1 595,5 504,9 R.S.=C aF2 505,8 482,7 376,8 377,1 374,8 374,8 374,3 514,6 514,7 514,9 514,7 515,0 969,9 970,1 969,0 969,6 969,0 556,5 556,7 557,6 556,3 557,7 236,1 236,1 236,1 236,1 236,1 30,4 30,4 30,4 30,4 31,3 1061,3 1061,5 1062,9 1061,3 1063,1 114,8 114,8 115,9 115,9 R.S.=H gC l2 107,9 979,3 979,5 978,6 979,5 978,7 Continued on next page . . . The reference environment Table 5.4: Standard chemical exergies of the elements – continued from previous page Element I2 In Ir K Kr La Li Lu Mg Mn Mo N2 Na Nb Nd Ne Ni O2 Os P Pb Pd Pr Pt Pu Ra Rb Re Rh Ru S Sb Sc Se Si Sm Sn Sr Ta Tb Te Th Ti Tl Standard chemical exergy of the elements, bch j (kJ/mole) This study This study Szargut Valero et al. Rivero et al. 1 2 [336] [371] [281] 175,0 175,0 174,7 174,8 175,7 437,4 437,5 436,8 437,6 436,9 256,1 256,4 246,8 256,5 247,0 366,5 366,5 366,6 366,7 366,7 34,4 34,4 34,4 34,4 34,3 994,3 994,5 994,6 994,5 994,7 392,9 392,9 393,0 393,0 392,7 946,6 946,9 945,7 946,7 945,8 629,6 629,4 626,1 R.S.=M g +2 626,9 611,0 484,6 490,1 482,0 482,9 487,7 730,5 730,5 730,3 730,3 731,3 0,7 0,7 0,7 0,7 0,7 336,6 336,6 336,6 336,7 336,7 900,2 900,3 899,7 899,4 899,7 969,8 970,0 970,1 970,1 970,1 27,2 27,2 27,2 27,2 27,1 232,5 232,5 232,7 232,7 R.S.=N iO 242,6 4,0 4,0 4,0 4,0 3,9 370,8 371,0 368,1 369,8 368,4 861,6 861,6 861,4 861,4 861,3 232,2 232,2 232,8 232,8 R.S.=P bCO3 249,2 145,7 145,9 138,6 146,0 138,7 963,8 964,1 963,8 964,0 963,9 146,5 146,7 141,0 140,9 141,2 1099,7 1099,9 1100,0 1099,8 1100,1 825,8 826,1 823,9 823,7 824,2 388,8 388,8 388,6 388,9 388,7 561,3 561,4 559,5 560,3 559,6 183,0 183,1 179,7 176,6 179,7 315,2 315,5 318,6 318,4 318,6 607,3 607,3 609,6 609,6 609,3 437,1 437,2 438,0 438,0 438,2 923,8 923,9 925,2 924,1 925,3 346,7 346,7 346,5 346,5 347,5 854,2 854,1 854,9 854,2 855,0 993,9 994,1 993,6 994,2 993,7 547,6 536,8 551,9 549,2 551,8 758,8 773,6 749,8 748,6 749,8 974,8 975,0 974,0 973,8 974,1 999,0 999,2 998,4 999,4 998,5 326,4 326,6 329,2 329,1 329,3 1214,5 1220,7 1202,6 1202,1 1202,7 904,4 902,0 907,2 902,9 907,2 193,8 194,0 194,9 194,2 194,9 Continued on next page . . . 155 156 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES Table 5.4: Standard chemical exergies of the elements – continued from previous page Element Tm U V W Xe Y Yb Zn Zr 5.2.4 Standard chemical exergy of the elements, bch j (kJ/mole) This study This study Szargut Valero et al. Rivero et al. 1 2 [336] [371] [281] 952,5 952,7 951,7 952,5 951,8 1196,1 1196,3 1196,6 1196,2 1196,6 721,5 721,6 720,4 722,2 721,3 827,7 827,7 827,5 827,5 828,5 40,3 40,3 40,3 40,3 40,3 966,3 966,5 965,5 966,4 965,6 944,9 945,2 944,3 944,8 944,3 339,0 339,0 339,2 339,2 R.S.=Z nCO3 344,7 1077,4 1080,9 1083,4 R.S.=Z rO2 1083,0 1060,7 End of the table Drawbacks of Szargut’s R.E. methodology As stated in section 5.2, the R.E. can be considered as one, in which all the substances contained in it have reacted, dispersed and mixed. Such an environment, would have probably a hydrosphere with a composition of groundwaters, rivers, lakes, etc. similar to that of the sea. The atmosphere would have a much greater CO2 and other pollutant’s content than it does now, due to the complete burning of fossil fuels. And the continental crust would have likely a very similar composition to the current one (except for the absence of fossil fuels), but completely dispersed with no enriched mineral deposits. Szargut’s and subsequent reference environments are composed of only one reference substance per element, i.e. 85 R.S. Obviously a degraded earth would contain many more substances. Additionally, the variables used in Szargut’s and subsequent models are based on current and not eventual values1 . Furthermore, many minerals that are more stable than the R.S. have negative exergies. This fact occurs not that often than with Ranz’s abundance criterion, but it still happens, as we will see later in chapter 6. A chemically inactive R.E. would be the one created by Ahrendts [4] and further developed by Diederichsen [74]. In both models the positiveness of any substance is assured. But as stated before, these reference environment’s compositions are far removed from the currently known and from an eventually degraded earth. 1 For instance partial pressures of gaseous R.S., temperatures or molalities are taken as those appearing currently in the atmosphere and the sea. The exergy of mineral resources 157 Hence, the reference environment based on Szargut’s criterion should not be considered as a dead R.E., but rather as a mathematical tool for obtaining standard chemical exergies of the elements. Furthermore, it is always subject to updates, as new geochemical information is more available. 5.3 5.3.1 The exergy of mineral resources The energy involved in the process of formation of a mineral deposit As stated in Ranz’s PhD [276], a mineral deposit can be seen as a very unfrequent aggregates of rocks, which in turn rocks are aggregate of minerals, and these are aggregates of certain molecular substances, which are composed by aggregates of atoms. This definition can be summarized as in Eq. 5.7: P PP Deposi t = r ocks = miner PPP PPP P als = mol ecul es = at oms (5.7) Each aggregate is characterized by two different properties: a cohesion energy or binding energy, represented by its enthalpy of formation, and the entropy of the mixture or of formation, which indicates the probability degree of forming the substance under consideration. The four steps implicated in the formation of the mineral deposit are outlined as follows [276]: Step I: Step II: Step III: Step IV: Formation of the molecule: Σ Atoms (g) → Molecule (g)+ ∆ H, ∆ S Solidification: Molecule (g) → Molecule (s)+ ∆ H, ∆ S Solid 1 + Solid 2 → Mineral+ ∆ H, ∆ S Formation of the deposit: % Mineral + Rocks → Mine + ∆ H, ∆ S The first two steps are basically chemical processes, in which the energies involved are determined by the change of enthalpy and entropy that accompanies the formation of 1 mole of a substance from its constituent elements. The solidification energy is much smaller than the thermodynamic process of formation of the mineral. Usually, the process of formation of a mineral proceeds directly to its solid phase. The third step is subdivided into two processes: mineralization and formation of the rock. The mineralization stage is a chemical process, in which the molecules combine to form the mineral. The formation of the rock is a physical process, where the solids (or minerals) are mixed to form a conglomeration. The general expression for the entropy generated in a mixture process of two ideal gases, solids or liquids is expressed as in Eq. 5.8. ∆S = ∆S1 + ∆S2 = −n1 R̄ Z x1 P P dP P Z x2 P − n2 R̄ P dP P = −R̄ n1 l nx 1 + n2 l nx 2 (5.8) 158 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES Generally, the generation of entropy in mixtures, and especially in solid solutions, is much smaller than that for thermal exchanges associated to the formation of the compound, temperature increases or phase changes. Finally, the fourth step deals with the formation of the mineral deposit. Mineral deposits have the special feature that contain certain minerals at much greater concentrations than in the earth’s crust. According to Faber [90], if the resource of a mineral deposit at a concentration x i is extracted, the entropy will decrease, and the entropy change per mole of the resource is given by Eq. 5.9. (1 − x i ) ∆S = R̄ l nx i + l n(1 − x i ) < 0 xi (5.9) According to the second law of thermodynamics, this negative entropy flux is only possible if there is another system to which it flows. Hence, an external energy supply is needed. The standard energy involved in separating the resource from the mineral deposit is then the concentration exergy bc , in kJ/mole: (1 − x i ) bc i = −R̄T 0 l nx i + l n(1 − x i ) xi (5.10) where R̄ is the universal gas constant (8,314 kJ/kmole K), T 0 is the standard ambient temperature (298,15 K) and x is the molar concentration of the substance. Additionally to the concentration exergy, which accounts for a minimum, the binding forces in the formation of the crystal should be accounted for [276]. The bonds generated are of different nature. 1) Covalent or ionic bonds, forming a threedimensional crystalline structure. In the absence of crystalline defects, the energy needed to separate them is equal to the interatomic bonding energy. 2) Cohesion of interphase forces and capillarity suction, which is commonly found in the agglomeration of a solid by a liquid, acting as an adhesive cement. 3) Intermolecular and electrostatic forces, binding very thin particles. 4) Mechanical interpenetration of particles, typically formed by compression. The energy needed to separate a solid particle from others of smaller size depend on different physical aspects such as size, hardness or surface area. Some expressions have been developed for relating the particle size with the grinding energy. Kicks’s law or Bond’s law are two of those studies (see for instance, [259] for more details). Both laws indicate that the grinding energy increases exponentially as the particle size decreases. As we will see in later sections, the chemical energies involved in the formation of the deposit are considerably higher than the physical energies explained in this last step. The exergy of mineral resources 5.3.2 159 The exergy of non-fuel mineral resources The thermodynamic value of a natural resource can be defined as the minimum work necessary to produce it with a specific structure and concentration from common materials in the environment. This minimum amount of work is theoretical by definition and is equal to the material’s exergy (Riekert [278]). The exergy of a system gives an idea of its evolution potential for not being in thermodynamic equilibrium with the environment, or what is the same, for not being in a dead state related to the reference environment (R.E.). The physical features that make minerals valuable are mainly their specific composition and the greater concentration in the ores in which they are found [371]. The energy involved in the process of formation of a mineral comprises the formation of the compound from its elements, and the cohesion of the molecules to form the mineral’s crystal structure (step 1 to 3 in section 5.3.1). The minimum theoretical work that nature should invest to provide minerals at a specific composition and structure from a degraded earth is equal to the standard chemical exergy [336] and it can be calculated by means of the exergy balance of a reversible formation reaction as in Eq. 5.1. bch i = ∆G f i + X r j,i bch j j Once the mineral has been created, it mixes with other minerals to form rocks, which in turn, are combined with other rocks forming the deposit (step 4 in section 5.3.1). The minimum theoretical work needed to concentrate a substance from an ideal mixture of two components is given by the concentration exergy (bc ), as in Eq. 5.10. The binding energy between minerals and rocks is not considered in the ideal case. Therefore, the exergy needed to separate the minerals from the deposit is the same as the exergy to mix them. Nevertheless this binding exergy is taken into account through the unit exergy costs explained in section 5.3.4. The difference between the concentration exergies obtained with the mineral concentration in a mine (x m )2 and with the average concentration in the earth’s crust (x c ) 3 is the minimum energy that nature had to spend to bring the minerals from the concentration in the reference state to the concentration in the mine. The concentration exergy of a mineral in a completely degraded planet is zero, and it increases, as its concentration increases. The work needed to separate a substance from a mixture does not follow a linear behavior with its concentration. On the contrary, the second law of thermodynamics, reflected in Eq. 5.10 and represented in Fig. 5.1 dictates that the effort required to separate the mineral from the mine follows a negative logarithmic pattern with its ore grade. This means that as the ore grade 2 3 x m replaces x in Eq. 5.3.4 for obtaining the concentration exergy of the mineral in the mine x c replaces x in Eq. 5.3.4 for obtaining the concentration exergy of the mineral in the R.E. 160 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES 35 bc, MJ/kmole 30 25 20 15 10 5 0 0,00001 0,15 0,4 0,65 0,9 xi Figure 5.1. Exergy required for separating a substance from a mixture, according to Eq. 5.10. tends to zero, the energy needed to extract the mineral tends to infinity. Right that component of the mineral’s exergy is what makes exergy a more realistic measure of magnitude than mass, for instance [392]. Furthermore, it invalidates the statement of Brooks and Andrews [41] that exhaustion of minerals is ridiculous because the entire planet is composed of minerals. The energy that nature saves us when concentrating minerals in high grade ores, is too elevated to reproduce it with current technology. The unit exergies are converted into absolute ones (here denoted by Bch and Bc ), by multiplying bch and bc with the moles of the resource under consideration (n). The sum of Bch and Bc , indicates the total exergy of the mineral deposit (B t ), including the chemical and concentration components (see Eq. 5.11). B t i = ni · bch i + ni · bc i = Bch i + Bc i 5.3.3 (5.11) The chemical energy and exergy of fossil fuels Fossil fuels are a type of minerals and therefore, their chemical and concentration exergies can be calculated with Eqs. 5.1 and 5.10. Liquid and gaseous fuels have the particularity, that their quality (grade) keeps nearly constant with extraction, The exergy of mineral resources 161 whereas solid minerals don’t (mineral’s concentration decreases as the deposit is being exploited). Hence, for those cases, the concentration exergy is not so relevant than with other types of mineral resources and it will not be taken into account for our calculations. Furthermore, the value of fuels is tightly related to its chemical exergy content. The heterogeneity and complexity of the chemistry of fuels make the chemical exergy to be very difficult to predict with Eq. 5.1. But different thermodynamic models have been proposed to calculate the exergy of fossil fuels. Stepanov [330], compiles some of the different methodologies proposed. Rant [275], for instance, calculated the ratios of exergies to heating values and then estimated average values of these ratios for liquid and gaseous fuels4 . Szargut and Styrylska [342] corrected Rant’s formulas by taking into consideration the chemical composition of fuels. Shieh and Fan [310] obtained expressions for the exergy calculation of materials with complex structures. We will focus on the models developed by Valero and Lozano [369] for obtaining the chemical exergy of fossil fuels, but it must be pointed out, that more complex calculation procedures, do not mean more reliable results. Both, the experimental error associated to the determination of the heating values and the error associated to the correlations are comprised reasonably in an interval close to ±2 %. Additionally, it has been largely demonstrated, that the chemical exergy of fuels can, in many cases, be satisfactorily approximated to the HHV. For the case of gaseous fuels, Valero and Lozano [369], showed that the chemical exergy can be estimated as the exergy of a mixture of ideal gases (Eq. 5.12). bch g as = X 0 x i (bch i + R̄T0 l nx i ) (5.12) 0 Where x i is the molar fraction of the chemical substance i and bch is the standard i chemical exergy of substance i. The exergy for gaseous fuels can thus be calculated with Eq. 5.12, or with the general methodology applied to liquid and solid fuels, explained next. The procedure is based on the general molecular formula of Eq. 5.13. C HhOo Nn Ss + Ww + Zz (5.13) Where W represents the moles of liquid water (moisture) and Z of the ashes. Coefficients h, o, n, s, w and z are the moles of elements H, O, N , S, water and ashes contained in the molecular structure of the fuel, per mole of C content, respectively: h= H 12,011 C 1,008 o= O 12,011 C 15,999 n= N 12,011 C 14,007 s= S 12,011 C 32,064 w= W 12,011 C 18,015 z= Z 12,011 C 1,000 4 The ratios determined by Rant were 0,975 for liquid fuels and 0,95 for gaseous fuels. This indicates that the chemical exergy is very close to the high heating value of the substance. 162 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES Note that W and Z apply only to solid fossil fuels and s = 0 in gaseous fuels. The standard average energy and exergy of the fuel on a molar basis is then: e0f uel = eC0 H h Oo Nn Ss 0 + ze0Z + weW (5.14) b0f uel = bC0 H h Oo Nn Ss 0 + z b0Z + w bW (5.15) And ei0 and bi0 are calculated as follows: ei0 = ∆H 0f ,i − X bi0 = ∆H 0f ,i − T 0 si0 − f j H j,00 (5.16) X (5.17) f j µ j,00 Where ∆H 0f ,i and si0 are the standard enthalpy and entropy of the fuel, T 0 the standard ambient temperature, f j the elements of the atomic composition vector of the fuel f = [1, h, o, n, s]0 , and H j,00 and µ j,00 the enthalpy and the chemical potential of the elements in the dead state. The atomic composition vector of a gaseous fuel f j,gas , can be obtained with Eq. 5.18: Pn f j,gas = i=1 r j,i · ξi (5.18) d1 Being r j,i the number of atoms j contained in component i of the mixture of gases 5 and ξi the molar composition of substance i in the . The moles of C contained Pfuel n in the fuel is expressed as d1 and is calculated as i=1 rC,i · ξi . The formation enthalpy can be calculated with the high or low heating values (HHV, LHV), using the following expressions: h ∆H 0f , f uel = H H V + ∆H f ,CO2 + ∆H 0f ,(H O) + s∆H 0f ,SO 2 2 l 2 H H V = LH V + h 2 h +w ∆H 0f ,(H 2 O) g − ∆H 0f ,(H i 2 O)l (5.19) (5.20) In case the experimental heating values are not available, they can be approximated through the following expressions: 5 Gaseous fuels are assumed to contain the following 7 gases: C H4 , C2 H6 , C3 H8 , C4 H10 , C5 H12 , N2 and CO2 . The exergy of mineral resources 163 Liquid fossil fuels. Lloyd’s correlation [198] in cal/mole C: H H V = 102720 + 27360 · h − 32320 · o + 19890 · n + 85740 · s (5.21) Solid fossil fuels. Boie correlation [279] in cal/ mole C: H H V = 100890 + 27990 · h − 42400 · o + 21010 · n + 80160 · s (5.22) For gaseous fuels, ∆H 0f can be calculated with the following equation: P ∆H 0f , f uel = ξi · ∆H 0f ,i (5.23) d1 The standard entropy is calculated with the correlations proposed by Ikumi [158] for liquid fossil fuels and those of Eisermann, Johnson and Conger [83] for solid fuels. Liquid fossil fuels, in cal/(mole C· K): s0f uel = 1, 12 + 4, 40 · h + 10, 66 · o + 20, 56 · n + 20, 70 · s (5.24) Solid fossil fuels, in cal/(mole C· K): s0f uel = 8, 88272 − 7, 5231e h −0,56482 1+n + 4, 80748 o 1+n + 12, 9807 n 1+n + 10, 6767 s 1+n (5.25) Gaseous fossil fuels, in cal/(mole C· K): P s0f uel = P ξi si0 − R̄l n( P 0i ) (5.26) d1 The calculation of the enthalpy and chemical potential for each element (H j,00 and µ j,00 ) are calculated with Eqs. 5.27 and 5.28 and depends on the species composing the reference environment. H j,00 = ∆H f , j + ∆C p, j T0 − T 0 µ j,00 = ∆H f , j − T0 ∆s j + ∆C p, j 0 T0 − T − T0 l n T0 T0 + R̄T0 l n (5.27) x j,00 · P0 P0 (5.28) 164 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES Where x j,00 is a vector, including the molar concentration of the gases in the reference environment, ∆H f , j , ∆s j and ∆C p, j are the enthalpy and entropy of formation and the specific heat change of the species in the reference environment required to form the element as in equations 5.29 and 5.30. Subscript 0 denotes the environment, while superscript 0, the standard reference environment. Lozano [201] proposed the three R.E. (I, II and III) shown in table 5.5, for calculating the chemical energy and exergy of the substances: Table 5.5. Composition of the three R.E. proposed (j=1) C ↔(jj=1) (j=2) H ↔(jj=2) (j=3) O ↔(jj=3) (j=4) N ↔(jj=4) (j=5) S ↔(jj=5) (j=6) C a ↔(jj=6) I CO2 (g) H2 O (g) O2 (g) N2 (g) SO2 (g) II CO2 (g) H2 O (l) O2 (g) N2 (g) SO2 (g) III CO2 (g) H2 O (l) O2 (g) N2 (g) C aSO4 · 2H2 O (s) C aCO3 (s) For R.E. I and II, ∆H f , j is calculated as in Eqs. 5.29. The expression for the calculation of ∆s j and ∆C p, j are analogous to that of ∆H f , j . Note that for element H, the enthalpy and specific heat taken for H2 O must be in the gaseous and liquid state for R.E. I and II, respectively. ( j = 1) ∆H f ,C = ∆H f ,CO2 − ∆H f ,O2 ∆H f ,H2 O ∆H f ,O2 ( j = 2) H : ∆H f ,H = − 2 4 ∆H f ,O2 ( j = 3) O : ∆H f ,O = 2 ∆H f ,N2 ( j = 4) N : ∆H f ,N = 2 ( j = 5) S : ∆H f ,S = −∆H f ,O2 + ∆H f ,SO2 C: For R.E. III, the following expressions are valid: (5.29) The exergy of mineral resources ( j = 1) C: ( j = 2) H: ( j = 3) O: ( j = 4) N: ( j = 5) S: 165 ∆H f ,C = ∆H f ,CO2 − ∆H f ,O2 ∆H f ,H2 O ∆H f ,O2 − ∆H f ,H = 2 4 ∆H f ,O2 ∆H f ,O = 2 ∆H f ,N2 ∆H f ,N = 2 (5.30) ∆H f ,S = ∆H f ,CO2 − 2∆H f ,H2 O − ( j = 6) C a : ∆H f ,C a = −∆H f ,CO2 − ∆H f ,O2 2 3∆H f ,O2 2 + ∆H f ,C aSO4·2H2 O − ∆H f ,C aCO3 + ∆H f ,C aCO3 The resolution of Eq. 5.28 is given in table 5.6. 1 1 1 0 0 0 R.E. I R.E. II R.E. III R.E. I R.E. II R.E. III T0 − T 0 − T0 l n 0 0 0 0 0 -1 T 0 T0 0 0 -194398 Ca 0 0 0 0,5 0 0 2,259 7,245 7,245 H O N S ∆C p, j , cal/(mole K) 3,508 3,481 2,515 3,508 3,481 2,515 3,508 3,481 -12,717 e2 0 0 0 0 0 0 0 0 0 e5 0 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 1,702 Ca -98546 -98546 -98546 -1 -1 -1 2,065 2,065 2,065 C -32760 -32767 -32767 -0,25 -0,25 -0,25 10,302 -3,876 -3,876 H O N S ∆s j , (cal/ mole K) 24,502 22,885 10,285 24,502 22,885 10,285 24,502 22,885 -31,77 e3 0,5 0 -1 0,5 0 -1 0,5 0 -1,5 µ j,00 , cal/mol e -7777 -6902 -85372 -7777 -6902 -85372 -7777 -6902 -145967 + R̄T0 l n (x CO2 ,00 · P0 )e1 · (x H2 O,00 · P0 )e2 · (x O2 ,00 · P0 )e3 · (x N2 ,00 · P0 )e4 · (x SO2 ,00 · P0 )e5 0 0 0 0 0 0 1,855 1,855 1,855 C (5.31) 0 0 -173192 0 0 -0,5 0 0 -53,373 Ca τ0 = T0 − 273, 15; F1 = −741, 9242; F2 = −29, 7210; F3 = −11, 55286; F4 = −0, 868535; F5 = 0, 1094098; F6 = 0, 439993; F7 = 0, 2520658 0 Where: e1, e2, e3, e4 and e5 are the exponentials used to calculate the contribution of the entropy change for gaseous reference substances. x j,00 is calculated with the following equations for each gaseous component [11]: x CO2 ,00 = 0, 0003(1 − x H2 O,00 ); x O2 ,00 = 0, 2099(1 − x H2 O,00 ); x N2 ,00 = 0, 7898(1 − x H2 O,00 ); h i P8 1−1 x SO2 ,00 = 10−9 (1 − x H2 O,00 ); x H2 O,00 = Pv,H2 O (T0 ) = 217, 99ex p 0,01 F (0, 65 − 0, 01τ ) (374, 16 − t ) i 0 0 i=1 T O N S ∆H f , j , cal/mole -28898 0 0 -70960 -34158 0 0 -70960 -34158 0 0 -152032 e1 0 0 0 0 0 0 0 0 0 0 0 1 e4 0 0 0,5 0 0 0 0,5 0 0 0 0,5 0 H THERMODYNAMIC µ j,00 = ∆H f , j − T0 ∆s j + ∆C p, j -94052 -94052 -94052 C R.E. I R.E. II R.E. III Element j Table 5.6. Calculation of the chemical potential of the elements according to three different R.E. 166 MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES The exergy of mineral resources 167 If the ambient temperature is different to that of the standard, then bi0 is replaced by bi in Eq. 5.15 (see Eq. 5.32). And bi is calculated with Eq. 5.33. Similarly, ei0 is replaced by ei in Eq. 5.14 and ei is calculated with Eq. 5.34. b f uel = bC Hh Oo Nn Ss + w · bW + z · b Z bi = ∆H f ,i − T0 si − ei = ∆H f ,i − X X f j µ j,00 f j µ j,00 (5.32) (5.33) (5.34) The enthalpy and entropy of the clean fuel and the moisture for liquid and solid fuels is obtained with Eqs. 5.35 and 5.36. ∆H f ,i = si = ∆H 0f ,i si0 + Z + Z T C p (T )d T (5.35) T0 T T0 C p (T ) T dT (5.36) The specific heat for liquid fuels at a density of 15◦ C (ρ15 ) comprised in an interval between 0,75 and 0,96 k g/d m3 , can be obtained through Eq. 5.37 in cal/(kgK) [258]. 1 C p,L (T ) = p (181 − 0, 81T ) ρ15 (5.37) The specific heats in cal/(kgK) for the clean solid fuel, the moisture W and the ashes Z are calculated with the correlations of Kirov6 [258]: C p,F (T ) = −52 + 0, 909T − 0, 420 · 1−3 T 2 (5.38) C p,W (T ) = 703 + 0, 632T + 9, 610 · 106 /T 2 (5.39) C p,Z (T ) = 142 + 0, 140T (5.40) The exergy of the ashes Z is obtained directly through Eq. 5.41: 6 Note that C p,L , C p,F and C p,W must be converted into cal/mole K for the calculation of the enthalpy and entropy. 168 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES bZ = T Z 1− CZ T0 T0 (5.41) dT T The enthalpy of gaseous fuels can be calculated with Eq. 5.42: Pn ∆H f ,i = ∆H 0f ,i + i=1 x i h∗i (T ) − h∗i (T 0 ) (5.42) d1 Where h∗i (T ) is obtained with the help of the method of Zelenik and Gordon [413]: h∗i (T ) = RT a1 + a2 T 2 + a3 T2 3 + a4 T3 4 + a5 T4 5 + a6 (5.43) T The entropy of the gaseous fuel can be calculated with Eq. 5.44: Pn s= i=1 P x i si∗ (T ) − Rl n P 0i (5.44) d1 Where si∗ (T ) is obtained through [413] with Eq. 5.45 si∗ (T ) = R a1 l nT + a2 T + a3 T2 2 + a4 T3 3 + a5 T4 4 + a7 (5.45) Coefficients a1 through a7 for the calculation of h∗ (T ) and si∗ (T ) are provided in table A.16 in the appendix for the different gases composing the gaseous fuel. From Eqs. 5.17 through 5.32, one can conclude that the exergy of fuels is a function of the conditions of the ambient. This means, that if the temperature, pressure or the concentration of for instance CO2 change, the exergy of fuels will do so accordingly. 5.3.4 The exergy costs The sum of the chemical and concentration components defined previously in section 5.3.2 represents the total exergy that can be understood as the minimum energy required for restoring the resource from the reference environment. As stated before, fuel minerals are useful for their inherent chemical exergy. Consequently, the value associated to fossil fuels is tightly related to its exergy. However, non-fuel minerals are not necessarily useful for their chemical exergy content. The value of a non-fuel mineral resource is rather associated to the extraction costs. A very abundant and concentrated mineral in the crust, such as iron, will have a high exergy value and a low exergy cost of extraction. On the contrary, a very dispersed The exergy of mineral resources 169 and scarce mineral such as gold, has a low exergy value, but a very high exergy cost of extraction. Obviously, the cost is a very important ingredient of the final price in the market and that is why scarce minerals tend to be the most expensive ones. The exergy replacement cost (B ∗ ) of minerals measures something similar to their natural cost. It was defined by Valero et al. [370] as the exergy required by the given available technology to return a resource from the dispersed state of the reference environment, into the physical and chemical conditions in which it was delivered by the ecosystems. Actual energy requirements to obtain a resource are always greater than those dictated by the second law. For instance, the thermodynamic energy required to separate two substances such as sugar and salt, is equal to the energy to mix them, which is in fact very low. This is the reason why concentration exergies of minerals are usually one order of magnitude greater than chemical ones. However, current processes are far from ideal conditions because of inefficiencies of our technology resulting in irreversibilities. In order to overcome that problem, we must include the actual physical unit costs, here named as unit exergy replacement costs, in the thermodynamic evaluation of resources. Valero et al. [370] defined them as the relationship between the energy invested in the actual process for obtaining the resource and the minimum energy required if the process were reversible. Unit exergy replacement costs are dimensionless and measure the number of exergy units needed to obtain one unit of exergy of the product. The actual exergy value of a resource (total exergy replacement cost) B ∗ is determined then by the sum of Bc and Bch multiplied respectively by the unit exergy replacement costs of the processes to obtain it (kch and kc ) as in Eq. 5.46. B ∗t = kch · Bch + kc · Bc (5.46) Where kc is the physical unit exergy replacement cost of concentration, calculated as the ratio between the real energy invested in the process and the minimum concentration exergy (Bc ). It has to be determined for each type of mineral. It is assumed that the same technology is applied in all concentration ranges, including the range between the concentration of the reference environment and the average concentration in the mineral deposits. And kch is the physical unit exergy replacement cost of the refining process, calculated as the ratio between the real energy invested in the process, and the minimum chemical exergy (Bch). As opposed to kc , the chemical unit cost of refining a mineral from the mine to the metallic state cannot be applied to the process of refining the mineral from the R.E. to the mine, due to the differences of both processes. However, once the refining costs of mineral oxides and sulfides were analyzed, Valero and Botero [371] realized that on average, the energy expenditure for obtaining a ton of the pure element from the oxide was about 80 GJ greater than from the sulfide. This 170 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES is as if sulfides would have a natural bonus of 80 GJ/ton and a chemical unit exergy replacement cost kch of 10 on average. On the other side, oxides and monatomic minerals are assumed to have a kch at least equal to one. The contribution of the chemical and concentration components to the actual exergy value of a resource is usually well balanced, since unit chemical exergy costs are one or two orders of magnitude smaller than unit concentration exergy costs. Note that it has no sense to apply exergy replacement costs to fossil fuels, due to the impossibility of current technology to replace the photosynthetic process that once created the resource. Table 5.7 shows the unit exergy replacement costs of some minerals, according to Valero and Botero [371], which in turn were improved from the initial ones given by Botero [34]. Martínez et al. [207] studied additionally the unit exergy costs for some minerals of industrial importance and updated Botero’s values of aluminium, gold, iron, zinc, lead, copper, nickel and silver. Table 5.7: Exergy costs of selected substances [371] & [207] Substance Ag Al As Au Ba Be Bi Cd Co Cr Cs Cu F Fe Ga Ge Hf Hg In K Li Mg kc 7042 2250 80 422879 N.A. 112 90 804 1261 37 N.A. 343 2 97 N.A. N.A. N.A. 1707 N.A. 39 158 1 kch 10 8,0 10 1 1 1 10 10 10 1 1 80,2 1 5,3 1 1 1 10 10 1 1 1 Substance Mn Mo Na Nb Ni P Pb Pt Re Sb Se Si Sn Ta Te Ti U V W Zn Zr kc 284 947 38 N.A. 432 44 219 N.A. 1939 28 N.A. 2 1493 12509 N.A. 348 7723 572 3105 126 7744 kch 1 1 1 1 58,2 1 25,4 1 10 10 1 1 1 1 1 1 188,3 1 1 13,2 1 Exergy replacement costs represent a suitable indicator for assessing the value of non-fuel mineral resources, as they integrate in one parameter, concentration, composition and also the state of technology. Nevertheless, as opposed to exergy, they The exergy of mineral resources 171 cannot be considered as a property of the resource, since unit exergy costs introduce to some extent an uncertain factor to the calculation. Something similar happens to the emergy analysis, explained in section 1.3, through the introduction of the transformities. It should be noted that as stated by Naredo and Valero [239], unit exergy replacement costs are a function of the state of technology and hence vary with time. A way to assess the evolution of technological development, is through the theory of learning curves. With learning-by-doing, increases in material and energy efficiency increase with cumulative production. Alchian [5] was the first to estimate the effects of cumulative production on changes in efficiency. He found a linear relationship between the logarithm of direct labor inputs per unit output and the logarithm of cumulative production, as in Eqs. 5.47. l n j(t) = a j1 − a j2 l nΓ(t) l ne(t) = ae1 − ae2 l nΓ(t) (5.47) With j(t) and e(t), the flows of materials and energy used to perform a certain process; a j1 and ae1 the intercepts of the learning curve with the vertical axes and a j2 and ae2 parameters relating material and energy inputs per unit output at time period t to cumulative production in period t, Γ(t). Ruth [294] argued that such a specification of the learning curves, allows materials and energy input per unit output to approach zero as cumulative production approaches infinity, thus violating thermodynamic lower limits on j(t) and e(t). The expressions of Eqs. 5.48 are according to Ruth more realistic in the sense that material and energy efficiencies decrease asymptotically towards zero in double-log space as Γ(t) approaches infinity. Thus as cumulative production increases, material and energy use per unit output can at best assume the value one, indicating perfect efficiency. l n j(t) = a j1 e x p(−a j2 l nΓ(t)) l ne(t) = ae1 e x p(−ae2 l nΓ(t)) (5.48) In this PhD, we have considered unit exergy replacement costs constant, i.e. we have assumed that the state of technology has been the same throughout the 20 th century. A more exact determination of the exergy costs of minerals throughout history would imply changing unit exergy replacement costs. These could be calculated through the help of the learning curves explained above. But this task remains outside the scope of this PhD and is open for further refinements. 172 THERMODYNAMIC 5.4 MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES Prediction of Enthalpy and Gibbs free energy of formation of minerals The determination of the thermodynamic properties of the substances requires the knowledge of their corresponding enthalpies and Gibbs free energies of formation. Many of these have been already estimated through empirical and semi-empirical processes7 and are tabulated. Comprehensive compilations of the thermodynamic properties of inorganic substances can be found in Faure [94], Wagman [391], Robie et al. [284], [285] or Weast et al. [400]. Unfortunately, not all the enthalpies and Gibbs free energies of the minerals that we have taken into account in our model are recorded in the literature. Nevertheless, many of them can be predicted satisfactorily through different semi-empirical methods. In the next sections, the estimation methods of the thermodynamic properties used to obtain the standard enthalpy and Gibbs free energy of formation of the minerals in the model of the upper crust developed in chapter 3 will be provided. 5.4.1 Calculation of ∆H 0f or ∆G 0f from s0 If either ∆H 0f or ∆G 0f and the entropy (s0 ) of the mineral under consideration are available, the unknown property can be easily calculated applying Eq. 5.49. ∆G 0f = ∆H 0f − T0 · ∆S (5.49) Where the entropy change ∆S is calculated from the standard entropy of the mineral and its constituent elements in the standard state (T0 = 298, 15 K and 1 bar), as in Eq. 5.50: 0 ∆S = sminer al − X 0 selements (5.50) Note that this procedure does not have associated any error, since it is based on the definition of ∆G f . Example: for mineral bronzite FeM gSi2 O6 , the enthalpy and entropy of formation is known from [309]: ∆H 0f = −2753, 38 kJ/mole and s0 = 149, 13 J/(mole K). The entropy change of bronzite is calculated as: ∆s FeM gSi2 O6 = s0FeM gSi 2 O6 0 − (s0M g + s0Fe + 2 · sSi + 3 · sO0 ) 2 = 149, 13 − (27, 09 + 32, 67 + 2 · 18, 81 + 3 · 205, 15) = −563, 70 J/(mole.K) 7 Such as calorimetric or solubility measurements. Prediction of Enthalpy and Gibbs free energy of formation of minerals 173 0 Where sel are obtained from [284]. The Gibbs free energy of formation of ements bronzite can be finally calculated with Eq 5.49: ∆G 0f ,FeM gSi 2 O6 5.4.2 = −2753, 38 − 298, 15 · 563, 70 1000 = −2585, 31 kJ/mole The ideal mixing model An ideal solid solution of i components with x i molar fractions obeys the equations: ∆H m = 0 (5.51) and ∆Gm = +RT X (5.52) x i l nx i Where ∆H m and ∆Gm , are the enthalpy and Gibbs free energy of mixing. This means that the ideal mixing will take place without any heat loss or heat production. Moreover, the different cations will be fully interchangeable [254]. The enthalpy and Gibbs free energy of formation of the solid solution is calculated then with Eqs. 5.53: ∆H 0f ,solut ion = X x i ∆H 0f ,i i ∆G 0f ,solut ion = X x i ∆G 0f ,i + RT X x i l nx i (5.53) i The error associated to the assumption of the mineral as an ideal solid solution varies greatly with the mineral under consideration and decreases with the disorder among components. We will assume a maximum error of ±1%. Example: mineral tetradymite Bi2 Te2 S can be considered as a solid solution of Bi2 Te3 , and Bi2 S3 , for which ∆H 0f and ∆G 0f are well known from [226] and [94]: Bi2 Te2 S ⇔ 2 1 Bi2 Te3 + Bi2 S3 3 3 Hence, ∆H 0f ,t et r ad y mi t e and ∆G 0f ,t et r ad y mi t e are calculated as follows with Eqs: 5.53: 174 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES ∆H 0f ,t et r ad y mi t e ∆G 0f ,t et r ad y mi t e 5.4.3 5.4.3.1 = 2 1 · ∆H f ,Bi2 Te3 + ∆H f ,Bi2 S3 3 3 1 2 · (−78, 7) + (−143, 2) = 3 3 = −100, 2 kJ/mole = 2 1 2 2 1 1 · ∆G f ,Bi2 Te3 + ∆G f ,Bi2 S3 + RT ln + ln 3 3 3 3 3 1 8, 314 · (−78, 3) + (−140, 7) + · 298, 15(−0, 63) = 3 3 1000 = −100, 6 kJ/mole 3 2 Assuming ∆G r and ∆H r constant Thermochemical approximations for sulfosalts and complex oxides Craig and Barton [67] developed an approximation method for estimating the thermodynamic properties of sulfosalts in terms of mixtures of the simple sulfides. The ideal mixing model does not apply correctly to most sulfosalts, because the mixtures of layers are rather ordered. The modified ideal mixing model of Craig and Barton involves a mixing term (∆Gm ) in the estimation of the Gibbs free energy of formation of the sulfosalt per gram atom of S that is added to the weighted sum of free energies of the simple sulfides: ∆Gm = (1, 2 ± 0, 8)(+RT X x i l nx i ) (5.54) The mixing term can be divided into two parts, one estimated from the crystal structure as an entropy change, and the reminder as a non-ideal term. The non-ideal term of this model was assumed to be constant for all sulfosalts. However, Vieillard [387] showed that the properties of complex sulfides with respect to their simple sulfides are a function of the electronegativity difference between the cations of the sulfosalt. The thermodynamic properties of sulfosalts may then be calculated by adding a term (∆H r or ∆G r ) to the appropriately weighted sum of the enthalpies or free energies of the simple component sulfides i (Eq. 5.55). ∆H f sul f osal t = X x i ∆H f i + nS sul f osal t ∆H r ∆G f sul f osal t = X x i ∆G f i + nS sul f osal t ∆G r (5.55) Prediction of Enthalpy and Gibbs free energy of formation of minerals 175 The reaction term, which is analogous to the mixing term of Craig and Barton is associated to one atom of sulfur in the mineral (nS,sul f osal t ) and is obtained from a sulfosalt for which its thermodynamic properties and those of its simple sulfides are known. The calculated reaction terms can be applied to a family of sulfosalts formed by the same cations and with partial element substitutions. Example: mineral cubanite CuFe2 S3 can be decomposed into the sulfides CuFeS2 and FeS, for which the thermodynamic properties are provided [226]. The properties of cubanite can be calculated with Eq. 5.55, once ∆H r and ∆G r are known. The reaction terms are obtained from mineral bornite Cu5 FeS4 as follows: ∆H r,Cu5 FeS4 = = ∆H f ,Cu5 FeS4 − ( 25 ∆H f ,Cu2 S + 12 ∆H f ,Fe2 S3 ) 4 (−371, 6) − [ 52 (−83, 9) + 12 (−279, 91)] 4 = −5, 48 kJ/mole S ∆G r,Cu5 FeS4 = (−394, 7) − [ 52 (−89, 2) + 12 (−280, 75)] 4 = −7, 83 kJ/mole S Where the properties of bornite and its constituents are provided in [284] and [241]. Hence, ∆H f and ∆G f of cubanite are calculated as: ∆H f ,CuFe2 S3 = ∆H f ,CuFeS2 + ∆H f ,FeS + 3 · ∆H r = (−176, 8) + (−99, 98) + 3 · (−5, 48) = −293, 22 kJ/mole ∆G f ,CuFe2 S3 = (−178, 49) + (−100, 40) + 3 · (−7, 83) = −302, 38 kJ/mole Vieillard et al. [387] demonstrated the analogy between the electronegativity scale of cations with respect to sulfur and to oxygen. They showed that the methodology of estimation of the thermodynamic properties of sulfosalts from simple sulfides can be equally applied to complex oxides able to be decomposed into simple oxides. As for sulfosalts, the reaction terms ∆H r and ∆G r (for this case denoted as ∆H ox and ∆Go x ) should be obtained for an oxide of the same family of the mineral under analysis. The maximum error associated to this methodology is assumed to be ±1%. 176 5.4.3.2 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES The method of corresponding states Similarly, the ∆H r and ∆G r can be assumed to be constant in the substitution reaction of minerals A-x and B-x into A-y and B-y, if A-x and B-y are isomorphous (Eq. 5.56). The associated error is assumed to be equal to the previous method, hence ±1%. A − x + y → A − y + x (∆H r , ∆G r ) B − x + y → B − y + x (∆H r , ∆G r ) (5.56) Consider mineral fluor-annite K Fe3 (Si3 Al)O10 (F )2 as an example, for which no empirical thermodynamic values are available. Fluor-annite can be formed from hydroxy-annite K Fe3 (Si3 Al)O10 (OH)2 as in the following reaction: K Fe3 (Si3 Al)O10 (OH)2 + 2H F → K Fe3 (Si3 Al)O10 (F )2 + 2H2 O Similarly, fluor-phlogopite can be formed from hydroxy-phlogopite. Since the thermodynamic properties of both substances are known, the reaction energy of substitution can be calculated: K M g3 (Si3 Al)O10 (OH)2 + 2H F → K M g3 (Si3 Al)O10 (F )2 + 2H2 O ∆H r = ∆H 0f ,K M g 3 (Si3 Al)O10 (F )2 + 2∆H 0f ,H 2O − ∆H 0f ,K M g 3 (Si3 Al)O10 (OH)2 − 2∆H 0f ,H F = (−6375, 5) + 2 · (−285, 8) − (−6246, 0) − 2 · (−332, 6) = −17, 9 kJ/mole H F ∆G r = ∆G 0f ,K M g 3 (Si3 Al)O10 (F )2 + 2∆G 0f ,H 2O − ∆G 0f ,K M g 3 (Si3 Al)O10 (OH)2 − 2∆G 0f ,H F = (−6030, 1) + 2 · (−237, 1) − (−5860, 5) − 2 · (−278, 8) = −43, 11 kJ/mole H F Where the thermodynamic properties are obtained from [391]. Fluor-annite can now be calculated, assuming the same reaction energy calculated with phlogopite: Prediction of Enthalpy and Gibbs free energy of formation of minerals ∆H 0f ,K Fe 3 (Si3 Al)O10 (F )2 = ∆H 0f ,K Fe 3 (Si3 Al)O10 (OH)2 + 2∆H 0f ,H F − 2∆H 0f ,H 177 2O + 2∆H r = (−5149, 3) + 2 · (−332, 6) − 2 · (−285, 8) + 2 · (−17, 9) = −5278, 8 kJ/mole ∆G 0f ,K Fe (Si Al)O (F ) 3 3 10 2 = ∆G 0f ,K Fe 3 (Si3 Al)O10 (OH)2 + 2∆G 0f ,H F − 2∆G 0f ,H 2O + 2∆G r = (−4798, 3) + 2 · (−278, 8) − 2 · (−237, 1) + 2 · (−43, 11) = −4967, 9 kJ/mole The thermodynamic properties of hydroxy-annite are obtained from [383]. 5.4.4 The method of Chermak and Rimstidt for silicate minerals The method proposed by Chermak and Rimstidt [55] predicts the thermodynamic properties (∆G 0f and ∆H 0f ) of silicate minerals from the sum of polyhedral oxide and hydroxide contributions. The technique is based on the observation that silicate minerals have been shown to act as a combination of basic polyhedral units. Chermak [4] and Rimstidt determined by multiple linear regression, the contribution of Al2 O3 , [6] [6] [4] [6] Al2 O3 , Al(OH)3 , SiO2 , M gO[6] , M g(OH)2 , C aO[6] , C aO[8−z] , N a2 O[6−8] , [6] K2 O[8−12] , H2 O, FeO[6] , Fe(OH)2 [6] and Fe2 O3 to the total ∆G 0f and ∆H 0f of a selected group of silicate minerals 8 . The thermodynamic properties of the minerals are calculated with Eqs. 5.57 and 5.58: ∆H 0f = X x i · hi (5.57) ∆G 0f = X x i · gi (5.58) Where x i is the number of moles of the oxide or hydroxide per formula unit and hi and g i are the respective molar enthalpy and free energy contribution of 1 mole of each oxide or hydroxide component. Table A.17 in the appendix shows the values of hi and g i for the different polyhedral components described in the methodology [55]. The errors associated to the estimated vs. experimentally measured values can reach ±1% for ∆G 0f and ∆H 0f , depending on the nature of the compounds. Note that this methodology can only be applied to those minerals able to be decomposed by the oxides and hydroxides mentioned before. 8 The brackets next to the chemical formulas of oxides and hydroxides indicate the coordination number of the polyhedral structure. 178 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES Example: the properties of mineral thomsonite N aC a2 Al5 Si5 O20 · 6H2 O are calculated as the sum of the g i and hi from its constituent oxides (N a2 O[6−8] , C aO[8−z] , [4] [4] Al2 O3 , SiO2 and H2 O): ∆H 0f ,N aC a 2 Al 5 Si5 O20 ·6H 2 O 5 hN a2 O[6−8] + 2hC aO[8−z] + hAl O[4] + 5hSiO[4] + 6hH2 O 2 2 2 2 3 1 5 = (−683, 00) + 2(−736, 04) + (−1716, 4) 2 2 +5(−910, 97) + 6(−239, 91) = 1 = −11543, 92 kJ/mole ∆G 0f ,N aC a 2 Al 5 Si5 O20 ·6H 2 O = 1 5 (−672, 50) + 2(−710, 08) + (−1631, 32) 2 2 5 + (−853, 95) + 6(−292, 37) = −12413, 65 kJ/mole 5.4.5 The ∆O−2 method The linear additivity procedures based on the ∆O−2 parameter were developed by Yves Tardy and colleagues [348], [349], [350], [351], [352], [347], [108], [380], [383]. The parameter ∆O−2 , corresponds to the enthalpy ∆H O−2 or Gibbs free energy ∆G O−2 of formation of a generic oxide M Ox (c) from its aqueous ion, where z + is the charge of the ion and x the number of oxygen atoms combined with one atom M in the oxide (x = z + /2): ∆H O−2 M z+ = ∆G O−2 M z+ = 1 x 1 x z+ ] [∆H 0f M Ox(c) − ∆H 0f M(aq) (5.59) z+ ] [∆G 0f M Ox(c) − ∆G 0f M(aq) (5.60) For hydroxides, silicates, phosphates, nitrates and carbonates involving two cations, it was found that the enthalpy and Gibbs free energy of formation of a given compound from its constituent oxides vary linearly with ∆O−2 and have the general expressions [347]: ∆H o0x = αH and ∆Go0x = αG ni · n j ni + n j ni · n j ni + n j 2− z+ z+ j Mi i (aq) − ∆H O2− M j (aq) (5.61) 2− z+ z+ j Mi i (aq) − ∆G O2− M j (aq) (5.62) ∆H O ∆G O Prediction of Enthalpy and Gibbs free energy of formation of minerals 179 Being ∆H o0x and ∆Go0x : ∆H o0x [(Mi )ni (M j )n j ON ] = ∆H 0f [(Mi )ni (M j )n j ON ](c) − ni ∆H 0f Mi Ox i (c) −n j ∆H 0f M j Ox j (c) (5.63) ∆Go0x [(Mi )ni (M j )n j ON ] = ∆G 0f [(Mi )ni (M j )n j ON ](c) − n1 ∆G 0f Mi Ox i (c) −n2 ∆G 0f M j Ox j (c) (5.64) z+ Where ni and n j are the numbers of oxygen ions linked, respectively, to the Mi i and z+ j M j cations; and N is the number of oxygens linked to the molecular structure of the double oxide (N = x i + x j ). Parameters αH and αG are empirical coefficients variable from one family of compounds to another one (αG is 0,84 for hydroxides, 1,01 for silicates, 1,15 for carbonates, 1,30 for nitrates, etc.). Equation 5.62, yields a statistical deviation of 35 kJ/mole for the Gibbs free energy of formation and depends on the family of compounds. We will assume a maximum error associated to the ∆O2− general method of ±1%9 . Example: for the silicate C a3 Si2 O7 , the α parameter was determined at -1,01 and 0 ∆G O−2 C a2+ = −50, 31 and ∆G O−2 Si 4+ = −188, 08 kJ/mole [350]; so that ∆Gox can be calculated with Eq. 5.64 as: 3·4 · [∆G O−2 C a2+ (aq) − ∆G O−2 Si 4+ (aq)] 3+4 = −238, 5 kJ/mole ∆Go0x (C a3 Si2 O7 ) = (−1, 01) And ∆G 0f (C a3 Si2 O7 )(c) = 3∆G 0f C aO(c) + 2∆G 0f SiO2 (c) 0 +∆Gox (C a3 Si2 O7 )(c) = −3748, 1 kJ/mole The value is close to ∆G 0f (C a3 Si2 O7 ) = −3760, 4 kJ/mole from Robie and Hemingway [284]. This methodology was later on improved by Vieillard ([380], [390], [381]) and Vieillard and Tardy [389], by introducing a new empirical parameter representing the electronegativity of the cation M z+ (comp). 9 180 THERMODYNAMIC 5.4.5.1 MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES The ∆O−2 method for hydrated clay minerals and for phyllosilicates Vieillard extended the methodology described above for the prediction of hydrated clay minerals [382] and for phyllosilicates [383]. Hydrated clay minerals, have formulas expressed as: (Ml1 , Ml2 , Ml3 ) (M g o1 , Feo2+ , Al o3 , Feo3+ ) (Si(4−t) Al t )O10 (OH)2 . Layer silicates can be 2 4 of two types: (a) 2:1 layer type, (Ml i , Mo j )(Si(4−t) Al t )O10 (OH)2 , with l i the number of interlayer atom which varies from 0 (pyrophyllite, talc) to 1 (micas, if M = K + or N a+ , brittle micas, if M = C a2+ , or Ba2+ ) and (b) 2:1:1 layer type (Mo j )Si(4−t) Al t )O10 (OH)2 · (M bk (OH)6 ), where bk is the number of brucitic cations. Subscripts l, o, and t denote, respectively, the interlayer, octahedral, and tetrahedral sites. The possible cations occupying each site of the mineral can be seen in table A.18 for clays and phyllosilicates. The Gibbs free energy of formation of a hydrated clay mineral or a phyllosilicate composed by ns cations located in different sites and with ns (ns − 1)/2 interaction terms is calculated as: ∆G 0f = i=n Xs 0 (ni )∆G 0f (Mi Ox i ) + ∆Gox (5.65) i=1 0 The Gibbs free energy of formation from the oxides ∆Gox is calculated with Eq. 5.66, which is analogous to Eq. 5.64: ∆Go0x = −N s −1 j=n X Xs i=n i=i j=i+1 h i zj+ z+ X i X j ∆G O2− Mi i (cl a y) − ∆G O2− M j (cl a y) where N is the total number of O atoms of all oxides; X i and X j are the molar z+ zj+ fraction of oxygen related to the cations Mi i and M j in the individual oxides Mi Ox i and M j Ox j , respectively (X i = (1/N )(ni x i ) and X j = (1/N )(n j x j )). Paramez+ zj+ ters Mi i (clay) and M j zj+ z+ (clay) characterize the electronegativity of cations Mi i and M j in a specific site and are calculated by minimizing the difference between experimental Gibbs free energies and calculated ones from constituent oxides. Table z+ A.18 in the appendix shows Mi i (clay) values for some of the main ions for hydrated clays and phyllosilicates. The predicted Gibbs free energy values showed an error between 0,0 and 0,6 %. Prediction of Enthalpy and Gibbs free energy of formation of minerals 181 The ∆O−2 method for different compounds with the same cations 5.4.5.2 Tardy [347] showed that the Gibbs free energy of formation of a compound from its two constituent oxides calculated per one oxygen in the formula was a parabolic function of mean ∆O−2 compound. Subsequently, an expression for calculating the Gibbs free energy of formation of a compound C intermediate in composition to two compounds A and B, A + B → C was developed: ∆Go x,A+B→C = +αG ∆G O 2− z+ Mi i − ∆G O 2− z+ j Mj nC (X iC − X iA)(X iC − X iB ) (5.66) where nc designates the total number of oxygens of the compound C and X iA, X iB , z+ X iC the mole fractions of oxygen that balance cation Mi i in compounds A, B, and C and α the correlation parameter for a given class of compounds, as in Eq. 5.62. 5.4.6 Assuming ∆S r zero Helgeson et al. [134] showed that the entropy of formation of mineral B can be determined, assuming that the entropy of the reaction involved in the formation of the mineral is zero (Helgeson’s algorithm). Helgeson algorithm is useful when either ∆G 0f or ∆H 0f are known. Once the entropy of the mineral is known, ∆G 0f (or ∆H 0f ) can be calculated with ∆H 0f (or ∆G 0f ) through Eq. 5.49. The error associated to this approximation is up to 5%. Example: T hSiO4 + UO2 → USiO4 + T hO2 0 0 s0 T hSiO4 = sUSiO + s0T hO − sUO 4 2 2 = 118, 0 + 62, 2 − 77, 0 = 106, 2 5.4.7 5.4.7.1 Assuming ∆G r and ∆H r zero The element substitution method In some cases, thermodynamic properties are available for a certain mineral (A), belonging to the same family of the substance under consideration (B), but with partial element substitutions. In such a case, the ∆H 0f and ∆G 0f of mineral B can be calculated from mineral A, assuming that the reaction enthalpy or free energy 182 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES of formation of mineral B from A is zero. This approximation increases with the magnitude of substitution and may yield to associated errors of up to 5%, although it rarely exceeds ±2%. We will outline this method with an example. Consider the mineral hydrosodalite N a8 Al6 Si6 O24 (OH)2 , for which no empirical thermodynamic values are available. Hydrosodalite can be formed from sodalite N a8 Al6 Si6 O24 (C l)2 as in the following reaction: N a8 Al6 Si6 O24 (OH)2 + 2H C l → N a8 Al6 Si6 O24 (C l)2 + 2H2 O Assuming that the energy of reaction is zero, ∆H 0f and ∆G 0f of hydrosodalite are calculated as: ∆H 0f ,N a 8 Al 6 Si6 O24 (OH)2 = ∆H 0f ,N a 8 Al 6 Si6 O24 (C l)2 + 2 · ∆H 0f ,2H 2O − 2∆H 0f ,H C l = (−13457) + 2 · (−285, 8) − 2 · (−167, 2) = −13408, 5 kJ/mole ∆G 0f ,N a Al Si O (OH) 8 6 6 24 2 = ∆G 0f ,N a 8 Al 6 Si6 O24 (C l)2 + 2 · ∆G 0f ,2H 2O − 2∆G 0f ,H C l = (−12703, 6) + 2 · (−237, 1) − 2 · (−131, 1) = −12678, 2 kJ/mole Where the thermodynamic properties of sodalite, H2 O and H F are obtained from [187] and [391], respectively. 5.4.7.2 The addition method for hydrated minerals Hydrated minerals have the ability to absorb nw water molecules, forming part of their crystal structure: A + nw · H 2 O → A · nw H 2 O Usually, thermodynamic properties are available for the non-hydrated mineral. But the enthalpy and Gibbs free energy of formation of the hydrated substance can be 0 estimated by addition of the hydration enthalpy and Gibbs free energy ∆Ghy or dr ∆Hh0y d r to those of the dehydrated substance, as in Eqs. 5.67. ∆H 0f ,A·n w H2 O ∆G 0f ,A·n w H2 O 0 = ∆H 0f ,A + nw · ∆Hhy d r,A 0 = ∆G 0f ,A + nw · ∆Ghy d r,A (5.67) Prediction of Enthalpy and Gibbs free energy of formation of minerals 183 If ∆Gh0y d r and ∆Hh0y d r are not available, one can assume that the enthalpy and Gibbs free energy of the hydration reaction are zero (as in section 5.4.7.1). And hence, the properties of the liquid water molecules contained in the hydrated sub0 0 stance must be added in place of ∆Ghy and ∆Hhy . This is not rigourously exact, dr dr as demonstrated by Vieillard and Jenkins ([386], [384], [385]) and the error associated depends on the nature of the dehydrated component10 . We will assume an associated error of ±5%, although it rarely exceeds ±2%. Example: the contribution of tetrahedral silica Si 4+ to the hydration energy is not known, so the enthalpy of opal SiO2 · 0, 5H2 O is calculated assuming that the reaction energy of the hydration process is zero. Hence, ∆H 0f ,SiO ·0,5H O = 2 2 ∆H 0f ,SiO +0, 5∆H 0f ,H O(l) = −901, 6 + 0, 5 · (−285, 8) = −1044, 5 kJ/mole. The en2 2 thalpy of formation of SiO2 (amorph.) and H2 O (l) are obtained from [284]. 5.4.7.3 The decomposition method If non of the previously described methods can be applied, the thermodynamic properties of a certain mineral can be estimated as the last resort by decomposing it into its major constituents for which the enthalpy and Gibbs free energy of formation are known. It will be assumed that the energy of reaction of the constituents to form the mineral under consideration is zero. The error associated to this methodology is significantly greater than with the substitution and addition methods, since in this case we are not dealing with partial substitutions or additions of a known mineral, but with the formation of a completely new mineral from its building blocks. The mineral under analysis will be decomposed into its most complex compounds (usually double silicates). If this is not possible, most minerals can be decomposed into its simple oxides, sulfides, carbonates, etc. We will assume that the decomposition method throws an error of up to 10%. Example: mineral pyroxene C aAl2 SiO6 can be decomposed into 1: C aO and Al2 Si2 O5. Alternatively, into 2: C aO, SiO2 and Al2 O3 . C aAl2 SiO6 → C aO + Al2 Si2 O5 → C aO + Al2 O5 + SiO2 10 This methodology is not applied for hydrated clay minerals and phyllosilicates. In those cases, the ∆O2− method is applied. 184 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES Hence, the Gibbs free energy of pyroxene is estimated as follows, with the help of the thermodynamic properties tabulated in [94]: ∆G 0f ,C aAl 2 SiO6 = ∆G 0f ,C aO + ∆G 0f ,Al 2 Si2 O5 = (−603, 1) + (−2440, 1) = −3043, 2 kJ/mole or ∆G 0f ,C aAl SiO 2 6 = ∆G 0f ,C aO + ∆G 0f ,Al 2 O3 + ∆G 0f ,SiO 2 = (−603, 1) + (−1583, 4) − (−856, 3) = −3042, 8 kJ/mole The measured Gibbs free energy of pyroxene reported in [94] is ∆G 0f = −3119, 7, what gives an error of 2,4 and 2,5% of the estimated values with decompositions 1 and 2, respectively. 5.4.8 Summary of the methodologies The described methodologies in the previous sections, will be used for calculating the thermodynamic properties of the most abundant minerals in the earth’s upper crust. Each methodology is given a number so as to specify in the next chapter, which methodology has been used for determining the enthalpy or free energy of formation of the minerals (see table 5.8). Additionally, the assumed maximum errors associated to the estimation methods (± Error %) are given. Table 5.8. Summary of the methodologies used to predict the thermodynamic properties of minerals Method Calculation of ∆H 0f or ∆G 0f from s0 The ideal mixing model Thermochemical approximations for sulfosalts and complex oxides The method of corresponding states The method of Chermak and Rimstidt for silicate minerals The ∆O−2 method The ∆O−2 method for hydrated clay minerals and for phyllosilicates The ∆O−2 method for different compounds with the same cations Assuming ∆S r zero The element substitution method The addition method for hydrated minerals The decomposition method Nr. 1 2 3 4 5 6 7 8 9 10 11 12 ±Error, % 0 1 1 1 1 1 0,6 1 5 5 5 10 Summary of the chapter 5.5 185 Summary of the chapter This chapter has provided the thermodynamic tools required for the calculation of natural resources, especially for minerals. We have seen, that the exergy of any substance is always associated to a reference environment. The conditions of the reference environment determine the final exergy value, therefore, the R.E. had to be carefully selected. For that purpose, the different R.E. proposed so far have been reviewed. It has been stated, that the best suitable R.E. for determining the exergy of natural resources is the one based on Szargut’s criterion. The model developed by Szargut has been adapted to our requirements with the help of new geochemical information and the updates carried out by other authors. As a result, two different R.E. have been proposed, the first one, taking into account the model of the continental crust developed in chapter 3, and the other one, considering the parameters included in Grigor’ev’s model [127]. It has been stated, that the difference between these R.E. and Szargut’s original environment, differ for both cases in less than 1%. Nevertheless, when the whole continental crust is considered, these small numbers become not so insignificant. Next, the energy involved in the formation processes of a mineral deposit has been shown. The most energy intensive processes are those related to the chemical formation of the mineral. The physical processes associated to the mixing and binding of the crystal structure of the mineral are not so energy-intensive. We have seen that the minimum exergy embedded in a mineral has two components: the chemical and concentration components. The first parameter accounts for the formation of the mineral from the R.E. The concentration exergy expresses the minimum energy that nature had to spend to bring the minerals from the concentration in the reference state to the concentration in the mine. We have seen, that the latter shows a negative logarithmic pattern with the grade. This means that as the ore grade of the mine tends to zero, the exergy of the deposit approaches also zero and the exergy required for replacing the mine tends to infinity. Fossil fuels are a type of minerals, in which the concentration exergy is not so relevant. The chemical exergy of fuels is difficult to obtain with the formulas provided for the rest of minerals, because of the complexity of their chemical structure. Hence, special calculation procedures are applied. It has been seen, that the chemical exergy of fossil fuels can be in many cases approximated to its HHV. Nevertheless, the different formulas developed by Valero and Lozano [369] have been provided, because through them, we can calculate the effect of variations in the conditions of the ambient on the exergy of fuels. The exergy values are very small, if compared to the real energy required for the replacement of natural resources to their original state. In order to account for the inefficiencies of man-made processes, the exergy values are multiplied by the unit exergy replacement costs. These are dimensionless and measure the number of exergy units needed to obtain one unit of exergy of the product. The resulting 186 THERMODYNAMIC MODELS FOR THE EXERGY ASSESSMENT OF NATURAL RESOURCES exergy costs represent the exergy required by the given available technology to return a resource into the physical and chemical conditions in which it was delivered by the ecosystem. As opposed to exergy, exergy costs cannot be considered as a property of the resource, since unit exergy costs introduce to some extent an uncertain factor to the calculation. Nevertheless, they can be used as a suitable indicator for assessing the value of non-fuel mineral resources, as they integrate in one parameter, concentration, composition and also the state of technology. Although unit exergy replacement costs are considered in this PhD to be constant, in reality they vary with time, as technology is being developed. The assessment of unit exergy replacement costs as a function of time with the help of learning curves is a task that remains open for further studies. The chapter ends with the description of the twelve semi-theoretical models for the calculation of enthalpies and Gibbs free energies of formation, required for the calculation of the chemical exergy of minerals. All these tools, will allow us to assess in subsequent chapters, the exergy of the substances that compose the earth, previously described in chapters 2, 3 and 4. Chapter 6 The thermodynamic properties of the earth and its mineral resources 6.1 Introduction This chapter is devoted to the calculation of the standard thermodynamic properties of the earth (enthalpy, Gibbs free energy and exergy) focusing on each of its outer layers: the atmosphere, hydrosphere and upper continental crust. For that purpose, the geochemistry of our planet described in Part I is required, together with the thermodynamic tools provided in chapter 5. Additionally, a first approach to the chemical composition of the entropic earth is provided. Finally, the exergy of the mineral resources of the earth (of fuel and non-fuel origin) will be calculated and added to the energy sources described in chapter 4. The exergy of the natural resources will be analyzed and compared to the global chemical exergy of the earth calculated before. 6.2 The properties of the earth As we anticipated in previous chapters, the thermodynamic properties of the earth are related to the species contained in it and not to their elements. In the model developed in section 3.4.1, this implies that the average Enthalpy (∆H f ), Gibbs free energy (∆G f ) or Chemical Exergy (b ch) of the earth expressed as kJ/g of earth, are calculated as: 187 188 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES ∆H f = m X (ξi · ∆H f i ) (6.1) i=1 ∆G f = m X (ξi · ∆G f i ) (6.2) i=1 b ch = m X (ξi · bch i ) (6.3) i=1 Being ξi , the specific quantity of the species composing the earth, expressed in mole/g, and ∆H f i , ∆G f i and bch i , their enthalpy, Gibbs free energy and chemical exergy in kJ/mole, respectively. The enthalpy and Gibbs free energy of the substances are obtained either through the literature or through the estimation methods described in section 5.4. Remember also that the chemical exergy of the substance (bch i ) in kJ/mole is calculated with Eq. 5.1: X bch i = ∆G f + r j,i bch j j where bch j is the standard chemical exergy of the elements that compose substance i. In our case we will use the chemical exergy of the elements obtained with the R.E. developed in this study and shown in table 5.4. Since we have divided the earth into three subsystems, its average properties will be first calculated separately for the atmosphere, hydrosphere and continental crust. The average enthalpy, Gibbs free energy and exergy of the earth’s layers, can be expressed in molar units by substituting ξi with the molar fraction x i for the i constituents of each sphere. Equation 6.4 relates both properties through the molecular weight of the sphere considered (M Wspher e ): x i = ξi · M Wspher e (6.4) Next, the specific and global standard properties of the substances composing the atmosphere, hydrosphere and upper continental crust are shown. 6.2.1 The thermodynamic properties of the atmosphere Table 6.1 shows the standard thermodynamic properties of the substances contained in the atmosphere (on a dry basis), according to the composition provided in section 2.3.1. Values for ∆H 0f ,i and ∆G 0f ,i are taken from Weast et al. [400]. The properties of the earth 189 Table 6.1: Thermodynamic properties of the atmosphere. Va0 lues of ∆H 0f i , ∆G 0f i , bch in kJ/mole i Substance Nitrogen Oxygen Argon Carbon dioxide Neon Helium Methane Hydrogen Nitrogen oxides Nitrous oxide Ozone (troposphere) Carbon monoxide NMHC (assuming ethylene) Ozone (stratosphere) Hydrogen peroxide Formaldehyde Chlorofluorocarbon 12 Ammonia Sulfur dioxide Carbonyl sulfide Chlorofluorocarbon 11 Hydrogen sulfide Carbon disulfide Carbon tetrachloride Methylchloroform Dimethyl sulfide Hydroperoxyl radical Hydroxyl radical Sum Formula N2 O2 Ar CO2 Ne He C H4 H2 N O2 N2 O O3 CO C2 H4 O3 H2 O2 C H2 O C F 2C l2 N H3 SO2 OC S C F C l3 H2 S C S2 C C l4 C H3 C C l3 C H3 SC H3 HO2 OH x i [-] 7,81E-01 2,09E-01 9,34E-03 3,60E-04 1,82E-05 5,24E-06 1,70E-06 5,50E-07 5,05E-07 3,10E-07 2,55E-07 1,25E-07 1,25E-08 5,25E-09 5,05E-09 5,50E-10 5,40E-10 5,05E-10 5,05E-10 5,00E-10 2,65E-10 2,53E-10 1,51E-10 9,80E-11 6,50E-11 5,50E-11 2,00E-12 5,00E-14 1,00 ∆H 0f i 0,0 0,0 0,0 -393,7 0,0 0,0 -74,8 0,0 33,2 82,1 142,7 -137,2 52,3 142,7 -191,3 -117,2 -477,2 -46,1 -297,0 -142,2 -276,3 -20,6 117,4 -103,0 35,6 -45,8 20,9 39,0 ∆G 0f i 0,0 0,0 0,0 -394,4 0,0 0,0 -50,8 0,0 51,3 104,2 163,3 -110,6 70,3 163,3 -131,9 -113,0 -439,5 -16,5 -300,3 -169,4 -238,6 -27,9 67,2 -60,7 51,9 -4,4 22,6 34,2 0 bch i 0,72 3,97 11,7 19,9 27,2 30,4 831,7 236,1 55,7 106,9 169,2 301,7 1363,0 169,2 108,2 535,3 651,1 338,0 310,9 850,1 636,1 815,5 1692,0 598,1 1412,9 2131,7 144,6 154,3 According to table 6.1, the average standard enthalpy, Gibbs free energy and chemical exergy of the atmosphere can be obtained as: 190 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES 0 m X (x i · ∆H 0f ,i ) = −1, 42E − 01 kJ/mole 0 m X = (x i · ∆G 0f ,i ) = −1, 42E − 01 kJ/mole (∆H f )at m = i=1 (∆G f )at m i=1 0 (b ch)at m m X 0 = (x i · bch i ) = 1, 51 kJ/mole i=1 Obviously, the average properties are very close to those of N2 and O2 , for being both the major constituents of the atmosphere. 6.2.2 The thermodynamic properties of the hydrosphere In this section, the thermodynamic properties of the main constituents of oceans, rivers, groundwaters and glacial runoff are provided. For all subsystems, values for ∆H 0f i and ∆G 0f i are taken from Weast et al. [400]. Table 6.2 shows the thermodynamic properties of the major substances that compose seawater. The composition of the oceans is the one listed in table 2.5. The more comprehensive composition given in table 2.6 could not be used, since although the concentration of minor elements found in seawater are listed, their specific molecular formulas are not specified1 . It should be noted however, that the first composition comprises more than 99% of the total substances included in seawater and hence, its uncertainty cannot be compared to that of the continental crust, which had to be estimated in this PhD. Table 6.2: Thermodynamic properties of seawater. Values in kJ/mole Substance H2 O C l− N a+ M g 2+ SO4−2 C a2+ K+ H CO3− 1 x i [-] 9,80E-01 9,98E-03 8,57E-03 9,65E-04 5,16E-04 1,88E-04 1,87E-04 3,20E-05 ∆H 0f i -286,0 -167,2 -240,2 -467,1 -909,7 -543,1 -252,5 -692,3 ∆G 0f i -237,3 -131,3 -262,0 -455,0 -745,0 -553,8 -283,4 -587,1 0 bch i 0,79 -69,2 74,6 174,6 -129,8 170,0 83,2 -52,9 For instance, the concentration of vanadium is given, but this element could be in the form of V + , V 3+ , etc. Obviously, the thermodynamic properties of the different forms of vanadium are different. V O2+ , The properties of the earth 191 Table 6.2: Thermodynamic properties of seawater. Values in kJ/mole. – continued from previous page. Substance Br − F− B(OH)3 CO32− B(OH)− 4 S r 2+ SUM x i [-] 1,54E-05 1,24E-05 5,67E-06 4,93E-06 1,83E-06 1,64E-06 1,00 ∆H 0f i -121,6 -332,8 -1072,8 -677,5 -1344,7 -547,2 ∆G 0f i -104,0 -279,0 -969,3 -528,1 -1153,9 -560,0 bch i 0 -53,5 -0,9 19,4 -111,9 -45,1 198,8 The average standard enthalpy, Gibbs free energy and chemical exergy of seawater (sw) can now be obtained as: 0 (∆H f )sw = −284, 9 kJ/mole 0 (∆G f )sw 0 (b ch)sw = −237, 0 kJ/mole = 0, 87 kJ/mole The average standard thermodynamic properties of rivers, according to the composition given by Livingstone [197] are shown in table 6.3. Table 6.3: Thermodynamic properties of average rivers. Values in kJ/mole Substance H2 O H CO3− C a2+ N a+ C l− SiO2 M g +2 SO4−2 K+ N O3− Fe2+ SUM x i [-] 1,00E+00 1,72E-05 6,74E-06 4,93E-06 3,96E-06 3,92E-06 3,04E-06 2,10E-06 1,06E-06 2,90E-07 2,16E-07 1,00 ∆H 0f i -286,0 -692,3 -543,1 -240,2 -167,2 -911,4 -467,1 -909,7 -252,5 -207,5 -89,2 ∆G 0f i -237,2 -586,9 -553,5 -261,9 -131,0 -856,7 -454,8 -774,5 -283,3 -111,3 -78,9 0 bch i 0,79 -52,9 170,0 74,6 -69,2 174,6 174,6 -129,8 83,2 -105,1 297,9 192 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES The average standard enthalpy, Gibbs free energy and chemical exergy of rivers (r w) is then: 0 (∆H f ) r w = −286, 0 kJ/mole 0 (∆G f ) r w 0 (b ch) r w = −237, 2 kJ/mole = 0, 79 kJ/mole The average standard properties of glacial runoff, obtained from the composition provided in section 2.4.3.1, are given in table 6.4. Table 6.4: Thermodynamic properties of glacial runoff. Values in kJ/mole Substance H2 O N a+ H CO3− C a+2 SO4−2 C l− M g +2 K+ SUM x i [-] 1,00E+00 1,44E-05 1,42E-05 5,71E-06 5,13E-06 3,92E-06 1,92E-06 9,13E-07 1,00 ∆H 0f i -286,0 -240,2 -692,3 -543,1 -909,7 -167,2 -467,1 -252,5 ∆G 0f i -237,2 -261,9 -586,9 -553,5 -774,5 -131,0 -454,8 -283,3 0 bch i 0,79 74,6 -52,9 170,0 -129,8 -69,2 174,6 83,2 The average standard enthalpy, Gibbs free energy and chemical exergy of glacial runoff (g l) is: 0 = −286, 0 kJ/mole 0 = −237, 2 kJ/mole 0 (b ch) gl = 0, 79 kJ/mole (∆H f ) gl (∆G f ) gl Since the composition of river waters and glacial runoff is very close, similar thermodynamic properties of both types of waters were expected, as corroborated by the figures provided above. The properties of the earth 193 Table 6.5. Thermodynamic properties of groundwaters. Values in kJ/mole Substance H2 O H CO3− C a2+ SO4−2 M g +2 SiO2 C l− N a+ Al +3 N O3− K+ Fe2+ SUM x i [-] 1,00E+00 6,46E-05 3,95E-05 2,96E-05 2,13E-05 7,54E-06 6,98E-06 6,66E-06 2,05E-06 1,47E-06 9,67E-07 5,55E-07 1,00 ∆H 0f i -286,0 -692,3 -543,1 -909,7 -467,1 -911,4 -167,2 -240,2 -531,6 -207,5 -252,5 -89,2 ∆G 0f i -237,3 -587,1 -553,8 -745,0 -455,0 -857,1 -131,3 -262,0 -485,6 -111,4 -283,4 -78,9 0 bch i 0,79 -52,9 170,0 -129,8 174,6 1,1 -69,2 74,6 308,7 -105,1 83,2 297,9 Table 6.5 shows the estimated average standard thermodynamic properties of groundwaters on earth. The mean composition of groundwaters has been assumed to be equivalent to the average of the compositions for granite, shale and serpentinite groundwaters given in table 2.10. According to table 6.5, the average standard enthalpy, Gibbs free energy and chemical exergy of groundwater (g w) is then: 0 = −286, 0 kJ/mole (∆G f ) g w 0 = −237, 4 kJ/mole 0 = 0, 80 kJ/mole (∆H f ) g w (b ch) g w Summarizing, table 6.6 shows the standard thermodynamic properties of the hydrosphere. Since the ocean accounts for 97% of all earth’s waters, the global enthalpy, Gibbs free energy and exergy of the hydrosphere can be approximated to that of seawater. It has been assumed, that the composition of lakes is equal to that of average rivers. It is remarkable in the hydrosphere’s tables presented above, that the specific exergy of all negative ions is also negative. As explained in the previous chapter, the chemical exergy expresses the minimum work required for combining chemically the reference substances dispersed in the reference environment to obtain the resource. If the reference species are more stable than the considered substance, then its chemical exergy will be negative. In Ranz’s R.E. [276], this situation came up very 194 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES Table 6.6. Summary of the thermodynamic properties of the hydrosphere. Values in kJ/mole Reservoir Oceans Ice Caps and Glaciers Groundwater Lakes Streams and Rivers SUM 0 0 0 0 Volume (M km3 ) 1370 29 xi 9,73E-01 2,05E-02 ∆H f i -284,9 -286,0 ∆G f i -237,0 -237,2 b ch i 0,87 0,79 x i .∆H f i -2,77E+02 -5,86E+00 x i . ∆G f i -2,30E+02 -4,86E+00 x i .b ch i 8,47E-01 1,63E-02 9,5 0,125 0,0017 6,80E-03 1,00E-04 1,00E-06 -286,0 -286,0 -286,0 -237,4 -237,2 -237,2 0,80 0,79 0,79 -1,94E+00 -2,86E-02 -2,86E-04 -1,61E+00 -2,37E-02 -2,37E-04 5,41E-03 7,93E-05 7,93E-07 1408,63 1,00 -284,9 -237,0 0,87 frequently, as she chose reference substances according to the abundance criterion. In the R.E. developed in this PhD, which is based on partial stability, we have selected reference substances trying to avoid negative chemical exergies. However, in the light of the hydrosphere’s results, we have not succeeded in that task. A deeper analysis of the equilibrium substances found in seawater should be carried out. A good starting point would be the work of Pinaev [266], [265]. Pinaev calculated the chemical exergy of elements, assuming that all reference substances are in the ocean medium, with the exception of gas reference substances, which were the same as in this PhD. As opposed to other methodologies, for Pinaev, the exergy of an element is not obtained from a single reference substance. He takes into account not only the dominant, but also the main secondary species found in the ocean medium of each element, at the concentration ruled by their equilibrium constants. This way, the exergy of an element is calculated as the sum of the exergy of the element previously obtained with the dominant reference substance and the exergy of their secondary species, obtained through their equilibrium concentrations. Nevertheless, Pinaev’s element exergies generate also negative chemical exergies of negative ions, as corroborated by the next example. Example: standard chemical exergy of C l − , calculated from the standard chemical 0 exergy of the elements proposed by Pinaev [265]: (bch = 60, 8 kJ/mole). Cl 0 bch C l− 0 = ∆G 0f ,C l − + bch Cl = −131, 3 + 60, 8 = −70, 5 kJ/mole It is not the point of this PhD to show the exergy of all substances on earth calculated with Pinaev’s R.E. But it has been stated, that the results are very close to ours. In the example, Pinaev’s exergy of C l − is -70,5 kJ/mole, versus -69,2 kJ/mole obtained here. That is because his methodology is based in outline on the conventional calculation procedures, also used in this PhD. This makes us to question the validity of the conventional methodology, when the chemical exergy of the natural capital is assessed. The properties of the earth 6.2.3 195 The thermodynamic properties of the upper continental crust Table 6.7 shows the standard thermodynamic properties of the major minerals that compose the upper continental crust, according to the model developed in chapter 3. Only the references (Re f .) of the experimental values of ∆H 0f i and ∆G 0f i are provided in the table. For those minerals where the latter values have been estimated in this PhD, the method used for its estimation (M eth.)2 , as well as its associated error (±" %) is given. The detailed calculations for the estimation of the mineral’s properties is shown in the appendix (section A.5.3). 2 See table 5.8 for details about the different estimation methods. -2587,4 -5932,5 -6841,0 -1118,3 -4117,7 -1237,2 -998,1 -10976,4 2,03E-04 1,42E-04 1,27E-04 9,25E-05 8,80E-05 8,00E-05 7,73E-05 6,15E-05 4,95E-05 3,88E-05 3,43E-05 3,24E-05 3,10E-05 2,95E-05 2,78E-05 2,54E-05 2,28E-05 2,09E-05 2,01E-05 2,01E-05 1,87E-05 1,84E-05 1,77E-05 N a0.6 C a0.4 Al1.4 Si2.6 O8 SiO2 · 0, 5H2 O 2+ Al0.4 T i0.1 Si1.9 O6 C a0.9 N a0.1 M g0.9 Fe0.2 N a0.5 C a0.5 Al1.5 Si2.5 O8 K(M g2,5 Fe0,5 )(Si3 Al)O10 (OH)1,75 F0,25 C aCO3 2+ Si3,5 O10 (OH)2 K0,6 (H3 O)0,4 Al2 M g0,4 Fe0,1 Al2 SiO5 N aAl3 Si3 O10 (OH)2 N a0.3 Fe23+ (Si3,7 Al0,3 )O10 (OH)2 · 4(H2 O) Fe23+ Fe2+ O4 Al2 Si2 O5 (OH)4 Fe2+ T iO3 AlO(OH) 3+ (Si7 AlO22 )(OH)2 C a2 Fe42+ Al0,75 Fe0,25 KAl3 Si3 O10 (OH)1,8 F0,2 C aT iSiO5 Fe32+ Al2 (SiO4 )3 C (M g3,75 Fe1,25 Al) (Si3 Al)O10 (OH)2 (OH)6 C a2 Fe3+ Al2 (SiO4 )3 (OH) C Al(OH)3 C aM gSi2 O6 N a0,33 Al2,33 Si3,67 O10 (OH)2 2+ C aFe0,6 M g0,3 M n2+ 0,1 (CO3 )2 N aFe3+ Si2 O6 Al2 SiO5 M g Fe2+ Si2 O6 Fe3+ O(OH) N aC l AlO(OH) N a0.2 C a0.8 Al1.8 Si2.2 O8 1,40E-05 -3031,2 1,39E-05 -5691,6 1,36E-05 -2076,8 1,32E-05 -2585,5 1,25E-05 -2590,4 1,17E-05 -2757,4 1,17E-05 -559,4 1,01E-05 -386,3 9,65E-06 -988,1 9,08E-06 -4186,8 Continued on next page . . . -3026,3 -5317,2 -1923,1 -2417,2 -24443,0 -2594,6 -489,2 -384,4 -914,1 -3960,7 -5616,6 -2455,1 -4969,8 0,0 -7788,2 -6076,3 N.A. -1155,8 -2441,0 -5557,6 -5447,7 -1015,9 -3796,0 -1163,5 -917,6 -10303,7 -763,7 -967,9 -3026,8 -769,8 -5706,7 -1129,0 -5499,1 ∆G 0f i , kJ/mole -857,2 -3704,5 -750,9 -3752,1 [284] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [284] [94] [94] [94] [94] [94] Reference 3 12 7 4 1 3 1; 7 5 2; 4 11 1 Method 1 10 0,6 1 0 0,6 1 1 5 0 ±ε, % 47,4 39,4 96,6 16,5 9,7 132,2 9,7 14,3 2,2 10,5 -13,1 37,2 335,7 410,3 175,2 43,1 N.A. -1,4 11,7 -15,7 738,2 122,6 -9,0 123,7 -1,3 398,5 3076,6 9,3 -446,9 3103,2 78,6 11,0 325,2 1,0 4,8 3023,9 -12,8 bch i , kJ/mole THE -5991,3 -2597,1 -5305,5 0,0 -8429,2 -6466,1 N.A. -1282,2 -808,9 -1044,5 -3201,5 -815,0 -6079,4 -1207,7 -5886,2 3,81E-03 5,14E-04 4,49E-04 4,22E-04 SiO2 N aAlSi3 O8 N a0.8 C a0.2 Al1.2 Si2.8 O8 KAlSi3 O8 Quartz Albite Oligoclase Orthoclase/ Kfeldspar Andesine Opal Augite Labradorite Biotite Calcite Hydromuscovite/ Illite Sillimanite Paragonite Nontronite Magnetite Kaolinite Ilmenite Diaspore HornblendeFe Muscovite Titanite Almandine Graphite Ripidolite Epidote C org Hydragillite/ Gibbsite Diopside Beidellite Ankerite Aegirine Andalusite Hyperstene Goethite Halite Boehmite Bytownite ∆H 0f i , kJ/mole -911,6 -3927,6 -796,0 -3977,5 Formula Mineral ξi , mole/g Table 6.7: Thermodynamic properties of the upper continental crust 196 THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES 8,99E-06 7,82E-06 7,63E-06 7,33E-06 6,52E-06 C a3 (PO4 )2 N a2 Al2 Si3 O10 · 2(H2 O) C aM g(CO3 )2 M g3,75 Fe1,25 Al2 Si3 O10 (OH)8 N a0,165 C a0,084 Al2,33 Si3,67 O10 (OH)2 Phosphate rock Natrolite Dolomite Clinochlore Montmorillonite Lawsenite Riebeckite Hematite Sepiolite Hydrobiotite -5722,1 -2327,9 -8435,5 -5523,8 ∆H 0f i , kJ/mole -3886,6 C aAl2 Si2 O7 (OH)2 · H2 O 6,36E-06 -4812,8 6,14E-06 -10087,1 N a2 Fe32+ Fe23+ (Si8 O22 )(OH)2 Fe2 O3 6,05E-06 -826,1 M g4 Si6 O15 (OH)2 · 6(H2 O) 5,67E-06 -10123,7 3+ Al0,1 )(Si2,8 Al1,2 ) O10 ((OH)1,8 F0,2 ) · 5,26E-06 -7362,2 (K0,3 C a0,1 )(M g2,3 Fe0,6 3(H2 O) 5,21E-06 -1489,4 Ulvöspinel T iFe22+ O4 Distene/Kyanite Al2 SiO5 4,37E-06 -2593,7 Cummingtonite/ M g7 (Si8 O22 )(OH)2 3,73E-06 -12070,0 Anthopyllite Glaucophane N a2 (M g3 Al2 )Si8 O22 (OH)2 3,65E-06 -12080,6 Celestine SrSO4 3,65E-06 -1454,1 Prehnite C a2 Al2 Si3 O10 (OH)2 3,58E-06 -6197,3 Rutile T iO2 3,41E-06 -945,4 Barite BaSO4 3,04E-06 -1470,4 Niter K N O3 2,96E-06 -495,0 Nitratine N aN O3 2,96E-06 -468,2 Pennine (M g3,75 Fe1,25 Al) (Si3 Al)O10 (OH)2 (OH)6 2,87E-06 -8429,2 Actinolite C a2 M g3 Fe2 Si8 O22 (OH)2 2,82E-06 -11519,4 Pyrite FeS2 2,75E-06 -175,0 Sanidine K0,75 N a0,25 AlSi3 O8 2,67E-06 -3860,7 2+ 3+ Hastingsite N aC a2 Fe4 Fe (Si6 Al2 O22 )(OH)2 2,60E-06 -11926,3 2+ Ferrosilite Fe M gSi2 O6 2,32E-06 -2757,4 Zircon Z rSiO4 2,11E-06 -2034,8 2+ Siderite Fe CO3 2,08E-06 -742,3 Spodumene LiAlSi2 O6 2,06E-06 -3056,8 Pigeonite M g1,35 Fe0,55 C a0,1 (Si2 O6 ) 1,99E-06 -1535,4 Leucoxene C aT iSiO5 1,90E-06 -2591,6 2+ Pyrrhotite Fe S 1,79E-06 -105,5 2+ 3+ Lepidomelane/ K Fe2,5 M g0,5 Fe0,75 Al0,25 Si3 O10 (OH)2 1,78E-06 -4995,0 Annite Bronzite M g FeSi2 O6 1,77E-06 -2753,4 Anhydrite C aSO4 1,73E-06 -1435,1 Continued on next page . . . ξi , mole/g Formula Mineral -2585,3 -1322,7 -11346,7 -1341,6 -5823,0 -890,1 -1361,9 -395,2 -367,1 -7788,2 -10801,5 -163,3 -3715,9 -11343,4 -2594,6 -1919,5 -671,1 -2882,9 -1448,8 -2454,8 -100,5 -4642,3 -1392,9 -2442,0 -11343,0 -4510,6 -9399,5 -742,2 -9257,8 -6238,9 -5316,6 -2167,9 -7796,6 -5354,5 ∆G 0f i , kJ/mole -3878,2 [94] [94] [94] [178] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [284] [94] [94] 1 3 2 3 7 3 12 1; 7; 10 3; 11 1 3 2 0 1 1 1 0,6 1 10 5 5 0 1 1 141,5 16,3 -78,8 32,4 35,7 18,3 18,8 -22,3 -24,2 175,2 405,9 1428,1 15,9 289,2 132,2 20,0 122,0 24,6 1401,1 37,5 883,6 284,8 273,1 10,7 181,6 2,2 318,9 17,4 1284,5 46,2 3,8 18,0 166,8 39,6 bch i , kJ/mole [94] [94] ±ε, % 32,4 Method [94] Reference Table 6.7: Thermodynamic properties of the upper continental crust. – continued from previous page. The properties of the earth 197 1,53E-06 1,39E-06 1,20E-06 1,14E-06 2+ (SiO4 ) M g1,6 Fe0.4 2+ M n2+ K N a2 LiFe1,5 0,5 T i2 Si8 O24 Z nS N aAlSi2O6 ∆(H2 O) C aAl2 Si2 O8 M nCO3 Fe2+ C r2 O4 C aSO4 · 2H2 O C a5 (PO4 )3 (OH)0,33 F0,33 C l0,33 Fe2+ Al9 Si4 O23 (OH) M g3 Si4 O10 (OH)2 C aCO3 C a2 Al3 (SiO4 )3 (OH) M g3 Si4 O10 (OH)2 · 2(H2 O) M n2+ 2 (SiO4 ) N aC a2 Al5 Si5 O20 · 6H2 O C a2 Al3 Si3 O12 (OH) M nO2 T iO2 4+ Ba2 M n2+ 2 M n3 O10 · 2H 2 O N a0,75 K0,25 Al(SiO4 ) M g2 SiO4 3+ N aAl0,9 Fe0,1 (Si2 O6 ) M n2 + 3Al2(SiO4)3 C e0,5 La0,25 N d0,2 T h0,05 (PO4 ) C a2 M g5 Si8 O22 (OH)2 N a2 M g2 Fe2+ Al2 (Si8 O22 )(OH)2 M n2+ M n3+ 6 SiO12 CuFeS2 H3 BO3 M gCO3 2+ T i0,7 N b0,15 Fe0,225 O2 BaCO3 K0,8 Fe8 Al0,8 5Si11,1 O21 (OH)8 · 6H2 O -2083,3 -3055,5 -1668,9 -7596,0 1,10E-06 -10724,6 1,02E-06 -206,1 1,01E-06 -3310,2 9,90E-07 -4274,4 9,48E-07 -894,7 8,83E-07 -1445,7 7,96E-07 -2024,0 7,91E-07 -6773,4 7,68E-07 -12066,8 7,67E-07 -5907,2 7,64E-07 -1207,9 7,51E-07 -6883,9 6,78E-07 -7018,8 6,30E-07 -1733,3 6,19E-07 -12413,7 5,68E-07 -6883,9 5,64E-07 -520,4 5,59E-07 -940,4 5,10E-07 -2569,1 5,09E-07 -2087,6 4,95E-07 -2175,5 4,78E-07 -2990,4 4,77E-07 -5646,3 4,29E-07 -2074,0 4,28E-07 -12367,8 4,06E-07 -11600,3 4,06E-07 -4260,0 3,62E-07 -194,6 3,60E-07 -1095,1 3,58E-07 -1114,1 3,22E-07 -864,6 3,04E-07 -1217,1 2,77E-07 -16655,5 Continued on next page . . . 1,64E-06 M g3 Si2 O5 (OH)4 Serpentine/ Clinochrysotile Olivine Enstatite Corundum ThuringiteChamosite Neptunite Sphalerite Analcime Anorthite Rhodochrosite Chromite Gypsum Apatite Staurolite Talc Aragonite Clinozoisite Vermiculite Tephroite Thomsonite Zoisite Pyrolusite Anatase Psilomelane Nepheline Forsterite Jadeite Spessartine Monazite (Ce) Tremolite Crossite Braunite Chalcopyrite Sassolite Magnesite Ilmenorutile Witherite Stilplomelane ∆H 0f i , kJ/mole -4363,4 -10061,3 -201,4 -3088,5 -4021,0 -817,1 -1358,4 -1798,6 -6386,9 -11215,6 -5543,0 -1128,6 -6483,9 -5957,2 -1632,1 -11543,9 -5416,5 -465,2 -883,7 -2347,2 -1972,4 -2057,8 -2812,1 -5326,3 -1943,3 -11639,3 -10925,8 -3944,7 -195,1 -969,0 -1030,2 -813,2 -1137,6 -15197,0 -1925,0 -2919,9 -1563,0 -6981,9 ∆G 0f i , kJ/mole -4035,4 [94] [284] [284] [94] [94] [94] [144] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] ∆G 0f : [94] Reference 1 1; 2 1; 2 12 3 0 1 1 10 1 1 1 1 5 3 3 10 ∆H 0f : 12 5 3; 10 10 0,6 1 1 5 0 ±ε, % ∆H 0f : 5 12 7 ∆H 0f : 1 Method 868,9 744,9 0,8 15,6 83,8 195,1 16,6 -23,2 269,1 22,6 11,4 53,0 1717,4 199,3 -49,1 1120,4 23,4 24,7 2103,1 28,1 63,6 -2,7 302,6 -43,3 73,7 133,0 325,8 1530,3 19,7 15,6 45,5 44,1 5459,7 95,3 59,6 31,5 -389,8 51,9 bch i , kJ/mole THE M g2 Si2 O6 Al2 O3 3+ 3+ Al0,5 ) (Si3 Al)O10 (OH)2 (Fe3 M g2 Fe0,5 ξi , mole/g Formula Mineral Table 6.7: Thermodynamic properties of the upper continental crust. – continued from previous page. 198 THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES 7,44E-08 7,19E-08 6,34E-08 6,18E-08 6,14E-08 5,99E-08 5,99E-08 5,24E-08 4,62E-08 4,23E-08 4,12E-08 4,09E-08 2+ N i4,5 S8 Fe4,5 N aC a(B5 O6 (OH)6 )· 5H2 O N a4 Al3 Si9 O24 C l 2+ Fe1,2 M g0,6 M n2+ 0,2 Al 4 Si2 O10 (OH)4 Cs0,6 N a0,2 Rb0,1 Al0,9 Si2,1 O6 · (H2 O) C a2 B6 O11 · 5H2 O Be3 Al2 Si6 O18 FeS2 C a3 Al2 (SiO4 )3 N iS2 M g5 Al2 (Si6 Al2 O22 )(OH)2 N aFe32+ Al6 (BO3 )3 Si6 O18 (OH)4 -6606,9 -3297,1 -6949,7 -9006,5 -154,9 -6631,1 -134,2 -12319,7 -14401,4 -778,3 -6762,2 -12197,4 ∆H 0f i , kJ/mole -2842,4 -4733,3 -1480,9 -1321,6 -910,1 -7148,6 -6292,8 -622,4 -1220,5 -307,1 -21175,8 -1237,4 -1660,9 -11926,3 -2281,0 -6003,2 -9114,7 -4104,9 -5632,5 -5984,4 -6481,6 4,08E-08 -1631,6 3,81E-08 -7657,8 3,09E-08 -3743,6 3,06E-08 -1602,1 Continued on next page . . . 2,75E-07 2,63E-07 2,34E-07 2,32E-07 2,06E-07 1,89E-07 1,58E-07 1,55E-07 1,44E-07 1,29E-07 1,20E-07 1,20E-07 1,16E-07 1,09E-07 1,07E-07 1,03E-07 9,52E-08 8,99E-08 8,93E-08 8,68E-08 7,81E-08 C aFe2+ Si2 O6 4+ Ba0,8 P b0,2 N a0,125 Fe1,3 Al0,2 Si0,1 M n2+ 0,5 M n6 O16 Fe22+ SiO4 M n2+ SiO3 SiO2 C a2 M gAl2 (SiO4 ) (Si2 O7 )(OH)2 · H2 O K M g3 AlSi3 O10 F (OH) M nO(OH) C aF2 Li0,75 N a0,25 Al(PO4 ) F0,75 (OH)0,25 C a10 M g2 Al4 (SiO4 )5 (Si2 O7 )2 (OH)4 3+ 2+ 2+ M n3+ Fe1,5 M n2+ 0,5 O4 0,6 Fe0,3 M g La(CO3 )F N a3 Fe42+ Fe3+ (Si8 O22 )(OH)2 M gAl2 O4 K Li2 AlSi4 O10 F (OH) M g2 Al4 Si5 O18 N a2 O · 2B2 O3 · 4H2 O Al2 Si4 O10 (OH)2 C a5 (PO4)2,63 (CO3 )0,5 F1,11 C a(C e0,4 C a0,2 Y0,133 ) (Al2 Fe3+ )Si3 O12 (OH) Hedenbergite Hollandite Fayalite Rhodonite Cristobalite Pumpellyte Phlogopite Manganite Fluorite Amblygonite Vesuvianite Jacobsite Bastnaesite Arfvedsonite Spinel Lepidolite Cordierite Kernite Pyrophyllite Francolite Orthite- Allanite Pentlandite Ulexite ScapoliteMarialite Chloritoid Pollucite Colemanite Beryl Marcasite Grossular Vaesite Gedrite TourmalineSchorl Wollastonite Clementite Cryptomelane Kieserite C aSiO3 Fe32+ M g1,5 Al Fe3+ Si3 AlO12 (OH)6 2+ K8 (M n4+ 7,5 M n0,5 ) O16 M gSO4 · (H2 O) ξi , mole/g Formula Mineral -1550,9 -7043,1 -3432,2 -1428,7 -6152,6 -3074,2 -6277,0 -8500,4 -156,6 -6281,0 -126,4 -11584,2 -13453,5 -766,2 -6151,5 -11504,2 ∆G 0f i , kJ/mole -2676,1 -4330,4 -1369,2 -1243,1 -855,5 -6672,5 -5902,2 -557,3 -1168,1 -282,7 -19948,7 -1137,5 -1527,8 -11201,5 -2172,5 -5654,7 -8603,9 -3713,1 -5257,6 -5698,1 -6055,4 [391] [94] [400] [94] [409] [94] [94] [178] [94] [144] [94] [94] [94] [94] [94] Reference Table 6.7: Thermodynamic properties of the upper continental crust. – continued from previous page. 5 3 1 1 3 12 1; 6; 11 1 12 1 1 1; 3; 9 3 10 7; 4 1; 2; 9 1; 8; 10 10; 12 3 4 ∆H 0f : 12 3 Method 1 1 0 0 1 10 5 0 10 0 0 1 1 5 1 5 5 10 1 1 10 1 ±ε, % 33,1 504,6 3409,1 54,2 159,8 10,0 -796,8 56,9 1434,8 65,4 1320,6 149,9 377,6 6833,9 2855,3 22,5 8651,4 288,3 246,6 101,7 2,7 57,9 128,1 49,4 111,9 1992,6 219,0 711,5 160,8 -1146,5 53,6 126,7 139,2 440,8 7,6 714,3 32,3 bch i , kJ/mole The properties of the earth 199 FeAsS P bS N a4 T i3,6 N b0,4 (Si2 O7 )2 O4 · 4(H2 O) KC l M g(OH)2 M g7 Si8 O22 (OH)2 Fe2+ N b2 O6 Arsenopyrite Galena Murmanite Sylvite Brucite Anthophyllite Ferrocolumbite Covellite Vernadite Thorite Nickeline Sapphirine Andradite Chrysoberyl Cassiterite Violarite Todorokite Cubanite Topaz Glauconite Garnierite Molybdenite Clinohumite Tridymite Euxenite Gersdorffite Jarosite Humite Scheelite Kornerupine Omphacite Phenakite Hisingerite Uraninite Malachite Strontianite Brookite Perovskite Yttrialite ∆H 0f i , kJ/mole -41,9 -100,5 -9804,0 -437,0 -925,9 -12094,6 -2172,8 2,27E-08 -53,2 2,18E-08 -637,8 2,13E-08 -2160,5 2,04E-08 N.A. 2,04E-08 -10563,3 1,96E-08 -5764,4 1,80E-08 -2302,3 1,73E-08 -581,1 1,72E-08 -378,0 1,34E-08 -4037,4 1,33E-08 -293,7 1,29E-08 -3044,4 1,21E-08 -5150,3 1,18E-08 -3494,6 1,14E-08 -271,8 1,10E-08 -8966,4 1,05E-08 -909,7 1,02E-08 -2671,5 9,70E-09 N.A. 9,57E-09 -3521,7 9,46E-09 -6953,7 9,28E-09 -1646,2 9,24E-09 -9172,9 7,48E-09 -3075,5 7,31E-09 -2146,2 6,25E-09 -3229,6 5,60E-09 -1085,6 5,46E-09 -1052,1 5,34E-09 -1220,9 5,27E-09 -942,4 5,10E-09 -1662,2 4,64E-09 N.A. Continued on next page . . . 2,89E-08 2,79E-08 2,78E-08 2,74E-08 2,71E-08 2,67E-08 2,40E-08 ξi , mole/g -53,6 -571,4 -2048,8 N.A. -9962,9 -5419,4 -2178,2 -519,6 -368,9 -3576,5 -302,8 -2875,2 -4785,6 -3267,1 -262,8 -8410,0 -855,9 -2506,3 -144,3 -3318,7 -6512,3 -1419,6 -8624,8 -2904,3 -2033,3 -2895,6 -1032,5 -906,0 -1140,1 -821,9 -1575,7 N.A. ∆G 0f i , kJ/mole -50,2 -95,9 -9096,6 -410,2 -834,8 -11396,0 -2018,6 [94] [383] [94] [94] [94] [94] [94] [94] [205] ∆G 0f : [94] [94] [284] [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] Reference 3 2 ∆H 0f : 12 3; 10 12 10 1; 9 3 3 10 7 1; 7; 9 3 1; 9 12 12 Method 1 1 10 5 10 1 1 1 1 5 0,6 1 1 5 10 10 ±ε, % 687,7 393,5 27,8 N.A. 2366,3 92,1 20,9 32,0 2902,0 742,6 2406,7 -11,4 52,1 25,9 1682,2 613,5 2,3 136,7 1189,5 208,5 504,3 139,8 173,8 38,7 34,1 1012,8 167,6 24,3 34,9 86,5 58,5 N.A. 1428,0 743,6 354,0 18,5 34,9 128,6 170,5 bch i , kJ/mole THE CuS 3+ M n4+ 0,6 Fe0,2 C a0,2 N a0,1 O1,5 (OH)0,5 · 1, 4(H 2 O) T hSiO4 N iAs M g4 Al6.5 Si1.5 O20 C a3 Fe22+ (SiO4 )3 BeAl2 O4 SnO2 Fe2+ N i2 S4 3+ N a2 M n4+ 4 M n2 O12 · 3H 2 O CuFe2 S3 Al2 (SiO4 )F1,1 (OH)0,9 2+ 3+ 3+ Al0,15 ) (Si3,8 Al0,2 )O10 (OH)2 M g0,4 Fe0,2 (K0,6 N a0,05 )(Fe1,3 (N i2 M g)Si2 O5 (OH)4 M oS2 M g6,75 Fe2,25 Si4 O16 (OH)0,5 F1,5 SiO2 Y0,7 C a0,2 C e0,1 (Ta0,2 )2 (N b0,7 )2 (T i0,025 )O6 N iAsS K Fe33+ (SO4 )2 (OH)6 2+ M g5,25 Fe1,75 (SiO4 )3 F1,5 (OH)0,5 C aW O4 M g1,1 Fe0,2 Al5,7 (Si3,7 B0,3 )O17,2 (OH) C a0,6 N a0,4 M g0,6 Al0,3 Fe0,1 Si2 O6 Be2 SiO4 Fe23+ Si2 O5 (OH)4 · 2(H2 O) UO2 Cu2 (CO3 )(OH)2 Sr CO3 T iO2 C aT iO3 Y1.5 T h0.5 Si2 O7 Formula Mineral Table 6.7: Thermodynamic properties of the upper continental crust. – continued from previous page. 200 THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES -1430,8 -1429,4 1,45E-09 1,41E-09 1,38E-09 1,29E-09 1,06E-09 9,06E-10 8,27E-10 8,10E-10 8,01E-10 6,83E-10 6,36E-10 4,96E-10 4,81E-10 4,40E-10 4,30E-10 4,02E-10 3,96E-10 3,87E-10 3,82E-10 3,62E-10 K M gC l3 · 6(H2 O) Y2 Fe2+ Be2 (Si2 O10 ) Y bPO4 N a8 Al6 Si6 O24 SO4 2+ M n0,5 W O4 Fe0,5 N a8 Al6 Si6 O24 (OH)2 P bCO3 S b2 S3 C dS Cu2 S Z nCO3 3+ U0,3 C a0,2 N b0,9 T i0,8 Al0,1 Fe0,1 Ta0,5 O6 (OH) N a0,6 C e0,22 La0,11 C a0,1 T i0,8 N b0,2 O3 M g Fe23+ O4 2+ N a4 C a2 Fe0,7 M n0,3 Z r Si8 O22 (OH)1,5 C l1,5 Z rSiO4 M gC l2 · 6(H2 O) Sn P bSO4 N a2 T i2 Si2 O9 Continued on next page . . . -11859,9 -2034,8 -2500,7 0,0 -920,0 -4360,1 -2946,7 -5220,0 -1868,6 -13936,7 -1246,2 -13408,5 -700,0 -175,0 -162,0 -79,5 -813,3 -2884,5 4,38E-09 3,90E-09 3,47E-09 3,38E-09 3,16E-09 2,80E-09 2,77E-09 2,76E-09 2,76E-09 2,65E-09 2,51E-09 2,36E-09 1,85E-09 1,84E-09 1,55E-09 1,45E-09 Cu3 (CO3 )2 (OH)2 Cu N aC aN b2 O6 (OH)0,75 F0,25 Be4 Si2 O7 (OH)2 N a2 Fe52+ T iSi6 O20 K2 (UO2 )2 (V O4 )2 · 3H2 O M gAlSi4 O10 (OH) · 4(H2 O) C a2 (IO3 )2 (C rO4 ) C a(IO3 )2 Cu5 FeS4 N aAl(CO3 )(OH)2 N a3 Al F6 As2 S3 S8 Zn M n4 Be3 (SiO4 )3 S Azurite Copper Pyrochlore Bertrandite Aenigmatite Carnotite Palygorskite Dietzeite Lautarite Bornite Dawsonite Cryolite Orpiment Sulphur Zinc Helvine/ Helvite Carnallite Gadolinite Xenotime Nosean Wolframite Hydrosodalite Cerussite Stibnite Greenockite Chalcocite Smithsonite Blomstrandite/ Betafite Loparite - (Ce) Pleonaste/ Magnesioferrite Eudyalite Sirtolite Bischofite Tin Anglesite Ramsayite/ Lorenzenite ∆H 0f i , kJ/mole -1633,3 0,0 -2897,9 -4586,1 -8184,4 -4907,3 -6477,8 -2425,4 -1002,5 -334,5 -1965,3 -3311,3 -169,1 0,0 0,0 -5843,9 ξi , mole/g Formula Mineral -11062,9 -1919,2 -2116,4 0,0 -784,5 -4103,9 -1343,6 -1351,0 N.A. -4943,3 -1790,3 -13131,5 -1146,4 -12678,2 -627,5 -173,7 -156,5 -86,2 -731,9 -2683,8 ∆G 0f i , kJ/mole -1447,5 0,0 -2687,3 -4300,6 -7660,9 -4585,5 -5939,9 -2148,1 -839,3 -393,1 -1787,3 -3144,7 -168,7 0,0 0,0 -5532,4 [94] [94] [94] [94] [94] [94] [94] [94] [94] [94] [388] [132] [391] [94] [94] [94] [94] [94] [94] [191] [94] [94] Reference Table 6.7: Thermodynamic properties of the upper continental crust. – continued from previous page. 12 1; 3; 10 12 12 10 2 3, 10 12 12 5 12 10; 12 1 12 Method 10 1 10 10 5 1 5 10 10 1 10 10 0 10 ±ε, % 335,0 20,3 66,0 547,6 62,9 104,3 181,6 40,2 N.A. 299,7 24,2 115,0 120,0 193,1 20,9 2522,3 743,9 789,1 23,3 90,0 39,0 134,0 345,0 72,3 -164,8 792,4 440,4 78,7 71,4 3083,0 -0,1 327,9 2641,2 4858,2 339,0 1407,7 bch i , kJ/mole The properties of the earth 201 Ag5 S bS4 Z rSiO4 Au -142,2 -323,6 -1169,6 -99,9 -3004,3 -2549,9 -184,5 -1919,2 0,0 7,72E-12 -166,1 6,98E-12 -2034,8 6,47E-12 0,0 Continued on next page . . . -1434,7 -9894,5 -40,3 -3925,1 -131,5 -307,3 -1227,2 -100,5 -3208,3 -2721,2 3,05E-11 2,76E-11 2,74E-11 2,59E-11 C aM oO4 3+ 2+ Si4 O22 M g0,5 T i2,5 Fe0,5 C e1,7 La1,4 C a0,8 T h0,1 Fe1,8 Ag2 S 2+ N a1,1 C a0,9 M n2+ 0,5 Fe0,5 Z r0,8 T i0,1 N b0,1 (Si2 O7 ) O0,6 (OH)0,3 F0,1 Ag3 S bS3 C o3 S4 T hO2 FeS N a0,4 C a1,6 Ta2 O6,6 (OH)0,3 F0,1 Y0,7 C a0,2 C e0,12 (Ta0,7 )2 (N b0,2 )2 (T i0,1 )O5,5 (OH)0,5 2,38E-11 1,69E-11 1,56E-11 1,19E-11 8,71E-12 8,33E-12 -1542,4 -10499,8 -32,4 -4191,1 3,07E-10 3,05E-10 2,93E-10 2,80E-10 2,46E-10 2,38E-10 2,18E-10 2,05E-10 1,94E-10 1,93E-10 1,40E-10 1,30E-10 1,19E-10 1,03E-10 9,91E-11 9,91E-11 9,75E-11 8,08E-11 5,06E-11 5,06E-11 4,99E-11 4,20E-11 3,51E-11 3,18E-11 Fe2+ Ta2 O6 Pb 2+ (SiO4 )2 F1,5 (OH)0,5 M g3,75 Fe1,25 As2 O3 H gS FeO C a2,9 C e0,9 T h0,6 La0,4 N d0,2 Si2,7 P0,5 O12 (OH)0,8 F0,2 N a8 Al6 Si6 O24 C l2 Ag C a2 Fe2+ Al2 BO3 Si4 O12 (OH) As4 S4 Bi Bi2 (CO3 )O2 C e0,75 La0,25 (PO4 ) · H2 O Bi 2O3 Bi2 S3 Z rO2 N d0,4 C e0,4 Sm0,1 Y0,1 N bO4 C oAsS C oAs2 Ag2 S N a6 C a2 Al6 Si6 O24 (CO3 )2 SiC T hSiO4 Ferrotantalite Lead Chondrodite Arsenolite Cinnabar Iotsite Britholite Sodalite Native silver Axinite- Fe Realgar Bismuth Bismutite Rhabdophane Bismite Bismuthinite Baddeleyite Fergusonite Cobaltite Smaltite Argentite Cancrinite Moissanite UraniumThorite Powellite Chevkinite Acanthite Lavenite ∆G 0f i , kJ/mole -2163,9 0,0 -4701,4 -579,1 -50,7 -251,5 -6666,9 -12703,6 0,0 -7180,9 -132,7 0,0 -888,7 -1821,9 -493,7 -140,6 -1043,3 -2631,2 N.A. N.A. -39,4 -14136,3 -60,3 -2048,8 [94] [94] [94] [94] [94] [94] [94] [94] [391] [94] [94] [94] [94] [94] [187] [94] [94] [94] [94] [94] Reference 3 10; 12 12 9 10; 12 12 1; 9 12 12 3 12 2 12 1 10; 12 10; 5 12 Method 5 10 10 5 10 10 5 10 10 1 10 1 10 0 10 5 10 ±ε, % 3030,3 20,3 51,5 2325,9 3032,2 48,8 884,2 315,1 54,6 27,6 1006,2 706,4 604,8 174,5 232,2 564,2 415,0 671,3 127,3 734,0 51,9 69,7 427,3 4272,6 274,8 81,1 325,0 61,9 2230,8 38,1 -717,4 N.A. N.A. 707,3 101,8 1204,1 27,8 bch i , kJ/mole THE Pyrargirite Linnaeite Thorianite Troilite Microlite Delorenzite/ Tanteuxenite Stephanite Naegite Gold ∆H 0f i , kJ/mole -2319,3 0,0 -5023,0 -659,8 -58,2 -272,1 -7057,3 -13457,0 0,0 -7640,4 -140,3 0,0 -968,0 -1964,9 -574,3 -143,2 -1101,3 -2808,3 -163,1 -61,5 -29,4 -14980,9 -62,8 -2160,5 ξi , mole/g Formula Mineral Table 6.7: Thermodynamic properties of the upper continental crust. – continued from previous page. 202 THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES -4652,2 N.A. N.A. -8568,0 -2681,3 0,0 N.A. -1023,7 -4170,0 -127,2 -602,2 -3279,4 -703,2 -53,6 -4608,4 -79,8 -11738,2 -4455,9 -1987,7 -1112,9 -85,7 -1968,6 -322,8 N.A. -8020,8 -19,0 -444,9 -1909,5 -3740,2 -100,2 -9415,1 -5173,2 N.A. N.A. -9109,0 -2847,7 0,0 N.A. 5,61E-12 5,47E-12 3,77E-12 3,54E-12 3,52E-12 3,17E-12 2,59E-12 2,11E-12 2,00E-12 1,81E-12 1,68E-12 1,66E-12 1,30E-12 1,24E-12 1,14E-12 7,62E-13 7,20E-13 5,71E-13 5,29E-13 3,47E-13 2,71E-13 2,27E-13 2,25E-13 2,20E-13 1,57E-13 1,50E-13 1,33E-13 2,46E-14 1,54E-14 1,20E-14 2,12E-15 -1034,5 1,27E-15 -4439,7 End of the table N a2 Sr BaT i3 Si4 O16 (OH)F AgC l M gO Cu2 Si2 O6 (H2 O)4 2+ S b3 AsS13 Ag7,2 Cu3,6 Fe1,2 H gS Fe3 (PO4 )2 (H2 O)8 P t 0,6 P d0,3 N i0,1 S KC a2 C e3 Si8 O22 (OH)1,5 F0,5 Cu(UO2 )2(PO4 )2 · 8(H2 O) Y PO4 P bM oO4 FeAs2 Cu10 Fe2 As4 S13 TeO2 Au0,75 Ag0,25 Te2 N a2,8 M n2+ 0,2 Sr0,5 C a0,5 La0,33 C e0,6 Z n0,6 M g 0,4 Si6 O17 AuTe2 Ag4 M nS b2 S6 Cu10 Fe2 S b4 S13 Sc1,5 Y0,5 Si2 O7 Bi2 Te2 S N a2 C a3 C e1,5 Y0,5 T i0,4 N b0,5 Z r0,1 (Si2 O7 )2 O1,5 F3,5 KAl3 (SO4 )2(OH)6 Os0.75 I r0.25 I r0.5 Os0.3 Ru0.2 Al6.9 (BO3 )(SiO4 )3 O2.5 (OH)0.5 Y0,5 C a0,1 C e0,1 U0,1 T h0,1 T i1,2 N b0,6 Ta0,2 O6 Pt P t Fe P b5 S b4 S11 N aC a2 Z r0,6 N b0,4 Si2 O8,4 (OH)0,3 F0,3 Lampro- phyllite Chlorargirite Periclase Chrysocolla Freibergite Metacinnabar Vivianite Cooperite Miserite Tortbernite Weinschenkite Wulfenite Loellingite Tennantite Tellurite Sylvanite Nordite Calaverite Samsonite Tetrahedrite Thortveitite Tetradymite Rinkolite/ Mosandrite Alunite Osmium Iridium Dumortierite Polycrase (Y) I-Platinum Polixene/ Tetraferroplatinum Boulangerite Wohlerite -109,9 -569,5 -2964,6 -727,5 -47,7 -4428,2 -73,8 -11035,1 -4129,8 -1871,1 -952,8 -80,2 -1999,6 -270,3 N.A. -7532,2 -17,4 -463,5 -1939,7 -3540,6 -100,6 -8808,5 ∆H 0f i , kJ/mole -8401,2 ξi , mole/g Formula Mineral ∆G 0f i , kJ/mole -7865,3 [94] [135] [94] [94] [94] [191] [94] [94] [94] ∆G 0f : [94] Reference Table 6.7: Thermodynamic properties of the upper continental crust. – continued from previous page. 1; 9 10; 12 12 12 1 3 1 2; 9 2 10; 12 1 1 1 ∆H 0f : 12 3 10; 12 ∆H 0f :12 3 10; 12 Method 5 10 10 10 0 5 0 5 1 10 0 0 0 10 1 10 10 5 10 ±ε, % 8565,5 466,6 127,3 342,1 N.A. 108,9 125,4 146,5 N.A. 22,0 62,1 -23,9 10786,0 674,3 457,4 688,3 1138,1 151,6 -35,2 17,8 1284,7 9965,1 60,0 N.A. 958,5 686,8 4817,9 9797,1 50,5 1709,0 1441,1 892,0 bch i , kJ/mole The properties of the earth 203 204 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES According to table 6.7, the thermodynamic properties of the 291 main minerals included in the crust have been obtained. About a half of the properties (159) were compiled directly from the literature. The remaining were obtained with the 12 different estimation methods described in section 5.4. From the latter, 18 minerals were calculated with method 1, and hence without committing any associated error. Five minerals were estimated with the method for hydrated clay minerals and for phyllosilicates (M.7), committing a maximum error of ε < 0, 6%. Thirty-eight minerals were estimated with an error smaller than 1%, 20 substances with ε < 5%, and 44 minerals with ε < 10%. Only the properties of 6 minerals3 : iridium, osmium4 , nickeline, polixene, sylvanite and yttrialite were not able to be estimated. Additionally, the enthalpy of formation of gersdorffite and the Gibbs free energy of smaltite are missing. Nevertheless, all together account for only 3, 5 × 10−6 % of the continental crust. The average standard enthalpy, Gibbs free energy and chemical exergy of the upper continental crust, for an average molecular weight of the crust5 equal to M Wcr = 157, 7 g/mole is: 0 (∆H f )c r m X = (ξi · ∆H 0f ,i ) · M Wcr = −1958, 92 kJ/mole i=1 0 (∆G f )c r m X = (ξi · ∆G 0f ,i ) · M Wcr = −1835, 82 kJ/mole i=1 0 (b ch)c r m X 0 = (ξi · bch i ) · M Wcr = 372, 60 kJ/mole i=1 As it happened to the hydrosphere, our R.E. generates some negative exergies of the minerals, but far less than with Ranz’s R.E [276]. This is because, as stated above, we chose our R.E. based on Szargut’s criterion of partial stability. According to this, among a group of reasonable abundant substances, the most stable will be chosen if they also complain with the “earth similarity criterion”. This criterium is different from that of Ahrendt’s [4] or Diederichsen [74], where complete stability was assumed. As a consequence, the latter R.E. do not generate any negative exergies, but the resulting environment is completely different from that of the current earth. 3 Excluding Cor g , since no exact composition can be applied. The standard enthalpy and Gibbs free energy of iridium and osmium (Os0,5 I r0,3 Ru0,2 and Os0,75 I r0,25 ) could be estimated considering the compunds as solid solutions of elements Os, I r, and Re. Since for all three substances ∆G f =0 and ∆H f =0, the standard enthalpy of formation of iridium and osmium would be also ∆H f =0, applying the solid solution method. Similarly, the standard Gibbs free energy of formation would correspond to the entropy of the mixture. Hence, ∆G f =2,5 kJ/mole for iridium and ∆G f =5,1 kJ/mole for osmium. We do not include these values in the table, since the errors associated might be very significant. 5 As calculated in this study (section 3.6). 4 An approach to the chemical composition of the crepuscular earth 205 Our chosen R.E. obeys in principle the “earth similarity criterion”, but does generate some negative exergies. Hence, this leads us to question again the methodology used and the proposed R.E. 6.2.4 The chemical exergy of the earth In chapter 2, we described some physical properties of the bulk earth that are now required for our calculations. According to Beichner [23], the earth has a mass of around 5, 98 × 1024 kg. The earth’s relative mass proportions of each of the earth’s spheres are according to Javoy [169]: core (35,5%), mantle (67%), oceanic crust (0,072%), continental crust (0,36%), hydrosphere (0,023%) and atmosphere (0,842 ppm). The upper layer of the crust constitutes a mass of around 50% of the whole continental crust [411]. With the information provided in the previous sections, we are now able to calculate the chemical exergy of the outer layers of the earth, namely the atmosphere, hydrosphere and upper continental crust. Table 6.8 shows the standard chemical exergy of the aforementioned layers and their sum. Table 6.8. The standard chemical exergy of the earth’s outer layers Layer Atmosphere Hydrosphere Upper continental crust SUM Mass, kg 5,04E+18 1,38E+21 1,08E+22 MW, g/mole 28,96 18,29 157,7 0 b ch, kJ/mole 1,51 0,87 372,60 0 B ch, Gtoe 6,27E+03 7,80E+05 1,21E+09 1,22E+09 The results of table 6.8 indicate that the standard chemical exergy of the earth’s outer spheres is 1, 22 × 109 Gtoe. This can be considered as a rough number, and is subject to updates, especially when a more appropriate R.E. is found. But the order of magnitude is good enough for realizing the huge chemical exergy content of the earth. From all layers, the upper continental crust is responsible for most of the exergy (99,9%), due to its greater mass portion and specific exergy. Although the relative proportion of the atmosphere and hydrosphere is small when compared to the whole, their chemical exergies are also huge: 6, 27 × 103 Gtoe and 7, 80 × 105 Gtoe, respectively. Since the earth can be considered as a closed system, its chemical exergy is considered as a non-renewable reservoir. 6.3 An approach to the chemical composition of the crepuscular earth As stated before, the crepuscular or entropic planet, is a completely degraded earth, where all materials have reacted, dispersed and mixed. And this degraded earth is 206 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES not necessarily equivalent to the reference environments used so far. The crepuscular earth represents a planet towards we are inexorably approaching, as mineral resources are extracted and dispersed, fossil fuels are burned, and waters are polluted by humankind. The model of crepuscular earth is composed by an atmosphere, hydrosphere and continental crust, but differs from the current one in the absence of concentrated minerals and freshwater. Furthermore, the atmosphere contains a higher CO2 concentration due to the complete burning of fossil fuels. According to table 4.10, the amount of the considered non-fuel mineral world resources by the USGS is in the order of 1015 kg. When the rest of minerals are considered, the total quantity of concentrated minerals might increase in one or two orders of magnitude, hence to around 1017 kg. The amount of possible available fuels, according to table 6.19 is around 1016 kg6 . This means that all concentrated mineral resources of fuel and non fuel origin only represent 0,001% of the total mass of the earth’s upper crust. Therefore, we can state with no significant error, that the upper continental crust of the entropic planet can be approximated to the average mineralogical composition of the earth’s crust. And this in turn can be approximated to the composition estimated in this PhD (table 3.5), at least until it is further improved with better geochemical information. Concerning the hydrosphere, we saw that the amount of freshwater on earth stored in the form of rivers, lakes, glaciers and groundwater represents only 3%. Therefore, the final composition of the hydrosphere of the crepuscular planet when all waters are mixed, can be very well approximated to that of seawater, which is well known (tables 2.5 and 2.6). Finally the atmosphere of the entropic planet will be composed of the same substances appearing in the current atmosphere (table 2.2), but presumably with a higher concentration of CO2 and other anthropogenic gases. According to the IPCC SRES report [160], in the worst scenario of emissions, where practically all available conventional fossil fuels are burned, the CO2 concentration in the atmosphere will increase to 710 ppm. Assuming that the ratio7 , of burned fuel to increase of CO2 concentration is 4 Gtoe/CO2 ppm, the burning of available unconventional fossil fuels (around 2600 Gtoe), would imply an additional increase of 650 ppm in the atmosphere. Consequently, the final carbon dioxide concentration in the atmosphere of the crepuscular planet would be around 1400 ppm. This value is only approximative, since it has been assumed a linear relationship between the burning of fossil fuels, and the increase of CO2 in the atmosphere. In fact, the processes that rule the carbon cycle and the earth’s climate are very complex and in many cases unpredictable. It should be noted, that an increase of CO2 concentration would imply an equivalent reduction of the O2 content in the atmosphere. Hence, instead of being 20,94% the volume fraction of oxygen in the atmosphere, this would be 20,83%, since 1100 6 This corresponds to around 300 Gtons of oil, 3000 Gtons of coal, 500 Gtons of natural gas and 7000 Gtons of unconventional fossil fuels. 7 According to the trends observed in the SRES report [160] for all six different scenarios analyzed. The exergy of the mineral resources 207 ppm would be included in the molecules of the extra CO2 appearing in the entropic earth. In addition to the latter, increases in the concentration of methane, nitrous oxide, carbon monoxide, nitrogen oxides, chlorides, sulphides, etc. are expected in the crepuscular planet, due to the anthropogenic action. But the latter figures cannot be easily estimated and remain open for further studies. With this preliminary model of crepuscular planet, together with the thermodynamic properties of all its constituents estimated in this PhD, a new reference environment could be proposed, for the calculation of the chemical exergies of the elements. A model of degraded earth would not contain only a reference substance per element, as it happens to the R.E. in which we have based our calculations. The new model should calculate the chemical exergy of the elements, taking into account all the substances appearing in the planet that contain that element. Hence, we think that the calculation procedures and even the philosophy for obtaining the chemical exergies of the elements should be reviewed, since the selection of an appropriate R.E. is a required but not a sufficient condition, as seen with Pinaev’s environment. But this activity remains open for further studies in the future. 6.4 The exergy of the mineral resources In the last sections, we have obtained the chemical exergy of the main substances that compose the earth. We will now focus on a very small part of the earth’s constituents: the mineral resources. For that purpose, the average exergy of the main fuel minerals (coal, oil and natural gas) is obtained, so as to calculate the world’s proven fuel reserves. Additionally, the exergy of the main non-fuel mineral reserves, reserve base and world resources is obtained. This information, together with the data provided in chapter 4 about other energy sources, will allow us to analyze the current state of the main natural resources on earth. 6.4.1 The exergy contained in fossil fuels We saw in chapter 5, that the physical value of fuels is tightly related to its chemical exergy content. Hence, the physical value of the world’s proven fuel reserves can be approximated to their chemical exergy8 , which is obtained with the equations provided in section 5.3.3. It must be remembered, that the exergy calculation of fuels is undertaken with the models developed by Valero and Lozano [369] and not with Eq. 5.1, due to the complexity and heterogeneity of the fuel’s composition. 8 It must be remembered that in chapter 4, an approximative exergy value in terms of Gtoe was given for the proven reserves of coal, oil and natural gas. 208 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES Table 6.9. High heating value and elementary analysis (% by weight) considered in the study of Valero and Arauzo [366] to define different types of coal. RANK Anthracite Bituminous Subbitum. Lignite HHV, kJ/kg 30675 28241 23590 16400 O H C N S Z W 2,4 7,6 12,2 8,9 3,0 4,5 3,8 2,7 80,9 68,7 58,8 38,9 1,0 1,6 1,3 0,6 0,5 1,2 0,3 5,3 10,1 8,4 4,0 19,8 2,1 8,0 19,6 23,8 Table 6.10. Thermodynamic properties of the different types of coal. Values in kJ/kg, except for s0 (kJ/kgK) Type Anthrac. Bitum. Subitum. Lignite HHV 30675 28241 23590 16400 ∆H 0f -136,2 -757,7 -1125,0 -662,7 s0 0,9 1,1 1,0 0,8 eI 29980,2 27083,4 22264,5 15241,9 eI I 30687,1 28262,1 23574,2 16413,9 eI I I 30739,9 28389,3 23606,0 16975,0 bI 31583,8 28950,6 24251,0 16930,2 bI I 31584,7 28952,1 24252,7 16931,6 bI I I 31624,2 29047,1 24276,5 17351,1 The calculations will be carried out, assuming an average composition of the different types of coal, oil and natural gas. A mean composition of the fuels, was already studied by Valero and Arauzo [366], taking into account the conversion factors reported by the IEA assigned to the fuels in each country. Their analysis will be used in this study. It must be pointed out, that although the latter analysis was carried out with quite old data (statistics from 1989), and that the reserves figures have changed since then, the average composition of the fuels should not have varied significantly. 6.4.1.1 Coal The elementary analysis of each rank of coal chosen by Valero and Arauzo [366] is shown in table 6.9. The composition of the fuels listed in table 6.9, throw up the properties shown in table 6.10, where ∆H 0f and s0 are the standard enthalpy and entropy of formation, e I , e I I and e I I I , the chemical energy of the fuel corresponding to the R.E. I, II and III from table 5.5, and b I , b I I and b I I I the chemical exergy for the three R.E., respectively. As can be seen from the table, R.E. III produces the greatest exergy values, although the difference between the three is very small (around 0,3% and a maximum of 2,5% for lignite between I and III). Assuming an exergy content of coal equal to the HHV, implies an associated error of about 3%, although for lignite, this could be up to 6%. Next, the exergy of the proven reserves of coal is calculated. The main sources of data for coal reserves come from BP and WEC. The WEC study complements the The exergy of the mineral resources 209 BP Statistical Review and the World Energy Outlook. It collects these data from 96 WEC Member Committees worldwide. The difference of the proven reserve figures between both entities (WEC and BP) is 7,3%. According to the Energy Watch Group [89], the BP report just reproduces the data which are collected by the World Energy Council. Therefore, we will take into account the figures of the WEC’s Survey of Energy Resources 2007 [401]. The proven reserves data are provided for the different countries, reported as three different types of coal: 1) anthracite and bituminous, 2) subbituminous and 3) lignite. Since we need to know the separate quantities of anthracite and bituminous in order to calculate the exergy, we will assume that only hard coal9 coming from the USA is anthracite10 . The exergy values shown in table 6.11, are generated from R.E. III, which is the most commonly used for fuel calculations (Lozano and Valero [202]). Table 6.11: The exergy of the world’s coal proven reserves reported in [401]. Values in million tonnes if not specified Country Algeria Botswana Central African Republic Congo (Democratic Rep.) Egypt (Arab Rep.) Malawi Morocco Mozambique Niger Nigeria South Africa Swaziland Tanzania Zambia 9 Anthracite Bitumin. 59 40 Subbitum. Lignite 3 Exegy, Mtoe 40,8 27,7 1,2 88 60,9 21 14,5 2 N.A. 212 70 21 169 48000 208 200 10 Continued on next page . . . 1,2 N.A. 146,6 48,4 112,2 33196,7 143,9 138,3 6,9 Hard coal is another name given to anthracite and bituminous, as opposed to brown coal, which is given to subbituminous and lignite. 10 The conversion factors reported by the IEA [153] for coal in the different countries indicates that US coal is the one with the highest heating capacity. 210 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES Table 6.11: The exergy of the world’s coal proven reserves reported in [401]. Values in million tonnes if not specified. – continued from previous page. Country Zimbabwe Total Africa Canada Greenland Mexico USA Total N. America Argentina Bolivia Brazil Chile Colombia Ecuador Peru Venezuela Total S. America Afghanistan China India Indonesia Japan Kazakhstan Korea (Democratic People’s Rep.) Korea (Republic) Kyrgyzstan Malaysia Mongolia Myanmar (Burma) Nepal Pakistan Anthracite Bitumin. 502 49431 3471 860 112261 112261 4331 Subbitum. Lignite 171 871 183 300 100086 101440 3 2236 51 30374 32661 424 1 31 6578 7068 1150 381 24 140 479 7229 66 62200 52240 1721 355 28170 300 9023 24 33700 18600 4258 798 Exegy, Mtoe 347,2 34286,5 3827,7 105,8 789,2 154926,6 159649,3 245,1 0,7 4085,4 686,2 4769,6 9,9 96,8 331,3 10224,9 300 45,6 70180,4 37888,2 2565,5 245,5 20775,4 380,9 135 78,0 1809 3130 812 4 335,5 2,8 2 1,4 1 1 167 Continued on next page . . . 1814 0,6 846,6 The exergy of the mineral resources 211 Table 6.11: The exergy of the world’s coal proven reserves reported in [401]. Values in million tonnes if not specified. – continued from previous page. Country Philippines Taiwan, China Thailand Turkey Uzbekistan Vietnam Total Asia Albania Bulgaria Czech Republic Germany Greece Hungary Ireland Italy Montenegro Norway Poland Portugal Romania Russian Federation Serbia Slovakia Slovenia Spain Ukraine United Kingdom Total Europe Iran (Islamic Rep.) Total Middle East Australia Anthracite Bitumin. 41 1 Subbitum. 170 Lignite 105 Exegy, Mtoe 170,0 0,7 1354 1814 2000 559,4 749,4 1517,8 103,7 136447,4 328,0 836,4 2756,9 1000 150 146251 36282 5 1673 63 2617 34685 794 1928 211 170 6556 3900 2933 152 199 14 10 5 6012 3 12 49088 6 2 2 97472 21 300 16577 13500 260 211 30 1945 5800,4 108,8 99,3 324,1 21001,9 107,2 72872 1386 117616 44649 136826,9 958,6 1386 0 0 958,6 37400 42322,9 200 15351 155 379 1490 33 408 10450 2813,5 1611,2 1447,6 9,7 5,8 0,0 2,9 4773,4 15,7 178,0 94606,2 37100 2100 Continued on next page . . . 212 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES Table 6.11: The exergy of the world’s coal proven reserves reported in [401]. Values in million tonnes if not specified. – continued from previous page. Country New Caledonia New Zealand Total Oceania Anthracite TOTAL WORLD 112261 Bitumin. 2 Subbitum. Lignite Exegy, Mtoe 1,4 33 37135 205 2305 333 37733 278,9 42603,1 318635 266837 149755 520996,7 End of the table According to table 6.11, the exergy of coal proven reserves is 521 Gtoe, which is very similar to the previous calculated value in chapter 4 (523 Gtoe). The 2006 production data in exergy terms is equal 3,3 Gtoe11 . Similarly, the WEC [401] estimated additional resources amount in place and the estimated additional recoverable reserves are 1025,7 and 108,6 Gtoe, respectively. It must be stressed, that different assumptions had to be made, such as considering only four different classes of coal, with the same composition and high heating values. Nevertheless, the error introduced with the previous assumption is most likely much smaller than the one made estimating the proven reserves. The Energy Watch Group [89], after analyzing present and historical trends, stated that data quality of coal reserves is poor, both on global and national levels. But there is no objective way to determine how reliable the available data actually are. 6.4.1.2 Oil The composition of the main types of fuel, according to the British standard BS2869:1998 (see section 4.6.6.2), is listed in table 6.12. Only Fuels 1, 2 and 4 are considered, since they are the most commonly used. The chemical composition of the fuels described above, throw up the thermodynamic properties of table 6.13. As it happened to coal, the energy and exergy of the fuels increase from R.E. I to III. For the case of oil, the exergy can be approximated with no significant error to the HHV of the fuel, since the maximum error introduced is 0,26%. 11 An average coal is considered to have an exergy content of 22692 kJ/kg and a HHV of 21876 kJ/kg. The exergy of the mineral resources 213 Table 6.12. High heating value and elementary analysis (% by weight) of the different types of oil, according to the British standard BS2869:1998 RANK Fuel-Oil 1 Fuel-Oil 2 Fuel-Oil 4 HHV, kJ/kg 46.365 45.509 43.920 O 0,2 0,2 0,4 H 13,2 12,7 11,9 C 86,5 86,4 86,1 N 0 0,1 0,2 S 0,1 0,6 1,4 Table 6.13. Thermodynamic properties of the different types of oil. Values in kJ/kg, except for s0 (kJ/kgK) Type Fuel-Oil 1 Fuel-Oil 2 Fuel-Oil 4 HHV 46365 45509 43920 ∆H 0f -622,1 -763,7 -1279,1 s0 2,8 2,7 2,6 eI 43591,5 42859,4 41359,3 eI I 46475,6 45633,9 43958,9 eI I I 46486,2 45697,2 44107,1 bI 46247,4 45466,2 43888,4 bI I 46251,3 45469,8 43891,7 bI I I 46259,1 45517,4 44002,4 Next, the exergy of the world’s proven reserves of oil will be calculated (table 6.14). For that purpose, the figures provided by BP in the Statistical Review 2007 will be used [35]. The estimates of BP are compiled using a combination of primary official sources, third-party data from the OPEC Secretariat, World Oil, Oil & Gas Journal and an independent estimate of Russian reserves based on information in the public domain. The WEC publishes regularly also reserve figures for oil in the Survey of Energy Resources. Nevertheless, the latest WEC publication [401] includes reserve values for the end of 2005 and not for 2006, as opposed to the BP report. The classification of the world’s oil proven reserves into the different types of fuel (1, 2 and 4) is taken from the study of Valero and Arauzo [366]. Table 6.14: The exergy of the world’s oil proven reserves reported in [35]. Values in thousand million tonnes if not specified Country USA Canada Mexico Total North America Argentina Brazil Colombia Ecuador Peru Trinidad & Tobago Venezuela Fuel-Oil 1 - Fuel-Oil 2 3,7 2,4 1,7 7,8 Fuel-Oil 3 - 0,3 1,7 0,2 0,7 0,1 0,1 11,5 Continued on next page . . . Exegy, Mtoe 3999,9 2586,0 1884,0 8469,9 294,7 1813,5 224,2 709,9 157,9 125,4 12494,6 214 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES Table 6.14: The exergy of the world’s oil proven reserves reported in [35]. Values in thousand million tonnes if not specified. – continued from previous page. Country Other S. & Cent. America Total S. & Cent. America Azerbaijan Denmark Italy Kazakhstan Norway Romania Russian Federation Turkmenistan United Kingdom Uzbekistan Other Europe & Eurasia Total Europe & Eurasia Iran Iraq Kuwait Oman Qatar Saudi Arabia Syria United Arab Emirates Yemen Other Middle East Total Middle East Algeria Angola Chad Rep. of Congo (Brazzaville) Egypt Equatorial Guinea Gabon Libya Nigeria Sudan Tunisia Fuel-Oil 1 Fuel-Oil 2 0,2 Fuel-Oil 3 Exegy, Mtoe 195,6 - 14,8 - 16015,9 10,9 1039,2 167,5 113,9 5912,8 1231,4 64,6 11415,4 1,0 0,2 0,1 5,5 1,1 0,1 0,1 0,5 0,1 0,3 - - 8,8 81,1 559,2 88,2 332,1 10,9 21005,3 18,9 15,5 14,0 0,8 2,0 36,3 0,4 13,0 0,0 20467,6 16819,3 15151,6 819,4 2162,8 39338,1 443,6 14038,5 0,4 0,1 404,8 54,2 101,2 - 1,5 109699,8 1,2 0,1 0,3 1702,0 1321,4 140,3 291,6 0,5 0,2 567,8 266,5 0,3 5,4 4,9 0,9 318,2 5851,1 5297,3 936,3 99,0 0,1 Continued on next page . . . The exergy of the mineral resources 215 Table 6.14: The exergy of the world’s oil proven reserves reported in [35]. Values in thousand million tonnes if not specified. – continued from previous page. Country Other Africa Total Africa Australia Brunei China India Indonesia Malaysia Thailand Vietnam Other Asia Pacific Total Asia Pacific TOTAL WORLD Fuel-Oil 1 1,6 0,5 Fuel-Oil 2 0,1 13,9 Fuel-Oil 3 - 0,2 2,2 0,8 0,6 0,5 0,1 0,4 0,1 0,5 2,2 4,9 - Exegy, Mtoe 85,2 16876,8 592,3 163,2 2409,0 851,8 644,7 595,8 63,8 456,8 116,5 5893,9 151,5 10,9 End of the table 177961,6 According to table 6.14, the world’s proven oil exergy reserves generated from R.E. III are 177,9 Gtoe. This means, that the reserves of oil have around one third of the coal’s exergy reserves. The 2006 production data in exergy terms of fuel-oil is equal 3,9 Gtoe12 It should be remembered, that in addition to the conventional oil reserves, a corresponding range of additionally recoverable resources in exergy terms between 40 and 150 Gtoe should be taken into account [211]. 6.4.1.3 Natural gas In the case of natural gas, Valero and Arauzo [366] took into account the average standard composition of table 6.15. Table 6.15. Standard volumetric composition of natural gas considered in [366] HHV, kJ/N m3 42110 C H4 0,9225 C2 H6 0,0653 C3 H8 0,0055 C4 H10 0,0007 C5 H12 0,0001 CO2 0,0001 N2 0,0058 The chemical composition of the average natural gas described above, throw up the thermodynamic properties of table 6.16. 12 An average fuel-oil is considered to have an exergy content of 45664 kJ/kg and a HHV of 45455 kJ/kg. 216 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES Table 6.16. Thermodynamic properties of natural gas. Values in kJ/N m3 , except for ∆H f (kJ/kg) and s0 (kJ/kgK) N. Gas HHV 42110 ∆H 0f -3117,4 s0 8,6 eI 38047,1 eI I 42108,7 eI I I 42108,7 bI 39388,6 bI I 39393,8 bI I I 39393,8 R.E. II and III generate for the case of natural gas, the same values of energy and exergy, since no sulphur is contained in the fuel. The difference between the exergy generated with I and III is very small, only 0,01%. For the case of natural gas, assuming the exergy as the HHV, introduces an error of around 6,5%, and hence this approximation should be taken with more precaution than for fuel-oil or coal. The calculated proven exergy reserves of natural gas are given in table 6.17. The values for the reserves are obtained from BP [35], because it presents more comprehensive and up-to-date data than the figures provided by the WEC. Table 6.17: The exergy of the world’s natural gas proven reserves reported in [35] Country Trillion N m3 USA 5,93 Canada 1,67 Mexico 0,39 Total North America 7,98 Argentina 0,42 Bolivia 0,74 Brazil 0,35 Colombia 0,12 Peru 0,34 Trinidad & Tobago 0,53 Venezuela 4,32 Other S. & Cent. America 0,07 Total S. & Cent. America 6,88 Azerbaijan 1,35 Denmark 0,08 Germany 0,16 Italy 0,16 Kazakhstan 3,00 Netherlands 1,35 Norway 2,89 Poland 0,10 Romania 0,63 Russian Federation 47,65 Turkmenistan 2,86 Ukraine 1,10 United Kingdom 0,48 Uzbekistan 1,87 Other Europe & Eurasia 0,45 Continued on next page . . . Exegy, Mtoe 5557,3 1561,7 363,9 7482,9 389,2 694,1 326,3 115,4 318,9 497,1 4047,2 63,8 6452,0 1266,2 72,2 145,4 149,6 2813,8 1263,4 2712,5 97,5 589,0 44693,9 2682,5 1031,7 451,2 1754,0 424,8 The exergy of the mineral resources 217 Table 6.17: The exergy of the world’s natural gas proven reserves reported in [35]. – continued from previous page. Country Total Europe & Eurasia Bahrain Iran Iraq Kuwait Oman Qatar Saudi Arabia Syria United Arab Emirates Yemen Other Middle East Total Middle East Algeria Egypt Libya Nigeria Other Africa Total Africa Australia Bangladesh Brunei China India Indonesia Malaysia Myanmar Pakistan Papua New Guinea Thailand Vietnam Other Asia Pacific Total Asia Pacific TOTAL WORLD Trillion N m3 64,13 0,09 28,13 3,17 1,78 0,98 25,36 7,07 0,29 6,06 0,49 0,05 73,47 4,50 1,94 1,32 5,21 1,21 14,18 2,61 0,44 0,34 2,45 1,08 2,63 2,48 0,54 0,80 0,44 0,30 0,40 0,34 14,82 181,46 End of the table Exegy, Mtoe 60148,0 84,4 26384,4 2973,3 1669,5 919,2 23787,3 6634,1 272,0 5684,9 454,9 47,8 68911,9 4224,7 1819,6 1234,3 4886,7 1137,7 13303,1 2443,4 408,0 314,2 2297,0 1008,3 2468,7 2326,1 504,6 748,5 408,0 282,3 375,2 316,1 13900,4 170198,3 According to table 6.17, the exergy reserves of natural gas are around 170 Gtoe, as opposed to the 163,4 estimated in chapter 4 with the conversion data provided by BP. This indicates, that the natural gas exergy reserves are very close to those of fueloil. The 2006 production data in exergy terms of natural gas is equal 2,4 Gtoe13 . It should be remembered, that additional available natural gas resources are estimated 13 An average natural gas is considered to have an exergy content of 51276 kJ/kg and a HHV of 54811 kJ/kg. 218 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES in exergy terms as between 210 and 520 Gtoe, according to the International Gas Union [156] and to Gregory and Rogner [123]. 6.4.2 The exergy of non-fuel mineral resources As opposed to fossil fuels, non-fuel minerals are physically valued not only by their chemical exergy content, but also by their concentration exergy. From the point of view of man, the value of non-fuel minerals is also associated to the extraction costs. A very abundant and concentrated mineral in the crust, such as iron, has a high exergy value and a low exergy cost of extraction. On the contrary, a very dispersed and scarce mineral such as gold, has a low exergy value, but a very high exergy cost of extraction. This is why the exergy replacement costs of minerals, explained in section 5.3.4 provide additional and interesting information for assigning a physical value to nonfuel minerals. Exergy costs are obviously closer to price than the minimum exergies. In fact, the exergy cost could be considered as a fundamental ingredient of the final price of non-fuel minerals. In this section, the total minimum exergy B t and total exergy cost B ∗t of the mineral’s reserve, base reserve and world resources compiled by the USGS and described in chapter 4 are calculated (Table 6.18). The total minimum exergy B t is the sum of the chemical Bch and concentration exergy Bc , which are calculated with Eqs. 5.1 and 5.10, from the R.E. developed in this PhD (section 5.2). The total exergy cost14 , which represents the exergy required for restoring the resource with the best available technology from the R.E. to the current conditions found in nature, is obtained with Eq. 5.46. The unit exergy costs are the ones shown in table 5.7. The detailed calculations for the chemical and concentration exergies of the mineral resources are shown in table A.20 and A.21 in the appendix. 14 Remember that the application of exergy costs to fossil fuels has no sense, since it is impossible with current technology to reproduce the photosynthetic process that once created the fuel resource. Aluminium Antimony Arsenic Barite Beryllium Bismuth Boron oxide Bromine Cadmium Cesium Chromium Cobalt Copper Feldspar Fluorspar Gallium Germanium Gold Graphite Gypsum Hafnium Helium Indium Iodine Iron Lead Lithium Magnesium Production Bt B ∗t 2,39E+04 5,19E+05 1,22E+01 1,36E+02 9,78E+00 1,23E+02 4,09E+01 N.A. 7,75E-03 4,05E-01 1,94E-01 3,16E+00 1,57E+02 N.A. 8,24E+00 N.A. 1,27E+00 6,93E+01 0,00E+00 N.A. 1,63E+03 3,70E+03 8,73E+00 4,38E+02 9,01E+02 9,35E+04 5,06E+01 N.A. 2,33E+02 N.A. 1,29E-02 1,29E-02 1,67E-02 1,65E-02 1,91E-02 1,56E+03 8,70E+02 N.A. 4,02E+02 N.A. N.A. N.A. 5,09E+00 5,09E+00 5,52E-02 5,29E-01 4,67E-01 N.A. 1,42E+05 9,97E+05 9,99E+01 3,90E+03 N.A. N.A. 4,33E+02 4,33E+02 Reserves Bt B ∗t 3,22E+06 6,99E+07 1,92E+02 2,13E+03 1,96E+02 2,46E+03 9,77E+02 N.A. N.A. N.A. 1,09E+01 1,77E+02 6,28E+03 N.A. N.A. N.A. 3,23E+01 1,76E+03 5,43E+00 5,09E+00 N.A. N.A. 9,06E+02 4,55E+04 2,92E+04 3,04E+06 N.A. N.A. 1,05E+04 N.A. N.A. N.A. N.A. N.A. 3,25E-01 2,66E+04 7,26E+04 N.A. N.A. N.A. 8,68E+01 N.A. N.A. N.A. 1,05E+00 1,00E+01 2,80E+02 N.A. 1,20E+07 8,40E+07 2,28E+03 8,88E+04 5,64E+03 2,11E+04 N.A. N.A. Continued on next page . . . Reserve base Bt B ∗t 4,13E+06 8,95E+07 3,93E+02 4,37E+03 2,93E+02 3,69E+03 4,53E+03 N.A. N.A. N.A. 2,32E+01 3,77E+02 1,51E+04 N.A. N.A. N.A. 7,92E+01 4,31E+03 8,53E+00 8,00E+00 N.A. N.A. 1,68E+03 8,44E+04 5,61E+04 5,82E+06 N.A. N.A. 2,10E+04 N.A. N.A. N.A. N.A. N.A. 6,97E-01 5,71E+04 1,77E+05 N.A. N.A. N.A. 1,57E+02 N.A. 1,17E+03 1,17E+03 1,52E+00 1,46E+01 5,04E+02 N.A. 2,63E+07 1,84E+08 4,90E+03 1,91E+05 1,51E+04 5,66E+04 N.A. N.A. Table 6.18: The exergy and exergy cost of the mineral reserves, base reserve and world resources. Values are expressed in ktoe Resources Bt B ∗t 9,67E+06 2,10E+08 N.A. N.A. 1,80E+03 2,26E+04 1,03E+04 N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. 3,96E+02 2,16E+04 N.A. N.A. 1,06E+06 2,40E+06 1,94E+03 9,74E+04 1,79E+05 1,86E+07 N.A. N.A. 2,19E+04 N.A. 1,77E+02 1,76E+02 N.A. N.A. N.A. N.A. 6,76E+05 N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. 6,35E+02 N.A. 3,78E+07 2,65E+08 4,32E+04 1,69E+06 1,79E+04 6,69E+04 N.A. N.A. The exergy of the mineral resources 219 Reserves Bt B ∗t 1,00E+05 9,68E+05 7,82E-01 2,67E+02 1,59E+03 2,99E+04 6,72E+03 5,33E+05 6,36E+02 6,25E+02 1,55E+05 2,00E+05 1,43E+00 N.A. 8,89E+05 1,38E+06 2,66E+03 N.A. 1,91E-01 2,33E+01 9,37E+00 8,60E+00 4,82E+00 4,63E+03 1,44E+03 N.A. 2,84E+01 7,88E+03 1,33E+00 1,28E+00 1,34E+02 N.A. 6,96E+02 3,58E+04 4,43E+03 1,15E+05 4,48E+03 5,05E+04 3,20E+02 2,42E+04 2,33E+04 4,26E+05 3,89E+02 3,73E+05 1,65E+07 1,61E+08 End of the table Reserve base Bt B ∗t 1,13E+06 1,09E+07 4,08E+00 1,39E+03 3,52E+03 6,61E+04 1,50E+04 1,19E+06 7,06E+02 6,94E+02 4,30E+05 5,56E+05 1,61E+00 N.A. 1,93E+06 2,99E+06 4,53E+03 N.A. 7,65E-01 9,31E+01 1,94E+01 1,78E+01 1,02E+01 9,78E+03 2,54E+03 N.A. 3,93E+01 1,09E+04 2,99E+00 2,87E+00 1,56E+02 N.A. 1,25E+03 6,46E+04 9,10E+03 2,36E+05 1,31E+04 1,48E+05 6,94E+02 5,26E+04 6,23E+04 1,14E+06 7,36E+02 7,07E+05 3,43E+07 2,98E+08 Resources Bt B ∗t N.A. N.A. 1,02E+01 3,48E+03 2,41E+03 4,52E+04 N.A. N.A. N.A. N.A. N.A. N.A. 2,02E+00 N.A. 2,68E+07 4,16E+07 N.A. N.A. 8,41E-01 1,02E+02 N.A. N.A. N.A. N.A. 2,12E+05 N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. 1,21E+04 3,15E+05 2,17E+04 2,45E+05 N.A. N.A. 2,46E+05 4,50E+06 N.A. N.A. 7,67E+07 5,44E+08 THE Manganese Mercury Molybdenum Nickel Niobium Phosphate rock (as fosforite) PGM Potash (K2 O) REE (as C e2 O3 ) Rhenium Selenium Silver Strontium Tantalum Tellurium Thorium Tin Titanium (T iO2 ) Vanadium Wolfram Zinc Zircon (Z rO2 ) Sum Production Bt B ∗t 2,59E+03 2,50E+04 2,51E-02 8,59E+00 3,41E+01 6,40E+02 1,58E+02 1,26E+04 1,05E+01 1,03E+01 1,22E+03 1,58E+03 1,05E-02 N.A. 3,12E+03 4,84E+03 3,72E+00 N.A. 3,61E-03 4,40E-01 1,76E-01 1,62E-01 3,61E-01 3,46E+02 1,24E+02 N.A. 3,03E-01 8,42E+01 8,39E-03 8,07E-03 N.A. N.A. 3,45E+01 1,77E+03 3,52E+01 9,13E+02 1,94E+01 2,19E+02 1,00E+01 7,58E+02 1,30E+03 2,37E+04 1,21E+01 1,16E+04 1,80E+05 1,70E+06 Table 6.18: The exergy and exergy cost of the mineral reserves, base reserve and world resources. Values are expressed in ktoe.– continued from previous page. 220 THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES The exergy of the mineral resources 221 According to table 6.18, the exergy of the mineral’s reserves, reserve base and world resources studied is at least 16,5, 34,3 and 76,7 Gtoe, respectively. Their associated exergy costs increase to 161, 298 and 544 Gtoe, respectively, what highlights how far is our technology from reversibility. The exergy cost of the reserve base and world resources are comparable to the exergy reserves of fossil fuels: 19%, 34% and 63% of the total available fossil fuels in 2006 (869 Gtoe), while their exergy represent only 2, 4 and 9%, respectively. The latest consumption rate of non-fuel minerals recorded in terms of exergy cost is 1,7 Gtoe/yr or around 0,6% (0,2 Gtoe/yr of exergy) of the total reserve base. Only four minerals account for near 96% of the total exergy cost consumption: iron (58,5%), aluminium (30,4%), copper (5,5%) and zinc (1,4%). However, the minerals which are consumed at the highest rates compared to the available reserves are in decreasing order indium, silver, arsenic, antimony, tin and gold, with a rate of between 3,5 and 2,5% of the reserves consumed yearly. As opposed to fossil fuels, minerals do not lose their exergy when they are consumed. In fact, through the process of refining and concentrating of ores, the exergy of the final product increases. The problem arises when the already refined mineral is dumped in landfills or becomes dispersed when the life cycle of the product has finished. In that case, the demand for the mineral must be satisfied by extracting new ore from the mine, thereby exhausting the resource and reducing the grade of the mineral deposit. As stated before, the second law of thermodynamics, reflected in Eq. 5.10 dictates that the effort required to separate the mineral from the mine follows a negative logarithmic pattern with its ore grade. This means that as the ore grade tends to zero, the energy needed to extract the mineral tends to infinity. This is why recycling is essential to our society. It must be stressed that neither reserves, nor reserve base are good indicators for assessing the earth’s mineral capital. As stated by Highley [141], total world reserve base of most mineral commodities are larger now than at any time in the past due to wider geological information, more efficient technologies and price changes. The world resources data would be the best approximation of numbers compiling the mineral capital on earth. However, for being indeed the most comprehensive classification, the information is often scarce, inaccurate and incomplete, as can be seen in table 6.18. The fact is that too little is still known about the earth’s crust, since exploration costs are extremely high. 6.4.3 The exergy of the natural resources on earth In the previous sections we have expressed all mineral resources of fuel and non-fuel origin with the same units, using the property exergy. We are now in a position of 222 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES analyzing and comparing the global exergy resources of the earth, with the information of the rest energy resources15 provided in chapter 4. Table 6.19 summarizes the results, showing the available exergy, potential exergy use and current exergy consumption of natural resources on earth. As stated in chapter 4, with potential exergy, we mean probable exergy capacity using advanced technology, not necessarily developed nowadays. Consumption values are referred to the end of 2006, except for geothermal, PV, wind, biomass and tidal energy, which are 2005 values. The information is divided into renewable (RW) and non-renewable resources (Non-RW). For the group of renewables, the ratio between the current exergy consumption and the potential exergy use (RW use %) is provided. For nonrenewables, the base reserve to production ratio (R/P, yrs) is given, as a measure of the depletion degree of the considered mineral. According to table 6.19, the available renewable resources on earth, which are the sum of solar, tidal and geothermal energy is huge: around 32.537 Gtoe/year16 . Of course this value is only theoretical, since currently and in the near future, there is no way to technologically recover so much energy. Nevertheless, the potential exergy use is not insignificant either: 62 Gtoe/year. This means, that with a feasible improve of our technology, we could supply with renewable energy more than 6 times the energy consumption of the entire world nowadays (10,9 Gtoe in 2006). The RW use indicator, shows that with the exception of water power, which is being used at 54% of its potential, the rest energy sources are barely exploited. Geothermal electricity is using 7,5% of its potential17 , biomass 3%, wind power 0,4%, tidal energy 0,2% and solar and ocean waves current energy use is practically imperceptible with respect to their capacities. Therefore, there is an enormous improving potential in the use of renewables. For the case of non renewable resources, including nuclear energy, fossil fuels and non-fuel minerals, the available exergy is at least around 114.000 Gtoe, from which 65% come from the not yet technologically developed fusion of deuterium and tritium. The potential exergy use of non-renewable resources is around 6.103 Gtoe. In fact, with the exception of the different types of nuclear energies and unconventional fossil fuels, our technology is developed enough to extract the majority of the available non-renewable resources on earth. And that is exactly what humankind has been doing since especially the beginning of the industrialization period. The R/P ratios show that there is enough uranium for at least 8667 years, coal for 156, natural gas for 63, oil for 42 and non-fuel minerals for 191, if the consump15 Note that the exergy of electrical energy is equivalent to its energy content. Hence, the figures of geothermal, solar, wind, water and oceans power are the same expressed in energy or exergy terms. The rest energy sources: nuclear and unconventional fuels were already expressed in table 6.19 through its exergy content. 16 Note that wind, water, ocean and biomass power are sun-driven. Obviously, solar energy is only accounted once. 17 The potential thermal use of geothermal energy is not quantified, but is presumably much higher than its potential for electricity generation. Hence, global geothermal RW use indicator is even smaller. The exergy of the mineral resources 223 tion rates of the commodities remain as in 2006. The total non-renewable energy resources, would last for at least 595 years. Taking up again the global chemical exergy of the earth obtained in section 6.2.4, we can now compare the order of magnitude of the resources, with the whole chemical exergy of our planet. The chemical exergy of the atmosphere, hydrosphere and continental crust, is equivalent to the renewables potential during more than 38.000 years. This value allows us to put into perspective the huge physical value of our planet. In fact, non-renewable available resources contribute to a very small fraction of the total chemical exergy of the earth: less than 0,01%. The exergy of conventional fossil fuels and non energy mineral resources, constitute only 0,0001% of the upper continental crust’s chemical exergy. And their exergy is equivalent to that of the atmosphere, which is the layer with the least chemical exergy content. The wealth of our planet is enormous, but man can only take advantage of a very small part of it: the resources. With current technology, it is impossible to use the chemical exergy of dispersed substances. Non-renewable resources are considered as such, because they represent a stock of concentrated chemical exergy. Therefore, the earth’s 1, 22 × 109 Gtoe of chemical exergy constitutes nowadays a useless reservoir of exergy. Consequently, we should resign ourselves with only 0,01% of that amount. The results obtained lead us to conclude that there is no energy scarcity, but mineral’s scarcity. Vast amounts of energy are available on earth, much more than we could ever use. The depletion of fossil fuels should not be a problem at least in the medium term, as there are many energy alternatives. Obviously, the way of recovering them needs to be developed, so as to be economically competitive. Hence we cannot speak about energy crisis, but rather material’s and environmental crisis. Unfortunately non-fuel minerals cannot be replaced by renewable resources. In the short term, substitution among minerals will be possible with technological development, but this can only last whenever other mineral resources are available. Furthermore, the extraction of minerals produce a considerable quantity of waste rock, pollutant emissions and consume considerable amounts of water, energy and in many cases toxic chemicals for refining processes. The consumption of these resources implies an even greater additional loss of natural resource wealth. Therefore, recycling and especially, the search of a dematerialized society becomes essential. Surprisingly, this fact that seems to be unquestionable has not really started the alarms bells ringing regarding resources scarcity, at least for non-fuel minerals. Many institutions, such as the European Commission, do not regard it as a prioritized issue in their environmental action plan [88], and claim that the environmental impacts of using non-renewable resources like metals, minerals or fossil fuels are of greater concern than their possible scarcity. Probably the lack of information about resource scarcity avoids assigning this problem the priority that deserves. Tidal power Solar PV Solar thermal power Water power Wind power Ocean thermal gradient Ocean conveyor belt Ocean waves Biomass Non renewable resources Uranium - fission Thorium - fission Deutorium + Tritium (fusion) Coal Natural gas Oil Unconventional fuels Non-fuel minerals RW w/o ocean th. grad. Non RW Conv. fuels + Min. AVAILABLE POTENTIAL TW Gtoe/yr TW Gtoe/yr 17,9 13,5 0,06 - 0,04 0,12 e 0,09 e 2,7 2 0,166 0,13 43200 32521 51,4 38,7 43200 32521 0,63 - 4,7 0,47 - 3,5 11 8,2 1,8 1,3 1000 753 14,5 10,9 1,4E+08 Gtoe 2.000 1506 3 2,3 0,5 0,4 92 70 19 - 56 14 - 42 Gtoe Gtoe 27.100 5.200 7.500 74000 1549 521 380-690 170,2 220-330 177,9 ∼ 2600 76,7 34,3 32537 Gtoe/yr 62Gtoe/yr >114000 Gtoe 6103 Gtoe ∼2800 Gtoe 903 Gtoe CURRENT TW Gtoe/yr 9,3E-03 e / 0,007 e / 0,03 th 0,02 th 3,00E-04 2,00E-04 0,003 0,002 0,00035 e 0,00026 e 0,92 0,7 0,06 0,045 7,50E-07 5,60E-06 1,7 1,3 Gtoe 0,6 3,3 2,4 3,9 0,07 0,18 1,33 Gtoe/yr 10,3 Gtoe 9,6 Gtoe 156 63 42 191 RW use: 1,9% R/P: 595 yrs R/P: 94 yrs 0,2 5,8E-03 7,4E-06 53,8 0,4 1,5E-04 3,0 R/P, yrs 8667 RW use % 7,5 e THE RESOURCE Renewable resources Geothermal Table 6.19. Available exergy, potential exergy use and current exergy consumption of natural resources on earth. Letter e denotes electrical consumption, while th thermal consumption. 224 THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES Summary of the chapter 6.5 225 Summary of the chapter In the first part of this chapter, the standard thermodynamic properties of the main constituents of the outer earth’s spheres have been provided for the first time. That is the standard enthalpy, Gibbs free energy and chemical exergy of more than 330 natural substances. The enthalpies and Gibbs free energies, have been obtained either from the literature, or have been calculated with the 12 estimation methods described in section 5.4. The exergy of the substances has been calculated with the chemical exergies of the elements, generated with the R.E. developed in this PhD. The average thermodynamic properties of the atmosphere, hydrosphere (divided into seawater, rivers, glacial runoff and groundwater) and upper continental crust have been calculated with the molar fractions of the substances in each layer. It has been stated, that all negative ions in the hydrosphere throw up negative chemical exergies. Additionally, some substances of the continental crust show also negative exergy values. This is because the reference species of our R.E. are more stable than the considered substance. This leads us to question the suitability of the R.E. developed in this PhD, for natural resource accounting. Furthermore, this R.E. differs substantially from the model of degraded earth (or entropic planet) that should become. A first approximation of the crepuscular planet has been provided. It has been stated, that this degraded earth contains an atmosphere similar to the current one, but with a higher CO2 concentration due to the burning of fossil fuels, a hydrosphere were all fresh waters are mixed with salt water, and a continental crust without fossil fuels or concentrated mineral deposits. Since the relative quantity of freshwater with respect to saltwater on earth is irrelevant, the hydrosphere of this hypothetical earth has the same composition of the oceans. Something similar occurs with the continental crust, the abundance of mineral deposits and fossil fuels is negligible when compared to the whole continental crust. Hence, the composition of the degraded crust can be approximated to the model developed in this PhD. This preliminary model of entropic planet, and the thermodynamic properties of the constituents of each sphere, are the starting point of a new conception of reference environment for the calculation of chemical exergies of the elements. But this task remains open for further studies. Despite of the limitations of the R.E. developed in this study, it still constitutes a tool for obtaining chemical exergies. Since the mass of the earth and of its spheres is known, we were able to calculate the absolute chemical exergy of the atmosphere, hydrosphere and upper continental crust: 6, 27 × 103 , 7, 80 × 105 and 1, 21 × 109 Gtoe, respectively. Of course these are very rough numbers, and are subject to ulterior updates, especially when a more appropriate R.E. is found. But they are good enough, for providing an order of magnitude of the huge chemical wealth of our planet. 226 THE THERMODYNAMIC PROPERTIES OF THE EARTH AND ITS MINERAL RESOURCES The second part of this chapter has provided an inventory of the most important resources on earth, expressed through a single unit of measure: exergy. The main novelty introduced in the inventory is the combined assessment of energy resources with non-fuel minerals, thanks to the use of the exergy indicator. We have stated that there is a huge amount of energy sources on earth, of both renewable and non-renewable nature. There are many energy alternatives that could replace fossil fuels when they become depleted. But obviously the technology for recovering these alternatives needs to be further developed. Despite of the enormous chemical exergy of our planet, only 0,01% of that amount can be considered as available for human use. With current technology, it is impossible to use the chemical exergy of dispersed substances. And only those minerals that are concentrated, can be considered as resources. In the short run, technological development will allow substitution among minerals, but this can only last whenever other concentrated mineral stocks are available. Hence, the scarcity problems that man could be facing are based on the use of materials, rather than on the use of energy sources. This is why recycling and especially, the search of a dematerialized society becomes essential, in order to be consistent with the sustainability doctrine. Chapter 7 The time factor in the exergy assessment of mineral resources 7.1 Introduction The aim of this chapter is to include a new dimension in the exergy evaluation of natural capital: time. A new concept called “Exergy distance” is presented. By means of the Exergy distance, we will be able to measure the level of degradation of mineral resources on earth and to evaluate the velocity of degradation of the mineral capital. The degradation might be assessed for the entire earth, as well as for local areas in the past, present and in the future with evolution models. This way, for example, we will be able to see how climate change or the extraction of mineral resources affect the degradation of the natural capital by the decrease of its exergy. Additionally, the Hubbert peak model is proposed for evaluating the peaking production of mineral commodities. The model is applied to the exergy production and not to the tonnage, thereby introducing the concentration factor not included in the conventional estimations. The theory behind the exergy distance and the Hubbert peak model applied to exergy is described, and two case studies are presented: 1) the exergy loss of copper in the US, and 2) the exergy loss of the main minerals in Australia. 7.2 The exergy distance As explained in chapter 2, the earth can be considered as a closed system with a finite number of substances in it, regardless the occasional input of meteorites. There is a constant mass and energy transfer among the different layers of the earth. These kinds of transfers can be of natural or anthropogenic nature. Usually, mass transfers 227 228 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES of natural origin between the earth’s layers follow cycles that are stabilized by negative feedbacks. These are at a stationary state, from a planetary perspective. This means that materials and energy flow from one system to another, but the systems themselves do not change much because the different parts of the flow paths balance each other. Most natural processes such as the hydrological cycle or photosynthesis are essential for life and do not alter the ecological equilibrium on earth. However human interactions with the environment may be changing the natural fluxes. Industrial processes consume natural resources and return them to nature as non-useful wastes mostly harmful for the ecosystem. A very clear case of this fact is for instance the burning of fossil fuels and the emission of CO2 to the atmosphere. The clearing of forests, intensive agriculture with massive additions of fertilizers to the soil and the mining of ever-larger amounts of mineral resources are other cases of human alterations of the planet. Furthermore, according to Skinner, [318] if changes are made in one part of a closed system, the results of those changes will eventually affect other parts of the system. Following the conservation mass principle, it will be true that the total mass of the elements (ε j ) in the atmosphere plus hydrosphere plus continental crust will remain constant, at any situation of the planet. Considering two different situations of the planet, (1) and (2), where (2) represents a more degraded earth due to the human P action, and taking into account that r j,i · ξi = ε j (Eq. 3.1)1 , then: X X X r j,i · ξi )at m + ( r j,i · ξi )hy d r + ( r j,i · ξi )cr = ( j j j 1 X X X r j,i · ξi )at m + ( r j,i · ξi )hy d r + ( r j,i · ξi )cr ( j j j 2 This means that regardless the human action, the total budget of elements in the earth will be constant. In the same way, the sum of the energy (ei ) contained in the three spheres of the earth will be also conserved in both situations: X X X (ξi · ei )at m + (ξi · ei )hy d r + (ξi · ei )cr ) = i i i 1 X X X (ξi · ei )at m + (ξi · ei )hy d r + (ξi · ei )cr i 1 Remember that elements ε j . P i i 2 r j,i represents the stoichiometric coefficient matrix between species ξi and The exergy distance 229 However, and regardless the small amount of solar energy that the earth converts into biomass through photosynthesis (only a 0,023%), this is not true if the parameter measured is exergy (bi ): X X X (ξi · bi )at m + (ξi · bi )hy d r + (ξi · bi )cr ) > i i i 1 X X X (ξi · bi )at m + (ξi · bi )hy d r + (ξi · bi )cr i i i 2 In other words, even if mass and energy are conserved in all processes according to the first law of thermodynamics, the second law states that as resources are consumed, the useful energy or exergy of the earth will decrease. The degradation of a natural resource can come from three effects: • an alteration of its composition, • a change of its concentration2 , • a variation of the reference environment. And all three effects can be detected by a decrease of its exergy. Hence, for instance, when a fossil fuel is burned with oxygen, its chemical composition is transformed into water, carbon dioxide and other gases, thereby, losing chemical exergy. In the same way, when minerals are extracted from a deposit, the mine decreases its ore grade, thereby losing concentration exergy. Therefore, the current exergy of the earth and its exergy evolution over time can be an objective measure for the depletion degree of the planet. We define the exergy distance (D) between two situations of the planet as the exergy difference between both states, as in Eq. 7.1: ! D= X i=1 ξi · bi ! − 1 X i=1 ξi · bi (7.1) 2 The exergy distance can be applied on a global scale to the total quantity of substances on earth, or to a certain natural resource, if the aim is to assess its specific degradation. In fact, due to the very small relative weight of what we consider resources with respect to the other substances on earth, it makes more sense to apply 2 Note that a decrease of its quantity is not considered as a degradation, since the conservation of mass statement must be obeyed. The matter is not lost, it is either chemically transformed or dispersed. 230 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES the exergy distance concept to the resources only, separating them from the rest components on earth. Additionally, we define the exergy degradation velocity ( Ḋ) between two states as the exergy distance between the states (D) divided by the period of time separating them (∆t), as in Eq. 7.2: Ḋ = ∆B ∆t P = i=1 ξi · bi − 1 P i=1 ξi · bi 2 (7.2) ∆t In the same way, the exergy distance and exergy degradation velocity can be applied to the exergy replacement costs3 , obtaining the irreversible exergy distance (D∗ ) and the irreversible exergy degradation velocity ( Ḋ∗ ). Through the exergy replacement costs, we introduce the irreversibility factor not included in the exergy parameter, since the latter only considers minimum energies. ! ∗ D = X ξi · bi∗ i=1 Ḋ∗ = ∆B ∗ ∆t P = ! X − i=1 1 i=1 ξi · bi∗ ξi · bi∗ − 1 P ∆t (7.3) 2 i=1 ξi · bi∗ 2 (7.4) Figure 7.1 shows a conceptual diagram of the exergy distance and exergy degradation velocity terms of mineral reserves. 7.3 The tons of mineral equivalent One of the drawbacks that could be attributed to exergy is that most people and policy makers are not familiar with energy units for natural resource accounting. So anybody can understand how much is a kg or a ton of a certain material, but the equivalent amount in kJ or kcal does not give any practical information to the majority of the population. Fortunately exergy can be measured in different kinds of units, not only kJ or kcal, but also in tons of oil equivalent -toe- (the exergy contained in one ton of oil). Therefore, the same principle can be applied to non-fuel minerals as with oil. Since the exergy of a resource, and particularly of a mineral deposit changes with the ore grade and the reference environment, the unit of measure ton of mineral equivalent has to be fixed to a specific year and a specific place. Hence, we define the parameter ton of Mineral equivalent t M e as the exergy content of one ton of mineral in a certain time and place, as in Eq. 7.5. 3 Explained in section 5.3.4 The tons of mineral equivalent 231 Degradation Exergy Resources D . D=dD/dt Δt Time Figure 7.1. Conceptual diagram for the terms exergy distance and exergy degradation velocity tMe = BM mM (7.5) t Being B M the absolute exergy of mineral M , and m M the tonnage of mineral M considered. Once the time and place has been specified and taken as reference (situation 1), one can calculate the tons of Mineral equivalent of the mineral deposit at another situation (2). Then the t M e of situation 2 will be: (t M e)2 = (B M )2 (t M e)1 (7.6) Again, this concept can be applied either to exergy or to exergy replacement costs. For the latter, the tons of Mineral equivalent will be calculated as: ∗ tMe = ∗ BM mM (7.7) t The t M e can be also used for comparing the quality of different mineral deposits, containing the same resource. This is clarified next through a simple example. Mine A contains in year 2007 mA tons of gold and BA toe of exergy. If mine A is taken as reference in that year, then one ton of gold equivalent has an exergy content of: 232 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES t Aue = BA/mA. Mine B has the same amount of gold than mine A (mA = mB ) but with a worse quality (lower ore grade) than that of A (BB < BA). In mass terms, mine B would be as good as mine A. But if we use the exergy indicator, mine B has less tons of gold equivalent than the reference: (tAue)B = BB /(tAue) = mA · (BB /BA). In the same way, the reserves of a certain mineral in a country could be expressed in a practical and elegant way as tons of Mineral equivalent. This combines the advantages of both indicators: on one hand the more comprehensive unit of measure exergy and on the other hand the more understandable unit of measure mass. Nevertheless, as the property mass is involved in the calculation, the t M e loses the additive capacity that characterizes the exergy indicator. 7.4 The R/P ratio applied to exergy The resources to production ratio (R/P) is an estimative measure for assessing the years until depletion of a certain resource. For that purpose, the tonnage of the estimated reserves is divided into the production of the year under consideration. Since both, production and reserves fluctuate throughout the years, R/P ratios may increase or decrease accordingly. Remember that the reserves might increase if new deposits are discovered or if technological development or mineral prices allow to extract lower grade deposits not considered as profitable before. Therefore, the R/P ratio should always be accompanied by the calculation year. In this PhD, we calculate the resources to production ratio in exergy terms. This allows to include additional information about the concentration of the deposit, not taken into account with the conventional calculation in mass terms. 7.5 The Hubbert peak applied to exergy M. King Hubbert ([146], [147]) found in the mid-fifties that the production of fossil fuel trends had a strong family resemblance. The curves started slowly and then rose more steeply tending to increase exponentially with time, until finally an inflection point was reached after it became concave downward. The observed trends are based on the fact that no finite resource can sustain for longer than a brief period such a rate of growth of production; therefore, although production rates tend initially to increase exponentially, physical limits prevent their continuing to do so. So for any production curve of a finite resource of fixed amount, two points on the curve are known at the outset, namely that at t = 0 and again at t = ∞. The production rate will be zero when the reference time is zero, and the rate will again be zero when the resource is exhausted, after passing through one or several maxima. The second consideration is that the area under the production curve must equal the quantity of the resource available (R). In this way, the production curve of a certain Production (P) The Hubbert peak applied to exergy 233 Q= R∞ Pdt 0 Time (t) Figure 7.2. The Hubbert’s bell shape curve of the production cycle of any exhaustible resource [146]. resource throughout history takes the ideal form of the bell-shape curve shown in Fig. 7.2. The model was successful in predicting the peak of oil extraction in the US lower 48 states and the subsequent decline in production. Recently, several authors used Hubbert’s model to predict the evolution of crude oil extraction at the planetary level (Deffeyes [72], Bentley [24], Campbell and Laherre [47], [46]). According to these estimates, the corresponding production peak could take place within the first decade of the 21st century or not much later. And as Campbell and Laherre [47] argue, from an economic perspective, when the world runs completely out of fuels is not directly relevant: what matters is when production begins to taper off. Beyond that point, prices will rise unless demand declines commensurately. It must be pointed out that the successful prediction of the model depends on many factors, being the most important one, the reliability of the estimated reserves. Forrester/Meadows models [96], [218] are almost always asymmetric with the decline much sharper than the growth. Bardi [18] showed that the bell-shaped curve may turn out to be strongly asymmetric depending on extraction strategies. As Bartlett argues [22], actual production curves will be probably modified by economic, geological, political, technological, and other factors, which may result in a deterioration of the quality of the fit between the data and the Gaussian, but the role of these important factors is limited to changing the quality of this fit. Basically, the Hubbert model can be applied to those minerals, where the concentration factor is not important, i.e. to liquid and gaseous fossil fuels. Roberts and Torrens [283] applied also the Hubbert model in 1974 to examine the production cycle of copper. At that time, there was not so much information as today regarding consumption rates or future reserve estimates, which are essential ingredients for the methodology. Therefore, the model had to be applied making quite lot assump- 234 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES tions. Nowadays, the curve can be defined through more points and there are more reliable estimations for mineral reserves (as for instance the data provided by the US Bureau of Mines). Furthermore, we think that the bell-shape curve is better suited to minerals, if it is fitted with exergy over time instead of mass over time. Oil quality keeps nearly constant with extraction, whereas other non-fuel minerals don’t (mineral’s concentration decreases as the mine is being exploited). Therefore exergy is a much better unit of measure than mass, since it accounts not only for quantity, but also for ore grades and composition. The well known bell-shaped curve can be fitted to the exergy consumption data provided, in order to estimate when mineral production will start declining. Next, the mathematical procedure for the application of the model is explained. Hubbert’s bell-shape curve can be described through the generic gaussian curve described in Eq. 7.8. f (t) = y0 e − t−t 0 b0 (7.8) The integral of the gaussian curve is equal to the reserves (R) of the commodity: Z +∞ f (t)d t = R (7.9) −∞ And the integral of Eq. 7.8 is given by Eq. 7.10. Z ∞ e − t−t 0 b0 dt = 0 p b0 π 2 (7.10) Combining Eqs. 7.9 and 7.10, and taking into account that the curve is symmetric, the reserves can be expressed as: p y0 b0 π = R (7.11) Hence, the model of the curve to be adjusted is given by Eq. 7.12: R − f (t) = p e b0 π t−t 0 b0 (7.12) Where parameters b0 and t 0 are the unknowns. In our case, we will represent the yearly exergy loss of the commodity vs. time. With a least squares procedure, the points will be adjusted to the curve given by Eq. 7.12. The maximum of the function is given by parameter t 0 , and it verifies that f (t 0 ) = b Rpπ . 0 The exergy loss of mineral deposits due to mineral extraction. The case of copper in the US 235 7.6 The exergy loss of mineral deposits due to mineral extraction. The case of copper in the US Before explaining the exergy decrease of mineral deposits, it must be pointed out that extraction does not necessarily mean that the inherent exergy of the mineral is being lost. On the contrary, through the process of mining and concentrating of ores, we are increasing the exergy per unit of resource and in fact, that exergy will remain in wires, buildings, industrial machinery and other products were the minerals are used. The problem arises when the objects made of the refined mineral are disposed of in landfills at the end of their useful life. In that case, the demand for the mineral must be satisfied by extracting new one from the mine, thereby exhausting the resource and reducing the exergy of the mine (the mine contains a lower quantity of mineral at a lower grade). Fortunately, recycling reduces the need for so much new mineral to be extracted. Therefore, recycling is very important to our society, by preventing dispersion once a material has been concentrated. Hence, when we refer to the exergy loss of mineral deposits, we are indicating the exergy that the mines are losing through mineral extraction. In practice, this exergy is only lost when the refined mineral is dumped in landfills or becomes dispersed. The calculation of the exergy loss of non-fuel minerals requires a great amount of information: world trends of natural resources production and consumption, trends of ore grades and mineral reserve projections. Unfortunately, these data is not always available and requires a lot of effort to gather it. The US Geological Survey, British Geological Survey, British Petroleum and other entities publish periodically new information about world mineral commodities. Nevertheless, the data is usually insufficient, since for most commodities, ore grade trends are not studied. In the next sections, we will present the application of the exergy analysis to the assessment of the exergy loss of US copper mines. The calculations will be explained in detail, so as to serve as an example for the Australian case, presented in section 7.7. 7.6.1 Copper mining features Copper has been mined in the United States at an industrial scale, at least from 1709, in Simbsbury, Connecticut. The industrial revolution intensified the use of copper in the mid of the nineteenth century, and consequently its production. The USGS provides historical production and grades data since year 1900. The published reserves and reserve base of US copper, as well as ore grade trends throughout the 20th century by the US Geological Survey [361], allow us to calculate the exergy decrease of US copper mines in the last century. Copper in mineral deposits is usually found in nature in association with sulfur, as chalcopyrite (CuFeS2 ), but it can be also found as an oxide. The most important 236 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES Naturally occurring chemical process [xc] Cu + 2SO4-2+1/2 Fe2O3 (0) +2 [xc] CuFeS2 + 19/2O2 (1) Naturally occurring concentration process [xm] CuFeS2 (2) (0) (1) Dispersed earth with R.S. Dispersed earth with minerals Cu is dispersed on Earth in form of Cu+2 (aq) A chemical reaction takes place, forming CuFeS2 from their corresponding reference substances (2) Minerals concentrated in mines Actual Earth The dispersed CuFeS2 at xc is concentrated into the mines at xm. Figure 7.3. Hypothetical processes involved in obtaining the mineral of copper from the reference environment copper ore deposits (the “porphyry coppers”) normally have quite low concentrations of copper (0,3 to 0,6% Cu) but this is compensated by their size (hundreds to thousands of million tons of ore). The production of pure copper from the ore can be summarized in two processes. The first one is concerned with the mining and concentrating of low grade ores containing copper mineral. The second one is fundamentally a chemical process in which the concentrated ore is smelted and then refined through an electrolytic process. The hypothetical processes needed for replacing the mineral from the reference earth to the conditions in the mine are outlined in Fig. 7.3. As a first approximation, it has been assumed, that all the copper occurs in the mines as chalcopyrite. These processes are needed to replace the mineral from the R.E. At state 0, the earth is composed of only reference substances (R.S.) dispersed in the three subsystems of the R.E.: continental crust, atmosphere and hydrosphere. At state 1, the reference substances of the reference environment defined in this PhD (section 5.2) composing the mineral (Cu+2 and SO4−2 from the hydrosphere and Fe2 O3 from the continental crust), react to form CuFeS2 . Finally, at state 2, the dispersed chalcopyrite is concentrated from x c to the ore grade of the mine x m . The exergy loss of mineral deposits due to mineral extraction. The case of copper in the US 237 The concentration of copper in the reference environment x c is assumed to be equal to 2,8E-5 g/g, which is the average concentration of copper in the earth’s crust, according to Rudnick and Gao [292]. The unit concentration cost of copper i.e. the energy required to concentrate copper from x c to x m with today’s technology was estimated by Valero and Botero [371] as kc = 385, 61. This value4 was obtained considering that the unit concentration cost for the real process of mining and concentrating is the same as in the hypothetical process of concentration between the R.E. and the mine conditions. The energy requirement for mining and concentrating considered (ec ) was the one obtained by Chapman and Roberts [53]: 66,7 GJ/ton for an ore grade of 0,5% Cu. The ratio between the real energy required and the minimum exergy to concentrate the mineral from the earth’s crust to the ore grade of the mine gives the unit exergy cost mentioned before. The result obtained means that with current technology, we have to invest 385,61 times more energy for concentrating copper from the R.E. to the mine than in the reversible process. Martínez et al. [207] updated the value of kc for copper with more recent information. The value obtained, which is the one used for our calculations was: kc,Cu = 343, 1. The real quantity of energy required for “refining” the mineral between the earth’s crust (as in the Reference Environment) and the conditions in the mine is also usually greater than the standard chemical exergy given by Eq. 5.1. As explained in section 5.3.4, Valero and Botero estimated the unit chemical exergy costs of sulfides as being at least kch = 10. Martínez et al. [207] updated that value for copper, obtaining kch,Cu = 80, 2. Remember that in chapter 5, table 5.7 shows the unit exergy costs of selected minerals, according to Valero and Botero [371] and Martínez et al. [207]. 7.6.2 Chemical exergy The reserves and reserve base of copper in the US in year 2000 were 45.000 kt and 90.000 kt respectively [362]. The chemical exergy of copper mines will be calculated assuming that Cu is found in the deposit as the metal. This approximation is used as there is a lack of information about the amount of copper extracted from chalcopyrite and the other copper ores such as oxides and other sulfides. Hence, our first goal is to obtain the exergy of state 1 in PFig. 7.3. The chemical exergy of Cu, calculated with Eq. 5.1 (bch i = ∆G f i + r j,i bch j ), being ∆G f Cu = −190, 9 kJ/mole and obtaining the chemical exergy of the elements from the R.E. developed in this study and described in section 5.2.3.5 is: bch Cu = 134, 0 MJ/kmole. Surprisingly, the chemical exergy of the mineral is higher than that of the pure element: bch CuFeS2 = 1534, 5 MJ/kmole (11,45 times greater). This is due to the fact 4 racy. Although 5 significant figures are given for kc , the number cannot be considered with that accu- 238 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES that since stability (criterion taken partially by Szargut et al. [343] and in this study for choosing the reference substances) does not coincide with abundance in a number of cases, some minerals that are quite abundant in nature, such as sulfides, have a fairly high chemical exergy that can be considered as an exergy reservoir that the earth provides us for free. This helps our technology to avoid the expenditure huge amounts of commercial energy during the process of obtaining the corresponding pure element. The component of the minimum chemical exergy of a substance remains constant over time, since it only depends on its chemical composition. Hence, in absolute terms, the chemical exergy consumption of any substance is proportional to its production rate. The chemical exergy decrease of copper mines in the United States in the 20th century (B), can be calculated by multiplying the molar copper primary production (ṁ) with the exergy of copper obtained before: B = ṁ · b. The production of copper in the US during the past century (see Fig. 7.4), was obtained from the Historical Statistics for Mineral and Material Commodities in the United States [361], which is a compilation of data from publications primarily of the USGS and USBM, such as the Minerals Yearbook [363]. Figure P 7.5 shows the cumulative chemical exergy decrease of copper mines in the US ( Bch). At the end of year 2000, the total chemical exergy distance of copper mines from the beginning of the century, was Dch = 5, 66 Mtoe. This exergy was consumed at an average degradation velocity Ḋch = 56, 04 ktoe/year, although the trend since the seventies shows an average degradation velocity of around 77,39 ktoe/year. The maximum velocity was attained in year 1998 (107,81 ktoe/year), while the minimum was in 1900 (14,66 ktoe/year). Copper production has shown a continuous growth, since it is strongly linked to the electrical and telecommunication industries. The chemical exergy of copper reserves, calculated as pure copper at the end of year 2000, was 2,27 Mtoe. If we add the cumulative chemical exergy consumption to the exergy reserves at the end of year 2000, we obtain the exergy reserves at year 1900: 7,93 Mtoe. Similarly, the chemical exergy of copper reserve base at the beginning and end of the century were 10,19 and 4,53 Mtoe, respectively. 7.6.3 Concentration exergy Next, the concentration exergy of the mine (step 3 in Fig. 7.3) will be obtained as the difference between the concentration exergies obtained with the mineral concentration in a mine (x m ) and with the average concentration in the earth’s crust h i (x c ). The (1−x ) latter are calculated with Eq. 5.10 (bc i = −R̄T0 l nx i + x i l n(1 − x i ) ). Since no i ore grades are provided between years 1901 and 1905, it has been assumed that the concentration of those years is the same as in 1900. The concentration exergy of the mine, i.e. the minimum energy that nature had to spend to bring minerals from x c to x m , is not constant over time, because it changes with the ore grade of the mine The exergy loss of mineral deposits due to mineral extraction. The case of copper in the US 239 120 140 100 120 100 80 60 60 40 40 20 bch,MJ/kmol Bch, ktoe 80 20 0 0 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 Year Bch (ktoe) bch (MJ/kmol) Figure 7.4. Yearly chemical exergy consumption in the US of pure copper due to copper production throughout the 20th century 6000 5000 ΣBch, ktoe 4000 3000 2000 1000 0 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 Year Figure 7.5. Cumulative chemical exergy decrease of copper mines in the US throughout the 20th century (see Fig. 7.6). The mine has the greatest exergy concentration, when the ore grade is at the maximum and becomes lower as the ore grade decreases. At the beginning of the century, when the ore grades were at above 2% Cu, the concentration exergy was the highest, namely bc Cu > 18 MJ/kmole. In the last years, the ore grades have declined to values less than 0,45% Cu and hence the concentration exergy of the mine has decreased accordingly: bc Cu < 15 MJ/kmole. Copper ore grade trends in 240 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES 12,0 20 19 10,0 18 8,0 Bc, ktoe 16 4,0 15 2,0 14 0,0 1900 bc, MJ/kmol 17 6,0 13 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 Year Bc (ktoe) bc (MJ/kmol) Figure 7.6. Yearly concentration exergy consumption in the US of pure copper due to copper production throughout the 20th century the US are obtained from the work done by Ruth [295] and completed and updated with information from the Minerals Yearbook [363]. Figure 7.7 Pshows the cumulative concentration exergy decrease of copper mines in the US ( Bc ). The total concentration exergy distance of copper mines between the beginning and end of the century was Dc = 628, 98 ktoe. This exergy was consumed at an average degradation velocity of Ḋc = 6, 22 ktoe/year. The maximum degradation velocity was attained in year 2000 (10,56 ktoe/year), while the minimum in year 1906 (1,89 ktoe/year). The concentration exergy of copper reserves and reserve base in year 1900 were 875,3 and 1121,71 ktoe respectively, while in year 2000, 246,36 and 492,73 ktoe. Figure 7.7 shows the cumulative concentration exergy decrease of copper mines in the US. 7.6.4 Total exergy We can now calculate the total exergy distance of US copper mines between the beginning and end of the century: D = (B t,1900 − B t,2000 ) = (Dch + Dc ) = (5660, 37 + 628, 98) = 6289, 35 ktoe. Dividing this quantity into the years considered, we obtain the average exergy degradation velocity of US copper: Ḋ = 62, 2 ktoe/year. As can be seen, the exergy concentration component is much lower than the chemical one. For more abundant minerals than copper, such as aluminium or iron, The exergy loss of mineral deposits due to mineral extraction. The case of copper in the US 241 700 600 ΣBc, ktoe 500 400 300 200 100 0 1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000 Year Figure 7.7. Cumulative concentration exergy decrease of copper mines in the US throughout the 20th century this fact is even more enhanced. The minimum thermodynamic energy required to separate two substances such as sugar and salt for example, is equal to the energy to mix them, which is in fact very low. This is of course not true and the exergy required to separate substances is much greater than in the reversible case. In order to overcome that problem, we need to resort to the exergy costs of the mine. 7.6.5 Exergy costs Through unit exergy costs, reversible exergies are converted into real exergies with Eq. 5.46 (B ∗t = kch · Bch + kc · Bc ). That equation assumes that exergy costs are constant over time. In fact this is not completely correct, because there are two factors that must be taken into account. The first one is that technological development improves the efficiency of mining and refining processes and thus costs tend to decrease (theory of learning curves). The second factor is that as extraction continues and technology is being improved, lower quality resources can be extracted. However, the use of lower quality resources requires an increase in energy input, which increases costs. If we convert the total minimum exergy consumption into real exergy, making the assumption that the costs are constant, we obtain that the irreversible exergy distance D∗ is: D∗ = (B ∗t,1900 − B ∗t,2000 ) = Dch · kch + Dc · kc = 5660, 37 ∗ 80, 2 + 628, 98 ∗ 343, 1 = 669.764, 7 ktoe And the average irreversible exergy degradation velocity Ḋ∗ = 6631, 3 ktoe/year. 242 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES Around 68% of the exergy costs are due to the chemical exergy of copper and 32% to its concentration exergy. The cost represents the exergy consumed of US copper mines during the 20th century and is equivalent to 71,3% of 2006 oil consumption in the US (938,8 Mtoe [35]). This figure gives an idea of the huge amount of energy that we are degrading by extracting minerals. It must be remembered, that this study only applies to copper mines in the US. Additionally, we can calculate the tons of copper equivalent (t Cue∗ ) associated to the exergy costs of the reserves and reserve base. For that purpose, we take as reference, the exergy cost B ∗t of the reserves in 1900 (5,95 toe/t of Cu extracted). The M t Cue∗ is slightly lower than the tonnage due to the loss of concentration exergy (44,7 M t Cue∗ vs 45 Mt for the reserves and 89,5 M t Cue∗ vs 90 Mt for the reserve base). 7.6.6 The R/P ratio and the depletion degree of the deposits The resources to production ratio for US copper, is calculated by dividing the reserve base’s exergy in year 2000 (5027 ktoe), with the exergy of the metal produced in that year (90,16 ktoe). The resulting R/P ratio indicates that if production of US Cu remains as in year 2000, and the reserve base does not increase after that year, the reserves would be completely depleted in 56 years. The depletion degree of US copper deposits (%R loss and %R.B. loss) is calculated as the ratio between the exergy distance D, and the total reserves of the commodity. The latter are obtained as the published reserves or reserve base of the commodity in 2000, plus the exergy distance D from 1900 to 2000. Accordingly, copper production in the US throughout the 20th century has leaded to the depletion of 71% and 56% of its national copper reserves and reserve base, respectively. 7.6.7 The Hubbert peak model We are now going to apply the Hubbert peak model to US copper mining, in order to estimate its peak of production. For that purpose, the exergy production has to be plotted against the corresponding years. At a first stage, we are going to adjust the points to the gaussian curve, given by Eq. 7.8, i.e. without applying the constraint about a fixed amount of reserves. The resulting curve represented in Fig. 7.8 is described by Eq. 7.13: f (t) = 107, 1e − 12 t−2041 87,08 (7.13) The maximum is reached at t = t 0 in year 2041. The integral of Eq. 7.13 represents R +∞ the reserves: −∞ f (t) = 24.053, 4 ktoe. The regression of the curve is quite low: RF = 0, 7532. The exergy loss of mineral deposits due to mineral extraction. The case of copper in the US 243 Therefore, the production behavior of US copper is associated to available reserves equal to around 24 Mtoe, assuming that it follows the bell-shaped curve defined by Hubbert. 120 2041 100 Bt 80 60 40 20 0 2.5 4 x 10 Integral Bt 2 1.5 1 0.5 0 1700 1800 1900 2000 2100 2200 2300 2400 Figure 7.8. The Hubbert peak applied to US copper production. Best fitting curve. Values in ktoe. Nevertheless, according to the USGS, the reserve base in year 2000 is equal to 5,02 Mtoe. Adding the already exergy extracted from 1900 to 2000, the base reserves increase to 11,3 Mtoe. Since no data is provided before 1900 and there were certainly important amounts of copper extracted at least in the second half of the nineteenth century, we will make the assumption, that Cu extraction from 1700 to 1900 followed the curve of Eq. 7.13. Hence, the 1700 reserve base are approximated to: R1700 = R2000 + 2000 X Bt + 1900 = 12549, 9ktoe Z 1900 107, 1e − 12 t−2041 87,08 = 5026, 7 + 6289, 4 + 1233, 8 1700 (7.14) 244 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES Therefore, instead of the 24 Mtoe of reserves obtained from the model without constraints, the US total base reserves amount to around one half of that: 12,55 Mtoe. With the constraint of the reserves, we can now apply the Hubbert peak model, adjusting the production points to Eq. 7.12. Figure 7.9 shows the final curve, with again a low regression factor RF = 0, 7305. According to the model, the production would have reached the peak in year 1994. In fact, recent data about copper production in the US reveals that the peak was reached in year 1998 with 2,1 Mt extracted. Since then production has decreased more rapidly than it increased before reaching the peak. This indicates that the observations of Meadows [218], where production follows asymmetric curves with the decline much sharper than the growth, apply better at least for US copper production. Another conclusion that can be extracted from the application of the model is that if the production curves are generally asymmetrical, the peak will be reached after the year predicted by the Hubbert model. During a short period of time, the commodities will be probably over-exploited and the production points will appear over the bellshaped curve. The compensation of the overproduction is the much sharper decrease of production after the peak, instead of a gradual and steady reduction. Applying the Hubbert peak model to production in mass terms, instead of exergy terms gives 1993 as the peaking year for US copper. As can be seen, the difference between both approaches is very small, since as stated before, in minimum exergy terms, the concentration component is considerably less important than the chemical one. And it should be remembered, that as opposed to the concentration exergy, the chemical exergy is proportional to the quantity of mineral extracted. The effect of decreasing ore grades with production would be better observed if exergy costs, rather than minimum exergies are used for the plotting. In such a case, the concentration and the chemical exergy terms are well balanced. However, in this study we have assumed that unit exergy costs remain constant over time. For a correct representation of exergy costs vs. time, we would require that the exergy costs are calculated with the corresponding unit exergy costs of the period of time considered, incorporating the learning curves of the technologies. But this task remains open for further studies. 7.6.8 Summary of the results Table 7.1 summarizes the results obtained, showing the exergy and exergy costs, the exergy distance, average degradation velocity, the tons of mineral equivalent, the R/P ratio, depletion degree of the reserves and reserve base (% R. loss and % R.B. loss) and the estimated and real peak of production of US copper reserves and reserve base during the 20th century. The exergy loss of a country due to mineral extraction. The case of Australia 245 120 100 1994 Bt 80 60 40 20 0 14000 12000 Integral Bt 10000 8000 6000 4000 2000 0 1800 1900 2000 2100 2200 Figure 7.9. The Hubbert peak applied to US copper base reserves. Values in ktoe. 7.7 The exergy loss of a country due to mineral extraction. The case of Australia In the example above, we have applied the exergoecological method to a single commodity of a country. Since exergy is an additive property, we can analyze the exergy loss due to mineral extraction of all commodities in a region, country or even in the entire world. The objective now it to assess from the exergoecological point of view, the degradation of the main mineral resources of fuel and non-fuel origin of a country throughout its mining history. Australia is the country chosen for our purpose for two reasons: 1) a comprehensive analysis of Australian mining data was provided by Mudd [234], [232], [233] and 2) Australia is a major mineral producer and exports numerous commodities around 246 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES Table 7.1. Summary of the results of the exergy distance of US copper mines during the 20th century. Year Bch Bc Bt D Ḋ, ktoe/yr ∗ Bch Bc∗ B ∗t D∗ Ḋ∗ , ktoe/yr mCu , Mtons M t Cue∗ R/P, yrs % R. loss Hubbert’s peak Real peak RESERVES BASE RESERVE 1900 2000 1900 2000 Minimum exergy, Mtoe 7,93 2,27 10,19 4,53 0,86 0,25 1,11 0,49 8,79 2,51 11,30 5,03 6,28 62,25 Non-reversible exergy, Mtoe 635,77 181,81 817,58 363,62 300,33 84,53 384,86 169,05 936,10 266,34 1202,44 532,68 669,76 6631,33 157,36 45,00 202,36 90,00 157,36 44,77 202,13 89,54 56 71 56 1994 1998 the world. Furthermore, its resources are periodically updated and published in Geoscience Australia [112]. The study of Mudd aims to shed light on the current debate on sustainable mining in Australia, establishing the extent of the changes in ore grades for various minerals and metals as well as quantifying the production of wastes. Mudd provides valuable information among others, about historical production data, ore grades and economic demonstrated reserves. For some commodities such as copper, the information dates back to 1844. Assimilating such a great amount of information for each commodity is not always easy and not very useful for decision makers. However, all these data can be easily processed and summarized in one indicator, namely the exergy indicator. 7.7.1 Non-fuel minerals The aim of this section is to obtain the exergy and exergy cost of the main Australian metals throughout their mining history: Au, Cu, N i, Ag, P b, Z n and Fe. The reversible and irreversible exergy distances D and D∗ , the exergy degradation velocities Ḋ and Ḋ∗ , and the tons of mineral equivalent t M e∗ lost of the economic demonstrated reserves are provided. The tons of mineral equivalent are calculated as the average exergy cost B ∗t of one ton of mineral in the Australian mineral deposits The exergy loss of a country due to mineral extraction. The case of Australia 247 in year 1900 (whenever data is available for that year). The reserves of the mine at the beginning of the mining period are considered to be equal to the cumulated production throughout the mining history until 2004, plus the published reserves in 2004 (the same principle is applied to the reserves in terms of exergy costs). The peaking of mineral production is estimated with the application of the Hubbert peak model described in section 7.5. Additionally, the R/P ratio assessed in exergy terms is given as a measure of the estimated years until depletion of the different commodities. The same equations, data sources and ideas used for US copper mines are here applied. For calculating bch, Eq. 5.1 is used, taking as input the chemical exergies of the elements generated from the R.E. defined in this study (Table 5.4). The concentration exergy bc is calculated with Eq. 5.10. The value of x c is taken from the latest geochemical study of the earth’s continental crust from Rudnick and Gao [292]. Finally, the unit exergy costs applied are those obtained by Valero and Botero [371] and updated by Martínez et al. [207]. Figures 7.10 through 7.22 show the cumulated minimum concentration and chemical exergy consumption over time on the left axis and the ore grade trend on the right axis of the main base-precious metals extracted in Australia. As can be seen from the figures, and as it happened to the case of copper in the US, the concentration exergy Bc is usually much smaller than the chemical one Bch. But this fact ∗ changes when the values are converted into exergy costs Bc∗ and Bch , as shown in tables 7.2 to 7.8. The graphs reveal as well that consumption of all commodities has increased continuously, following a general exponential trend. The quality of Australian mines, or in other words, their ore grade trends, have been notably reduced throughout the last century. This implies an even greater loss of the mine’s exergy and an important production of waste rock. For the sake of simplicity, the direct results are provided. 7.7.1.1 Gold Gold has played an important role in Australia’s history, influencing the economic, social, environmental and political life of the country. The decade of 1850’s is often denoted as the gold rush decade and since then, great amounts of gold have been extracted from all states. Australian gold industry is characterized as having continuous cycles of boom and bust. The most representative inflection points occurred in the late 1800’s and around 1980. In both cases, the discovery of new fields caused that production, which had gradually declined before those dates, rose to new highs (see Fig. 7.10). Gold’s ore grade has followed a general declining trend, even though there have been various intermediate peaks coinciding with new discoveries. Ore grades have descended from 37,27 g/t in 1859, to the current 2,02 g/t. The concentration exergy costs of gold mines (bc∗ ) decreased respectively from 1,28 to 0,91 toe/kg. 248 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES 100 40 35 80 30 70 25 60 50 20 40 15 30 Ore grade Xm, g/t Cumulative total exergy Bt, toe 90 10 20 5 10 0 1859 1869 1879 1889 1899 1909 1919 1929 1939 1949 1959 1969 1979 1989 1999 0 Year Bc Bch Xm Figure 7.10. Ore grade and cumulated exergy consumption of Australian gold mines The exergy distance (D) between Australian gold mines in 2004 and 1859 is equal to 88,97 toe, while the irreversible exergy distance D∗ : 10.683 ktoe. The great difference between the reversible and irreversible exergy distances are due to the extremely high unit concentration costs for gold: 422.879 [207]. The average exergy degradation velocity ( Ḋ) of Australian gold mines is 0,61 toe/year, ranging from 0,12 toe/year reached in 1929, to the last high of 2,64 toe/year in 1997. This figure has fluctuated frequently due to changing gold prices, available resources, policy, technology and socioeconomic factors. The average irreversible degradation velocity Ḋ∗ is equal to 73,17 ktoe/year. The ktons of gold equivalent in terms of exergy costs extracted in the mining period from 1859 to 2004 was 11,06 ktAue∗ , being the reference actual exergy of one ton of gold in year 1900 equal to 0,97 ktoe. The economic demonstrated reserves of gold in year 2004 are estimated as 5,59 kt, or 5,30 ktAue∗ (B ∗t = 5118,61 ktoe), although they might probably increase in the future, since exploration continues to take place and technological development will probably allow to mine low grade deposits. Note that since year 1900 was taken as reference for estimating the ktons of gold equivalent, the ktAue∗ before that year will be greater than the tonnage, since the ores were more concentrated. The contrary happens after the reference year. The R/P ratio for Australian gold deposits is estimated as 22 years, being 2004 the reference year for the calculations. Additionally, gold production in Australia has depleted around 65% of its economic demonstrated reserves. The Hubbert peak is applied for Australian gold deposits since year 1943. Previous years are discarded in the analysis due to the fluctuation of the production rates, as new gold fields were found. Since 1943, it is assumed that most of the reserves The exergy loss of a country due to mineral extraction. The case of Australia 249 have been found. The value for R in that year is calculated as the sum of the exergy reserves in 2004, plus the cumulated exergy between 1943 and 2004 (R1943 = 96, 02 toe). Accordingly, the production peak is reached in year 2006 (see Fig. 7.11), with a regression factor of the fitting curve of RF = 0, 9014. This implies, that although production in the last years has decreased, it was not caused by the resource limitation and rather by external factors such as company’s strategies. 3 2006 2.5 Bt 2 1.5 1 0.5 0 100 Integral Bt 1943 80 60 40 20 0 1940 1960 1980 2000 2020 2040 2060 2080 Figure 7.11. The Hubbert peak applied to Australian gold reserves. Values in toe. The results for Australian Gold deposits is summarized in table 7.2. 7.7.1.2 Copper Copper has been also a relevant contributor to the country’s richness, since Australia is a major copper producer in the world. Their metal deposits were discovered and worked on a significant and profitable scale from 1842. The production of copper has been continuous ever since. 250 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES Table 7.2. Summary of the results of the exergy distance of Australian gold mines. Year Bch Bc Bt D Ḋ, toe/yr ∗ Bch Bc∗ B ∗t D∗ Ḋ∗ , ktoe/yr t Au ∗ tAue1900 R/P, yrs % R. loss Year of the peak Reserves 1859 2004 Minimum exergy, toe 98,62 34,91 37,37 12,10 135,99 47,02 88,97 0,61 Non-reversible exergy, ktoe 0,10 0,03 15801,82 5118,57 15801,92 5118,61 10.683,31 73,17 15.789 5.589 16.358 5.299 22 65 2006 Australian copper ore grades have declined from over 26% to 1,33%, accordingly, its concentration exergy costs decreased from a maximum of 2,97E-3 toe/kg reached in year 1849 to 1,97E-3 toe/kg in 2004. Despite the 33% of bc∗ decrease, Australian copper ore grades are still greater than in other countries (according to the USGS [363] in the US, the current ore grade is around 0,5%). Additionally, a significant amount of copper mines have been discovered throughout the past century and prospects for the current scale of the Australian copper industry to continue remain promising. The exergy distance D from 1844 to 2004 is 956,12 ktoe, and the irreversible one D∗ : 103,93 Mtoe. The exergy degradation velocity ( Ḋ) increased from less than 1 ktoe/year before year 1898, to 50,5 ktoe/year in 2001. On average the minimum and irreversible exergy degradation velocities were Ḋ = 5, 94 and Ḋ∗ = 645, 5, respectively. In the period of 1844 to 2004, Australian copper mines lost 17,2 M t Cue∗ (1900 reference exergy cost of 1 t Cue∗ is equal to 6,04 toe). The economic demonstrated reserves of copper in year 2004 are estimated as 42,1 Mt, or 41,88 MtCue (B ∗t = 253, 1 Mtoe). The resources to production ratio (R/P) is 48 years, and the percentage of the economic reserves loss is about 29%. The Hubbert peak model applied to Australian copper reserves is shown in Fig. 7.11. Considering that the reserves of copper since 1884 are R = 3.319 ktoe, the peak is reached in year 2021. The regression factor is RF = 0, 9336. Table 7.3 shows a summary of the results. The exergy loss of a country due to mineral extraction. The case of Australia 30 900 25 800 700 20 600 500 15 400 10 300 200 Ore grade Xm, % Cumulative total exergy Bt, ktoe 1000 251 5 100 0 18 44 18 54 18 64 18 74 18 84 18 94 19 04 19 14 19 24 19 34 19 44 19 54 19 64 19 74 19 84 19 94 20 04 0 Bc Year Bch Xm Figure 7.12. Ore grade and cumulated exergy consumption of Australian copper mines 60 2021 50 Bt 40 30 20 10 0 4000 Integral Bt 3000 2000 1000 0 1850 1900 1950 2000 2050 2100 2150 Figure 7.13. The Hubbert peak applied to Australian copper reserves. Values in ktoe. 252 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES Table 7.3. Summary of the results of the exergy distance of Australian copper mines. Year Bch Bc Bt D Ḋ, ktoe/yr ∗ Bch Bc∗ B ∗t D∗ Ḋ∗ , Mtoe/yr M t Cu ∗ M t Cue1900 R/P, yrs % R. loss Year of the peak 7.7.1.3 Reserves 1844 2004 Minimum exergy, ktoe 2973,36 2120,87 345,65 242,02 3319,01 2362,89 956,12 5,94 Non-reversible exergy, Mtoe 238,46 170,09 118,59 83,04 357,06 253,13 103,93 0,645 58,98 42,10 59,08 41,88 48 29 2021 Nickel The large-scale production of nickel is one of Australia’s most recent additions to its mining industry. Although the earliest nickel production started in year 1913, it was not until 1966, with the discovering of a large high grade deposit, when N i production and exploration boomed. Since then, extraction has continued to increase, even though in the period from 1977 to 1994, N i production suffered a slight stagnation (see Fig. 7.14). The ore grade has decreased from 4,57 to 1,16%. Accordingly, the concentration exergy costs of N i mines (bc∗ ) decreased from 3,01 to 2,44 tep/t. The exergy distance D between 1963 and 2004 is equal to 323,68 ktoe, while D∗ = 9, 46 Mtoe. The exergy degradation velocity Ḋ increased from 0,26 ktoe/year to around the current 19 ktoe/year. On average, the minimum and irreversible exergy degradation velocities of nickel mines are Ḋ = 8, 52 and Ḋ∗ = 683, 13 ktoe/year, respectively. The megatons of N i equivalent lost in the period 1967 to 2004 are equal to 3,27 M t N ie∗ (the reference year is in this case 1967, since there is no information for for∗ mer years; M t N ie1967 = 7, 93 toe). The economic demonstrated reserves of nickel in year 2004 are estimated as 22,6 Mt, or 22,55 M t N ie∗ (B ∗t =178,8 Mtoe). The R/P ratio of Australian nickel deposits, indicate that there is enough metal for at least 121 years. Additionally, the percentage of the economic reserves loss is around 13%. The exergy loss of a country due to mineral extraction. The case of Australia 350 253 5,0 4,5 Cumulative total exergy, ktoe 300 4,0 250 3,0 2,5 150 2,0 1,5 100 Ore grade Xm, % 3,5 200 1,0 50 0,5 0 1967 0,0 1972 1977 1982 1987 1992 1997 2002 Year Bc Bch Xm Figure 7.14. Ore grade and cumulated exergy consumption of Australian nickel mines 40 2040 Bt 30 20 10 0 3000 Integral Bt 2500 2000 1500 1000 500 0 1960 1980 2000 2020 2040 2060 2080 2100 2120 2140 Figure 7.15. The Hubbert peak applied to Australian nickel reserves. Values in ktoe. Figure 7.15 shows the Hubbert peak model applied to Australian nickel reserves. Considering that the reserves of nickel in 1967 are R1967 = 2.587, 6 ktoe, the peak is reached in year 2040. The regression factor of the curve is RF = 0, 7549. Table 7.4 shows a summary of the results. 254 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES Table 7.4. Summary of the results of the exergy distance of Australian nickel mines. Year Bch Bc Bt D Ḋ, ktoe/yr ∗ Bch Bc∗ B ∗t D∗ Ḋ∗ , ktoe/yr M tN i ∗ M t N ie1967 R/P, yrs % R. loss Year of the peak 7.7.1.4 Reserves 1967 2004 Minimum exergy, ktoe 2442,76 2138,14 144,80 125,75 2587,57 2263,89 323,68 8,52 Non-reversible exergy, ktoe 142198,16 124465,18 62524,61 54298,66 204722,77 178763,84 25968,93 683,13 25,82 22,60 25,82 22,55 121 13 2040 Silver Silver is usually found in mines containing also lead and zinc and hence their production rates are tightly connected. The establishment of major mining companies in Australia was in the decade of the 1880’s. The ore grades of silver have suffered a drastic reduction, passing from over 3000 g/t at the initial years, to less than 800 g/t in just one decade. Since 1931, the ore grades have declined to less than 200 g/t, being the current ore grade equal to 133,5 g/t (see Fig. 7.16). This quality loss of silver mines is reflected in the actual concentration exergy component: in year 1884, bc∗ was equal to 42,9 tep/t, while in 2004, 30,3 tep/t (30% of concentration exergy loss). The exergy distance between the reserves in 1884 and 2004 are D = 1416, 91 toe and D∗ = 2227, 4 ktoe. This minimum exergy was consumed at an average rate of Ḋ = 11, 71 toe/year ( Ḋ∗ = 18.407 toe/yr), but since year 2000, the silver degradation velocity has increased to about Ḋ = 40 ( Ḋ∗ = 61.129) toe/year. Silver mines in Australia lost throughout their mining history a total of 72,81 ktAg e∗ (being the 1900 reference exergy equal to 30,6 toe/t). The economic demonstrated reserves of silver in year 2004 are estimated as 41,0 kt, or 40,8 ktAge (B ∗t = 1247, 4 ktoe). The R/P ratio indicates that the depletion of silver mines could occur in 19 years, if production remains as in 2004 and no further reserves are found. Sixtyfour of the economic reserves of silver in Australia have been already extracted, as indicated by the %R loss ratio. The exergy loss of a country due to mineral extraction. The case of Australia 1500 255 3500 1400 3000 1200 1100 2500 1000 900 2000 800 700 1500 600 500 1000 400 Ore grade Xm, g/t Cumulative total exergy, toe 1300 300 500 200 100 0 18 84 18 89 18 94 18 99 19 04 19 09 19 14 19 19 19 24 19 29 19 34 19 39 19 44 19 49 19 54 19 59 19 64 19 69 19 74 19 79 19 84 19 89 19 94 19 99 20 04 0 Year Bc Bch Xm Figure 7.16. Ore grade and cumulated exergy consumption of Australian silver mines The Hubbert peak model applied to Australian silver reserves does not throw out good results. The regression factor is very low (RF = 0, 577), considering the reserves in year 1884: R = 2226 toe. The maximum of the peak would have been reached in year 2005 (see Fig. 7.17). It must be pointed out that silver is a special mineral commodity in Australia, since it is extracted only as a by-product of other minerals such as copper, lead zinc and to a lesser extent, gold [112]. Hence, the production patterns may not follow the general rules expected for other commodities. Table 7.5 summarizes the results obtained. 7.7.1.5 Lead Lead production has followed a general increasing trend since the beginning of its mining industry. In deposits mined today, lead (in the form of galena, P bS) is usually associated with zinc, silver and commonly copper, and is extracted as a co-product of these metals [112]. As in the case of silver, lead ore grades decreased dramatically in a short period of time. During the first 20 years of the lead industry, ore grades kept at around 60%. From that point, the quality of P b in the mines dropped to levels below 20%, reaching the current level of 4,32%. The concentration exergy cost of P b in the mines (bc∗ ) decreased from 0,63 toe/t at the highest point reached in 1877, to 0,49 toe/t in 2004 (see Fig. 7.18). The exergy distance of lead between 1859 and 2004 is equal to D = 982, 10 ktoe, and D∗ = 40, 74 Mtoe. The exergy degradation velocity of lead increased from 256 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES 50 40 30 Bt 2005 20 10 0 2500 Integral Bt 2000 1500 1000 500 0 1900 1950 2000 2050 2100 2150 Figure 7.17. The Hubbert peak applied to Australian silver reserves. Values in toe. Table 7.5. Summary of the results of the exergy distance of Australian silver mines. Year Bch Bc Bt D Ḋ, toe/yr ∗ Bch Bc∗ B ∗t D∗ Ḋ, ktoe/yr t Ag ∗ tAg e1900 R/P, years % R. loss Year of the peak Reserves 1880 2004 Minimum exergy, toe 1735,08 632,91 490,99 176,24 2226,07 809,15 1416,91 11,71 Non-reversible exergy, ktoe 17,35 6,33 3459,49 1241,07 3476,84 1247,40 2227,36 18,42 112399 41000 113588 40777 19 64 2005 1000 90 900 80 800 257 70 700 60 600 50 500 40 400 30 300 Ore grade Xm, % Cumulative total exergy, ktoe The exergy loss of a country due to mineral extraction. The case of Australia 20 200 10 100 0 1859 1869 1879 1889 1899 1909 1919 1929 1939 1949 1959 1969 1979 1989 1999 0 Year Bc Bch Xm Figure 7.18. Ore grade and cumulated exergy consumption of Australian lead mines Ḋ = 0, 20 toe/year ( Ḋ∗ = 9 toe/year) to around 20 ktoe/year ( Ḋ∗ = 780 ktoe/year) registered since year 2000. On average, Ḋ and Ḋ∗ are 6,73 and 279,04 ktoe/year, respectively. The megatons of lead equivalent lost in Australia’s mining history are equal to 34,12 M t P be∗ (being the 1900 reference actual exergy of one ton of lead equal to 0,766 toe). The economic demonstrated reserves of lead in year 2004 are estimated as 22,9 Mt, or 22,45 M t P be (B ∗t = 26, 81 Mtoe). According to the R/P ratio, the complete degradation of Australian lead deposits would occur in 34 years, if the reference year is 2004. Additionally, the percentage of the economic demonstrated reserves loss is around 60%. Figure 7.19 shows the Hubbert peak model applied to lead. The peaking year is reached in 1997, considering that the economic demonstrated reserves are R1859 = 1646, 6 ktoe. The regression factor of the curve is RF = 0, 8691. And the production points for the latest years (1998 - 2004) are not included under the curve. According to the production data, the real peak might have been reached in year 2002. This might indicate that, in the period between 1997 to 2002, there has been an overproduction of the reserves. Consequently an abrupt decrease of production rates is now expected, as it happens with US copper. Nevertheless, the production pattern for lead might not follow the general behavior of other commodities, as it is extracted as a by-product, and the model cannot be applied satisfactorily. Table 7.6 summarizes the results obtained for Australian lead mineral deposits. 258 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES 25 20 1997 Bt 15 10 5 0 2000 Integral Bt 1500 1000 500 0 1850 1900 1950 2000 2050 2100 2150 Figure 7.19. The Hubbert peak applied to Australian lead reserves. Values in ktoe. Table 7.6. Summary of the results of the exergy distance of Australian lead mines. Year Bch Bc Bt D Ḋ, ktoe/yr ∗ Bch Bc∗ B ∗t D∗ Ḋ, ktoe/yr M tPb M t ∗P be,1900 R/P % R. loss Year of the peak Reserves 1859 2004 Minimum exergy, ktoe 1513,39 613,09 133,24 51,44 1646,63 664,53 982,10 6,73 Non-reversible exergy, ktoe 38394,47 15554,01 29156,24 11256,51 67550,71 26810,52 40740,19 279,04 56,53 22,90 56,57 22,45 34 60 1997 The exergy loss of a country due to mineral extraction. The case of Australia 6000 259 20 16 14 4000 12 10 3000 8 2000 6 Ore grade Xm, % Cumulative total exergy, ktoe 18 5000 4 1000 2 3 3 8 3 8 3 8 3 8 3 8 3 8 3 8 3 8 3 8 8 20 0 19 9 19 9 19 8 19 8 19 7 19 7 19 6 19 6 19 5 19 5 19 4 19 4 19 3 19 3 19 2 19 2 19 1 19 1 19 0 19 0 18 9 3 0 8 0 Year Bc Bch Xm Figure 7.20. Ore grade and cumulated exergy consumption of Australian zinc mines 7.7.1.6 Zinc Very little interest was shown in zinc until the beginning of the 20th century because no known method for efficient Z n separation and recovery was found. At that time, Z n was seen as a problem appearing in silver and lead mining. However, with the new method of flotation, firstly applied in 1905, the Z n industry started to emerge. The Z n grade of Australian mines has fluctuated strongly between 3 and 17%, especially until the late 1940’s. Since then, Z n grades tend to stabilize to around 8,5% (bc∗ = 0, 82 toe/t). The exergy distance since 1905 has been D = 5381 ktoe, and D∗ = 102 Mtoe. The exergy has been extracted at an average rate of Ḋ=50 ktoe/year ( Ḋ∗ =950 ktoe/year). In the last 5 years, the yearly minimum and irreversible exergy degradation velocity of zinc ( Ḋ and Ḋ∗ ) has increased to about 178 and 3367 ktoe/year, respectively. The megatons of zinc equivalent lost in the mining period from 1898 to 2004 was 441,27 M t Z ne (M t Z ne1900 = 2, 46 toe). The economic demonstrated reserves of zinc in year 2004 are estimated as 41 Mt, or 37,69 M t Z ne (B ∗t = 100, 90 Mtoe). The R/P ratio of Z n economic reserves is estimated at around 30 years. The depletion degree of the economic reserves is around 51%. The Hubbert peak model applied to the Australian Z n reserves is shown in Fig. 7.21. As zinc mining is closely related to the mining of lead and silver, a similar behavior of the model to the latter minerals is expected. The latest production points are not included under the curve (from 2000 to 2004). However, the adjusted curve has a better regression factor than that of lead and silver, namely RF = 0, 8806. 260 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES 200 2010 Bt 150 100 50 0 12000 Integral Bt 10000 8000 6000 4000 2000 0 1900 1920 1940 1960 1980 2000 2020 2040 2060 2080 2100 Figure 7.21. The Hubbert peak applied to Australian zinc reserves. Values in ktoe. Table 7.7. Summary of the results of the exergy distance of Australian zinc mines. Year Bch Bc Bt D Ḋ, ktoe/yr ∗ Bch Bc∗ B ∗t D∗ Ḋ, ktoe/yr M tZn M t ∗Z ne,1900 R/P, yrs % R. loss Year of the peak Reserves 1898 2004 Minimum exergy, ktoe 10188,07 5078,73 540,61 268,98 10728,68 5347,71 5380,97 50,3 Non-reversible exergy, ktoe 134494,54 67045,15 68057,12 33862,36 202552,16 100907,50 101644.,60 950,09 82,25 41,00 82,25 40.97 30 51 2010 The expected peaking year, assuming the economic demonstrated reservers R1898 = 10728, 7 ktoe is 2010. Table 7.7 summarizes the results obtained for Australian zinc mineral deposits. 700000 70 600000 60 500000 50 400000 40 300000 30 200000 20 100000 10 0 1907 261 Ore grade Xm, % Cumulative total exergy Bt, ktoe The exergy loss of a country due to mineral extraction. The case of Australia 0 1917 1927 1937 1947 Bc 1957 Year Bch 1967 1977 1987 1997 Xm Figure 7.22. Ore grade and cumulated exergy consumption of Australian iron mines 7.7.1.7 Iron Australia is the third iron ore production country in the world, after China and Brazil. The economic demonstrated iron ore reserves have fluctuated throughout last century and accordingly, its associated ore grade. In addition to the discoveries of new iron deposits, others have been reclassified as economic due to the increase of iron prices. The available reliable data about grades and production trends for iron dates back to 1907, although there are single figures for some years since 1850. There are ore grades missing for the following year periods: 1930 - 1934; 1936 - 1940; 1946 1951; 1966 and 1994. For the latter, the same ore grade of the previous year, where grade data was available, was assumed. The missing grades are represented hence as a horizontal straight line in figure 7.22. The abundance of iron rich deposits has allowed the ore grades to stabilize and even increase throughout its mining history. Iron concentration in Australia rarely goes down to 62%, equivalent to around bc∗ =0,29 toe/t (see Fig. 7.22). The exergy distance between 1907 and 2004 has been D = 704 Mtoe, and D∗ = 4.901 Mtoe. The average exergy degradation velocity since 1907 was Ḋ = 7183 ktoe/year ( Ḋ∗ = 50.012 ktoe/year), although it increased sharply since the seventies to near Ḋ = 40.000 ktoe/year ( Ḋ∗ = 265.000 ktoe/year). The megatons of iron equivalent lost in the mining period from 1907 to 2004 was 4289 M t Fee∗ (The first available year was taken as the reference, 1907: 1t Fee∗ =1,14 toe). The economic demonstrated reserves of iron in year 2004 are estimated as 14.600 Mt, or 14.556 M t Fee (B ∗t = 16665 Mtoe). Additionally, the percentage of the economic demonstrated reserves loss is around 23%. 262 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES 4 5 x 10 2026 4 Bt 3 2 1 0 3.5 6 x 10 3 Integral Bt 2.5 2 1.5 1 0.5 0 1900 1950 2000 2050 2100 2150 Figure 7.23. The Hubbert peak applied to Australian iron reserves. Values in ktoe. The Hubbert peak model is satisfactorily applied to Australian iron reserves, as can be seen in Fig. 7.23. The peaking year will be reached in 2026, considering that the economic demonstrated reserves R1907 = 3100 Mtoe. The regression factor is very acceptable: RF = 0, 9515. Table 7.8 shows a summary of the results obtained for Australian iron mineral deposits. 7.7.2 Fuel minerals In this section we are going to calculate the exergy degradation of Australian fuel reserves, which are composed of vast amounts of coal and some oil and natural gas. The exergy is calculated with the equations provided in section 5.3.3, with the methodology developed by Valero and Lozano [369]. As stated in previous chapters, the exergy of fuels is tightly related to its chemical exergy content (the concentration exergy component is insignificant). Note also that it has no sense of calculating exergy costs of fossil fuels, as it is impossible to replace the photosynthesis process with current technology. As for the case of non-fuel minerals, R/P ratios, the depletion degree, and the year estimation of maximum peaks of production are provided for Australian coal, oil and natural gas. The exergy loss of a country due to mineral extraction. The case of Australia 263 Table 7.8. Summary of the results of the exergy distance of Australian iron mines. Year Bch Bc Bt D Ḋ, ktoe/yr ∗ Bch Bc∗ B ∗t D∗ Ḋ, Mtoe/yr M t Fe M t ∗Fee,1907 R/P, yrs % R. loss Year of the peak 7.7.2.1 Reserves 1907 2004 Minimum exergy, Mtoe 3044,65 2353,31 55,50 42,86 3100,15 2396,17 703,98 7.183,45 Non-reversible exergy, Mtoe 16163,18 12493,08 5403,71 4172,74 21566,89 16665,82 4901,07 50,01 18.889,23 14.600,00 18.889,23 14.596,65 63 23 2026 Coal Coal was first discovered in Australia in 1791 in New South Wales and the first coal mining settlement was established there in 1801 [12]. Since then, coal production has increased dramatically. It is mined in every state of Australia. Around 75% of the coal mined in Australia is exported, mostly to eastern Asia. Consequently, Australia has become the fourth largest coal producer in the world. Coal also provides about 85% of Australia’s electricity production The relative abundance, reliability and low cost of coal have ensured that it remains the most commonly used fuel source for electricity generation in Australia [164]. The main type of coal extracted in Australia is bituminous and to a lesser extent lignite. Small amounts of subbituminous and traces of semi-anthracite are also produced. Table A.22 in the appendix, shows the production of the different types of Australian coal in the period between 1913 and 2006. The data has been extracted from the historical statistics compiled by the British Geological Survey and its preceding organizations. The exergies of the coal extracted in the mentioned period are shown in figure 7.24. The specific exergies of anthracite, bituminous, subbituminous and lignite used are the ones listed in table 6.10 (b I I I ). According to BP [35], Australian coal’s reserves are in 2006, around 38,6 Mtons of anthracite and bituminous, and 39,9 Mtons of subbituminous and lignite. The latter reserves expressed in exergy terms, are equivalent to a total of 37,7 Gtoe. 264 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES Bt, ktoe 250000 Coal production in Australia 200000 Lignite 150000 100000 50000 Subbituminous Bituminous 19 13 19 17 19 21 19 25 19 29 19 33 19 37 19 41 19 45 19 49 19 53 19 57 19 61 19 65 19 69 19 73 19 77 19 81 19 85 19 89 19 93 19 97 20 01 20 05 0 Year Semi-anthracite Bituminous Subbituminous Lignite Figure 7.24. The exergy loss of Australian coal reserves. Values in ktoe. The exergy loss of Australian coal reserves, i.e. the exergy distance D, between 1913 and 2006 has been around 5,6 Gtoe. This exergy was consumed at an average exergy degradation velocity Ḋ of near 60 Mtoe/year, but since year 2000, the velocity has increased to more than 200 Mtoe/year. Assuming that the exergy reserves in 1913 were those of year 2006 plus the exergy distance between 1913 and 2006, i.e. R1913 = 43, 4 Gtoe, the Hubbert’s bell-shaped curve applied to Australian coal production reveals that the peak of production will be reached in year 2048. As can be seen in fig. 7.25, the model has been very well fitted, with a regression factor of 0,9883. The resources to production ratio R/P in 2006, calculated as the ratio between the exergy reserves in 2006 and the exergy production in the same year, indicates that it will be enough coal for at least 153 years. The percentage of the economic reserves loss is around 13%, what indicates that there are still large amounts of coal in the country. 7.7.2.2 Oil According to BP [35], Australia has around 0,54 Gtons of oil reserves. The majority of these reserves are located off Western Australia in the Carnarvon basin and in the Bass Strait off Southern Australia. Australian oil production does not cover internal consumption and around 39% of total consumption needs to be imported. Oil production in Australia has increased gradually since 1980, peaking in 2000. Thereafter, The exergy loss of a country due to mineral extraction. The case of Australia 265 5 x 10 2048 5 Bt 4 3 2 1 Integral Bt 0 7 x 10 5 4 3 2 1 0 1900 1950 2000 2050 2100 2150 2200 Figure 7.25. The Hubbert peak applied to Australian coal reserves. Values in ktoe. Australia has experienced decreasing oil production due to oil producing basins such as Cooper-Eromanga and Gippsland experiencing natural declines, coupled with a lack of new fields coming online [82]. However, new exploration efforts, especially offshore could help stabilize the country’s oil production over the next few years. Historical data about Australian oil production is very fragmented. Reliable and continuous information can only be found since the sixties. In fact, it was not until those years, when the country started to produce considerable amounts of oil. It is worth to mention that in addition to crude petroleum, oil shale5 has been extracted in the past and might be taken up again in the future. Table A.23 shows Australian oil production data from 1913 until 2006, published by the British Geological Survey and its former organizations. With the specific exergy of Fuel-oil Nr.1 (46259,1 kJ/kg - table 6.13), we obtain that the exergy distance D of Australian oil production from 1964 to 2006 is equal to around 1 Gtoe. This exergy was consumed at an average degradation velocity Ḋ of 21,7 Mtoe/year, reaching a peak in 2000 of more than 40 Mtoe/year (see table 7.26). The Hubbert peak model has been applied also for Australian oil production (see fig. 7.27). It has been assumed, that the total amount of exergy reserves are equal to the current ones (0,59 Gtoe), plus the exergy degradation due to extraction in past years (1,02 Gtoe), i.e. R = 1, 61 Gtoe. Our results throw up that the peak6 should 5 Oil Shales are sedimentary rocks containing a high proportion of organic matter (kerogen) which can be converted to synthetic oil or gas by processing. 6 The fit has a regression factor of RF=0,853. 266 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES Oil production in Australia Bt, ktoe 45000 40000 35000 30000 25000 20000 15000 10000 5000 6 2 4 20 0 20 0 8 0 20 0 20 0 4 6 19 9 19 9 0 2 19 9 19 9 6 8 19 9 19 8 2 4 19 8 19 8 8 0 19 8 19 8 4 6 19 7 19 7 0 2 19 7 19 7 6 8 19 7 19 6 2 4 19 6 19 6 19 6 19 6 0 0 Year Figure 7.26. The exergy loss of Australian oil reserves. Values in ktoe. 4 4 x 10 1997 Bt 3 2 1 Integral Bt 6 0 x 10 2 1.5 1 0.5 0 1940 1960 1980 2000 2020 2040 2060 Figure 7.27. The Hubbert peak applied to Australian oil reserves. Values in ktoe. have been reached in 1997. The real peak was however reached in year 2000, and was followed by a sharp production decrease afterwards. This behavior is the same found in US copper mines and in the models of Meadows et al. [218], indicating that the symmetrical exponential curve of Hubbert might not be the best fit. The exergy loss of a country due to mineral extraction. The case of Australia 267 The resources to production ratio for Australian oil production indicates that in less than 26 years, oil reserves will be completely depleted, if no more deposits are found. Additionally, around 60% of the economic reserves have been also exploited. As stated before, this situation might change, since Australia is investing in oil exploration. 7.7.2.3 Natural gas Australia has sizable natural gas reserves located in offshore basins, and in most of all Australia’s states. The country is the fifth largest exporter of liquefied natural gas (LNG) in the world. Natural gas production in Australia has increased steadily over the last decade. In the same time period, consumption has grown as well. Australia is expected to maintain natural gas self-sufficiency for the ensuing decade at a minimum. Additionally, recent natural gas exploration in Australia has resulted in several important discoveries, mainly offshore. Further natural gas discoveries will likely be made inadvertently as a byproduct of Australia’s recent surge in petroleum exploration [82]. Historical data on Australian natural gas production dates back to 1961. Table A.24 shows production data compiled by the British Geological Survey. The 2006 Australian natural gas reserves are around 2,61 trillion of cubic meters, according to BP [35]. The exergy loss of Australian natural gas reserves due to extraction is shown in fig. 7.28. The specific exergy of natural gas assumed is 39393,8 kJ/N m3 (table 6.16). Accordingly, Australia has lost in the period between 1961 to 2006, 649 Mtoe. This exergy was consumed at an average degradation velocity Ḋ of 13,8 Mtoe/year, although it has increased to more than 30 Mtoe/year since the last decade (see fig. 7.28). The application of the Hubbert bell shape-curve to Australian natural gas production, throws up a peak of production in year 2025. It has been assumed, that the total reserves are equal to 3,1 Gtoe7 . The regression factor of the curve RF was 0,98. Assuming that production will stabilize to 2007 rates and that reserves will not increase in the future, the R/P ratio of Australian natural gas reserves would be equal to 67 years. Furthermore, about 21% of the natural gas reserves have been already extracted. Of course these numbers are only hypothetical and will presumably increase, as new deposits are found. 7.7.3 Summary and discussion of the results Table 7.9, summarizes the results obtained from this study, showing the year were the peak of production is reached (Peak), the R/P ratio of the last recorded year, 7 The total reserves are obtained as the exergy reserves in 2006, plus the exergy distance between 1961 and 2006. 268 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES Natural gas production in Australia Bt, ktoe 40000 35000 30000 25000 20000 15000 10000 5000 6 2 4 20 0 20 0 8 0 20 0 20 0 4 6 19 9 19 9 0 2 19 9 19 9 6 8 19 9 19 8 2 4 19 8 19 8 8 0 19 8 19 8 4 6 19 7 19 7 0 2 19 7 19 7 6 8 19 7 19 6 2 4 19 6 19 6 19 6 19 6 0 0 Year Figure 7.28. The exergy loss of Australian natural gas reserves. Values in ktoe. 4 6 x 10 2025 5 Bt 4 3 2 1 Integral Bt 6 0 x 10 4 3 2 1 0 1940 1960 1980 2000 2020 2040 2060 2080 2100 2120 Figure 7.29. The Hubbert peak applied to Australian natural gas reserves. Values in ktoe. The exergy loss of a country due to mineral extraction. The case of Australia 269 Table 7.9. Summary of the results of the exergy assessment of the main Australian minerals. Mineral ∆t Peak Au Cu Ni Ag Pb Zn Fe C oal Oil N .Gas TOTAL 1859 - 2004 1844 - 2004 1967 - 2004 1884 - 2004 1859 - 2004 1897 - 2004 1907 - 2004 1913 - 2006 1964 - 2006 1961 - 2006 2006 2021 2040 2005 1997 2010 2026 2048 1997 2025 R/P, yrs 22 48 121 19 34 30 63 153 26 67 % R Loss 65 29 13 64 60 51 23 13 63 21 ∆M t M e D, ktoe D∗ , Mtoe Ḋ, ktoe, yr Ḋ∗ , ktoe, yr 1,11E-02 17,2 3,3 7,28E-02 34,1 41,3 4292,6, - 0,1 956,1 323,7 1,4 982,1 5381,0 703978,4 5637923,1 1019500,0 649045,8 8018091,5 10,7 103,9 26,0 2,2 40,7 101,6 4901,1 5186,3 6,1E-04 5,9 8,5 0,0 6,7 50,3 7183,5 59977,9 21691,5 13809,5 102733,8 73,2 645,5 683,1 18,4 279,0 950,1 50012,4 52661,8 the depletion degree of the commodities (% R. loss), the quantity of Metal extracted (∆M t M e) in Mtons, the minimum and irreversible exergy distance (D and D∗ ) and degradation velocities ( Ḋ and Ḋ∗ ) of the fuel and non-fuel mineral Australian reserves throughout the period of time considered (∆t). Thanks to the additive property of exergy, the total minimum and irreversible exergy distance of the mines in Australia considered can be calculated. The Hubbert peak model to the exergy reserves of the Australian minerals considered was satisfactorily applied to gold, copper, nickel, iron, coal, oil8 and natural gas. That was not the case for commodities silver, lead and zinc were the regression factors of the curves were quite low and the latest production points were not included under the bell-shaped curve. Probably the fact that the production of all three metals are tightly connected, makes that their production patterns do not follow the general behavior of other commodities. According to the economic demonstrated reserves of the listed minerals, the Hubbert peak model applied in this study predicts that the maximum production has been already reached for gold (2006), silver (2005), lead (1997) and oil (1997). Zinc will reach the peak in 2010, copper in 2021, natural gas in 2025, iron in 2026, nickel in 2040, and finally coal in 2048. The resources to production data, informs us about the estimated years until depletion. Accordingly, the most depleted commodities are in decreasing order: silver, gold, oil, zinc and lead, with R/P ratios below 35 years. They are followed by the commodities of copper, iron, natural gas, nickel and finally coal, with R/P ratios of 48, 63, 67, 121 and 153 years, respectively. Of course these figures are only approximative, since they depend strongly on production rates and reserves. The latter might increase as new discoveries are found, or as technology or the increase of prices allows to extract lower-grade deposits. Although the quantity extracted of all commodities in terms of mass cannot be summed up (gold and silver are extracted at rates of some tons per year, whereas the 8 Despite of the irregular oil production in Australia, the Hubbert peak model here applied has predicted with only three years of difference the peaking of production. 270 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES other metals at rates of kilotons/year), the order of magnitude in terms of exergy costs (B ∗ ) is similar for all commodities and its sum gives valuable information. The irreversible exergy distance D∗ obtained for all metals in Australia listed in Table 7.9 is equal to 5186 Mtoe. The irreversible degradation velocity of the same metals is on average 52,6 Mtoe/yr. This means that if we would like to replace the metals extracted throughout Australia’s mining history, with current available technology, we would require 154 times the 2006 primary energy consumption of that country (33,7 Mtoe [35]). Moreover, each year Australia is degrading on average by the extraction of metals the equivalent of 1,56 times its primary oil consumption. From all metals, iron is responsible for 95% of the exergy consumption, due to the great quantity of iron ore produced in Australia. Figures 7.30 to 7.32 show the total consumption in exergy replacement costs terms (B ∗t ) of all metals considered, from 1844 to 2004. In the first period illustrated in Fig. 7.30, the extraction of copper and gold contribute to most of the exergy consumed, although lead acquires a relevant role from the last years of the 19th century. In the second period, from 1907 to 1963 (Fig. 7.31), the extraction of zinc, lead and iron represents the major exergy consumption. From 1950 to our days, iron dominates clearly the non-fuel mineral exergy consumption in Australia. 700 B*t, ktoe 600 Zinc 500 Lead 400 300 Copper 200 100 Gold Silver 18 44 18 46 18 48 18 50 18 52 18 54 18 56 18 58 18 60 18 62 18 64 18 66 18 68 18 70 18 72 18 74 18 76 18 78 18 80 18 82 18 84 18 86 18 88 18 90 18 92 18 94 18 96 18 98 19 00 19 02 19 04 19 06 0 Silver Gold Copper Iron Nickel Lead Zinc Figure 7.30. Irreversible exergy consumption of the main non-fuel minerals in Australia in the period from 1884 to 1906 We have stated before, that calculating exergy costs of fuel minerals has no sense, as it is impossible to replace them, at least with current technology. Nevertheless, its chemical exergy is so large, that can be compared to the exergy costs of the metals The exergy loss of a country due to mineral extraction. The case of Australia 271 10000 B*t, ktoe 9000 8000 7000 6000 Zinc Lead 5000 4000 Iron 3000 2000 1000 Copper 19 07 19 09 19 11 19 13 19 15 19 17 19 19 19 21 19 23 19 25 19 27 19 29 19 31 19 33 19 35 19 37 19 39 19 41 19 43 19 45 19 47 19 49 19 51 19 53 19 55 19 57 19 59 19 61 19 63 0 Silver Gold Copper Iron Nickel Lead Zinc Figure 7.31. Irreversible exergy consumption of the main non-fuel minerals in Australia in the period from 1907 to 1964 300000 B*t, ktoe 250000 200000 Zinc 150000 100000 Iron 50000 01 97 95 03 20 20 19 19 93 Lead 19 91 19 89 87 Nickel 19 19 85 Iron 19 83 81 Copper 19 19 77 75 73 71 69 79 Gold 19 19 19 19 19 19 19 65 67 19 19 Silver 99 Copper 0 Zinc Figure 7.32. Irreversible exergy consumption of the main non-fuel minerals in Australia in the period from 1965 to 2004 272 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES 80000 B*t, ktoe 70000 60000 50000 40000 Oil 30000 Coal 20000 10000 Iron 66 64 62 60 58 56 54 52 50 68 19 19 19 19 19 19 19 19 19 46 48 N.G. 19 19 42 44 Oil 19 38 40 Iron 19 19 36 34 32 30 28 26 24 20 22 16 Other metals 19 19 19 19 19 19 19 19 19 19 19 19 18 Other metals 19 19 14 0 Coal Figure 7.33. Irreversible exergy consumption of the main fuel and non-fuel minerals in Australia in the period of 1914 to 1968 studied. This way, we can estimate the exergy destruction of the global mineral resources of a country. We have divided the information into the commodities coal, oil, natural gas, iron and other non-fuel metals. This is because the exergy cost of iron is significantly greater than the rest of the metals and is comparable to that of the fuel minerals. Furthermore, we have considered two periods of time: from 1914 to 1968 and from 1969 to 2004 (before and after the significant production of oil and natural gas). As can be seen in figure 7.33, in the first period of time considered, the exergy consumption was clearly dominated by the extraction of coal and to a lesser extent of iron, especially towards the end of the period. The global extraction trend increased very rapidly, following an exponential-like behavior. This way, the exergy degradation velocity increased from around 10 Mtoe/year at the beginning of the period, until the 70 Mtoe/year reached in 1968. The coming out of significant reserves of oil and natural gas (cleaner and more handy fuels than coal), lead to an important drop of coal’s production in the beginning of the second period considered (see fig. 7.34). This resulted in a 25-year hegemony of iron production in Australia. Nevertheless, the abundance of coal in the country, together with the foreseeable depletion of oil, provoked a new increase of coal extraction. Since then, both coal and iron dominate the exergy destruction each year of the mineral capital in Australia (see fig. 7.35). Despite of the shifts in extraction trends among the different commodities, it is remarkable that the global behavior has continued to be exponential-like. In 2004, the exergy degradation velocity exceeded 550 Mtoe/year (around 15% of current The exergy loss of a country due to mineral extraction. The case of Australia 273 600000 B*t, ktoe 500000 400000 Coal 300000 N.G. Oil 200000 Iron 100000 Other metals Iron Oil N.G. 20 03 20 01 19 99 19 97 19 95 19 93 19 91 19 89 19 87 19 83 19 85 19 79 19 81 19 75 19 77 19 71 19 73 19 69 0 Coal Figure 7.34. Irreversible exergy consumption of the main fuel and non-fuel minerals in Australia in the period of 1969 to 2004 100 %, B*T 90 Coal 80 70 60 50 40 30 Iron 20 Oil Other metals 10 N.G. 0 1914 1924 1934 1944 1954 1964 1974 1984 1994 2004 Year Other metals Iron Oil N.G. Coal Figure 7.35. Relative contribution of the extraction of fuel and non-fuel minerals to the global exergy degradation of Australia in the period of 1914 to 2004 274 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES world’s oil consumption). And presumably, it will continue to increase exponentially at least for 20 to 40 years, until the peaks of iron and coal are reached. In figures 7.36 and 7.37, we have represented the Hubbert’s bell-shaped curves of all mineral commodities considered in terms of their exergy replacement costs. This type of representation will be named here as “Exergy countdown”, since it shows in a very schematic way the amount of exergy resources available and the possible exhaustion behavior that they will follow. It should be noted that representing B vs t or B ∗ vs t brings up in our case similar results for the peaking year, as unit replacement costs have been considered constant throughout the time considered. The use of exergy replacement costs allows us to compare the exergy content of fuels and non-fuel minerals. However, as stated before, a better fit should take into account the change of technology, thereby using the appropriate unit exergy costs at each period of time. In figure 7.36, the bell shaped curves of all fuels plus those of iron and copper are represented. As can be seen, in exergy cost terms, coal is the most abundant resource, followed by iron. Until the first decade of the 21st century, both commodities will be extracted at similar rates. However, the coming of the peak of iron production in the second decade of the 21st century, will slow down the extraction of the metal, while coal will clearly dominate the mineral extraction in Australia. Fig. 7.36 shows additionally the significant lower amount of the reserves of natural gas and oil, with respect to iron and coal. The same thing occurs with the rest of the metals considered, which are shown in a separate figure (fig. 7.37). It is interesting to notice that although copper is the most abundant commodity in exergy terms, the greater extraction rate of that mineral will provoke a faster depletion of copper than of nickel. Similarly, although the irreversible exergy reserves of zinc and nickel are similar, the greater extraction rate of zinc, implies that the peaking year of that metal will be reached before that of nickel. The graph also shows the smaller relative amount of the commodities of lead, gold and silver, being the reserves of the latter commodity barely perceptible in the figure. The exergy countdown diagram of a country allows us to predict future mineral productions and the depletion degree of the commodities. This way, for instance, we can forecast according to our results, that in year 2050, about 64% of the total considered mineral reserves in Australia will be depleted. Particularly, gold will be depleted at 99,9%, copper at 90,3%, lead at 87%, zinc at 97,3%, nickel at 60,4%, iron at 80%, coal at 52,4%, oil at 95,9% and natural gas at 85,2%. It must be pointed out, that the latter minerals are not the only ones extracted in Australia. Other non-fuel minerals such as uranium, alumina, manganese, tin, diamonds and industrial sands are also produced. The lack of information of especially ore grade trends for the latter materials avoids us to complete the analysis. Nevertheless, the figures provided are good enough for giving an order of magnitude of the depletion of Australian mineral reserves due to mineral extraction. Conversion of exergy costs into monetary costs 275 Bt*, ktoe Coal 500000 400000 Iron 300000 200000 100000 Natural gas Oil Copper 0 1890 1940 1990 2040 2090 2140 2190 Year Figure 7.36. Exergy countdown of the main consumed minerals in Australia 7.8 Conversion of exergy costs into monetary costs The conversion of exergy costs into monetary costs is a rather simple task through conventional energy prices. It must be stated though, that this should not be necessarily the final objective, as the physical information is valuable by itself. As an example, we will estimate the monetary cost of the main mineral reserve’s depletion suffered in Australia in year 2004, due to mineral extraction. The monetary value of fuel minerals, can be directly calculated by their corresponding prices in the year under consideration. For non-fuel minerals, we will consider an average price of the energy mix consumed in the country. This is because the exergy cost of non-fuel minerals represents the amount of energy required to restore them with current technology. According to the 2007 BP statistical report [35], the average price of coal9 in 2004 was 64,33 $US/t or 118,91 US$/toe, considering the specific exergy of coal. The same report includes oil and natural gas prices10 : 40,83 $US/barrel (274,62 $US/toe), and 5,85 $US/million Btu (232,14 $US/toe), respectively. According to ABARE [1], the 2004 primary consumption energy mix in Australia was: 41% of coal, 35% of oil, 19% of natural gas and 5% of renewables. Assuming zero the renewables cost, we obtain an average energy price in Australia of 189,0 $US/toe. 9 10 This price corresponds to the US Central Appalachian coal spot price. The natural gas price corresponds to USA Henry Hub &. 276 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES 7000 Bt*, ktoe Copper 6000 5000 4000 3000 Zinc Nickel 2000 1000 Lead Gold 0 1890 Silver 1940 1990 2040 2090 2140 Year Figure 7.37. Exergy countdown of metals copper, zinc, nickel, lead and silver in Australia Table 7.10 shows an estimation of the monetary costs associated to the depletion of the main Australian mineral reserves due to mineral extraction in year 2004. Table 7.10. Monetary costs of the main mineral reserves depletion suffered in Australia due to mineral production in year 2004 Mineral Coal Oil N. Gas Non-fuels TOTAL Exergy Mtoe 231,3 22,6 33 274,7 561,6 extracted, Mineral’s US$/toe 118,9 274,6 232,1 189,0 price, Monetary cost, Billion US$ 27,5 6,2 7,7 51,9 93,3 According to the results obtained, Australia would have lost in 2004 an equivalent of 93,3 billions of $US of its mineral capital, due to resource extraction. This corresponds to 15,2% of the 2004 Australian GDP (611,7 billions of $US [56], adjusted for the countrie’s purchasing capacity11 ). The same amount of physical capital lost, calculated with 2006 and 2008 energy prices, would be equivalent to around 115 and 178 billions of $US, respectively 11 The Purchasing Power Parity takes into account how much an individual can buy within a country along with the currency exchange rate between the individual country’s currency and the U.S. dollar. Summary of the chapter 277 (19 and 29% of the 2004 Australian GDP12 ). This clearly indicates, that assessing the loss of mineral capital in monetary costs is not very suitable, as the volatility and arbitrariness of prices distorts the real physical value, which is absolute and understandable worldwide. However, monetary values provides us with an order of magnitude of the importance of mineral extraction. The considerable amount of money just calculated as an example, is what Australia should pay the earth, for the amount of mineral extracted only in year 2004. It should be stated, that less developed countries, whose economy is mainly based on the extraction of their mineral capital could even obtain negative GDP values. That maybe the case for countries like South Africa or Chile, but this should be studied more carefully with detailed production data of those countries. What is clear is that economy treats our planet as a reservoir of free goods. As the earth becomes depleted, man slowly realizes the importance of conserving its resources. And maybe in a not very distant future, we will have to take “Nature into account”, as stated by Dieren’s book of the same name [75], and correct accordingly the economic indices. As King argues in the book, if production is creating scarcity rather than reducing it, economic growth is negative. 7.9 Summary of the chapter We have seen in this chapter that neither mass, nor energy are appropriate indicators for assessing the loss of mineral wealth on earth, as they are conservative properties. In all physical transformations of matter or energy, it is always exergy that is lost. Therefore, any degradation of the mineral capital which can come either from an alteration in its composition, a decrease of its concentration, or a change in the reference environment, can be accounted for with exergy. Starting from the property exergy, we have built a series of indicators which should measure the scarcity degree of the mineral reserves on earth. The exergy difference between two situations of the planet has been named as exergy distance D. The exergy degradation velocity Ḋ, calculated as the exergy distance divided by the period of time considered, should account for the rate of exergy destruction of a certain resource. We have also defined the ton of mineral equivalent (t M e), as the exergy content of one ton of mineral in a certain time and place. The reference value of the ton of mineral equivalent has to be established for each resource. The t M e is analogous to the ton of oil equivalent, but it accounts for the tonnage, grade and chemical composition of the substance. This new indicator allows us to assess the exergy content of a certain deposit before and after extraction, and to compare the quality 12 For the following energy prices in 2006 and 2008, respectively: 116,4 and 167,7 $US/toe of coal; 438,2 and 807,1$US/toe of oil; 268,3 and 287,0 $US/toe of natural gas. 278 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES of different deposits containing the same mineral, but with a more understandable unit of measure. The estimated years until depletion of a resource are usually calculated with the R/P ratio, which is obtained as the quotient between its reserves and its production in a certain year in mass terms. We have proposed to calculate the R/P ratio in exergy terms, thereby accounting for the concentration factor as well. All indicators described above can be assessed either with minimum exergies, or with exergy replacement costs. With the latter, the irreversibility factor present in all real processes is taken into account. Finally, we have proposed the application of the Hubbert peak model for the assessment of the production peak of non-fuel minerals. It has been stated that the bell-shape curve is better suited to non-fuel minerals if it is fitted with exergy over time, instead of mass over time. This way, we would not ignore the concentration factor, which is very important for the case of solid minerals. As a first case study, we have obtained the exergy decrease of US copper deposits throughout the 20th century, and have applied all indicators described above. For that purpose, the chemical and concentration exergy components of the mines, as well as their associated exergy replacement costs have been obtained for the period between years 1900 and 2000. It has been estimated, that the global exergy cost associated to the degradation of US copper deposits in the 20th century was around 700 Mtoe, consumed at an average exergy degradation velocity of 6,6 Mtoe/year. The R/P ratio of US copper deposits reveals for year 2000, that reserves would be completely depleted after 56 years. Moreover, the application of the Hubbert peak in exergy terms, gives as a result, that the peak was already reached in year 1994. In fact the real peak was attained in year 1998. Although the exergy production pattern did not perfectly fit in the bell-shaped curve, interesting conclusions have been extracted. Generally, production follows asymmetric curves with the decline much sharper than the growth. Hence, the real production peak is most probably attained after the year predicted by the Hubbert model. During a short period of time, the commodities will be probably over-exploited and the production points will appear over the bell-shaped curve. The compensation of the overproduction is the much sharper decrease of production after the peak, instead of a gradual and steady reduction. The second case study was aimed at assessing the exergy loss of a country due to mineral extraction. Australia has been chosen for the analysis, because it is one of the most important mineral exporting countries in the world and is the only one with registered ore grade trends of its main minerals. The commodities analyzed throughout their mining history until 2004 were gold, copper, nickel, silver, lead, zinc, iron, coal, oil and natural gas. It has been stated, that generally, production of all commodities has followed an exponential-like behavior. The most depleted commodities are in decreasing order: silver, gold, oil, zinc and lead, with R/P ratios Summary of the chapter 279 below 35 years. On the contrary, the reserves of copper, iron, natural gas, nickel and finally coal will last at least for 48, 63, 67, 121 and 153 years, respectively. The Hubbert peak model was satisfactorily applied for all commodities, with the exception of the group lead-zinc-silver, whose production patterns differ from the rest, as they are extracted together. The study predicts that the maximum production has been already reached for gold (2006), silver (2005), lead (1997) and oil (1997). Zinc will reach the peak in 2010, copper in 2021, natural gas in 2025, iron in 2026, nickel in 2040, and finally coal in 2048. By the extraction of metals, Australia has degraded the equivalent of 5,2 Gtoe (in exergy replacement cost terms). This corresponds to 154 times the 2006 primary energy consumption of that country. Moreover, each year Australia is degrading on average by the extraction of metals the equivalent of 1,6 times its primary oil consumption. Adding the exergy loss of fossil fuels, the global degradation of the mineral reserves in Australia increase to 12,5 Gtoe. And this degradation is dominated by the extraction of two commodities, coal and iron. In 2004, the global exergy degradation velocity exceeded 550 Mtoe/year (around 15% of current world’s oil consumption). And it will probably continue to increase exponentially at least for 20 to 40 years, until the peaks of iron and coal are reached. A very practical representation of the mineral reserves available and the possible extraction behavior of the commodities is through the “Exergy countdown” graphs. In the latter, the different Hubbert peak models in terms of irreversible exergy are shown in a single diagram. This has allowed us to compare the past, present and possible future extraction rates and available reserves of fuel and non-fuel minerals in Australia. With the exergy countdown, we have predicted that in year 2050, about 64% of the main mineral commodities produced in Australia will be depleted. Moreover, except for coal, iron and nickel, more than 85% of the mineral reserves will be exhausted by then. The exergy analysis together with the exergy countdown of minerals could constitute a universal and transparent prediction tool for assessing the degradation degree of non-renewable resources, with dramatic consequences for the future management of the earth’s physical stock. We additionally estimated the monetary cost of the main mineral reserve’s depletion suffered in Australia in year 2004. This was carried out, by the conversion of exergy costs into monetary costs through conventional energy prices. According to the results obtained, Australia would have lost an equivalent of 93,3 billions of $US of its mineral capital, due to resource extraction in 2004. This corresponds to 15,2% of the 2004 Australian GDP. However, if 2006 and 2008 energy prices are considered, the same amount of physical stock extracted would correspond to 19 and 29% of 2004 Australian GDP. This indicates that monetary costs might not be a very suitable indicator for assessing the mineral capital, as the volatility and arbitrariness of prices distorts the real physical value. Nevertheless, it provides an order of magnitude of the importance of the extraction of minerals to the economy. 280 THE TIME FACTOR IN THE EXERGY ASSESSMENT OF MINERAL RESOURCES It should be noted, that the results obtained are estimations and hence the numbers cannot be taken as final. More reserves could be found in the future, thereby increasing the years until depletion and the peak of production of the commodities. However, the huge amount of energy and its equivalent in money terms involved in the degradation of minerals on earth, alerts us about the importance of conserving our resources. Chapter 8 The exergy evolution of planet earth 8.1 Introduction The aim of this chapter is to analyze the depletion of the exergy reservoir of minerals on earth, due to the human action. For that purpose, the mineral exergy degradation throughout the 20th century, will be studied. Furthermore, we will analyze the effect of the emission of greenhouse gases in the exergy loss of fossil fuels. Finally, with the help of scenarios, we will estimate the exergy depletion of mineral resources in the next century. 8.2 The exergy loss of world’s mineral reserves in the 20th century As stated before, exergy is an accounting tool that allows us to assess resources of single or aggregated commodities of a region, country or even of the whole world. In chapter 7 we evaluated the exergy degradation of mineral capital of a country and our aim now is to extrapolate the assessment to the entire planet. This ambitious task is not free of difficulties. The first and most important problem that we have to face is the lack of current and historical data of many commodities. A few geological institutions, such as the USGS or BGS, compile world production data of the most important minerals. But only the USGS provides estimations of non-fuel mineral reserves. Furthermore, with the exception of copper in the US, no ore grade trends of the commodities are compiled. The case of Australia is an exceptional example of a country with available historical ore grades of the main metals produced. And this was thanks to the own initiative of Mudd [232], [234]. 281 282 THE EXERGY EVOLUTION OF PLANET EARTH To these limitations, we have to add that unit exergy replacement costs are available for many important non-fuel mineral commodities, but not for all of them. In order to overcome the difficulties mentioned before, we are obliged to make different assumptions at the expense of an important accuracy loss in the results. Firstly, we will assume that the ore grade of non-fuel mineral commodities remains constant and equal to the average ore grades estimated in this PhD (table 4.10). This implies that the specific concentration exergy will not change over time. Consequently, the calculation of tons of mineral equivalent has no practical sense anymore. Moreover, the application of the Hubbert peak model in terms of exergy will ignore the concentration factor, which is quite significant in many non-fuel minerals. As it happened to the previous case studies, unit exergy replacement costs are assumed to be constant. In reality, unit costs are a function of the state of technology and hence vary with time. With the latter assumptions, we can make a rough estimate of the following variables for fuel and non fuel minerals: • The mineral exergy degradation on earth since the beginning of the 20th century (D), • the earth’s exergy degradation velocity due to mineral extraction ( Ḋ), • the depletion degree of the reserves and reserve base (% R. loss and % R.B. loss), • the years until depletion of the commodities (R/P), and • the year where the peak of production is reached (Year of the peak) 8.2.1 Non-fuel minerals With the help of the historical data compiled by the USGS [361], and the same calculation procedures applied for US copper and the main metals in Australia, we have calculated the exergy distances D and D∗ and the average exergy degradation velocities Ḋ and Ḋ∗ of the main non-fuel mineral commodities throughout the 20th century1 . Since production rates usually increase exponentially, it is interesting to analyze the latest exergy degradation velocities registered. Therefore, we have additionally calculated the average degradation velocities of the last decade (from 2000 to 2006). The depletion degree of the commodities (% R and % R.B.) has been obtained as the ratio between the exergy distance D, and the total reserves of the commodity. The latter are obtained as the published reserves or reserve base of the commodity in 2006, plus the exergy distance D from 1900 to 2006. Finally, the R/P ratio applied to exergy is provided, as a measure of the years until depletion. It has 1 Some commodities have started to be extracted after the beginning of the century. The exergy loss of world’s mineral reserves in the 20th century 283 been assumed that production remains as in year 2006, and that reserves do not increase after that year. The mineral of uranium has been included in the non-fuel mineral classification2 . For that purpose, the world uranium statistics published by the World Nuclear Association [408] have been used (see table A.25). Current uranium assured reserves were estimated by the OECD [248] as 3,804 Mtons, while the inferred reserves, as 4,742 Mtons. The average ore grade of U3 O8 is 0,33%, as calculated in this study (table 4.9), or 0,28% of U). Table 8.1 shows a summary of the results obtained for the 51 mineral commodities taken into account. As can be seen from the table and in figure 8.1, in reversible exergy terms, the exergy degradation of the non-fuel mineral capital on earth is clearly dominated by the extraction of two commodities: iron and aluminium, representing around 81 and 10% of the total exergy consumption. The exergy distance due to non-fuel mineral extraction between 1900 and 2006 is at least3 5,68 Gtoe. As expected, the general consumption pattern has followed an exponential-like behavior4 . This is reflected in the drastic change of the exergy degradation velocity Ḋ, passing from around 10 Mtoe/year in 1910, to 180 Mtoe/year in 2006. In irreversible terms, i.e. analyzing the exergy replacement costs (actual exergy) of the commodities, we observe in fig. 8.2, that copper acquires a more important role. Copper is responsible for 6% of the total exergy degradation costs on earth, while iron and aluminium, 63 and 24%, respectively. The irreversible exergy distance D∗ of all analyzed commodities is at least 51 Gtoe. This means that with current technology, we would require a minimum of a third of all current fuel oil reserves on earth (178 Gtoe [35]) for the replacement of all depleted non-fuel mineral commodities. Excluding iron and aluminium, which eclipse the rest commodities, we observe in fig. 8.3 that in decreasing order, the production of manganese, zinc, nickel, zirconium, lead, chromium, uranium, tin and gold contribute also significantly to the planet’s non-fuel mineral capital degradation. Again, an exponential behavior of the exergy costs of all commodities is observed. The average exergy cost degradation velocity D∗ in the 20th century is at least 0,5 Gtoe/year. However in the last decade, this velocity increased to 1,3 Gtoe/year. 2 The nuclear exergy of uranium, which is huge compared to its chemical exergy (see chapter 4), has not been taken into account. 3 This value corresponds only to the 51 mineral commodities taken into account. 4 With the exception of uranium, whose production depends on other external factors, such as political decisions. D 5,64E+05 5,13E+02 5,75E+02 1,53E+03 6,88E-01 7,61E+00 4,04E+03 2,41E+02 6,51E+01 6,62E-02 4,53E+04 2,20E+02 2,96E+04 8,77E+02 9,95E+03 2,75E-01 6,52E-01 9,98E-01 3,26E+04 1,40E+04 1,32E+02 5,45E-01 1,12E+01 4,60E+06 6,01E+03 9,32E+03 1,01E+04 Mineral Aluminium Antimony Arsenic Barite Beryllium Bismuth Boron oxide Bromine Cadmium Cesium Chromium Cobalt Copper Feldspar Fluorspar Gallium Germanium Gold Graphite Gypsum Helium Indium Iodine Iron Lead Lithium Magnesium Ḋ∗ Ḋ 4,01E+05 1,31E+02 8,70E+01 N.A. 4,17E-01 2,50E+00 N.A. N.A. 6,98E+01 N.A. 3,00E+03 2,86E+02 8,24E+04 N.A. N.A. N.A. N.A. 1,58E+03 N.A. N.A. N.A. N.A. N.A. 7,26E+05 3,51E+03 1,22E+03 2,96E+02 1996-2006 Ḋ∗ 5,27E+03 1,14E+05 1,85E+04 4,80E+00 5,34E+01 1,18E+01 5,37E+00 6,76E+01 6,91E+00 1,43E+01 N.A. 3,47E+01 6,43E-03 3,37E-01 7,97E-03 7,12E-02 1,16E+00 1,54E-01 3,78E+01 N.A. 1,69E+02 2,26E+00 N.A. 7,96E+00 6,08E-01 3,31E+01 1,28E+00 6,18E-04 N.A. N.A. 4,23E+02 9,62E+02 1,32E+03 2,05E+00 1,03E+02 5,70E+00 2,76E+02 2,87E+04 7,94E+02 8,20E+00 N.A. 3,51E+01 9,30E+01 N.A. 2,03E+02 2,57E-03 N.A. 1,31E-02 6,09E-03 N.A. 1,24E-02 9,33E-03 7,64E+02 1,93E-02 3,05E+02 N.A. 7,13E+02 1,30E+02 N.A. 3,51E+02 1,23E+00 N.A. 4,11E+00 5,10E-03 N.A. 3,35E-02 1,05E-01 N.A. 3,86E-01 4,30E+04 3,01E+05 1,04E+05 5,62E+01 2,19E+03 8,99E+01 8,71E+01 3,26E+02 3,26E+02 9,45E+01 9,45E+01 2,96E+02 Continued on next page . . . 1900-2006 Ḋ 1,22E+07 5,71E+03 7,23E+03 N.A. 3,60E+01 1,24E+02 N.A. N.A. 3,54E+03 N.A. 1,03E+05 1,10E+04 3,07E+06 N.A. N.A. N.A. N.A. 8,17E+04 N.A. N.A. N.A. N.A. N.A. 3,22E+07 2,35E+05 3,49E+04 1,01E+04 D∗ 14,9 72,8 74,6 61,0 N.A. 41,1 39,2 N.A. 66,8 1,2 N.A. 19,5 50,3 N.A. 48,6 N.A. N.A. 75,4 31,0 N.A. N.A. 34,3 3,8 27,7 72,5 62,3 N.A. % R loss Table 8.1: The exergy loss of the main mineral commodities in the world. Values are expressed in ktoe 2006 % R. B. R/P, yrs loss 12,0 135 56,6 16 66,2 20 25,2 24 N.A. N.A. 24,7 56 21,1 40 N.A. N.A. 45,1 25 0,8 N.A. N.A. N.A. 11,5 104 34,5 32 N.A. N.A. 32,1 45 N.A. N.A. N.A. N.A. 58,9 17 15,5 83 N.A. N.A. N.A. N.A. 26,4 19 2,2 600 14,9 84 55,1 23 38,1 12 N.A. N.A. R.B./P, yrs 173 32 30 111 N.A. 119 96 N.A. 62 N.A. N.A. 193 62 N.A. 90 N.A. N.A. 37 204 N.A. N.A. 28 1080 185 49 33 N.A. 284 THE EXERGY EVOLUTION OF PLANET EARTH D 1,08E+05 9,24E+00 9,58E+02 4,48E+03 1,57E+02 5,47E+04 2,41E-01 1,30E+05 6,65E+01 6,10E-02 8,72E+00 1,76E+01 1,83E+03 4,71E+00 4,65E-01 1,58E+00 2,11E+03 2,47E+02 4,40E+02 3,01E+02 4,98E+04 3,03E+02 5,68E+06 Mineral Manganese Mercury Molybdenum Nickel Niobium Phosphate rock PGM Potash REE Rhenium Selenium Silver Strontium Tantalum Tellurium Thorium Tin Uranium Vanadium Wolfram Zinc Zirconium SUM 1,01E+03 8,63E-02 8,95E+00 4,18E+01 1,46E+00 5,12E+02 2,25E-03 1,22E+03 6,22E-01 5,70E-04 8,15E-02 1,65E-01 1,71E+01 4,41E-02 4,35E-03 1,47E-02 1,97E+01 2,31E+00 4,11E+00 2,81E+00 4,65E+02 2,83E+00 5,31E+04 1900-2006 Ḋ 1,04E+06 3,16E+03 1,80E+04 3,55E+05 N.A. 7,08E+04 N.A. 2,02E+05 N.A. 7,43E+00 N.A. 1,69E+04 N.A. 1,31E+03 N.A. N.A. 1,08E+05 7,29E+04 4,96E+03 2,28E+04 9,09E+05 2,91E+05 5,11E+07 D∗ Ḋ 1,76E+04 9,40E+00 4,92E+02 1,04E+04 N.A. 1,54E+03 N.A. 4,56E+03 N.A. 3,30E-01 N.A. 3,11E+02 N.A. 6,38E+01 N.A. N.A. 1,51E+03 1,38E+03 1,76E+02 4,56E+02 2,06E+04 8,18E+03 1,29E+06 1996-2006 Ḋ∗ 9,75E+03 1,82E+03 2,95E+01 2,75E-02 1,68E+02 2,62E+01 3,32E+03 1,31E+02 N.A. 6,90E+00 6,62E+02 1,19E+03 N.A. 8,35E-03 1,89E+03 2,94E+03 N.A. 2,85E+00 6,95E-02 2,71E-03 N.A. 1,77E-01 1,58E+02 3,24E-01 N.A. 8,52E+01 1,22E+01 2,30E-01 N.A. 7,03E-03 N.A. N.A. 1,01E+03 2,92E+01 6,81E+02 4,68E+00 4,64E+01 1,56E+01 2,13E+02 6,02E+00 8,49E+03 1,13E+03 2,72E+03 8,52E+00 4,78E+05 1,34E+05 End of the table Ḋ∗ 51,9 92,2 37,5 40,0 19,8 26,1 14,4 12,8 2,4 24,2 48,2 78,5 56,0 14,2 25,8 1,2 75,2 34,8 8,9 48,5 68,1 43,8 25,6 % R loss Table 8.1: The exergy loss of the main mineral commodities in the world. Values are expressed in ktoe.– continued from previous page. 2006 % R. B. R/P, yrs loss 8,7 39 69,4 31 21,4 47 22,9 42 18,1 61 11,3 127 13,0 137 6,3 285 1,4 715 7,4 53 31,0 53 63,4 13 41,9 12 10,7 94 13,5 159 1,0 N.A. 62,7 20 29,9 96 3,2 231 30,2 32 44,4 18 29,2 32 14,2 92 R.B./P, yrs 437 162 103 95 67 352 154 619 1220 212 110 28 21 130 356 N.A. 36 120 675 69 48 61 191 The exergy loss of world’s mineral reserves in the 20th century 285 286 THE EXERGY EVOLUTION OF PLANET EARTH 200000 BT, ktoe 180000 160000 140000 120000 100000 80000 60000 Iron 40000 20000 Aluminium 19 00 19 04 19 08 19 12 19 16 19 20 19 24 19 28 19 32 19 36 19 40 19 44 19 48 19 52 19 56 19 60 19 64 19 68 19 72 19 76 19 80 19 84 19 88 19 92 19 96 20 00 20 04 0 Uranium Zirconium Zinc Wolfram Vanadium Tin Thorium Tellurium Tantalum Strontium Silver Selenium Rhenium REE Potash PGM Phosphate rock Niobium Nickel Molybdenum Mercury Manganese Magnesium Lithium Lead Iron Iodine Indium Helium Gypsum Graphite Gold Germanium Gallium Fluorspar Feldspar Copper Cobalt Chromium Cesium Cadmium Bromine Boron oxide Bismuth Beryllium Barite Arsenic Antimony Aluminium Figure 8.1. The exergy loss of the main non-fuel mineral commodities on earth in the twentieth century According to the depletion ratios (% R loss and % R.B. loss) in table 8.1, man has depleted in just one century around 26% of its world non-fuel mineral reserves, and around 14% of its reserve base. The estimated years until depletion of the total reserves and reserve base are around 92 and 191 years, respectively. It must be pointed out that these are only minimum numbers, as it has been assumed that no more deposits are going to be found. However, as we observed before, extraction follows an exponential behavior, what may lead that the finding of new deposits does not compensate the increasing production rates. According to fig. 8.4, the most depleted commodities are in decreasing order: mercury, with 92% of the reserves extracted, silver (79%), gold (75%), tin (75%), arsenic (75%), antimony (72%) and lead (72%). On the other hand, the minerals of cesium, thorium, REE, iodine vanadium, PGM’s, tantalum, aluminium cobalt and niobium are the least depleted commodities, having extracted less than 20% of their respective world resources. The depletion degree of minerals depend on two factors: the abundance of the considered mineral reserve, and its production rates. Usually, the least depleted minerals coincide with those substances, for which no important usefulness has been found until to date. Nevertheless, it can also be due to the important abundance of the resource. That is the case for iodine, aluminium or iron. The exergy loss of world’s mineral reserves in the 20th century 287 1800000 B*T, ktoe 1600000 1400000 1200000 1000000 800000 600000 400000 200000 Manganese Iron Copper Aluminium 19 00 19 04 19 08 19 12 19 16 19 20 19 24 19 28 19 32 19 36 19 40 19 44 19 48 19 52 19 56 19 60 19 64 19 68 19 72 19 76 19 80 19 84 19 88 19 92 19 96 20 00 20 04 0 Uranium Zirconium Zinc Wolfram Vanadium Tin Thorium Tellurium Tantalum Strontium Silver Selenium Rhenium REE Potash PGM Phosphate rock Niobium Nickel Molybdenum Mercury Manganese Magnesium Lithium Lead Iron Iodine Indium Helium Gypsum Graphite Gold Germanium Gallium Fluorspar Feldspar Copper Cobalt Chromium Cesium Cadmium Bromine Boron oxide Bismuth Beryllium Barite Arsenic Antimony Aluminium Figure 8.2. The actual exergy loss of the main non-fuel mineral commodities on earth in the twentieth century Despite of the intensive extraction of iron and aluminium throughout the 20th century, their respective abundances have avoided scarcity problems. Their reserve’s depletion rates are around 28 and 15%, respectively. Unfortunately that is not the case for copper, which has been and is still being massively extracted. More than 50% of the world’s copper reserves have been already depleted. For the latter three minerals we have applied the Hubbert peak model, considering their respective reserve base in year 19005 . Since unit exergy replacement costs are assumed to be constant over time, plotting production versus time in minimum exergy or in exergy replacement cost terms will not affect the final result. In this case, the exergy replacement costs (B ∗t ) versus time and not the minimum exergies (B t ) versus time have been plotted, because the production patterns obtained will be later used for estimating exergy degradation costs of the reserves in the future. Accordingly, it has been obtained that the peak of production of iron will be reached in year 2068, of aluminium in 2057 and of copper in 2024 (see figs. 8.5, 8.6, and 8.7). It must be remembered, that the concentration factor has not been accounted for. 5 The reserve base in year 1900 is calculated as the reserve base in year 2006 plus the exergy distance in the period between 1900 and 2006. 288 THE EXERGY EVOLUTION OF PLANET EARTH 200000 Uranium B*T, ktoe Zirconium 180000 Zinc 160000 Tin Silver 140000 Nickel 120000 Mercury Zirconium Uranium 100000 Manganese Tin Magnesium Zinc 80000 Nickel Lead Gold Lead 60000 Gypsum Manganese Graphite 40000 Gold Copper 20000 Gallium 04 96 92 Copper Chromium 20 20 19 88 19 84 19 76 72 80 19 19 19 68 19 64 19 56 52 60 19 19 19 48 19 44 19 36 32 40 19 19 19 28 19 20 16 24 19 19 19 12 19 08 19 00 04 19 19 19 00 Chromium 0 Figure 8.3. The actual exergy loss of the main 15 non-fuel mineral commodities on earth in the twentieth century, excluding iron and aluminium 100 % Mercury 90 Silver 80 Gold Arsenic Antimony 70 Tin Lead Zinc Cadmium Lithium Barite 60 Strontium Manganese Copper Fluorspar 50 Wolfram Selenium Zirconium Bismuth Boron oxide 40 Nickel Molybdenum Uranium Indium Graphite Iron 30 20 Phosphate rock Rhenium Tellurium Niobium Cobalt Aluminium PGM Potash Tantalum Vanadium 10 Iodine Cesium REE Thorium 0 Figure 8.4. Depletion degree in % of the main non-fuel mineral commodity reserves The exergy loss of world’s mineral reserves in the 20th century 289 The results obtained should not be taken as definitive. They should be rather considered as an approximation of the state of non-fuel mineral reserves on earth. In addition to the assumptions made, we should not forget that there are still many places in the world that remain unexplored. Nevertheless, and despite that the numbers are only approximations, the results are pointing out that the rate of mineral extraction in just one century has been excessive, when compared to past periods of time. Moreover, many commodities are already suffering scarcity problems. In a not very distant future, man will have to search for material alternatives of the most depleted commodities. This has already occurred for some applications, for example the shift away from copper to aluminium for conductors in wires and cables. But substitution will be only possible, whenever other mineral resources are available. 5 x 10 15 2068 Bt* 10 5 8 0 x 10 2.5 Integral Bt* 2 1.5 1 0.5 0 1900 1950 2000 2050 2100 2150 2200 2250 Figure 8.5. The Hubbert peak applied to world iron production. Data in ktoe 290 THE EXERGY EVOLUTION OF PLANET EARTH 5 10 x 10 2057 8 Bt 6 4 2 7 0 x 10 12 Integral Bt 10 8 6 4 2 0 1900 1950 2000 2050 2100 2150 2200 Figure 8.6. The Hubbert peak applied to world aluminium production. Data in ktoe 4 10 x 10 2024 8 Bt 6 4 2 6 0 x 10 10 Integral Bt 8 6 4 2 0 1900 1950 2000 2050 2100 2150 Figure 8.7. The Hubbert peak applied to world copper production. Data in ktoe The exergy loss of world’s mineral reserves in the 20th century 8.2.2 291 Fuel minerals The degradation of fuel minerals throughout history, requires historical production data of coal, oil and natural gas. Historical statistics of world fuel minerals had to be reconstructed from different information sources, being the most important ones those from the British Geological Survey and its preceding organizations. Tables A.26, A.27 and A.28 in the appendix show world production data of coal, oil and natural gas, between years 1900 and 2006. The exergy of the three types of fuel minerals has been obtained in the same way as for the case of Australia, and assuming a single type of coal and oil6 , with the average properties calculated by Valero and Arauzo [366]. This way, the exergy of average coal and oil on earth are assumed to be 22.692 and 45.664 kJ/kg, respectively. Table 8.2 summarizes the results obtained for world fuels throughout the 20th century. Table 8.2. The exergy loss of coal, oil and natural gas in the 20th century. Mineral Coal Oil Natural gas SUM 1900-2006 D, Mtoe Ḋ, Mtoe/yr 1,45E+05 1,61E+05 7,60E+04 3,82E+05 1,37E+03 1,50E+03 1,74E+03 4,61E+03 1996-2006 Ḋ, M t oe/ y r % R. loss 2006 R/P, yrs 2,73E+03 3,96E+03 2,34E+03 9,03E+03 27,9 47,5 30,9 30,5 156 42 63 114 Year of the Peak 2060 2008 2023 2029 Figure 8.8 shows the exergy loss of coal, oil and natural gas deposits in the last century. Although the most extracted fuel in the world is coal, as revealed by the historical statistics included in tables A.26, A.27 and A.28, in exergy terms, the most consumed fuel has been oil. Oil has accounted for 42% of the total fuel exergy degradation in the 20th century, while coal and natural gas for 38 and 20%, respectively. The exergy distance between 1900 and 2006 (D), i.e. the total fuel’s exergy depleted has been 382 Gtoe, corresponding to 30,5% of total world’s proven fuel reserves in 2006. The exergy of fuels was consumed at an average exergy degradation velocity ( Ḋ) of 4,6 Gtoe/year. However in the last decade, this velocity increased to around 9 Gtoe/year. From the latter figure, coal contributes to 2,7, oil to 4,0 and natural gas to 2,3 Gtoe/year. If we add the exergy loss of fossil fuels, to the exergy replacement costs of non-fuel minerals, we obtain that man has depleted in the 20th century a total of 433 Gtoe, which were consumed at an average velocity of around 4 Gtoe/year. However, the 6 Natural gas was already assumed to have a single composition, with a standard exergy of 39.394 kJ/N m3 (see section 6.4.1.3). 292 THE 12000000 12000 EXERGY EVOLUTION OF PLANET EARTH B*t, Mtoe 10000000 10000 8000000 8000 N. Gas 6000000 6000 Oil 4000000 4000 Coal 2000000 2000 Iron Copper Aluminium 19 00 19 04 19 08 19 12 19 16 19 20 19 24 19 28 19 32 19 36 19 40 19 44 19 48 19 52 19 56 19 60 19 64 19 68 19 72 19 76 19 80 19 84 19 88 19 92 19 96 20 00 20 04 0 Figure 8.8. Actual exergy consumption of the world’s fuel and non-fuel minerals throughout the 20th century 2006 mineral’s exergy degradation velocity increased to around 12 Gtoe. Most part of this exergy degradation (82%) was due to the combustion of fossil fuels. The extraction of iron was responsible for 7,4% of the total exergy destruction, aluminium for 2,8%, copper for 0,7% and the remaining minerals for 0,8% (see fig. 8.8). Without exception, production of all fossil fuels have followed an exponential-like behavior, what allows a satisfactorily application of the Hubbert’s bell-shaped curve. Among all conventional fossil fuels, coal is the least depleted commodity (27,9%), because of its large reserves worldwide. Assuming that no more coal reserves will be found, and that the production rate remains as in 2006, the R/P ratio indicates that there will be enough resource for 156 years. The Hubbert peak model applied to the exergy consumption of coal (fig. 8.9), reveals that the peak will be reached in year 20607 . Our study contradicts the recent estimate by the Energy Watch Group (EWG), which reports that global coal production could peak in 2025 [89]. The reserves of natural gas are significantly more depleted than coal. In the period between 1900 and 2006, natural gas consumption has leaded to the depletion of 30,9% of its exergy reserves. Its R/P ratio for 2006, reveals that there is enough natural gas for 63 years. The peak of world’s natural gas production will be reached in year 2023, according to the Hubbert peak model applied and represented in fig. 7 It has been assumed that the quantity of coal extracted in the period between 1800 and 1900 followed the same exponential behavior detected by the rest of the points. Hence, it has been assumed that the total reserves in 1800 were 675 Gtoe. The exergy loss of world’s mineral reserves in the 20th century 293 2060 4000 Bt 3000 2000 1000 5 0 x 10 8 Integral Bt 6 4 2 0 1800 1850 1900 1950 2000 2050 2100 2150 2200 2250 2300 Figure 8.9. The Hubbert peak applied to world coal production. Data in Mtoe 2023 3000 2500 Bt 2000 1500 1000 500 5 0 x 10 2.5 Integral Bt 2 1.5 1 0.5 0 1900 1950 2000 2050 2100 2150 Figure 8.10. The Hubbert peak applied to world natural gas production. Data in Mtoe 8.10. Bentley estimated in year 2002 [24] that the global peak in conventional gas production was already in sight, in perhaps 20 years. Hence, Bentley’s estimation fits very well with the calculation carried out in this study. Beyond doubt, oil is the most depleted commodity, having extracted almost half of its resources (47,5%). The R/P ratio of oil indicates that there is enough fuel for only 294 THE EXERGY EVOLUTION OF PLANET EARTH 5000 2008 4000 Bt 3000 2000 1000 0 3.5 5 x 10 3 Integral Bt 2.5 2 1.5 1 0.5 0 1900 1950 2000 2050 2100 Figure 8.11. The Hubbert peak applied to world oil production. Data in Mtoe 42 years, before complete depletion occurs. Hubbert’s bell-shaped curve applied to world oil’s exergy (fig. 8.11) alerts that the peak is reached in year 2008. The latter value fits very well with the predictions of other authors, such as Hatfield [133], Kerr [183] or Campbell and Laherre [47], who estimated that the peak year of world oil will be between 2004 and 2008. In fact, Campbell and Laherre’s prediction in 1998 that the world could see radical increases in oil prices ten years later, has turned out to be completely right. The price of a barrel of crude oil increased by a 100% in just one year, surpassing in January 2008, the psychological barrier of 100 $US. And the observed tendency is that it will probably reach 200 $US by the end of year 2008 or not much later. Since exergy is an additive property, we can apply Hubbert’s bell-shape curve to the sum of all three fuels. In fact, the depletion of one fossil fuel may lead to a greater consumption of the others. This way, the fact that the peak of oil has been already reached, will probably lead in the short and mid-run, to the consumption of more natural gas and coal. Therefore, it is interesting to analyze all three fuels as a single entity, making the assumption that they are mutually replaceable. If no more fuel resources are found, and if the production rate remains as in 2006, the R/P ratio indicates that in 114 years, all conventional fossil fuels will be completely depleted. Moreover, as revealed by fig. 8.12, the peak of production of all conventional fossil fuels would be reached in 2029. If this prediction is true, fuel prices will increase sharply8 , putting at risk world economies. Hopefully other energy alternatives will be ready by then and are able to supply the increasing world energy demand. 8 As it is happening already with oil and natural gas. The exergy loss of world’s fossil fuel reserves due to the greenhouse effect 12000 295 2029 10000 Bt 8000 6000 4000 2000 Integral Bt 5 0 x 10 15 10 5 0 1900 1950 2000 2050 2100 2150 Figure 8.12. The Hubbert peak applied to the world’s conventional fossil fuel production. Data in Mtoe Similarly, the Hubbert peak model can be applied to the exergy cost of non-fuel minerals plus the exergy of fossil fuels. Taking into account the global extraction of iron, aluminium, copper, coal, oil and natural gas, the peak of production would be reached in year 2034, as shown in fig. 8.13. The same figure presents also the derivative of the bell shape curve, i.e. the acceleration experienced in the production processes throughout history. Accordingly, we observe that mineral production has undergone acceleration until 1989. From that moment on, the velocity of extraction rises until 2034, but at increasingly slower rates. Figure 8.14 summarizes the results obtained in the previous sections, showing the exergy countdown of the main minerals extracted on earth, of fuel and non-fuel nature. As it can be seen, coal, iron and aluminium are the commodities having the least scarcity problems. On the other end we find in decreasing order of scarcity degree, oil, natural gas and copper. These values assume that no more resources than the reserve base for non-fuel minerals, and the proven reserves for fuels will be available in the future. Obviously the figures may change, as new discoveries are made. 8.3 The exergy loss of world’s fossil fuel reserves due to the greenhouse effect The exergy of fossil fuel reserves may decrease either through extraction and subsequent burning, or through an alteration of the reference environment. This section 296 THE 15 EXERGY EVOLUTION OF PLANET EARTH 2034 Bt 10 5 0 1989 Derivative Bt 0.2 0.1 0 -0.1 -0.2 1900 1950 2000 2050 2100 2150 2200 Figure 8.13. The Hubbert peak applied to the world’s main minerals production. Data in Mtoe 4500 Bt*, Mtoe Oil Coal 4000 3500 Natural gas 3000 2500 2000 Iron 1500 Aluminium 1000 500 Copper 0 1890 1940 1990 2040 2090 2140 2190 2240 2290 Figure 8.14. The exergy countdown of the main minerals extracted on earth The exergy loss of world’s fossil fuel reserves due to the greenhouse effect 297 is devoted to analyze the exergy loss of fossil fuel reserves due to the increase of greenhouse gases in the atmosphere (mainly CO2 ) and the subsequent temperature rise. A similar study was carried out for the first time in 1991 by Valero and Arauzo [366]. In their analysis, the exergy decrease of an “average fossil fuel” was determined, assuming that CO2 concentration would double over the next hundred years. In this section, the information provided by the latter authors will be updated with recent GHG emission scenarios and the exergy loss of the reserves of coal, natural gas and oil will be studied separately. 8.3.1 The carbon cycle and the greenhouse effect The carbon cycle is a well-known natural flux occurring on earth. The mass transfer of carbon takes place between the three spheres of our planet: hydrosphere, continental crust and atmosphere. According to Post [270], the annual natural flux of carbon in the form of CO2 between terrestrial plus oceanic reservoirs and the atmosphere is about 200 Gt per year, from which 100-115 are exchanged between the ocean and atmosphere, and 100-120 between earth biomasses and the atmosphere (see Fig. 8.15). On the other hand, the anthropic annual flux of CO2 from fossil fuel combustion and modification of terrestrial ecosystems is estimated at 7-8 Gt C/year [296], or only 3,5 to 4% of the natural flux. Nevertheless, the combined climate and biogeochemical systems that regulate the CO2 content of the atmosphere cannot handle the anthropogenic perturbation without accumulating in the atmosphere in the near term about half of the CO2 being released. According to the IPCC’s forth assessment report [162], annual fossil carbon dioxide emissions increased from an average of 6,4 GtC (23,5 GtCO2 ) per year in the 1990s to 7,2 GtC (26,4 GtCO2 ) per year in 2000-2005. Accordingly, the annual carbon dioxide concentration growth rate in the atmosphere was larger during the years 1995-2005 (average: 1,9 ppm per year), than it has been since the beginning of continuous direct atmospheric measurements (1960-2005 average: 1,4 ppm per year). The record at Mauna Loa observatory shows that concentrations have increased from about 310 to the current 379 ppm since 1958. And preindustrial CO2 concentrations did not exceed 280 ppm. Eleven of the twelve years between 1995 and 2006 rank among the 12 warmest years in the instrumental record of global surface temperature (since 1850). The linear warming trend over the last 50 years (0,13◦ C per decade) is nearly twice of that for the last 100 years. The total temperature increase from 1850-1899 to 2001-2005 is 0,76◦ C [162]. There is considerable scientific consensus that the rapid buildup of CO2 is tightly related to the increase of atmospheric temperature, due to the well known greenhouse 298 THE EXERGY EVOLUTION OF PLANET EARTH Figure 8.15. Schematic presentation of the global carbon cycle as estimated by Post et al. [270] effect. Other gases cause the same or even a more enhanced greenhouse effect on the atmosphere. The most important ones are methane C H4 (released from agriculture, waste and energy) and nitrous oxides N2 O (from agriculture and industry), accounting for about 14 and 8% of the total greenhouse gas (GHG) emissions, respectively. The global warming impact of GHG gases is related to that of CO2 and is measured in CO2 − eq units. The global warming impact of C H4 is 21 times of that of CO2 , while that of N2 O is 310 greater. According to the IPCC [162], atmospheric concentrations of CO2 (379 ppm) and C H4 (1774 ppb) in 2005 exceeded by far the natural range over the last 650.000 years. Greenhouse gases are already having a major impact on the world climate and sea level; and within 40 to 80 years atmospheric greenhouse gases will more than double with alarming implications for world climate, agriculture, sea levels, national economics, etc. 8.3.2 Scenarios There is a great variety of scenarios published about national and world energy consumptions. Two of the latest world scenarios are the ones carried out by the The exergy loss of world’s fossil fuel reserves due to the greenhouse effect 299 World Energy Council in 2007 [44] and the International Energy Agency in 2006 [152]. The WEC report, more focused on political actions, takes into account four scenarios, based on economic, population and policy aspects. The main conclusion of the study is that to meet the energy demand of all households worldwide, energy supplies must double by 2050. The IEA considers two different scenarios: the reference and the alternative policy scenario. In the latter one, governments take stronger action to steer the energy system onto a more sustainable path. Globally, fossil fuels will remain the dominant source of energy to 2030 in both scenarios. Primary energy demand in the reference scenario is projected to increase by just over one-half between now and 2030 and the associated carbon dioxide emissions increase by 55%. World primary energy demand in 2030 is about 10% lower in the alternative policy scenario than in the reference scenario, coming the biggest energy savings from coal. The carbon dioxide emissions are cut by 16% in 2030 relative to the reference scenario. The scenarios for GHG emissions most widely used are those of the IPCC published in 2000 for use in the Third Assessment Report (Special Report on Emissions Scenarios - SRES - [160]). We will focus on the SRES scenarios, as they were constructed to explore future developments in the global environment with special reference to the production of greenhouse gases and aerosol9 precursor emissions. The SRES defined four scenarios A1, A2, B1 and B2, describing the relationships between the forces driving greenhouse gas and aerosol emissions and their evolution during the 21st century for large world regions and globally. Each scenario represents different demographic, social, economic, technological, and environmental developments that diverge in increasingly irreversible ways. The scenarios are summarized as follows: • A1 scenario family: a future world of very rapid economic growth, global population that peaks in mid-century and declines thereafter, and rapid introduction of new and more efficient technologies. • A2 scenario family: a very heterogeneous world with continuously increasing global population and regionally oriented economic growth that is more fragmented and slower than in other storylines. • B1 scenario family: a convergent world with the same global population as in the A1 storyline but with rapid changes in economic structures toward a service and information economy, with reductions in material intensity, and the introduction of clean and resource-efficient technologies. • B2 scenario family: a world in which the emphasis is on local solutions to economic, social, and environmental sustainability, with continuously increasing population (lower than A2) and intermediate economic development. 9 Aerosol emissions cause the opposite effect of greenhouse gases. 300 THE EXERGY EVOLUTION OF PLANET EARTH Figure 8.16. Scenarios for GHG emissions from 2000 to 2100 and projections of surface temperatures [160] Table 8.3. Projected global averaged temperature change (◦ C at 2090-2099 relative to 1980-1999) at the end of the 21st century. After [160] Scenario Constant year 2000 concentrations B1 A1T B2 A1B A2 A1FI Temperature change 0,6 1,8 2,4 2,4 2,8 3,4 4,0 Six groups of scenarios were drawn from the four families: one group each in the A2, B1 and B2 families, and three groups in the A1 family, characterizing alternative developments of energy technologies: A1FI (fossil intensive), A1T (predominantly non-fossil) and A1B (balanced across energy sources). The SRES scenarios project an increase of global GHG emissions by 25-90% (CO2 eq) between 2000 and 2030 (Fig. 8.16), with fossil fuels maintaining their dominant position in the global energy mix to 2030 and beyond. According to those scenarios, the projected global averaged surface warming is the one shown in table 8.3. In order to stabilize the concentration of GHGs in the atmosphere, emissions would need to peak and decline thereafter. Table 8.4 and figure 8.17 summarize the re- The exergy loss of world’s fossil fuel reserves due to the greenhouse effect 301 Table 8.4. Characteristics of stabilization scenarios and resulting long-term equilibrium global average temperature rise above pre-industrial at equilibrium from thermal expansion only. After [162] Category I II III IV V VI CO2 conc. CO2 -eq conc. ppm 350-400 400-440 440-485 485-570 570-660 660-790 ppm 445-490 490-535 535-590 590-710 710-855 855-1130 Peaking year for CO2 emissions year 2000-2015 2000-2020 2010-2030 2020-2060 2050-2080 2060-2090 Global aver. temp. ◦ C 2,0-4,0 2,4-2,8 2,8-3,2 3,2-4,0 4,0-4,9 4,9-6,1 Figure 8.17. CO2 emissions and equilibrium temperature increases for a range of stabilization levels [162] quired emission levels for different group of stabilization concentrations and the resulting equilibrium global warming, according to the IPCC [162]. Combining the scenarios of table 8.3 and the stabilization temperatures of table 8.4, we obtain the required variables to be introduced in the model of fossil fuels (table 8.5). The more energy intensive scenario, with an intensive use of fossil fuels (A1FI) leads to the greatest CO2 concentrations and temperature increase. On the contrary, scenario B1 is the most sustainable one in terms of CO2 emissions. Scenarios B2 and A1T throw out the same CO2 concentrations and temperature increase, since the rapid economic growth assumed in A1T is mainly achieved through non-fossil fuel technologies. Scenario A1B, which assumes a balanced use of fossil and nonfossil fuel energies, comes right after the latter scenarios in terms of CO2 emissions, followed by scenario A2. 302 THE EXERGY EVOLUTION OF PLANET EARTH Table 8.5. Temperature rise and CO2 concentration in the SRES scenarios Scenario ∆T , ◦ C CO2 , ppm B1 1,8 350 A1T 2,4 400 B2 2,4 400 A1B 2,8 440 A2 3,4 620 A1FI 4 710 Table 8.6. Specific exergy (b in kJ/kg) and Exergy loss (%) of anthracite, bituminous, subbituminous, and lignite coal according to the different SRES scenarios Scenario 0 B1 A1T B2 A1B A2 A1FI 8.3.3 Anthracite b loss, % 31624,2 0,00 31603,6 0,07 31582,7 0,13 31582,7 0,13 31567,8 0,18 31511,4 0,36 31489,9 0,42 Bituminous b loss, % 29047,1 0,00 29028,7 0,06 29010,7 0,13 29010,7 0,13 28997,8 0,17 28949,7 0,34 28931,0 0,40 Subbituminous b loss, % 24276,5 0,00 24261,7 0,06 24246,5 0,12 24246,5 0,12 24235,7 0,17 24194,9 0,34 24179,3 0,40 Lignite b loss, % 17351,1 0,00 17340,2 0,06 17329,5 0,12 17329,5 0,12 17321,9 0,17 17293,3 0,33 17282,3 0,40 The fossil fuel exergy decrease With the help of the equations explained in section 5.3.3 and the fossil fuel’s reserves data provided in section 6.4.1, we are able to calculate the fossil fuel exergy decrease of the different scenarios of table 8.5, with respect to the current situation. For that purpose, the exergy difference will be calculated for the four types of average coal: anthracite, bituminous, sub-bituminous and lignite; for the three most common types of average oil: fuel-oil 1, fuel-oil 2 and fuel-oil 4; and for natural gas10 . The composition of the R.E. chosen for the calculations is number III, which contains the following substances11 : O2 , N2 , CO2 , H2 O, C aSO4 · 2H2 O and C aCO3 . Tables 8.6 through 8.8 and Figs. 8.18 to 8.20 show the exergy loss of the different fuels, according to the SRES scenarios. Scenario “0” is the starting point, where the R.E.’s temperature is assumed to be 298,15 K and the CO2 concentration, 300 ppm. As can be seen from the figures and tables, the exergy loss increases with temperature and CO2 concentration. Therefore, the maximum exergy loss is achieved in the scenario A1FI (rapid economic and population growth, intensive in fossil fuels), with an exergy decrease of around 0,4%. This figure is very close to the one found by Valero and Arauzo [366], where the exergy loss fell by approximately 0,31 to 0,38% if the CO2 concentration would double. 10 11 See section 6.4.1 for the properties of the different types of fuels. See section 5.3.3 for more details about the different R.E. proposed for fossil fuels. The exergy loss of world’s fossil fuel reserves due to the greenhouse effect 303 0,45 0,40 0,35 Exergy loss, % 0,30 0,25 0,20 0,15 0,10 0,05 0,00 300 360 420 480 540 600 660 720 CO2, ppm Anthracite Bituminous Subbituminous Lignite Figure 8.18. Exergy loss of the different types of coal as a function of the CO2 concentration in the atmosphere Table 8.7. Specific exergy (b) and Exergy loss (%) of fuel-oil 1, fuel-oil 2 and fuel-oil 4, according to the different SRES scenarios. Scenario 0 B1 A1T B2 A1B A2 A1F1 T0 298,15 299,95 300,55 300,55 300,95 301,55 302,15 CO2 , ppm 300 350 400 400 440 620 710 Fuel-oil1 b, kJ/kg loss, % 46259,1 0,00 46229,9 0,06 46205,2 0,12 46205,2 0,12 46187,4 0,16 46124,6 0,29 46099,3 0,35 Fuel-oil 2 b, kJ/kg loss, % 45517,4 0,00 45488,2 0,06 45463,5 0,12 45463,5 0,12 45446,0 0,16 45383,4 0,29 45358,1 0,35 Fuel-oil 4 b, kJ/kg loss, % 44002,4 0,00 43973,9 0,06 43949,6 0,12 43949,6 0,12 43931,9 0,16 43869,5 0,30 43844,5 0,36 304 THE EXERGY EVOLUTION OF PLANET EARTH 0,40 0,35 Exergy loss, % 0,30 0,25 0,20 0,15 0,10 0,05 0,00 300 360 420 480 540 600 660 720 CO2, ppm Fuel-oil1 Fuel-oil 2 Fuel-oil 4 Figure 8.19. Exergy loss of the different types of fuel-oils as a function of the CO2 concentration in the atmosphere Table 8.8. Specific exergy (b) and Exergy loss (%) of natural gas according to the different SRES scenarios. Scenario 0 B1 A1T B2 A1B A2 A1F1 T0 298,15 299,95 300,55 300,55 300,95 301,55 302,15 CO2 , ppm 300 350 400 400 440 620 710 Natural gas b, kJ/N m3 loss, % 39393,8 0,00 39355,7 0,10 39333,0 0,15 39333,0 0,15 39317,2 0,19 39269,3 0,32 39246,3 0,37 The exergy loss of world’s fossil fuel reserves due to the greenhouse effect 305 0,40 0,35 Exergy loss, % 0,30 0,25 0,20 0,15 0,10 0,05 0,00 300 360 420 480 540 600 660 720 CO2, ppm Figure 8.20. Exergy loss of natural gas as a function of the CO2 concentration in the atmosphere Among all fuels, the different types of coal are the most sensible to CO2 concentrations, leaded by anthracite. Natural gas follows coal, while fuel-oils are the least affected fossil fuels by the greenhouse effect. Tables 8.9 through 8.11 show the exergy loss of the world’s 2006 coal, fuel-oil and natural gas reserves, considering only the change of the conditions of the R.E. The reserves for coal are the ones provided by the World Energy Council, while those for fuel-oil and natural gas come from the statistics of BP12 . As can be seen from the tables, the worst scenario A1F I would lead to an exergy loss of 2102,4 Mtoe of coal, 623,7 Mtoe for fuel-oil and 637,3 Mtoe for natural gas. The global fossil fuel exergy loss would amount to 3363,4 Mtoe, 84% of the 2006 USA oil reserves (4000 Mtoe). Obviously the real exergy loss would be much greater, since the consumption of the resource in the different scenarios has not been taken into account. The latter analysis is accomplished in the next section. 12 See the detailed reserves in tables 6.11, 6.14 and 6.17. 306 THE EXERGY EVOLUTION OF PLANET EARTH Table 8.9. Exergy loss of the 2006 coal reserves due to the increase of GHG emissions, according to the different SRES scenarios. Values in Mtoe Scen. 0 A1 A1T&B2 A1B A2 A1F1 Africa B B ∆B B ∆B B ∆B B ∆B B ∆B 34286,5 34264,7 21,8 34243,5 43,0 34228,2 58,2 34171,4 115,05 34149,4 137,1 N. America 159649,3 159548,3 101,0 159445,7 203,6 159372,3 277,0 159095,8 553,50 158990,4 658,9 S. America 10224,9 10218,5 6,4 10212,2 12,7 10207,6 17,3 10190,5 34,34 10184,0 40,9 Asia Europe 136447,4 136361,5 85,9 136277,0 170,4 136216,3 231,1 135989,9 457,59 135902,3 545,2 136826,9 136742,1 84,9 136657,0 169,9 136596,1 230,8 136367,9 459,00 136280,2 546,7 Middle East 958,6 957,9 0,6 957,4 1,2 956,9 1,6 955,3 3,22 954,7 3,8 Oceania WORLD 42603,1 42576,3 26,9 42549,9 53,2 42531,1 72,1 42460,6 142,56 42433,3 169,8 520996,7 520669,4 327,4 520342,8 654,0 520108,6 888,1 519231,5 1765,26 518894,3 2102,4 Table 8.10. Exergy loss of the 2006 fuel-oil reserves due to the increase of GHG emissions, according to the different SRES scenarios Scen. A1 A1T&B2 A1B A2 A1FI B, Mtoe ∆B B, Mtoe ∆B B, Mtoe ∆B B, Mtoe ∆B B, Mtoe ∆B N. America S. & C. America 8464,5 5,44 8459,9 10,03 8456,6 13,28 8445,0 24,94 8440,2 29,64 16005,6 10,28 15997,0 18,97 15990,8 25,11 15968,8 47,15 15959,9 56,06 Europe & Eurasia 20991,7 13,55 20980,2 25,06 20972,0 33,33 20942,6 62,73 20930,8 74,52 Middle East Africa Asia Pacific WORLD 109629,4 70,40 109569,9 129,92 109527,8 172,02 109376,8 322,98 109315,8 383,95 16866,0 10,81 16856,8 19,96 16850,4 26,43 16827,2 49,62 16817,8 58,99 5890,1 3,78 5886,9 6,97 5884,7 9,23 5876,6 17,33 5873,3 20,60 177847,3 114,26 177750,7 210,90 177682,2 279,41 177436,8 524,76 177337,8 623,76 Table 8.11. Exergy loss of the 2006 natural gas reserves due to the increase of GHG emissions, according to the different SRES scenarios Scen. A1 A1T&B2 A1B A2 A1FI B, Mtoe ∆B B, Mtoe ∆B B, Mtoe ∆B B, Mtoe ∆B B, Mtoe ∆B N. America S. & C. America 7475,7 7,23 7471,4 11,54 7468,4 14,54 7459,3 23,64 7454,9 28,02 6445,8 6,24 6442,1 9,95 6439,5 12,54 6431,7 20,38 6427,9 24,16 Europe & Eurasia 60089,8 58,14 60055,2 92,72 60031,1 116,90 59957,9 190,03 59922,7 225,23 Middle East Africa Asia Pacific WORLD 68845,3 66,61 68805,7 106,23 68778,0 133,93 68694,2 217,72 68653,9 258,04 13290,2 12,86 13282,6 20,51 13277,2 25,85 13261,1 42,03 13253,3 49,81 13886,9 13,44 13878,9 21,43 13873,4 27,02 13856,5 43,92 13848,3 52,05 170033,8 164,52 169935,9 262,37 169867,5 330,78 169660,6 537,73 169561,0 637,31 A prediction of the exergy loss of world’s mineral reserves in the 21st century 8.4 307 A prediction of the exergy loss of world’s mineral reserves in the 21st century Future consumption of minerals will be affected by many different factors, such as economic, population, policy, or environmental aspects. In addition to the latter, mineral extraction will be obviously constrained by the amount of available resources. We will explore seven different scenarios, for which the future mineral degradation will be calculated: a scenario based on the Hubbert models developed in the last sections, and the six scenarios included in the IPCC SRES report [160]. 8.4.1 Hubbert scenario At a first stage, we will suppose that the amount of available resources are those of the reserve base for non-fuel minerals published by the USGS for year 2006 [362], and the proven reserves of fuel commodities, published by BP [35] and WEC [401] for the same year. It is assumed that no more resources are going to be found, and that production of the commodities will follow the bell-shaped curves obtained before. As we saw in section 8.2.1, iron, aluminium and copper dominate the world’s non fossil fuel extraction, representing 93% of the total actual exergy degradation in the 20th century. We will consider that the same behavior will be found in this new century and hence only the latter three metals will be analyzed inside the nonfuels category. Moreover, the only fossil fuel minerals considered will be coal, oil and natural gas, although the extraction of other types such as tar sands, oil shales, natural bitumen or heavy crude oil might be economically competitive by then. In order to be compared, the exergy of fuels (B) is added to the exergy costs (B ∗ ) of non-fuel minerals13 . Figure 8.21 shows the possible mineral reserve’s degradation in the 21st century based on the latter assumptions. According to fig. 8.21, if the reserves of the different commodities do not increase, the peak of maximum mineral extraction will be reached in the decade of the 2020s, exceeding 12 Gtoe/year. By then, production of all minerals would increase with respect to 2010, with the exception of oil, which had reached the peak in 2008. In the 2030s, the exergy consumption of conventional fossil fuels will come at approximately equal rates from all three fuels. From that moment on, oil will lose the hegemony of exergy production in favor of coal. In the middle of the 21st century, oil extraction will be reduced to more than a half of the amount produced in 2010. Natural gas and copper production, which should reach the peak in years 2023 and 2024, respectively, will be reduced to 23 and 13% 13 Remember that calculating exergy costs of fuel minerals has no sense, as it is impossible to replace them at least with current technology. Nevertheless, its chemical exergy is so large, that can be compared to the exergy costs of the metals studied. 308 THE EXERGY EVOLUTION OF PLANET EARTH 2050 2060 14 Bt* 12 Copper Aluminium Iron 10 N. Gas 8 6 Oil 4 2 Coal 0 1990 2000 2010 2020 2030 2040 2070 2080 2090 2100 Year Coal Oil N. Gas Iron Aluminium Copper Figure 8.21. Actual exergy consumption of the main minerals in the 21st century based on the Hubbert peak model. Values in Gtoe of their respective extractions in 2010. On the contrary, iron, aluminium and coal production will continue to increase exponentially. By the decade of 2070s, all considered minerals would have reached the peak, leading to production decelerations also of the most abundant ones, i.e. of iron, aluminium and coal. At the end of the 21st century, the exergy degradation velocity due to mineral extraction will be reduced to 5,3 Gtoe/year (a reduction of more than 50% with respect to the peaking year). By then, 82% of the mineral’s exergy reserves available in year 1900 will be depleted. Among all, the reserves of oil, natural gas and copper will be almost completely exhausted (more than 99%). Aluminium, coal and iron commodities will be depleted at 83%, 72% and 69% respectively. Table 8.12 shows the exergy distance and the degradation degree of the reserves for the periods from 1900 to 2000 and from 1900 to 2100. It should be noted however that future exploration efforts will result in the discovery of new deposits. Moreover, technological development will likely allow to extract mines that are economically unaffordable nowadays. In the next scenarios, we will assume that the registered world resources by the USGS [361] of the non-fossil fuel commodities, rather than the reserve base will be available for extraction. This supposes that technology is enough developed and mineral prices are high enough to extract resources that are currently not prifitable. Accordingly, the peak of production of iron, aluminium and copper will be reached in years 2087, 2089 and 2066, respectively (see figures A.1, A.2, and A.3 in the ap- A prediction of the exergy loss of world’s mineral reserves in the 21st century 309 Table 8.12. Actual exergy degradation of the main extracted minerals in the 21st century based on the Hubbert peak model Mineral Coal Oil Natural gas Iron Aluminium Copper SUM 1900 R.B., Gtoe 666,4 338,8 246,2 216,4 101,8 8,9 1578,4 1900 - 2000 D∗ , Gtoe % R.B. Loss 127,8 19,2 136,3 40,2 61,0 24,8 26,5 12,3 9,6 9,4 2,6 29,5 363,9 23,1 1900 - 2100 D∗ , Gtoe % R.B. Loss 480,2 72,1 333,9 98,6 243,9 99,1 145,1 67,0 84,7 83,2 8,9 99,7 1296,6 82,1 pendix). The extraction of coal, oil and natural gas is defined by the assumptions of the IPCC SRES scenarios, which indirectly assume an increase of all proven reserves. Tables A.29 through A.34 show the primary energy consumption and cumulative resources production assumed in each SRES scenario. Additionally, the exergy loss of fossil fuels due to the greenhouse effect will be taken into account. We will assume that this decrease will affect the fuels consumed from year 2050 on, letting CO2 emissions and temperatures stabilize in the atmosphere. 8.4.2 The IPCC’s B1 scenario As stated before, IPCC’s B1 [160] scenario is characterized by a world toward a service and information economy, with reductions in material intensity, and the introduction of clean and resource-efficient technologies. Among all SRES scenarios, it is the most respectful with the extraction of fuel resources. In addition to the exergy loss of the reserves due to mineral extraction, the exergy degradation of fuels due to the greenhouse effect is taken into account. In scenario B1, we obtained that the exergy loss of fuels was 0,06% for average coal and oil and 0,10% for natural gas. Figure 8.22 shows the actual exergy consumption of the main minerals extracted in the 21st century, based on the hypothesis of the B1 scenario for fuels. For non fuel minerals it has been assumed that the extraction behavior follows Hubbert’s bellshaped curve, considering that the world resources published by the USGS [361] are available for extraction. According to B1 scenario, the peak of production of all considered fuels will be reached in the decade of the 2040s with 13,2 Gtoe extracted each year, and declining thereafter. Current relative consumptions of each fuel will be kept until the peak, i.e. oil will dominate world’s extraction, followed by coal and finally natural gas. After the peaking year, the relative consumption of coal will gradually decrease in favor of the cleaner fuel natural gas. But oil will still dominate world’s fuel consumption. 310 THE EXERGY EVOLUTION OF PLANET EARTH 2050 2060 18 Bt* Copper 16 Aluminium Iron 14 N. Gas 12 10 8 Oil 6 4 Coal 2 0 1990 2000 2010 2020 2030 2040 2070 2080 2090 2100 Year Coal Oil N. Gas Iron Aluminium Copper Figure 8.22. Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s B1 scenario. Values in Gtoe The dynamic of the B1 scenario would imply an exergy degradation cost of minerals in the 21st century of over 1300 Gtoe, from these, around 1050 come only from the consumption of fossil fuels. With the exception of coal, the total exergy cost degraded of all considered commodities is greater than in the previous Hubbert scenario. In order to meet the fuel consumption expectations of B1 scenario, the oil proven reserves should increase by 69% and of natural gas by 52%. On the contrary, current proven reserves of coal would suffice for meeting future world’s consumption. In fact, in year 2100, 64% of the current proven coal reserves will be depleted. Obviously, the degradation of non-fuel minerals here is greater than in Hubbert’s scenario, as the peaks are reached 20 to 40 years later, due to the greater available resources considered. Moreover the depletion degree of the commodities would be also smaller: 57% for iron, 58% for aluminium and 74% for copper. Table 8.13 shows the irreversible exergy distance D∗ of the considered mineral resources in the period from 1900 to 2100, and the depletion degree of the commodities, according to the B1 scenario. 8.4.3 The IPCC’s A1T scenario In the IPCC’s AIT scenario, the very rapid economic growth, and the rapid introduction of new and more efficient technologies is achieved with predominantly non-fuel technologies. A prediction of the exergy loss of world’s mineral reserves in the 21st century 311 Table 8.13. Actual exergy degradation of the main extracted minerals in the 21st century based on the B1 scenario Mineral Coal Oil Natural gas Iron Aluminium Copper SUM 1900 W.R., Gtoe 666,4 338,8 246,2 297,0 222,0 21,6 1792,0 1900 - 2000 D∗ , Gtoe % W.R. Loss 127,8 19,2 136,3 40,2 61,0 24,8 26,5 8,9 9,6 4,3 2,6 12,1 363,9 20,3 1900 - 2100 D∗ , Gtoe %W.R. Loss 427,0 64,1 573,1 169,2 373,9 151,9 169,0 56,9 129,4 58,3 16,0 74,3 1688,5 94,2 According to the calculations carried out before, the exergy loss of fossil fuels due to the greenhouse effect in the A1T scenario are: 0,12% for average coal and oil, and 0,15% for natural gas. Taking into account the extraction of minerals, and the exergy decrease of fuels due to the GHG emissions in the A1T scenario, we obtain that the peak of mineral extraction is reached in the middle of the 21st century, with 19 Gtoe/year, coinciding with the peak of population. At the end of the century, the global irreversible exergy degradation velocity Ḋ∗ decreases to 10,4 Gtoe/year. Oil dominates world fuel consumption until the 2040s. Thereafter, natural gas is the most extracted fuel, followed by oil and finally by coal (see fig. 8.23). The exergy cost degradation of the mineral reserves considered in the 21st century amounts to more than 1500 Gtoe. And the extraction of fossil fuels is responsible for around 80% of the global mineral depletion. Coal is the least depleted fuel commodity, with a degradation degree of its proven reserves since 1900, of 59%. On the other hand, the reserves of natural gas and oil should increase by 77% and 144%, in order to meet the world fuel requirements specified in scenario A1T. The depletion degrees of the non-fuel mineral commodities are the same as for the latter scenario, since the same assumptions have been taken into account (see table 8.14). 8.4.4 The IPCC’s B2 scenario In the IPCC’s B2 scenario, a world with continuously increasing population and intermediate economic development, mineral consumption increases continuously throughout the century, although the rate of increase slows down in the decade of the 2050s. The exergy loss of fuels due to the greenhouse effect in the B2 scenario is identical to the previous case, namely 0,12% for coal and oil, and 0,15% for natural gas. 312 THE EXERGY EVOLUTION OF PLANET EARTH 2050 2060 20 Bt* Copper 18 Aluminium Iron 16 14 N. Gas 12 10 8 Oil 6 4 Coal 2 0 1990 2000 2010 2020 2030 2040 2070 2080 2090 2100 Year Coal Oil N. Gas Iron Aluminium Copper Figure 8.23. Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s A1T scenario. Values in Gtoe Table 8.14. Actual exergy degradation of the main extracted minerals in the 21st century based on the A1T scenario Mineral Coal Oil Natural gas Iron Aluminium Copper SUM 1900 W.R., Gtoe 666,4 338,8 246,2 297,0 222,0 21,6 1792,0 1900 - 2000 D∗ , Gtoe % W.R. Loss 127,8 19,2 136,3 40,2 61,0 24,8 26,5 8,9 9,6 4,3 2,6 12,1 363,9 20,3 1900 - 2100 D∗ , Gtoe %W.R. Loss 393,3 59,0 598,9 176,7 600,6 244,0 169,0 56,9 129,4 58,3 16,0 74,3 1907,2 106,4 According to figure 8.24, in year 2100, the global mineral degradation velocity will reach near 20 Gtoe/year. By then, fuel demand will be satisfied at approxamtely equal rates with natural gas and coal. Oil will reach the peak of production in the 2040s. From that moment on, coal and natural gas production will increase, compensating the lack of oil, although the peak of natural gas will be reached in the 2080s. At the end of the century, the global exergy degradation cost of the mineral reserves will be around 1580 Gtoe, slightly greater than in the A1T scenario. From these, 83% correspond to the consumption of fossil fuels. Since 1900, coal extraction would A prediction of the exergy loss of world’s mineral reserves in the 21st century 313 20 Bt* 18 Copper 16 Aluminium Iron 14 12 N. Gas 10 8 6 Oil 4 2 Coal 0 1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 Year Coal Oil N. Gas Iron Aluminium Copper Figure 8.24. Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s B2 scenario. Values in Gtoe Table 8.15. Actual exergy degradation of the main extracted minerals in the 21st century based on the B2 scenario Mineral Coal Oil Natural gas Iron Aluminium Copper SUM 1900 W.R., Gtoe 666,4 338,8 246,2 297,0 222,0 21,6 1792,0 1900 - 2000 D , Gtoe % W.R. Loss 127,8 19,2 136,3 40,2 61,0 24,8 26,5 8,9 9,6 4,3 2,6 12,1 363,9 20,3 ∗ 1900 - 2100 D , Gtoe %W.R. Loss 417,6 62,7 567,4 167,5 644,8 261,9 169,0 56,9 129,4 58,3 16,0 74,3 1944,2 108,5 ∗ lead to the degradation of 63% of the total reserves. However, the proven reserves of natural gas and oil should increase by 63% and 167%, in order to meet the world fuel requirements specified in scenario B2. Again, the same figures than in the previous scenarios are obtained for non-fuel minerals, as the same assumptions have been taken into account (see table 8.15). 314 8.4.5 THE EXERGY EVOLUTION OF PLANET EARTH The IPCC’s A1B scenario In the A1B scenario, the rapid economic growth and rapid increase of new and more efficient technologies is achieved with a balance between fuel and non-fuel energy sources. It is assumed that since the decade of the 2030s, the consumption of fossil fuels is dominated by natural gas. The exergy loss of fossil fuels due to the greenhouse effect was calculated for A1B scenario as 0,17% for average coal, 0,16% for average fuel, and 0,19% for natural gas. According to the hypothesis of the A1B scenario, the peaks of oil and coal production are reached in the decades of 2030s and 2050s, respectively with around 5,7 Gtoe of oil extracted per year and 4,6 Gtoe/year of coal. The global mineral production peak is reached in the decade of 2070s, with around 24 Gtoe/year extracted (see fig 8.25). 25 Bt* Copper Aluminium 20 Iron 15 N. Gas 10 Oil 5 Coal 0 1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 Year Coal Oil N. Gas Iron Aluminium Copper Figure 8.25. Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s A1B scenario. Values in Gtoe The global exergy degradation cost of all considered mineral reserves in the 21st century exceeds 2000 Gtoe, from which 86% correspond to the extraction of fuels. At the end of the 21st century, 74% of the total coal reserves would be depleted. The A1B scenario assumes that oil and natural gas proven reserves should increase by 76% and 200%, respectively, in order to meet future fuel demands. The depletion degree of non-fuel mineral reserves are identical to the previous cases, since the same assumptions have been considered. Table 8.16 shows a summary of the results for the A1B scenario. A prediction of the exergy loss of world’s mineral reserves in the 21st century 315 Table 8.16. Actual exergy degradation of the main extracted minerals in the 21st century based on the A1B scenario Mineral Coal Oil Natural gas Iron Aluminium Copper SUM 8.4.6 1900 W.R., Gtoe 666,4 338,8 246,2 297,0 222,0 21,6 1792,0 1900 - 2000 D∗ , Gtoe % W.R. Loss 127,8 19,2 136,3 40,2 61,0 24,8 26,5 8,9 9,6 4,3 2,6 12,1 363,9 20,3 1900 - 2100 D∗ , Gtoe %W.R. Loss 495,4 74,3 595,1 175,6 982,1 399,0 169,0 56,9 129,4 58,3 16,0 74,3 2387,1 133,2 The IPCC’s A2 scenario The energy demand of the continuously increasing global population of IPCC’s A2 scenario is mainly satisfied by the increasing consumption of fossil fuels. World oil consumption reaches the maximum of production in the 2020s, decreasing thereafter until its complete substitution towards the end of the century. Since the peaking of oil production, coal is the dominant fuel consumed in this scenario. It passed from representing 25% of all fossil fuels consumed in the 2020s, to over 75% in year 2100. To the exergy decrease of minerals due to extraction, we add the fuel’s exergy degradation due to the greenhouse effect, which is in the A2 scenario: 0,34% for average coal, 0,29% for average fuel, and 0,32% for natural gas. Accordingly the global peak of world mineral extraction in the 21st century is reached in year 2100, with over 33 Gtoe/year extracted. In order to satisfy this energy demand, the proven reserves of coal, oil, and natural gas should increase by 89%, 50%, and 140%, respectively (see fig. 8.26). In table 8.17, the irreversible exergy distance between 1900 and 2100 is shown. According to it, A2 scenario would imply a global exergy degradation in the 21st century of over 2300 Gtoe (6,3 times more the exergy degraded in the previous century). This implies the degradation of almost 150% of the global mineral resources available in 1900. Again, the same figures than in the previous scenarios are obtained for non-fuel minerals, as the same assumptions have been taken into account. 8.4.7 The IPCC’s A1FI scenario In the IPCC’s A1FI scenario, the world’s rapid economic growth and rapid introduction of new and more efficient technologies is achieved through the intensive 316 THE EXERGY EVOLUTION OF PLANET EARTH 2050 2060 35 Bt* 30 25 Copper 20 Aluminium Iron 15 N. Gas 10 Oil 5 Coal 0 1990 2000 2010 2020 2030 2040 2070 2080 2090 2100 Year Coal Oil N. Gas Iron Aluminium Copper Figure 8.26. Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s A2 scenario. Values in Gtoe Table 8.17. Actual exergy degradation of the main extracted minerals in the 21st century based on the A2 scenario Mineral Coal Oil Natural gas Iron Aluminium Copper SUM 1900 W.R., Gtoe 666,4 338,8 246,2 297,0 222,0 21,6 1792,0 1900 - 2000 D∗ , Gtoe % W.R. Loss 127,8 19,2 136,3 40,2 61,0 24,8 26,5 8,9 9,6 4,3 2,6 12,1 363,9 20,3 1900 - 2100 D∗ , Gtoe %W.R. Loss 1261,8 189,3 510,0 150,5 592,0 240,5 169,0 56,9 129,4 58,3 16,0 74,3 2678,2 149,5 consumption of fossil fuels. Consequently, it is the most mineral predatory scenario taken into account. The decrease of fuel’s exergy due to the greenhouse effect in the scenario A1FI obtained was: 0,4% for average coal, 0,35% for average fuel, and 0,37% for natural gas. According to figure 8.27, the peak of mineral production is reached in the decade of the 2080s, coinciding with the peaks of oil and natural gas consumption. Thereafter, the decrease of oil and natural gas production is compensated by an increase in the world extraction. The global mineral degradation velocity in the eighties reaches A prediction of the exergy loss of world’s mineral reserves in the 21st century 317 39,8 Gtoe/year, from which over 90% are due to the extraction of fossil fuels. It should be remembered, that the consumption of non-fuel minerals has been assumed to be identical to the previous cases. 45 Bt* Copper 40 Aluminium Iron 35 30 N. Gas 25 20 Oil 15 10 Coal 5 0 1990 2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100 Year Coal Oil N. Gas Iron Aluminium Copper Figure 8.27. Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s A1FI scenario. Values in Gtoe The global mineral exergy degradation cost in the 21st century is in the A1FI scenario over 2750 Gtoe. This implies that man would have depleted 7,6 times more mineral reserves than in the 20th century, and the degradation of around 174% of the global mineral resources available in 1900 (see table 8.18). Furthermore, the proven reserves of coal, oil and natural gas should increase at least by 56%, 140% and 289%, in order to meet the fuel requirements of scenario A1FI. 8.4.8 Summary of the scenarios Table 8.19 and figure 8.28 show a summary of the possible exergy degradation costs of the main mineral reserves extracted in the period between 1900 and 2100, according to the different scenarios considered before. It should be noted that to the obtained values, we should add the exergy loss of other minerals not accounted for in this study. Additional non-fuel minerals could increase the global mineral exergy consumption in 20% or more. As can be seen from the table and the figure, the scenario that leads to the least degradation degree of the mineral reserves, is the one based on the Hubbert model. It should be remembered, that for this scenario it has been assumed that the only available mineral resources for extraction are those of the reserve base, and that 318 THE EXERGY EVOLUTION OF PLANET EARTH Table 8.18. Actual exergy degradation of the main extracted minerals in the 21st century based on the A1FI scenario Mineral Coal Oil Natural gas Iron Aluminium Copper SUM 1900 W.R., Gtoe 666,4 338,8 246,2 297,0 222,0 21,6 1792,0 1900 - 2000 D∗ , Gtoe % W.R. Loss 127,8 19,2 136,3 40,2 61,0 24,8 26,5 8,9 9,6 4,3 2,6 12,1 363,9 20,3 1900 - 2100 D∗ , Gtoe %W.R. Loss 1036,9 155,6 811,3 239,4 955,6 388,2 169,0 56,9 129,4 58,3 16,0 74,3 3118,1 174,0 Table 8.19. Summary of the actual exergy degradation of the main extracted minerals in the period between years 1900 and 2100 based on the Hubbert and the IPCC’s SRES scenarios Scenario D∗ 1900 - 2100 % Reserves lost Hubbert 1297 82 B1 1689 94 A1T 1907 106 B2 1944 108 AIB 2387 133 A2 2678 149 A1FI 3118 174 no more resources will be found in the future. Accordingly, at the end of the 21st century, man would have depleted around 82% of the reserve base available in 1900. For the rest scenarios, it has been assumed that the non-fuel mineral reserves available for extraction, are those of the world resources published by the USGS [361]. Accordingly, the rate of extraction of non-fuel minerals is greater than in the previous case, as more resources can be extracted. In addition to the consumption of fossil fuels assumed in the different SRES scenarios, we have taken into account the exergy loss of fuels due to the emission of greenhouse gases to the atmosphere. Depending on the scenario considered, the greenhouse effect increases the global mineral exergy loss between 0,04% and 0,31%. Among all SRES scenarios, A1FI implies the greatest degradation of mineral reserves, leading to the depletion of more than 3100 Gtoe. On the other end, scenario B1 leads to the least mineral degradation, with near 1700 Gtoe depleted. Nevertheless, all IPCC’s scenarios involve greater degradation degrees of the mineral reserves than in the case where the Hubbert behavior has been assumed. This indicates that for satisfying the energy consumption assumed in the SRES scenarios, the proven reserves of coal, oil and natural gas should increase considerably. New discoveries are indeed increasing the reserves of many mineral resources. A recent case has been the discovery of the Carioca oil well in the Santos Basin off- A prediction of the exergy loss of world’s mineral reserves in the 21st century 319 3500 Bt*, Gtoe 3000 2500 Copper 2000 Aluminium Iron 1500 Natural gas 1000 Oil 500 Coal 0 Hubbert B1 A1T Coal B2 Oil Natural gas A1B Iron Aluminium A2 A1FI Copper Figure 8.28. Summary of the actual exergy degradation of the main extracted minerals in the period between years 1900 and 2100 based on the Hubbert and the IPCC’s SRES scenarios shore Brazil, which registered a test production of 2900 barrels/day of oil and 57000 m3 /day of gas. But in the relatively mature oil industry, the quantity of additional reserves that remain to be discovered is unclear [160]. Ivanhoe and Leckie [165], Laherrere [190], Campbell [45] or Hatfield [133] argue that few new oil fields are being discovered and that most of the increases in reserves results from revisions of underestimating existing reserves. However, optimistic views such as the one of Smith and Robinson [324], appeal to improvements in technology, which will increase recovery rates from existing reservoirs and make profitable the development of fields previously regarded as uneconomic. In the case of natural gas, estimates of reserves and resources are being revised continuously. Optimistic additional gas reserves are estimated as between 200, according to the International Gas Union [156] and 500 Gtoe, according to Gregory and Rogner [123]. Coal proven reserves are larger than those of oil and natural gas. Furthermore, according to the WEC [401] estimates of additional resources in place, the global coal reserves could be multiplied by more than two. But as the EWG [89] argues, the historical assessment of global resources has revealed substantial downgradings over the last decades. Estimated coal resources have declined from 10 billion tons coal equivalent ( 8300 Mtoe) to about 4,5 billion tons coal equivalent ( 3750 Mtoe), a decline of 55% within the last 25 years. Moreover, this downgrading of estimated 320 THE EXERGY EVOLUTION OF PLANET EARTH coal resources shows a trend supported by each new assessment. Therefore it is possible that resource estimates will be further reduced in the future. Hence, it remains to be seen whether the rate of discoveries and the reclassification of mineral reserves as recoverable are sufficient to meet the demands of a rapidly industrializing world. 8.5 8.5.1 Final reflections The Limits to Growth to be reconsidered? In the early seventies, Meadows et al. [218] raised the concern about the limits to growth. Their conclusion was that if no immediate action is undertaken, the current standard of living will not be sustained and world economies will eventually collapse. Pollution will increase and food and mineral commodities will suffer important shortages, leading to a reduction in population. The book constituted a world shock and incited reflection about the urgent need for a sustainable development. The Limits to Growth predicted oil running out in 1992 among other natural resources14 . Instead of shortages, the last two decades of the 20th century were marked by a generalized excess. The world ended up enjoying significant declines in almost all commodity prices. Consequently, the message of the Club of Rome was soon discredited. But the lack of precise data and hence inexact and early predictions about future shortages does not excuse the reality of the message provided in the Meadow’s book. It was also in the late eighties and early nineties when more voices were raised on a global scale in favor of putting limits to growth, in view of the systematic destruction of the environment. Clear examples of that were the Brundtland report [398] in 1987 or the Earth Summit celebrated in Rio de Janeiro in 1992. The beginning of the 21st century has been marked by a drastic increase of mineral and food prices. In the period between may 2007 and may 2008 the prices of wheat, soy or rice have increased by 62, 79 and 95%, respectively. Similarly, the prices of aluminium, gold, natural gas or brent increased in the same period by 25, 36, 238 and 57%, respectively. These few examples can be extrapolated to other commodities. The sharp increase of prices that we are currently facing, together with the results offered in this PhD more than justify to reconsider the reflections incited by the Club of Rome. Obviously the aim of this PhD was not to reanalyze the truth or falseness of their predictions, but to shed light on a more precise methodology that could improve the capacity of the analysis, almost forty years later. The exergoecological analysis of fuel and non-fuel minerals could be extended to the loss of fertile soils and 14 The authors of the report offered also an upper value for the expiry time, as they accepted that the known resources of minerals and energy could, and would, grow in the future, and consumption growth rates could also decline. Assuming that the resources are multiplied by two, virtually all major minerals and energy resources would expire within the following 100 years. Final reflections 321 consequently to the analysis of the increasing world food demand and the carrying capacity of the planet. If the demand of biofuels as an alternative to conventional oil should compete with food production, one could question which will be the availability of food, biofuels and biodiversity in a world with increasing demands and accelerated degradations. The analysis could be also extended to the growing freshwater requirements in a world with unpredictable climate changes. On the other hand, the production of materials is still cheap, so even if they are partially recycled, extraction continues to increase. This indicates that mankind has put neither energy nor mass limits to the extraction of minerals. Maybe the solution is to establish some kind of global law stating that extraction should be limited to the quantity of minerals that are naturally degraded through oxidation. This is, humanbeings should live with a certain amount of recyclable metals and materials and should exploit only limited resources. Ulterior extractions should not be permitted, except for extraordinary cases. This is, it should be stated that there has been extracted enough iron, aluminium, copper and other mineral commodities throughout history, and mankind should learn to recycle and save materials, instead of promoting wasting. This new economy would be more focused toward use than toward the consumption of raw materials. The dematerialization of a society could only be achieved by limiting drastically the extraction of the earth’s resources. It should be noted that this limitation would not avoid an increasing energy consumption. The energy demand should be supplied through renewable resources for compensating the exergy destruction associated to recycling. It is not enough to establish conventional measures of energy efficiency, renewable energies or more advanced energy technologies such as CO2 sequestration, fission or fusion. We should propose a drastic limitation in the extraction of raw materials from the earth. We should live from and with the already extracted materials, converting their use and their recycling into an art that comes from the necessity. As long as the “Great Mine Earth” continues providing cheap materials in which their value is associated to extraction costs, rather than replacement costs, it will be always less expensive to continue exhausting the planet, than to live with the available and already extracted minerals. Society requires development, not growth. However, as the former UK prime minister Tony Blair stated [84], “we cannot forget that more than three and a half billion people live in countries rich in oil, gas or minerals. These natural resources provide great opportunities to improve the lives of poor people. But there are risks. Bad management and lack of transparency of these resources can lead to poverty, conflict and corruption. However this is not inevitably”. If economic development of so many people in the world depends on the extraction of their raw materials, limiting such activity is at the present time unfeasible and not very practical. If this drastic limitation will surely come eventually, today the immediate and realistic requirement is to promote conservation measures of the resources for the future use of coming generations and a more rational management of the 322 THE EXERGY EVOLUTION OF PLANET EARTH extraction and use of minerals. The conservation of natural resources has worried a number of renowned economists throughout the middle of the 20th century. Although this topic exceeds the objectives of this PhD, we want to shortly address this problem. As stated by Ciriacy-Wantrup [57], the economy is the study of the election between alternative ways of action for solving scarcity. Conservation is interested in when resources should be used. Conservation and its antithesis depletion are defined in terms of the change in the intertemporal distribution of the use of resources. Such changes lead to the comparison of two or more alternative temporal distributions of resources extraction. According to Ciriacy-Wantrup, the optimum conservation state is the temporal distribution of the use that maximizes the current value and the income flux. An economic study of conservation should explain how a conservation state is produced and how it changes. In many practical situations, keeping a minimum standard of living does not imply any abstention in the use of resources, it rather implies a change in the technical ways (not in the quantity) of use. 8.5.2 The need for global agreements on the extraction and use of natural resources In the previous chapters, we have stated that there are two different types of accelerations appearing in the use of natural resources. One is the increasing demand of minerals, and the other more subtle one is associated to the decline of ore grades. This last phenomenon, corroborated throughout the 20th century for almost all minerals lead to increasing energy requirements per unit of mineral extracted. The result is that not only the absolute quantity of energy increases for the extraction of minerals in the planet, but also the energy per unit of mineral, as the ore grade decreases. Currently, between 5 and 6% of the yearly world’s fossil fuel consumption is used for the extraction and processing of iron, aluminium, copper and cement15 . If the demand of minerals increase and at the same time ore grades decline, the energy demand for extraction will likely suffer a doubly exponential increase in the next decades. Although the recycling of materials, especially of metals has grown in the last decades, these are far from reaching the accelerated extraction rate of their precursors. It is still cheaper to continue extracting than to save materials. And probably this trend will not change in the short run. Therefore, global agreements are urgently required. Paraphrasing the words of the e-Parliament16 [86], “We are burning oil, coal and gas and extracting minerals and rocks at an ever increasing rate, while at the same time destroying our forests, our biodiversity, our land and our mines. As a result, the earth is heating up fast. These 15 According to energy requirements data from the SimaPro 7.1 LCA software. The e-Parliament is the first world institution whose members are elected by the people. It links democratic members of parliament and congress into a global forum, combining meetings and electronic communication. 16 Final reflections 323 problems are global, but we are trying to solve them with an international system of some 200 national interests. Each national capital makes policy decisions within its own borders, with no easy way to learn from the experience of the others. The governments have been trying for years to agree on what to do to protect the planet. It isn’t working. To act in time, we need to create quickly a critical mass of lawmakers from all parties who understand the dangers, share a vision for a sustainable world, and are ready to take the lead in their national parliaments. We need to invest not only in renewable energy, but in information for planet management and political leadership. The only shortage we face is a lack of political will and political leadership to make the transition to a sustainable world.” It is surprising that the international worries are still very far removed from this topic. Pancala and Socolow [256] have laid out a menu of 15 currently available options for meeting the world’s energy needs over the next 50 years while stabilizing CO2 emissions near the current level of 7 billion tons of carbon per year. These options include energy efficiency, renewable energies, CO2 capture and storage, new generations of nuclear power plants, the massive use of hybrid and hydrogen vehicles and even a change in the energy model. Nevertheless, it has not been proposed in a quantitative way what it may suppose a drastic world reduction and an appropriate management of the massive use of the extractive mining industry. It seems though, that early birds in the sector are determined to improve public transparency in their activities at least in economic terms. This way, the Extractive Industries Transparency Initiative (EITI) [84] came into being in 2002 at the World Summit on Sustainable Development in Johannesburg. It brought together a global coalition of governments, companies, civil society organizations and investors to promote greater transparency in the payment and receipts of natural resource revenues. As a consequence, EITI is becoming the internationally accepted standard for transparency in the oil, gas and mining sectors. If EITI is an initiative that should be applauded, it is still not ambitious enough in the physical frame. Indeed, we share with the EITI the following principles and most relevant criteria [84]: • We share the belief that the prudent use of natural resource wealth should be an important engine for sustainable economic growth that contributes to sustainable development and poverty reduction, but if not managed property, can create negative economic and social impacts. • We affirm that management of natural resource wealth for the benefit of a country’s citizens is in the domain of sovereign governments to be exercised in the interests of their national development. • We recognize that the benefits of resource extraction occur as revenue streams over many years and can be highly price dependent. 324 THE EXERGY EVOLUTION OF PLANET EARTH • We recognize that public understanding of government revenues and expenditure over time could help public debate and inform choice of appropriate and realistic options for sustainable development. • We underline the importance of transparency by governments and companies in the extractive industries and the need to enhance public financial management and accountability. • In seeking solutions we believe that all stakeholders have important and relevant contributions to make, including governments and their agencies, extractive industry companies, service companies, multilateral organizations, financial organizations, investors and non-governmental organizations. • Regular publication should be accomplished of all material oil, gas and mining payments by companies to governments and all material revenues received by governments from oil, gas and mining companies should be forwarded to a wide audience in a publicly accessible, comprehensive and comprehensible manner. • Civil society is actively engaged as a participant in the design, monitoring and evaluation of this process and contributes towards public debate. Obviously, the global benefits obtained through a global EITI implementation would be impressive. Underlying this work is the belief that more public accountability and more transparency can raise the quality of public expenditure, cut corruption, reduce poverty and raise the credibility and prestige of extractive companies. Moreover, it provides the information that allows to decide on a global scale whether or not to change extraction rates from an economic perspective. Nevertheless, the EITI lays stress only on economic transparency, forgetting physical parameters that are extraordinarily relevant for understanding the decline of benefits or the extractive velocity in relation to its reserves. So EITI proposes transparency in extraction, but after all it enhances extraction. Physical and objective information about the amount of available resources, their composition and quality, the ore grades, the quantity of energy and water required for extraction, the amount of waste rock and other physical parameters that would allow an objective analysis of the state of our mineral capital is rarely published. In fact, in many cases this information is hidden or distorted by companies, institutions or even governments for their own economic benefits. The EITI simply ignores this issue. What really matters is the amount of money produced by a country through the extraction of its mineral resources, for carrying out a more transparent and credible management in the international markets. In short, it is about where do the profits from extraction go to and in any case, maximize them for a more universal and fair benefit. But the possibility of reducing or stopping extraction is not even questioned. Final reflections 8.5.3 325 The need for an accountability theory of mineral resources. The Physical Geonomics On the other hand, it is surprising how the mineral’s wealth classification has been carried out traditionally through purely qualitative criteria: the terms reserves or resources are accompanied by adjectives like economically or technically feasible to extract, hypothetical, identified, indicated, probable, etc. The definition is usually imprecise and depends generally on those owning the data, who diminish or increase the resources for their own interest. The countries account economically for their increase of wealth through the GDP indicator. However, the physical wealth, its decline and its eventual replacement does not appear in any national account. The depletion of natural resources of a country are seen as an asset that generates immediate wealth. Neither the associated pollution, nor the loss of wealth are considered in the national accounts of the countries. It is as if we would sell the bricks of cathedrals to tourists, thereby increasing the wealth of local people. As stated by Seymour and Zadek [305], we need to examine the underlying assumptions about energy and the environment on which today’s governance and accountability systems have been built. Such an assessment challenges us to develop a new generation of institutions with system of rules for our economy and politics which incorporates energy, materials and water scarcity and environmental fragility into its design. This will require dramatic innovations moving forward in our understanding and practice of governance and accountability. As long as there is not a unifying theory that allows to convert quantities, compositions and ore grades into non monetary units and thus not subject to variabilities beyond mining extraction such as currency value, this physical and parallel accountability will probably remain in the level of dialectic speeches. But this PhD, and in general, the development of the Exergoecology approach, could break this theoretical barrier and provoke a global stream in favor of the physical accountability of the mineral wealth on a global and local scale and disaggregated by mineral type, companies involved, etc. Hence, we propose a physical accountability of mineral resources taking into account at least three physical properties: quantity, composition and ore grade. Additionally, an estimation of the environmental impact for the opening, exploitation and shutdown of mining activities in terms of energy, water and material costs (not only in economic cost-effective terms) should be required. This is, mining resources should be evaluated in the same way as industrial products, which can be assessed through the Life Cycle Assessment methodology. On the other hand, the relationship between physical and monetary cost will be always possible through energy prices. This could at the same time keep the objectivity of physical data and the more intelligible meaning of monetary units. In any case, more high quality data collection processes and better indicators are required. Despite of the enormous currently available IT means, governmental agencies do not have the mineralogical information level attained until the seventies of 326 THE EXERGY EVOLUTION OF PLANET EARTH last century. Those series and the critical mass built around the knowledge about the mineralogical wealth of the countries and their yearly physical exploitation and associated impacts, were progressively disappearing throughout the 20th century. This was due to the neoliberal streams that transferred to the private initiative and the markets, the responsibility of mineral extraction. The government agencies that carried out the surveys through a network of experts were converted into research institutes, leaving the systematic and controlled knowledge of the mineral and natural environment. Under this information and databases gap, it is impossible to develop laws for improving the governance of national and global resources. Because in practical terms, current economy considers that we live in a planet full of resources and it is only a matter of prices, i.e. of supply and demand, the solution of the scarcity problem. The theoretical principles of Exergoecology, stated in this thesis and in preceding studies show the way. Nevertheless, it is necessary to work in the field and put into practice these principles. This is already happening with the recent developed methodology for water cost assessment called “Physical Hydronomics” developed by Valero et al. [412], [372], which is based on the principles of Exergoecology. Physical Hydronomics assesses the physical cost of a water body along its course with a single unit of measure, exergy, which accounts for chemical quality, height, temperature, velocity and flow. This way, any natural or human alteration of the water body can be physically accounted for. Through the exergy replacement costs, we have an objective tool for environmental cost assessment, allowing an alternative management of water bodies for a certain region. The rules or accounting principles are being developed thanks to specific experiences were problems are detected and solved by the simple method of learning by doing. In the same way, this thesis proposes as final corollary a new accounting tool for the management of the mineral wealth on earth, including not only fossil fuels, but also the much more complex and apparently less relevant information of non-fuel minerals. We propose to call this tool “Physical Geonomics”. Obviously, the accounting principles on which it is based will be created through the learning by doing technique. If Exergoecology considers that a mineral deposit is a thermodynamic system that contains exergy because it is differentiated from its environment, the accounting principles that allow to convert the theory into numbers should be further developed. And this should be carried out not only for exergy, but also for the exergy replacement costs. The latter provide more significant numbers, but are more arbitrary, since they depend on technologies and hence on international agreements. Physical Geonomics should not only account for the minerals extracted from the planet, but also for those that are being recycled. Consequently, we could obtain a global accountancy of the planetary stocks of chemical elements available for mankind in a certain period of time. This would allow to detect the quantity of minerals that have been returned to the planet in a complete dispersed way. That quantity is always positive, what tells us that the planet inexorably approaches the degraded state. The assessment of that entropic planet will have to be further de- Summary of the chapter 327 veloped in other studies for thinking over the degradation velocity of our planetary resources. Can we move to more efficient, equitable and cleaner use of the earth’s resources by shifting conventional accountability practices into physical accounting systems? The answer is not simply a clear “yes”, but we think that Physical Geonomics proposed in this thesis can positively help in this task. 8.6 Summary of the chapter This chapter has extrapolated at planetary level, the analysis of the exergy degradation of mineral reserves carried out before for Australia. For that purpose, many assumptions had to be made at the expense of accuracy loss in the results. This is because there is an important information gap about current and historical data of many commodities. Bearing in mind these considerations, we have been able to give a rough estimate of the mineral loss on earth since the beginning of the 20th century, the earth’s degradation velocity, the depletion degree of the reserves and reserve base, the years until depletion of the commodities, and the year where the peak of production is reached for the main minerals extracted on earth. According to our calculations, the irreversible exergy distance D∗ of the 51 non-fuel mineral commodities analyzed is at least 51 Gtoe, consumed at an average exergy degradation velocity Ḋ∗ of 1,3 Gtoe/year in the last decade. This means that with current technology, the replacement of all depleted non-fuel commodities would require a third of current world fuel oil reserves (178 Gtoe). The exergy degradation of the non-fuel mineral reserves on earth is clearly dominated by the extraction of iron, aluminium and to a lesser extent of copper. Nevertheless, the latter three minerals are not the most depleted commodities. We have stated that the reserves of mercury, silver, gold, tin, arsenic, antimony and lead are suffering the greatest scarcity problems. On the other hand, the minerals of cesium, thorium, REE, iodine, vanadium, PGM’s, tantalum, aluminium, cobalt and niobium are the least depleted commodities. For the most extracted non-fuel minerals on earth, we have applied the Hubbert bell-shaped curve, assuming that only the reserve base published by the USGS [362] are available for extraction. Accordingly, we have obtained that the peak of production for iron, aluminium and copper is reached in years 2068, 2057 and 2024, respectively. With respect to fossil fuels, we have stated that in exergy terms, oil has been the most consumed fuel, accounting for 42% of the total fuel exergy degradation in the 20th century (coal and natural gas accounted for 38 and 20%, respectively). The total fuel’s exergy depleted between 1900 and 2006 is estimated at 382 Gtoe, consumed at an average exergy degradation velocity of 9 Gtoe/year in the last decade. The degradation corresponds to 30,5% of total world’s proven fuel reserves in 2006. 328 THE EXERGY EVOLUTION OF PLANET EARTH Hubbert’s bell shaped curves applied to the exergy production of fossil fuels revealed that the peak of coal will be reached in year 2060, of natural gas in 2023, and of oil in 2008. The latter value fits very well with the predictions of other authors, who estimated that the peak year of world oil will be between 2004 and 2008. Furthermore, it gives sense to the radical increase of oil prices registered recently. The price of a barrel of crude has been doubled in just one year, surpassing in January 2008, the psychological barrier of 100 $US. If we add the exergy loss of fossil fuels to the exergy replacement costs of non-fuel minerals, we obtain that man has depleted in the 20th century a total of 433 Gtoe. In 2006, the exergy of mineral deposits was depleted at a degradation velocity of around 12 Gtoe. Furthermore, considering all main mineral resources on earth, we have estimated that the peak of production will be reached in year 2034. The exergy of mineral reserves can be also affected by the conditions of the environment. With the help of the IPPC’s reference scenarios, we were able to estimate the exergy loss of fuels due to the increase of GHG emissions in the atmosphere and the temperature rise. According to our calculations, the exergy of fossil fuels could decrease to up to 0,40%, if the current CO2 concentration in the atmosphere doubles. Finally, we have made an estimation of the possible depletion degree that mineral reserves might suffer in the 21st century. For that purpose, we took into account seven different scenarios. In the first scenario, we assumed that production of the main mineral commodities extracted, namely coal, oil, natural gas, iron, aluminium and copper, would follow the bell-shaped curves calculated before. Accordingly, the global mineral exergy decrease in the period between 1900 and 2100 would be near 1300 Gtoe. Furthermore, at the end of the 21st century, man would have depleted around 82% of the reserve base available in 1900. The other six case studies correspond to the IPPC’s SRES scenarios concerning fossil fuel consumption. For non-fuel minerals, we assumed that world resources, rather than the reserve base are available for extraction. Additionally, we have taken into account the exergy loss of fuels due to the emission of greenhouse gases to the atmosphere. All IPCC’s scenarios involve greater degradation degrees of the mineral reserves than in the case where the Hubbert behavior has been assumed. In the worst case, the exergy of the mineral resources degraded exceeds 3100 Gtoe. This indicates that for satisfying the energy consumption assumed in the SRES scenarios, the proven reserves of coal, oil and natural gas should increase considerably. Although new discoveries are indeed increasing the reserves of many mineral resources, it remains to be seen whether the rate of discoveries and the reclassification of mineral reserves as recoverable are sufficient enough to supply the huge future mineral demand. Summary of the chapter 329 In the final reflections of this PhD, we have taken up again the ideas provided by Meadows et al. [218] in their book “The Limits to Growth”. In view of the results obtained in this study, we have stated that the message of the Club of Rome was not as false as many claimed, even if the last decades of the 20th century indicated the contrary. In fact, we have reached a point in which we might think about limiting radically extraction and living only with the already extracted materials. This is recycling, rather than wasting should be promoted. But nowadays, this practice would be impossible to undertake, as many economies are sustained by the extraction of resources. Hence, the realistic requirement now is to promote conservation measures for assuring enough resources for coming generations and a more rational management of the extraction and use of minerals. We have stated that conventional measures of energy efficiency, renewable energies, CO2 sequestration, etc., are not enough for achieving sustainability. We believe that a drastic world reduction and an appropriate management of the massive use of the extractive mining industry should be also required. For that purpose, global agreements are a must. An appropriate management should be based on a solid, transparent and objective physical accountability system of resources. As final corollary of this PhD, we have proposed a new accountability tool for the management of the mineral wealth on earth, based on the Exergoecological principles stated in this study. We have proposed to call this tool “Physical Geonomics”. Obviously, the accounting principles on which it is based will have to be further developed through the learning by doing technique. Chapter 9 Conclusions 9.1 Introduction In this chapter, a synthesis of this PhD is accomplished and the main scientific contributions of the work are outlined. Finally, the perspectives of future interesting studies that have arisen from this PhD are presented. 9.2 Synthesis of the PhD The aim of this PhD has been the assessment of the resources available on earth and their degradation velocity, due to human action. This has been accomplished under the framework of the exergoecological analysis. The latter allows to value mineral resources, according to the physical cost that would require to obtain them from the materials contained in a hypothetical earth that has reached the maximum level of deterioration. In other words, it quantifies the physical cost of restoring natural resources from a degraded state in the so called reference environment to the conditions in which they are currently presented in nature. The exergoecology approach uses the property exergy as the universal unit of measure. The main advantage of its use with respect to other physical indicators is that in a single property, all the physical features of a resource are accounted for. Furthermore, exergy has the capability of aggregating heterogeneous energy and material assets. This is not the case, if the assessment is carried out in terms of mass, because we cannot add tons of oil with tons of gold, for instance. Unlike standard economic valuations, the exergy analysis gives objective information since it is not subject to monetary policy, or currency speculation. This PhD has been structured into two different parts. The first one, of an eminently geological and geochemical character, has described and modeled the geochemistry 331 332 CONCLUSIONS of the earth and its resources. The second part has developed and used the thermodynamic tools required for analyzing the state of our planet. In chapter 2, a comprehensive analysis of the physical and geochemical features of the earth has been undertaken as a starting point for determining its properties. First, a coarse composition of the bulk earth with the relative mass proportions of each sphere has been presented. This overview has given way to the more detailed explanation of the geochemistry of the atmosphere, hydrosphere and upper continental crust, which are the layers of the earth with which man interacts. It has been stated that the chemical composition of the atmosphere is rather uniform to heights up to 100 km. Apart from the natural occurring gases, there are traces of anthropogenic substances in the atmosphere that may alter the conditions on earth. The hydrosphere is composed by the oceans (representing over 97% of the hydrosphere’s volume), renewable water resources (rivers, lakes and underground water), ice, and atmospheric water. As it happens to the atmosphere, the composition of seawater is quite uniform. On the contrary, the composition of the rest hydrosphere’s components may vary from place to place. Nevertheless, some examples and averages have been provided for all water reservoirs. The continental crust is the outer layer of the solid earth, and is composed by the core, mantle and crust. The crust is further divided into the lower, middle and upper crust. We have focused our attention only in the upper part of it, as it is the reservoir of the main minerals and other natural resources for mankind. The chemical composition of the upper continental crust in terms of minerals is well known, although it is still subject of numerous updates. However, its composition in terms of minerals has been barely studied. Since the determination of the thermodynamic properties of the upper continental crust requires the knowledge of the minerals included in it, the aim of chapter 3 was to obtain a model of its mineralogical composition. For that purpose, a revision of the studies concerning the mineralogical composition of the earth’s crust was carried out. It was stated, that the heterogeneity and complexity of the crust have hindered deep and accurate studies of its composition in terms of minerals. In fact a single author N.A. Grigor’ev has been very recently the first one in giving a comprehensive mineralogical composition of the upper crust. We checked the satisfaction of the mass balance between the minerals proposed by Grigor’ev and the better known chemical composition in terms of elements of the upper crust. The no satisfaction of the mass balance, lead us to update Grigor’ev’s composition. The methodology used minimizes the difference between Grigor’ev’s and our target composition, under the constraint of assuring chemical coherence with the average chemical composition of the earth’s crust in terms of elements. Furthermore, the final composition includes important minerals not taken into account in Grigor’ev’s analysis. As a result, we obtained an estimate of the average Synthesis of the PhD 333 mineralogical composition of the upper crust, consisting of the 307 most abundant minerals. The composition obtained should not be considered as final and closed, since many assumptions had to be made. Nevertheless, it is the first step for obtaining a coherent mineralogical composition of the crust. Chapter 4 closes the analysis of the earth’s components (Part I of this report), by undertaking a review of the different natural resources useful to man. Generally, information is available for most of the energy resources. This is not the case for non-fuel minerals, where the data is often scarce and inaccurate. Hence at a first step, the revision was focused on the energy sources of renewable and non renewable nature. With the most updated information sources, the available energy, potential energy use and current world energy consumption has been provided. The energy resources studied were: geothermal, nuclear, tidal, solar, wind and ocean power, as well as biomass, coal, natural gas, oil and unconventional fuels. For the most important non-fuel minerals, the current production, and the available reserves, reserve base and world resources has been obtained from the US Geological Survey. But as opposed to fossil fuels, the abundance of minerals is not important if these are dispersed throughout the crust. Therefore, the grade of the mineral deposits is also required for assessing the state of mineral resources. From different information sources, we were able to estimate world mineral average ore grades. Part II of this PhD begins in chapter 5 with the description of the thermodynamic models required for assessing the properties of the earth and its resources. In order to obtain the exergy of any substance, a reference environment (R.E.) should be defined. Therefore, the first aim of chapter 5 was to select an appropriate R.E. for the exergy assessment of the mineral capital on earth. For that purpose, the different R.E. proposed so far were reviewed. It was stated, that the best suitable available R.E. for determining the exergy of natural resources was the one based on Szargut’s criterion. Hence, Szargut’s R.E. [336], later modified by Ranz [276], was updated and adapted to our requirements with the help of new geochemical information and the model of continental crust developed in this PhD. Next, we analyzed the energy involved in the formation processes of a mineral deposit from a defined R.E., and provided the equations required for the exergy calculation of minerals. We stated that the minimum exergy embedded in a mineral has two components, one based on the chemical composition and the other one on its concentration or ore grade. The first parameter accounts for the formation of the mineral from the R.E. The concentration exergy expresses the minimum energy that nature had to spend to bring the minerals from the concentration in the reference state to the concentration in the mine. We saw, that the latter shows a negative logarithmic pattern with the grade. This means that as the ore grade of the mine tends to zero, the exergy of the deposit approaches also zero and the exergy required for replacing the mine tends to infinity. 334 CONCLUSIONS In theory, the exergy of fossil fuels can be calculated with the general formulas provided for minerals. However, the complexity of their chemical structure, makes this task very difficult and special calculation procedures are applied. It was stated that the chemical exergy of fossil fuels can be in many cases approximated to its HHV. Nevertheless, we used the different formulas developed by Valero and Lozano [369], since they take into account the conditions of the environment. Generally, the minimum exergy values are very small, if compared to the real energy required for the replacement of natural resources to their original state. In order to account for the inefficiencies of man-made processes, the exergy values are multiplied by the unit exergy replacement costs. These are dimensionless and measure the number of exergy units needed to obtain one unit of exergy of the product. The resulting exergy costs represent the exergy required by the given available technology to return a resource into the physical and chemical conditions in which it was delivered by the ecosystem. As opposed to exergy, exergy costs cannot be considered as a property of the resource, since unit exergy costs introduce an arbitrary factor to the calculation. Nevertheless, they can be used as a suitable indicator for assessing the value of non-fuel mineral resources, as they integrate in one parameter, concentration, composition and also the state of technology. The chapter ends with the description of the twelve semi-theoretical models for the estimation of enthalpies and Gibbs free energies of formation, required for the calculation of the chemical exergy of minerals. In chapter 6, the standard thermodynamic properties of the main constituents of the outer earth’s spheres have been provided for the first time. That is the standard enthalpy, Gibbs free energy and chemical exergy of more than 330 natural substances. The enthalpies and Gibbs free energies, have been obtained either from the literature, or have been calculated with the 12 estimation methods described in the previous chapter. The exergy of the substances has been calculated with the chemical exergies of the elements, generated with the R.E. developed in this PhD. Through the molar fractions of the substances in each layer, determined in part I of this report, we were able to determine the average thermodynamic properties of the atmosphere, hydrosphere (divided into seawater, rivers, glacial runoff and groundwater) and upper continental crust. It has been stated, that all negative ions in the hydrosphere throw up negative chemical exergies. Additionally, some substances of the continental crust show also negative exergy values. This is because the reference species of our R.E. are more stable than the considered substance. This lead us to question the suitability of the R.E. developed in this PhD, for natural resource accounting. Furthermore, this R.E. differs substantially from the model of degraded earth that should become. The degraded earth could be assimilated to a dead planet, with an atmosphere similar to the current one, but with a higher CO2 concentration due to the burning of fossil fuels, a hydrosphere were all fresh waters are mixed with salt water, and Synthesis of the PhD 335 a continental crust without fossil fuels or concentrated mineral deposits. Since the relative quantity of freshwater with respect to saltwater on earth is irrelevant, the hydrosphere of this hypothetical earth has the same composition of the oceans. Something similar occurs with the continental crust, the abundance of mineral deposits and fossil fuels is negligible when compared to the whole continental crust. Hence, the composition of the degraded crust can be approximated to the model developed in this PhD. From this model of degraded earth firstly defined in this PhD, we could recalculate the chemical exergy of the elements. We think that the calculation procedures and even the philosophy for obtaining the chemical exergies of the elements should be reviewed, since the selection of an appropriate R.E. is a required but not a sufficient condition. However, this activity remains open for further studies in the future. Despite of the limitations of the R.E. developed here with Szargut’s methodology, it still constitutes a tool for obtaining chemical exergies. Since the mass of the earth and of its spheres is known, we were able to calculate the absolute chemical exergy of the atmosphere, hydrosphere and upper continental crust: 6, 27 × 103 , 7, 80 × 105 and 1, 21 × 109 Gtoe, respectively. Of course these are very rough numbers, and are subject to ulterior updates, especially when a more appropriate R.E. is found. But they are good enough, for providing an order of magnitude of the huge chemical wealth of our planet. The second part of chapter 6 has provided an inventory of the most important energy resources and non-fuel minerals on earth, expressed through a single unit of measure: exergy. We have stated that there is a huge amount of energy sources on earth, of both renewable and non-renewable nature. There are many energy alternatives that could replace fossil fuels when they become depleted. But obviously the technology for recovering these alternatives needs to be further developed. Despite of the enormous chemical exergy of our planet, only 0,01% of that amount can be considered as available for human use. With current technology, it is impossible to use the chemical exergy of dispersed substances. And only those minerals that are concentrated, can be considered as resources. In the short run, technological development will allow substitution among minerals, but this can only last whenever other concentrated mineral stocks are available. Hence, we have stated that the scarcity problems that man could be facing are based on the use of materials, rather than on the use energy sources. This is why recycling and especially, the search of a dematerialized society becomes essential, in order to be consistent with the sustainability doctrine. In chapter 7, we have included the time dimension in the exergy evaluation of mineral capital on earth. We stated that neither mass, nor energy are appropriate indicators for assessing the degradation of mineral wealth on earth, as they are conservative properties. On the contrary, in all physical transformations of matter or energy, it is always exergy that 336 CONCLUSIONS is lost. Therefore, any degradation of the mineral capital which can come either from an alteration in its composition, a decrease of its concentration, or a change in the reference environment, can be accounted for with exergy. Starting from the property exergy, we have built a series of indicators which should measure the scarcity degree of the mineral reserves on earth. The exergy difference between two situations of the planet has been named as exergy distance D. The exergy degradation velocity Ḋ, calculated as the exergy distance divided by the period of time considered, should account for the rate of exergy destruction of a certain resource. We have also defined the ton of mineral equivalent (t M e), which allows us to assess the exergy content of a certain deposit before and after extraction, and to compare the quality of different deposits containing the same mineral, but with a more understandable unit of measure. Furthermore, we have proposed to calculate the resources to production ratio of mineral deposits in exergy terms, thereby accounting for the concentration factor as well. All indicators described above can be assessed either with minimum exergies, or with exergy replacement costs. With the latter, the irreversibility factor present in all real processes is taken into account. Finally, we have proposed the application of the Hubbert peak model for the assessment of the production peak of non-fuel minerals. It has been stated that the bell-shape curve is better suited to non-fuel minerals if it is fitted with exergy over time, instead of mass over time. This way, we would not ignore the concentration factor, which is very important for the case of solid minerals. As a first case study, we have obtained the exergy decrease of US copper deposits throughout the 20th century, and have applied all indicators described above. It has been estimated, that the global exergy cost associated to the degradation of US copper deposits in the 20th century was around 700 Mtoe, consumed at an average exergy degradation velocity of 6,6 Mtoe/year. The R/P ratio of US copper deposits reveals for year 2000, that reserves would be completely depleted after 56 years. Moreover, the application of the Hubbert peak in exergy terms, gave as a result, that the peak was already reached in year 1994. In fact the real peak was attained in year 1998. Although the exergy production pattern did not perfectly fit in the bell-shaped curve, interesting conclusions could be extracted. Generally, production follows asymmetric curves with the decline much sharper than the growth. Hence, the real production peak is most probably attained after the year predicted by the Hubbert model. During a short period of time, the commodities will be probably over-exploited and the production points will appear over the bell-shaped curve. The compensation of the overproduction is the much sharper decrease of production after the peak, instead of a gradual and steady reduction. Synthesis of the PhD 337 The second case study was aimed at assessing the exergy loss of a country due to mineral extraction. Australia has been chosen for the analysis, because it is one of the most important mineral exporting countries in the world and is the only one with registered ore grade trends of its main minerals. It has been stated that the most depleted commodities are in decreasing order: silver, gold, oil, zinc and lead, with R/P ratios below 35 years. On the contrary, the reserves of copper, iron, natural gas, nickel and finally coal will last at least for 48, 63, 67, 121 and 153 years, respectively. The Hubbert peak model was satisfactorily applied for all commodities, with the exception of the group lead-zinc-silver, whose production patterns differ from the rest, as they are extracted together. The study predicts that the maximum production has been already reached for gold (2006), silver (2005), lead (1997) and oil (1997). Zinc will reach the peak in 2010, copper in 2021, natural gas in 2025, iron in 2026, nickel in 2040, and finally coal in 2048. By the extraction of minerals, Australia has degraded the equivalent of 12,5 Gtoe. And this degradation is dominated by the extraction of two commodities, coal and iron. In 2004, the global exergy degradation velocity exceeded 550 Mtoe/year (around 15% of current world’s oil consumption). And it will probably continue to increase exponentially at least for 20 to 40 years, until the peaks of iron and coal are reached. We additionally estimated the monetary cost of the main mineral reserve’s depletion suffered in Australia in year 2004. This was carried out, by the conversion of exergy costs into monetary costs through conventional energy prices. According to the results obtained, Australia would have lost an equivalent of 93,3 billions of $US of its mineral capital, due to resource extraction only in year 2004. This corresponds to 15,2% of the 2004 Australian GDP. It should be noted, that the results obtained are estimations and hence the numbers cannot be taken as final. More reserves could be found in the future, thereby increasing the years until depletion and the peak of production of the commodities. However, the huge amount of energy and its equivalent in money terms involved in the degradation of minerals on earth, alerts us about the importance of conserving our resources. The last chapter of this PhD, chapter 8, has extrapolated at planetary level, the analysis of the exergy degradation of mineral reserves carried out for Australia. For that purpose, many assumptions had to be made at the expense of accuracy loss in the results. This is because there is an important information gap about current and historical data of many commodities. Bearing in mind these considerations, we have been able to give a rough estimate of the mineral loss on earth since the beginning of the 20th century, the earth’s degradation velocity, the depletion degree of the reserves and reserve base, the years until depletion of the commodities, and the year where the peak of production is reached for the main minerals extracted on earth. 338 CONCLUSIONS According to our calculations, the irreversible exergy distance D∗ of the 51 nonfuel mineral commodities analyzed is at least 51 Gtoe, consumed at an average exergy degradation velocity of 1,3 Gtoe/year in the last decade. This means that with current technology, the replacement of all depleted non-fuel commodities would require a third of current world fuel oil reserves (178 Gtoe). The exergy degradation of the non-fuel mineral reserves on earth is clearly dominated by the extraction of iron, aluminium and to a lesser extent of copper. Nevertheless, the latter three minerals are not the most depleted commodities. We have stated that the reserves of mercury, silver, gold, tin, arsenic, antimony and lead are suffering the greatest scarcity problems. On the other hand, the minerals of cesium, thorium, REE, iodine vanadium, PGM’s, tantalum, aluminium cobalt and niobium are the least depleted commodities. For the most extracted non-fuel minerals on earth, we have applied the Hubbert bell-shaped curve, assuming that only the reserve base published by the USGS [362] are available for extraction. Accordingly, we have obtained that the peak of production for iron, aluminium and copper is reached in years 2068, 2057 and 2024, respectively. With respect to fossil fuels, we have stated that in exergy terms, oil has been the most consumed fuel, accounting for 42% of the total fuel exergy degradation in the 20th century (coal and natural gas accounted for 38 and 20%, respectively). The total fuel’s exergy depleted between 1900 and 2006 is estimated at 382 Gtoe, consumed at an average exergy degradation velocity of 9 Gtoe/year in the last decade. The degradation corresponds to 30,5% of total world’s proven fuel reserves in 2006. Hubbert’s bell shaped curves applied to the exergy production of fossil fuels revealed that the peak of coal will be reached in year 2060, of natural gas in 2023, and of oil in 2008. The latter value fits very well with the predictions of other authors, who estimated that the peak year of world oil will be between 2004 and 2008. Furthermore, it gives sense to the radical increase of oil prices registered recently. The price of a barrel of crude has been doubled in just one year, surpassing in January 2008, the psychological barrier of 100 $US. If we add the exergy loss of fossil fuels to the exergy replacement costs of non-fuel minerals, we obtain that man has depleted in the 20th century a total of 433 Gtoe. In 2006, the exergy of mineral deposits was depleted at a degradation velocity of around 12 Gtoe. The exergy of mineral reserves can be also affected by the conditions of the environment. With the help of the IPPC’s reference scenarios, we were able to estimate the exergy loss of fuels due to the increase of GHG emissions in the atmosphere and the temperature rise. According to our calculations, the exergy of fossil fuels could decrease to up to 0,40%, if the current CO2 concentration in the atmosphere doubles. Synthesis of the PhD 339 Finally, we have made an estimation of the possible depletion degree that mineral reserves might suffer in the 21st century. For that purpose, we took into account seven different scenarios. In the first scenario, we assumed that production of the main mineral commodities extracted, namely coal, oil, natural gas, iron, aluminium and copper, would follow the bell-shaped curves calculated before. Accordingly, the global mineral exergy decrease in the period between 1900 and 2100 would be near 1300 Gtoe. Furthermore, at the end of the 21st century, man would have depleted around 82% of the reserve base available in 1900. The other six case studies correspond to the IPPC’s SRES scenarios concerning fossil fuel consumption. For non-fuel minerals, we assumed that world resources, rather than the reserve base are available for extraction. Additionally, we took into account the exergy loss of fuels due to the emission of greenhouse gases to the atmosphere. All IPCC’s scenarios involve greater degradation degrees of the mineral reserves than in the case where the Hubbert behavior has been assumed. In the worst case, the exergy of the mineral resources degraded exceeds 3100 Gtoe. This indicates that for satisfying the energy consumption assumed in the SRES scenarios, the proven reserves of coal, oil and natural gas should increase considerably. Although new discoveries are indeed increasing the reserves of many mineral resources, it remains to be seen whether the rate of discoveries and the reclassification of mineral reserves as recoverable are sufficient enough to supply the huge future mineral demand. In the final reflections of this PhD, we have taken up again the ideas provided by Meadows et al. [218] in their book “The Limits to Growth”. In view of the results obtained in this study, we have stated that the message of the Club of Rome was not as false as many claimed, even if the last decades of the 20th century indicated the contrary. In fact, we have reached a point in which we might think about stopping extraction and living only with the already extracted materials. This is recycling, rather than wasting should be promoted. But nowadays, this practice would be impossible to undertake, as many economies are sustained by the extraction of resources. Hence, the realistic requirement now is to promote conservation measures for assuring enough resources for coming generations and a more rational management of the extraction and use of minerals. We have stated that conventional measures of energy efficiency, renewable energies, CO2 sequestration, etc. are not enough for achieving sustainability. We believe that a drastic world reduction and an appropriate management of the massive use of the extractive mining industry should be also required. An appropriate management should be based on a solid, transparent and objective physical accountability system of resources. As final corollary of this PhD, we have proposed a new accountability tool for the management of the mineral wealth on earth, based on the Exergoecological principles stated in this study. We have proposed to call this tool “Physical Geonomics”. Obviously, the accounting principles on 340 CONCLUSIONS which it is based will have to be further developed through the learning by doing technique. 9.3 Scientific contributions of the PhD The main scientific contributions generated in this PhD are outlined next. 1. This PhD has provided average chemical compositions of the atmosphere, seawater, rivers, lakes, groundwater and glacial-runoff. Furthermore, the main studies about the chemical composition in terms of elements of the upper continental crust, have been compiled. Although this information is available in the literature, it is rather dispersed in a significant number of different publications. The integration of all these data accomplished in this work, provides a global overview of the geochemistry of our planet with special attention to the substances that compose the earth’s outer spheres. 2. We have estimated for the first time the composition of the upper continental crust in terms of minerals, through a procedure that assures chemical coherence between species and elements. The model of upper crust developed in this PhD is based on the recent and single published study concerning the mineralogical composition of the upper crust, by the Russian geochemist Grigor’ev [127]. He calculated the average contents of 265 rock forming and accessory minerals in the upper part of the continental crust. Grigor’ev’s model accounts for 56 elements, as opposed to the 78 included in the chemical composition of the continental crust of Rudnick and Gao [292]. Since the earth and in particular the upper continental crust can be considered as a closed system, the mass conservation principle dictates that the elements contained in the minerals of the crust, must be equal to the chemical composition of the crust, which is reasonably known. We stated that Grigor’ev’s mineralogical composition, although comprehensive, does not fulfill the mass balance of the earth. Therefore, we optimized Grigor’ev model, assuring the mass balance between species and elements. A rigorous analysis of the main minerals of each element was carried out, and some important substances not included in Grigor’ev’s composition were considered in this model. As a result, we obtained a model of upper continental crust, consisting of the 307 most abundant minerals. Furthermore, the new model takes into account all 78 elements included in the chemical composition of Rudnick and Gao [292]. Although the composition obtained should not be considered as definitive, since different assumptions had to be made, it constitutes the first step for obtaining a coherent and comprehensive mineralogical composition of the upper earth’s crust. 3. The full physical characterization of non-fuel mineral resources should be based on at least two physical features: the tonnage and the grade of the deposits. Only the Scientific contributions of the PhD 341 US Geological Survey provides world figures of the reserves for the most important mineral commodities. However, average ore grades of the reserves are unknown. This study has estimated the weighted average grades of the most important nonfuel mineral reserves. This was mainly accomplished basing on the the compendium of the descriptive geologic models of Cox and Singer [66], who estimated pre-mining tonnage’s grades from over 3900 well-characterized deposits all over the world. With the published information about the reserves by the USGS, and the average ore grade of the mineral commodities estimated here, we have been able to illustrate for the first time in global terms, the quantity and quality of the main mineral deposits on earth. 4. We have stated in this PhD, that the most appropriate of the reference environments published so far for assessing the chemical exergy of natural resources, is the one based on Szargut’s methodology [336]. Ranz [276] and Rivero [281] made important contributions to the update of Szargut’s R.E, proposing new reference substances. Nevertheless, it was stated that the latter studies could be further adapted to our requirements. Consequently, we have improved Szargut’s R.E., with the help of new geochemical information, and the model of continental crust developed in this study. The criterion used for choosing the reference substances of the R.E., which differs from Ranz’s and Rivero’s models, is based on Szargut’s partial stability. This is, among a group of reasonable abundant substances, the most stable will be chosen if they also fulfill the “earth similarity criterion”. If the stability of the possible different reference substances for a specific element (measured in terms of the formation Gibbs energy) is within a certain threshold, then the most abundant R.S. will be chosen. If the differences exceed this threshold, the most stable substance will be taken as R.S. as long as the “earth similarity criterion” is not contradicted. The new R.E. generates chemical exergies of the elements that differ on average in only 1% with respect to the original environment. Nevertheless, when the whole earth is considered, these small numbers become not so insignificant. 5. In this study a compendium of twelve different estimation methods for calculating standard enthalpies and Gibbs free energies of substances are provided for the first time. The calculation methodologies come from different thermochemical studies published in the literature. The novelty introduced in this PhD is the compilation of all procedures, the specification of their respective applications within the geochemical framework, and the estimation of the relative errors introduced with each methodology. This way, we have provided methodologies with estimation errors comprised between 0% and 10%. The first method is based on the definition of the Gibbs free energy and therefore does not introduce any error in the calculation. The second most accurate estimation procedure is Vieillard’s method for hydrated clay minerals and for phyllosilicates, entailing an error of around ±0, 6%. Five further methods 342 CONCLUSIONS have associated an estimation error of ±1%. These are: the ideal mixing model; the thermochemical approximations for sulfosalts and complex oxides; the method of corresponding states; the method of Chermak and Rimstidt for silicate minerals; the ∆O−2 method; and the ∆O−2 method for different compounds with the same cations. The following three methods entail a maximum error of ±5%: assuming ∆S r zero; the element substitution method; and the addition method for hydrated minerals. Finally, the estimation procedure proposed with the greatest associated error (±10%) is the decomposition method. 6. We have developed for the first time a complete thermochemical data base of the main substances that compose the atmosphere, hydrosphere and upper continental crust. For that purpose, the standard Gibbs free energy, enthalpy of formation and specific exergy of more than 330 natural substances has been provided. The enthalpy and Gibbs free energy of the compounds have been compiled from the literature, or have been calculated with the 12 estimation methods described previously. Generally, published thermochemical data is available for those substances with industrial importance. Consequently, many components of the crust (a total of 125), lacked of experimental thermochemical values and had to be estimated. From the Gibbs free energy data and the chemical exergies of the elements generated from the R.E. developed in this PhD, we were able to obtain the specific chemical exergy of the considered substances. 7. With the relative abundance of the substances in each of the earth’s outer spheres obtained in this PhD, and the thermochemical information, we were able to calculate for the first time, the average Gibbs free energy, enthalpy of formation and chemical exergy of the atmosphere, hydrosphere and upper continental crust. Furthermore, since the mass of each layer of the earth is well known, we have obtained the first estimation of the earth’s specific chemical exergy: 1, 22 × 109 Gtoe. We have stated that the upper continental crust is responsible for most of the exergy (99,9%), due to its greater mass portion and specific exergy. Although the relative proportion of the atmosphere and hydrosphere is small when compared to the whole, their chemical exergies are also huge: 6, 27 × 103 Gtoe and 7, 80 × 105 Gtoe, respectively. 8. This PhD has provided the first model of degraded earth. It has been stated, that this crepuscular planet is composed of an atmosphere similar to the current one, but with a CO2 concentration of around 1400 ppm due to the complete burning of fossil fuel resources. The composition of the hydrosphere is equivalent to that of seawater, since in the degraded planet all fresh waters are mixed with salt water. We stated that the freshwater contribution to the final composition of the seas is irrelevant, due to their small relative volume. Finally, the continental crust of the degraded planet is one in which no fossil fuels or concentrated mineral deposits exist. Since the abundance of mineral deposits and fossil fuels is negligible when compared to the whole continental crust (they account for about 0,001%), the composition of the degraded crust can be approximated to the model developed in this PhD. Scientific contributions of the PhD 343 9. This study has obtained an inventory of the most important renewable and nonrenewable resources on earth measured in exergy terms. The main novelty introduced in the inventory is the combined assessment of energy resources with nonfuel minerals. Since exergy is an additive property, we have been able to obtain the total exergy of the non renewable energy resources, including nuclear, fossil fuels and non-fuel mineral reserves. Furthermore we could estimate for all renewable resources, the rate of current consumption with respect to the available potential use. Similarly, for non-renewables, we estimated the resource to production ratio. We came to the important conclusion that vast amounts of energy resources are available on earth, especially of renewable nature. However, we are currently using less than 2% of its potential. On the other hand, we have estimated that the reserves of concentrated fuel and non fuel minerals, which can be practically used by man, represent only 0,01% of the chemical exergy of the earth. Furthermore, their global R/P ratio excluding nuclear materials, is less than 100 years. Hence, humankind is not facing an energy crisis, as many claim, but rather a material’s scarcity. 10. An important advance entailed in this PhD with respect to the works of Ranz [276] and Botero [34] has been the inclusion of the time factor in the exergy assessment of natural resources. Consequently, we have been able not only to calculate what is the exergy reservoir of the earth’s mineral capital, but also at which rate these resources are being degraded by man. For that purpose, we defined several indicators, aimed at quantifying the degradation degree of our planet. The exergy distance (D) accounts for the total exergy degraded by man in a certain period of time. Its derivative, the exergy degradation velocity ( Ḋ), measures the rate at which the resources are being depleted. The resource to production ratio (R/P), usually calculated in mass terms, is proposed to be assessed in exergy terms, thereby taking also into account the concentration factor of the mineral deposits. We have additionally defined a new indicator called the ton of mineral equivalent (t M e), as the exergy content of one ton of mineral in a certain time and place. The t M e is analogous to the ton of oil equivalent, but it accounts at the same time, for the tonnage, grade and chemical composition of the considered mineral. This indicator allows us to assess the exergy content of a certain deposit before and after extraction, and to compare the quality of different deposits containing the same mineral, but with a more understandable unit of measure. 11. This PhD has applied for the first time the Hubbert model to non-fuel minerals, with the aim of estimating the year were the peak of production is reached. It has been stated that the bell-shape curve is better suited to non-fuel minerals if it is fitted with exergy over time, instead of mass over time. This way, we take into account the concentration factor, which is very important for the case of solid minerals. Consequently, we have developed the required equations for estimating the Hubbert’s peak for all kinds of minerals in exergy terms. 12. With the help of the indicators previously defined, we were able to analyze the exergy degradation of US copper during the 20th century, the average exergy degra- 344 CONCLUSIONS dation velocity, the R/P ratio, and the peak of US copper production. Among others, it has been estimated, that the global exergy cost associated to the degradation of US copper deposits in the 20th century was around 700 Mtoe, and that the peak of production was reached in 1994. Since the real peak of production was reached in 1998, we came to the interesting conclusion that in fact production follows rather an asymmetric curve with the decline much sharper than the growth. 13. This PhD has analyzed for the first time the degradation of the main mineral deposits in a country, Australia. For that purpose, historical statistics of mineral consumption and average ore grade trends have been taking into account of fuel and non-fuel origin. We have been able to estimate the amount of exergy depleted through mineral extraction, the rate at which that exergy is degraded, and the depletion degree of the commodities. Furthermore, the application of the Hubbert peak model in exergy terms to all considered minerals has allowed us to establish the “Exergy countdown of the country”. This is, in a single graphic, we have represented the bell-shaped curves of the production of Australian gold, silver, iron, zinc, lead, nickel, copper, coal, oil and natural gas. Such a representation would be impossible if the analysis were carried out in mass terms, as the orders of magnitude are radically different. The exergy countdown diagram provides in a simple and visual way a comparative of the available reserves of the country, the year were the peak of production is reached, or the depletion degree of the different commodities. Furthermore it allows to predict future mineral productions and the depletion degree of the commodities. This way, for instance, we could forecast that in year 2050, about 64% of the total considered mineral reserves in Australia will be depleted. Particularly, gold will be depleted at 99,9%, copper at 90,3%, lead at 87%, zinc at 97,3%, nickel at 60,4%, iron at 80%, coal at 52,4%, oil at 95,9% and natural gas at 85,2%. The results obtained could lead to spectacular consequences in the future of Australian mining and its economic implications. Furthermore, the exergy countdown of minerals could constitute a universal and transparent prediction tool for assessing the degradation degree of non-renewable resources, with dramatic consequences for the future management of the earth’s physical stock. 14. The physical analysis of the mineral degradation of a country has allowed us to assess in monetary terms the value associated to mineral extraction. The conversion of exergy into money is accomplished through conventional energy prices. The resulting monetary value represents the price that a country should pay the earth, for degrading the resources that are being extracted. This way, we have provided a first example of the contribution of mineral extraction in the GDP of a country. Assuming 2004 energy prices, Australia would have lost through mineral extraction in the same year, the equivalent of 15% of its 2004 GDP. However, if 2006 or 2008 energy prices are considered, the corresponding monetary cost associated to the same degradation of mineral capital would increase to 19 and Scientific contributions of the PhD 345 29% of the Australian 2004 GDP, respectively. This ratifies that the physical cost is a more objective and robust unit of measure than the monetary cost, which is highly dependent on external factors. However, the monetary value provides us with an order of magnitude of the importance of mineral extraction, which is understandable by the majority of the population. This procedure would allow to correct the economic indices, taking nature into account, as stated by Dieren [75]. 15. With the available information about world mineral historic statistics and available reserves, we have carried out the first diagnosis of the state of non-renewable minerals on earth. This PhD has estimated through the exergy analysis, the degradation degree of the mineral commodities, detecting the ones being degraded at the highest rates, and the ones facing important scarcity problems. We have stated that iron and aluminium are the most extracted commodities but not the most depleted ones, due to their crustal abundance. On the contrary, copper, which is also being extracted at very high rates, is already suffering scarcity problems, with more than 50% of its world reserves depleted. Other commodities such as mercury, silver, gold, tin, arsenic, antimony or lead are even more degraded, with more than 70% of their reserves depleted. Additionally, we have estimated the peak of production of the main mineral reserves. Extensive literature is found on the application of the Hubbert peak model for local and world oil production ([147], [133], [183], [47]). To our knowledge, there is also at least one study about world coal production [89] and one about natural gas [24]. The novelty introduced by our work is the application of the Hubbert peak in exergy terms, what allows not only to obtain the peaking year of the separated commodities, but also for the whole minerals. Our results fit very well with the already published studies about the peaking of oil and natural gas, which are reached in years 2008 and 2023, respectively. This is not the case with our prediction about the peaking of coal, which is achieved according to this study in 2060. The Energy Watch Group [89] reported recently that global coal production could peak in 2025. If all fossil fuels are considered as a single entity, assuming that they are mutually replaceable, the peaking of production will be reached in year 2029. Moreover the R/P ratio reveals that there will be enough conventional fossil fuels for 114 years more. In addition to the analysis of fossil fuels, we have applied the Hubbert peak model to world’s iron, copper and aluminium production. This task was never accomplished before. According to our results, the peak of world iron production will be reached in year 2068, of aluminium in 2057 and of copper in 2024. Thanks to the use of the unit of measure exergy, we have been able to provide for the first time the “the exergy countdown of the main minerals on earth”, representing in a single graph the Hubbert peak curves for coal, oil, natural gas, iron, copper and aluminium. 16. This PhD has assessed the loss of fossil fuel exergy due to the greenhouse effect. This estimation was firstly carried out by Valero and Arauzo [366], for an average 346 CONCLUSIONS fuel composition that should account for the coal, oil and natural gas reserves, and assuming that CO2 concentration in the atmosphere would double. In our case, we have considered separately the world resources of each type of coal, oil and natural gas. Furthermore, we have based our calculations on the IPCC’s SRES scenarios of future CO2 concentration. According to our results, in the worst case, the reserves of fossil fuels would be decreased by 0,4%. 17. In addition to the global overview of the state of our mineral resources in the past and in the present provided before, this PhD has estimated the possible exergy degradation of minerals throughout the 21st century. This was carried out considering 7 different scenarios. In the first scenario, the production of minerals was constrained by the current available reserves (i.e. base reserves for non-fuel minerals and proven reserves for fossil fuels). Accordingly if the 2006 reserves do not increase, at the end of the 21st century man would have depleted around 82% of the reserve base available in 1900. The remaining 6 scenarios are based on the IPCC’s SRES models, which indirectly assume a considerable increase of fossil fuel reserves. To the fossil fuel consumption estimated by the IPCC, we have included as a novelty the possible consumption of the main non-fuel minerals, namely iron, aluminium and copper, assuming that the world resources, rather than the reserve base published by the USGS [362] are available for extraction. This way, we have provided a global perspective of future mineral production. According to our results, for satisfying the demand of fossil fuels in the SRES scenarios, the reserves of fossil fuels should double and in some cases, they should be multiplied by a factor of four. Consequently, we think that the fuel consumption estimations of the SRES scenarios should be reviewed. 18. This PhD has proposed an accounting tool for the management of the mineral wealth on earth, including not only fossil fuels, but also the much more complex and apparently less relevant information of non-fuel minerals. This tool has been named here as “Physical Geonomics”. It should take into account all physical changes of the mineral stock on earth, considering both the extracted and recycled materials. The concrete accounting procedures of Physical Geonomics should be created with the learning by doing technique. But the principles on which it is based have been already developed in this PhD and in other exergoecological studies. Physical Geonomics should help to achieve a more rational management of the extraction and use of minerals. 9.4 Perspectives This PhD has opened the way for assessing the exergy resources of the earth and their degradation rate, providing the theoretical tools required for filling the existing knowledge gap on that field. Obviously it is subject to further improvements and refinements in future studies, with the help of better statistics, geochemical updates Perspectives 347 and especially, the conception of a new model of degraded earth. Next, the ideas and calculations that have arisen throughout the accomplishment of this PhD but that have remained undone, are discussed. The first thing that we realized when we embarked on the adventure of assessing the state of the earth’s resources was that there is a huge information gap about our mineral capital. It is incredible that in this high developed and ironically named “knowledge society”, the mineralogical composition of the earth’s continental crust is unknown. Similarly, data on the available mineral resources or the average ore grade of the deposits on earth is uncertain. An efficient management of our resources should be based on global and reliable information sources. Hence, more data bases, better global statistics, the opening of global information channels and impartial and serious interpretations of the information are urgently required. But for that purpose, we think that at least the following data should be compiled worldwide for all mineral commodities: • Yearly production data. • Ore grade trends of all mineral deposits. • Energy, water and raw material consumption. • Production of waste rock. • Tonnage and grade of available reserves. In many cases, this information is hidden or distorted by companies or even governments for their own economic benefits. We cannot forget that the earth and its resources are a common good. Consequently the state of our planet should be of global knowledge. This work has been based on many different and partially fragmented information sources. Furthermore, the lack of some data needed for the calculations, lead us to make important assumptions at the expense of accuracy loss in the results. This way, for instance, the first step for determining the mineralogical composition of the earth’s crust has been accomplished. Now is the turn of world geologists and geochemists to update the model with better geochemical information. Something similar occurs with the exergy assessment of the mineral reserves on earth and their degradation velocity, carried out in this PhD. With the help of improved statistical data, an update of the results would be expected. But the results of our study cannot only be improved with better data bases. We have stated that some calculation procedures could be further developed and adapted to the requirements of the study. 348 CONCLUSIONS The main activity that has remain undone and that is crucial for an appropriate natural resource assessment, is a deeper analysis of the entropic earth towards we are approaching. Moreover, the establishment of a methodology able to calculate the chemical exergies of the elements from a realistic degraded reference environment is still missing. In this PhD, we have stated that the R.E. based on Szargut’s criterion gives some problems when calculating the exergy of certain natural substances. With the help of the model of continental crust developed in this PhD and the well known average compositions of the atmosphere and seawater, we have been able to develop the first model of a realistic degraded earth (or entropic planet). However, the selection of an appropriate R.E. is a required but not a sufficient condition. Hence, the calculation procedures and even the philosophy for obtaining the chemical exergies of the elements should be reviewed. But this activity remains open for further studies in the future. In this PhD, we have stated that exergy replacement costs represent a suitable indicator for assessing the value of non-fuel mineral resources, as they integrate in one parameter, concentration, composition and also the state of technology. Exergy costs are calculated through unit exergy replacement costs, which are a function of the state of technology and hence vary with time. Nevertheless, in this work, we have considered unit exergy replacement costs to be constant. A more exact determination of the exergy costs of minerals throughout history would imply changing unit exergy replacement costs, according to the corresponding energy requirements. Generally, historical information of energy of extraction is usually unavailable for most commodities. But future energy requirements could be assessed with the help of the theory of learning curves. With learning-bydoing, increases in material and energy efficiency increase with cumulative production. The assessment of unit exergy replacement costs as a function of time remains open for further studies. However, it should be noted that with appropriate historical and future unit exergy replacement costs, the Hubbert peak model could be applied to exergy replacement costs, rather than to minimum exergies, thereby introducing the technological factor. This would provide a more accurate prediction of the peaking year of mineral commodities. Finally, we have stated that a gaussian model applied to the behavior of world mineral production might not be the perfect fit. We have seen, that generally production follows asymmetric curves with the decline much sharper than the growth. Hence other types of curves should be analyzed for improving the accuracy of the results. In summary we have stated that with the required information, the exergoecological approach used here could constitute a universal and transparent tool for assessing natural resources. The study could be extended to the loss of fertile soils and consequently to the analysis of the increasing world food demand and the carrying capacity of the planet. Similarly, it could be also extended to the growing freshwater requirements in a world with unpredictable climate changes. Perspectives 349 From the principles of the exergoecological approach, a new physical accounting tool could be developed. This proposed tool, that we have called “Physical Geonomics”, would account for all physical changes in the mineral stock on earth. Furthermore, the conversion of physical into monetary costs with the procedure shown in this PhD, would allow to keep at the same time the objectivity of physical data and the more intelligible meaning of monetary units. But the specific accounting principles of Physical Geonomics need to be developed with the help of the learning by doing technique. In fact, the materialization of the proposal would require the formation of international working groups participated by governments, the scientific community, industry and civil society organizations, allowing international agreements on the methodological principles. Obviously, that would require a firm political will of extending the current economic criteria. In short, the Exergoecology method and its corollary, Physical Geonomics, could help decision makers for an appropriate management of the earth’s physical stock. Appendix A Additional calculations A.1 Input data. Mineralogical composition of the earth’s crust This section shows vectors ε̂i , ξi and matrix R[ j × i] required for the calculation of the mineralogical composition of the earth’s crust, according to Eq. 3.1. Additionally, the resulting vector ξ̂i is presented. Table A.1 shows vector εˆj from Rudnick and Gao [292] and ε j , obtained applying Eq. 3.1 to Grigorev’s mineralogical composition (ξi ) [127]. Table A.2, shows vectors ξi and the resulting ξ̂i . Finally, tables A.3 and A.4 show the transposed of the coefficient matrix R [ j × i]. R0 of dimensions [307 × 78] is given rather than R [78 × 307] in order to make easier its representation. Additionally, the matrix is divided into two tables because of lack of space. Table A.1: Vector ε̂ j [78×1], according to Rudnick and Gao [292] and vector ε j [78 × 1], obtained from Grigor’ev [127]. Values in mole/g Element Au Te Cs Na Rb Al Si O H Ge Y Sc j 1 2 3 4 5 6 7 8 9 10 11 12 εˆj 7,62E-12 3,92E-11 3,69E-08 1,19E-03 9,83E-07 3,02E-03 1,10E-02 εj Element j 9,14E-13 Ag 40 4,54E-13 Sb 41 0 Bi 42 8,65E-04 Os 43 0 Ir 44 2,60E-03 Ru 45 1,02E-02 Pt 46 2,97E-02 Pd 47 2,11E-03 Ni 48 1,93E-08 0 Rh 49 2,36E-07 1,12E-08 Sm 50 3,11E-07 4,07E-13 Pr 51 Continued on next page . . . 351 εˆj 4,91E-10 3,29E-09 7,66E-10 1,63E-13 1,14E-13 3,36E-12 2,56E-12 4,89E-12 8,01E-07 5,83E-13 3,13E-08 5,04E-08 εj 2,82E-11 4,14E-12 1,07E-11 0 0 0 2,51E-14 4,83E-15 6,94E-09 0 8,08E-12 0 352 ADDITIONAL CALCULATIONS Table A.1: Vector ε̂ j [78×1], according to Rudnick and Gao [292] and vector ε j [78×1], obtained from Grigor’ev [127]. Values in mole/g – continued from previous page. Element Ga Re Tb Dy Ho Er Eu Tm Gd Lu Hf Cd S Hg Ca I Cr In N K Se Tl W Fe Mn Yb P j 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 εˆj 2,51E-07 1,06E-12 4,40E-09 2,40E-08 5,03E-09 1,38E-08 6,58E-09 1,78E-09 2,03E-08 1,77E-09 2,97E-08 8,01E-10 1,93E-05 2,49E-10 6,40E-04 1,10E-08 1,77E-06 4,88E-10 5,93E-06 5,95E-04 1,14E-09 4,40E-09 1,03E-08 7,02E-04 1,41E-05 1,13E-08 2,11E-05 εj Element 0 Nd 0 Ce 0 Nb 0 Pb 0 Sn 0 Sr 0 C 0 Ba 0 F 0 Ti 0 B 0 Mg 1,91E-05 Li 2,57E-12 Mo 9,64E-04 U 0 Th 1,70E-08 V 0 Ta 0 Cu 6,22E-04 Be 0 Zr 0 Cl 2,52E-10 La 6,41E-04 Zn 1,10E-06 Co 1,38E-09 As 8,15E-06 Br End of the table j 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 εˆj 1,87E-07 4,50E-07 1,29E-07 8,20E-08 1,77E-08 3,65E-06 1,66E-04 4,57E-06 2,93E-05 8,01E-05 1,57E-06 6,15E-04 3,46E-06 1,15E-08 1,13E-08 4,53E-08 1,90E-06 4,97E-09 4,41E-07 2,33E-07 2,12E-06 1,04E-05 2,23E-07 1,02E-06 2,94E-07 6,41E-08 2,00E-08 εj 1,09E-08 5,84E-08 1,28E-09 2,34E-09 1,70E-10 9,28E-09 6,85E-04 4,26E-08 5,73E-05 3,13E-05 1,34E-07 9,24E-04 8,15E-11 7,52E-10 2,51E-10 4,68E-09 0 8,87E-11 7,30E-09 1,07E-08 5,46E-07 3,37E-05 2,82E-08 4,75E-09 5,06E-11 1,23E-09 0 Table A.2: Vector ξi [324 × 1], according to Grigor’ev [127] and vector ξ̂i [324 × 1] obtained in this study Mineral Gold Calaverite Sylvanite Pollucite Dispersed Ge Thortveitite Dispersed Sc Dispersed Ga Dispersed Re Dispersed Tb Dispersed Dy i ξi , mole/g 1 9,14E-13 2 0 3 0 4 0 5 0 6 2,71E-13 7 0 8 0 9 0 10 0 11 0 Continued on next page . . . ξ̂i , mole/g 6,47E-12 5,71E-13 7,62E-13 6,14E-08 1,93E-08 2,71E-13 3,11E-07 2,51E-07 1,06E-12 4,40E-09 2,40E-08 Input data. Mineralogical composition of the earth’s crust 353 Table A.2: Vector ξi [324 × 1], according to Grigor’ev [127] and vector ξ̂i [324 × 1] obtained in this study – continued from previous page. Mineral i ξi , mole/g Dispersed Ho 12 0 Dispersed Er 13 0 Dispersed Eu 14 0 Dispersed Tm 15 0 Dispersed Gd 16 0 Dispersed Lu 17 0 Hf in Zr ores 18 0 Greenockite 19 0 Metacinnabar 20 3,27E-14 Cinnabar 21 2,54E-12 Lautarite 22 0 Dietzeite 23 0 In in ZnS 24 0 Nitratine 25 0 Niter 26 0 Se in copper ores 27 0 Dispersed Tl 28 0 Scheelite 29 2,26E-10 Wolframite 30 2,57E-11 Xenotime 31 1,38E-09 Yb in monazite 32 0 Native silver 33 1,11E-11 Samsonite 34 3,04E-14 Tetradymite 35 2,27E-13 Tellurite 36 0 Te in Cu ores 37 0 Iridium 38 0 Osmium 39 0 Polixene/ Tetraferroplatinum 40 1,20E-14 I-Platinum 41 1,54E-14 Cooperite 42 1,61E-14 Pt in Ni-Cu ores 43 0 Pd in Ni-Cu ores 44 0 Rh in Ni-Cu ores 45 0 Ru in Ni-Cu ores 46 0 Fergusonite 47 8,08E-11 Sm in Monazite and Bastnasite 48 0 Pr in Monazite and Bastnasite 49 0 Stibnite 50 1,30E-13 Boulangerite 51 2,12E-15 Sb in galena 52 0 Tin 53 3,71E-12 Cassiterite 54 1,66E-10 Lamprophyllite 55 5,61E-12 Celestine 56 9,26E-09 Strontianite 57 1,35E-11 Tourmaline 58 4,09E-08 Kornerupine 59 9,24E-09 Axinite -Fe 60 1,93E-10 Continued on next page . . . ξ̂i , mole/g 5,03E-09 1,38E-08 6,58E-09 1,78E-09 2,03E-08 1,77E-09 2,97E-08 8,01E-10 3,17E-12 2,46E-10 2,76E-09 2,76E-09 4,88E-10 2,96E-06 2,96E-06 1,14E-09 4,40E-09 9,28E-09 1,06E-09 1,38E-09 9,95E-09 1,94E-10 5,29E-13 2,27E-13 1,14E-12 3,49E-11 1,50E-13 1,57E-13 1,20E-14 1,54E-14 2,11E-12 1,27E-12 4,25E-12 5,83E-13 3,33E-12 8,08E-11 3,12E-08 5,04E-08 8,10E-10 2,12E-15 1,62E-09 3,87E-10 1,73E-08 5,61E-12 3,65E-06 5,34E-09 4,09E-08 9,24E-09 1,93E-10 354 ADDITIONAL CALCULATIONS Table A.2: Vector ξi [324 × 1], according to Grigor’ev [127] and vector ξ̂i [324 × 1] obtained in this study – continued from previous page. Mineral i ξi , mole/g Dumortierite 61 1,33E-13 Sassolite (natural boric acid) 62 0 Colemanite 63 0 Kernite 64 0 Ulexite 65 0 Psilomelane 66 5,25E-09 Barite 67 3,13E-08 Witherite 68 0 Bismutite 69 2,16E-12 Bismuthinite 70 1,79E-12 Bismuth 71 2,34E-12 Bismite 72 0 Spodumene 73 5,16E-11 Neptunite 74 2,75E-11 Amblygonite 75 3,24E-12 Staurolite 76 6,28E-07 Chromite 77 8,49E-09 Molybdenite 78 7,50E-10 Powellite 79 2,00E-12 Wulfenite 80 1,09E-13 Uraninite 81 2,44E-10 Blomstrandite/ Betafite 82 2,17E-11 Metatorbenite 83 7,89E-14 Polycrase (Y) 84 1,07E-15 Carnotite 85 0 Beryl 86 2,98E-09 Phenakite 87 3,63E-10 Bertrandite 88 1,68E-10 Helvine/ Helvite 89 7,21E-11 Chrysoberyl 90 0 Gadolinite 91 7,03E-11 Zircon 92 5,46E-07 Naegite 93 1,80E-12 Sirtolite 94 1,04E-10 Eudialyte 95 1,11E-10 Baddeleyite 96 2,52E-11 Lavenite 97 6,68E-12 Rinkolite/ Mosandrite 98 5,80E-14 Wohlerite 99 3,29E-16 Ferrotantalite 100 5,06E-12 Microlite 101 1,44E-13 Delorenzite/ Tanteuxenite 102 1,37E-13 Bastnasite 103 1,46E-08 Loparite - (Ce) 104 6,08E-11 Rhabdophane-Ce 105 1,31E-11 Chevkinite 106 3,48E-12 Monazite (Ce) 107 5,41E-08 Britholite 108 2,75E-11 Thorite 109 1,76E-09 Continued on next page . . . ξ̂i , mole/g 1,33E-13 3,60E-07 5,99E-08 8,99E-08 7,19E-08 5,78E-07 3,44E-06 3,44E-07 1,19E-10 9,91E-11 1,30E-10 9,91E-11 2,06E-06 1,10E-06 1,29E-07 7,70E-07 8,83E-07 1,14E-08 3,05E-11 1,66E-12 5,60E-09 4,96E-10 1,81E-12 2,46E-14 2,80E-09 5,99E-08 7,31E-09 3,38E-09 1,45E-09 1,80E-08 1,41E-09 2,11E-06 6,98E-12 4,02E-10 4,30E-10 9,75E-11 2,59E-11 2,25E-13 1,27E-15 3,07E-10 8,71E-12 8,33E-12 1,16E-07 4,81E-10 1,03E-10 2,76E-11 4,29E-07 2,18E-10 2,13E-08 Input data. Mineralogical composition of the earth’s crust 355 Table A.2: Vector ξi [324 × 1], according to Grigor’ev [127] and vector ξ̂i [324 × 1] obtained in this study – continued from previous page. Mineral i ξi , mole/g Uranium- Thorite 110 2,63E-12 Yttrialite 111 3,83E-10 Thorianite 112 1,29E-12 Dispersed V 113 0 Halite 114 3,25E-05 Apatite 115 2,55E-06 Scapolite 116 2,05E-07 Sylvite 117 8,85E-08 Carnallite 118 4,68E-09 Sodalite 119 6,60E-10 Bischofite 120 1,28E-09 Diadochic Nd 121 0 Sphalerite 122 4,74E-09 Zinc 123 7,19E-12 Smithsonite 124 2,95E-12 Cobaltite 125 5,06E-11 Smaltite 126 0 Linnaeite 127 0 Dispersed Co 128 0 Arsenopyrite 129 5,40E-10 Orpiment 130 3,45E-11 Realgar 131 2,62E-12 Fahlerz Group: Tennantite 132 2,31E-14 Lollingite 133 2,43E-14 Nickeline 134 3,82E-10 Gersdorffite 135 1,81E-10 Arsenolite 136 0 Pentlandite 137 1,09E-09 Garnierite 138 1,73E-10 Violarite 139 2,52E-10 Vaesite 140 6,19E-10 Diadochic Ni 141 0 Galena 142 7,94E-10 Lead 143 8,69E-12 Cerussite 144 2,36E-11 Anglesite 145 1,09E-11 Murmanite 146 2,26E-10 Ferrocolumbite 147 1,95E-10 Pyrochlore 148 2,83E-11 Ilmenorutile 149 2,62E-09 Euxenite 150 1,68E-10 Miserite 151 2,00E-12 Diadochic Ce 152 0 Weinschenkite 153 1,68E-12 Francolite 154 1,70E-07 Vivianite 155 2,59E-12 Biotite 156 1,73E-04 Muscovite 157 4,99E-05 Hydrobiotite 158 1,03E-05 Continued on next page . . . ξ̂i , mole/g 3,18E-11 4,64E-09 1,56E-11 1,90E-06 1,01E-05 7,91E-07 6,34E-08 2,74E-08 1,45E-09 2,05E-10 3,96E-10 1,01E-07 1,02E-06 1,55E-09 6,36E-10 5,06E-11 5,06E-11 1,69E-11 2,93E-07 2,89E-08 1,85E-09 1,40E-10 1,24E-12 1,30E-12 2,04E-08 9,70E-09 2,80E-10 7,44E-08 1,18E-08 1,72E-08 4,23E-08 3,35E-07 2,79E-08 3,05E-10 8,27E-10 3,82E-10 2,78E-08 2,40E-08 3,47E-09 3,22E-07 1,02E-08 2,00E-12 2,02E-07 1,68E-12 8,68E-08 2,59E-12 8,80E-05 2,54E-05 5,26E-06 356 ADDITIONAL CALCULATIONS Table A.2: Vector ξi [324 × 1], according to Grigor’ev [127] and vector ξ̂i [324 × 1] obtained in this study – continued from previous page. Mineral i ξi , mole/g Phlogopite 159 3,10E-07 Clinohumite 160 2,16E-08 Fluorite 161 2,82E-07 Humite 162 1,86E-08 Topaz 163 2,52E-08 Chondrodite 164 5,76E-10 Cryolite 165 0 Orthite-Ce/ Allanite 166 7,81E-08 Diadochic Y 167 0 Phosphate rock 168 0 Chalcopyrite 169 5,99E-09 Cubanite 170 2,21E-10 Covellite 171 3,77E-10 Azurite 172 7,25E-11 Bornite 173 4,38E-11 Malachite 174 9,04E-11 Copper 175 6,45E-11 Chalcocite 176 1,13E-11 Chrysocolla 177 5,87E-14 Diodochic Rb 178 0 Lepidolite 179 0 Ankerite 180 1,50E-06 Rhodochrosite 181 1,04E-07 Chloritoid 182 6,81E-09 Pyrolusite 183 6,21E-08 Todorokite 184 1,48E-09 Vernadite 185 2,40E-09 Spessartine 186 5,25E-08 Orthoclase 187 3,52E-04 Hydromuscovite/ Illite 188 6,45E-05 Glaukonite 189 3,04E-06 Lepidomelane/ Annite 190 1,48E-06 Sanidine 191 2,22E-06 Stilpnomelane 192 2,31E-07 Nepheline 193 4,24E-07 Jarosite 194 7,99E-09 Alunite 195 1,83E-13 Calcite 196 3,98E-04 Dolomite 197 3,80E-05 Graphite 198 9,99E-05 Siderite 199 1,04E-05 C org 200 9,16E-05 Aragonite 201 3,80E-06 Magnesite 202 1,78E-06 Dawsonite 203 1,25E-08 Cancrinite 204 2,09E-10 Moissanite 205 1,75E-10 Augite 206 5,12E-05 Ilmenite 207 1,25E-05 Continued on next page . . . ξ̂i , mole/g 1,58E-07 1,10E-08 1,44E-07 9,46E-09 1,29E-08 2,93E-10 2,36E-09 7,81E-08 2,09E-07 8,99E-06 3,62E-07 1,33E-08 2,27E-08 4,38E-09 2,65E-09 5,46E-09 3,90E-09 6,83E-10 3,54E-12 9,77E-07 1,03E-07 1,31E-05 9,14E-07 5,96E-08 5,44E-07 1,29E-08 2,10E-08 4,60E-07 4,22E-04 7,73E-05 3,65E-06 1,78E-06 2,67E-06 2,77E-07 5,09E-07 9,57E-09 2,20E-13 8,05E-05 7,69E-06 2,02E-05 2,10E-06 1,86E-05 7,69E-07 3,60E-07 2,53E-09 4,23E-11 3,54E-11 1,27E-04 3,10E-05 Input data. Mineralogical composition of the earth’s crust 357 Table A.2: Vector ξi [324 × 1], according to Grigor’ev [127] and vector ξ̂i [324 × 1] obtained in this study – continued from previous page. Mineral i ξi , mole/g Titanite 208 9,18E-06 Ulvöspinel 209 2,10E-06 Leucoxene 210 7,65E-07 Rutile 211 1,38E-06 Anatase 212 2,25E-07 Aenigmatite 213 1,28E-09 Perovskite 214 2,06E-09 Brookite 215 2,13E-09 Ramsayite/ Lorenzenite 216 1,46E-10 Kieserite 217 4,84E-08 Crossite 218 6,41E-07 Glaucophane 219 1,91E-08 Omphacite 220 1,18E-08 Clinochlore 221 1,16E-05 Cordierite 222 1,50E-07 Gedrite 223 6,51E-08 Palygorskite 224 4,38E-09 Pumpellyite 225 2,99E-07 Ripidolite 226 3,18E-05 Sapphirine 227 3,22E-08 Spinel 228 1,69E-07 Thuringite/ Chamosite 229 1,81E-06 Vermiculite 230 1,07E-06 Vesubianite/ Idocrase 231 1,90E-07 Actinolite 232 4,45E-06 Diopside 233 2,22E-05 Pigeonite 234 3,14E-06 Tremolite 235 6,77E-07 Anthophyllite 236 4,23E-08 Bronzite 237 2,80E-06 Brucite 238 4,29E-08 Cummingtonite 239 5,89E-06 Enstatite 240 2,19E-06 Forsterite 241 7,82E-07 Hypersthene 242 1,85E-05 Olivine 243 2,41E-06 Periclase 244 5,96E-12 Pleonaste/ Magnesioferrite 245 6,96E-10 Sepiolite 246 8,96E-06 Serpentine/ Clinochrysotile 247 2,60E-06 Talc 248 1,21E-06 Clementite 249 6,02E-08 Pyrite 250 5,25E-06 Anhydrite 251 3,31E-06 Pyrrhotite 252 3,41E-06 Gypsum 253 1,52E-06 Marcasite 254 1,00E-07 Sulphur 255 3,51E-09 Nosean 256 2,47E-09 Continued on next page . . . ξ̂i , mole/g 2,28E-05 5,21E-06 1,90E-06 3,41E-06 5,59E-07 3,16E-09 5,10E-09 5,27E-09 3,62E-10 3,06E-08 4,06E-07 1,21E-08 7,49E-09 7,34E-06 9,52E-08 4,12E-08 2,77E-09 1,89E-07 2,01E-05 2,04E-08 1,07E-07 1,14E-06 6,78E-07 1,20E-07 2,82E-06 1,40E-05 1,99E-06 4,29E-07 2,68E-08 1,77E-06 2,71E-08 3,73E-06 1,39E-06 4,95E-07 1,17E-05 1,53E-06 3,77E-12 4,41E-10 5,67E-06 1,64E-06 7,68E-07 3,81E-08 2,64E-06 1,66E-06 1,71E-06 7,64E-07 5,03E-08 1,77E-09 1,24E-09 358 ADDITIONAL CALCULATIONS Table A.2: Vector ξi [324 × 1], according to Grigor’ev [127] and vector ξ̂i [324 × 1] obtained in this study – continued from previous page. Mineral i ξi , mole/g Troilite 257 2,28E-11 Oligoclase 258 5,39E-04 Andesine 259 2,44E-04 Labradorite 260 1,11E-04 Montmorillonite 261 7,83E-06 Hastingsite 262 3,13E-06 Bytownite 263 1,09E-05 Thomsonite 264 7,44E-07 Anorthite 265 1,19E-06 Clinozoisite 266 9,02E-07 Epidote 267 2,25E-05 Grossular 268 5,55E-08 Hornblende (Fe) 269 3,34E-05 Prehnite 270 4,30E-06 Zoisite 271 6,82E-07 Andradite 272 2,36E-08 Hedenbergite 273 3,31E-07 Wollastonite 274 4,91E-08 Albite 275 1,52E-04 Nontronite 276 1,15E-05 Riebeckite 277 1,82E-06 Beidellite 278 4,11E-06 Aegirine 279 3,90E-06 Natrolite 280 2,31E-06 Analcime 281 3,00E-07 Arfvedsonite 282 3,23E-08 Jadeite 283 1,41E-07 Hydrosodalite 284 2,68E-10 Fayalite 285 1,91E-07 Ferrosilite 286 1,89E-06 Goethite 287 9,57E-06 Hematite 288 4,95E-06 Hisingerite 289 5,11E-09 Magnetite 290 2,81E-05 Iotsite 291 1,95E-10 Almandine 292 1,71E-05 Andalusite 293 3,89E-06 Boehmite 294 3,00E-06 Corundum 295 3,73E-07 Diaspore 296 9,17E-06 Distene/ Kyanite 297 1,36E-06 Hydragillite/ Gibbsite 298 5,51E-06 Kaolinite 299 1,01E-05 Pyrophyllite 300 2,78E-08 Sillimanite 301 1,91E-05 Cristobalite 302 2,16E-07 Opal 303 1,49E-04 Quarz 304 3,99E-03 Tridymite 305 1,10E-08 Continued on next page . . . ξ̂i , mole/g 1,14E-11 4,49E-04 2,03E-04 9,24E-05 6,52E-06 2,60E-06 9,08E-06 6,19E-07 9,90E-07 7,51E-07 1,87E-05 4,62E-08 2,78E-05 3,58E-06 5,68E-07 1,96E-08 2,75E-07 4,08E-08 5,14E-04 3,88E-05 6,14E-06 1,39E-05 1,32E-05 7,82E-06 1,01E-06 1,09E-07 4,78E-07 9,06E-10 2,35E-07 2,32E-06 1,17E-05 6,06E-06 6,27E-09 3,44E-05 2,39E-10 2,09E-05 1,25E-05 9,65E-06 1,20E-06 2,95E-05 4,37E-06 1,77E-05 3,24E-05 8,93E-08 6,15E-05 2,06E-07 1,42E-04 3,81E-03 1,05E-08 Input data. Mineralogical composition of the earth’s crust 359 Table A.2: Vector ξi [324 × 1], according to Grigor’ev [127] and vector ξ̂i [324 × 1] obtained in this study – continued from previous page. Mineral Dispersed Br Acanthite Argentite Stephanite Pyrargirite Chlorargirite Freibergite Tetrahedrite Nordite Hollandite Jacobsite Cryptomelane Manganite Tephroite Braunite Rhodonite Pennine Lawsenite Paragonite i ξi , mole/g 306 0 307 1,57E-12 308 2,87E-12 309 4,43E-13 310 1,37E-12 311 3,14E-13 312 2,02E-13 313 3,47E-13 314 7,20E-13 315 7,50E-09 316 1,32E-08 317 3,40E-09 318 1,71E-08 319 6,93E-08 320 4,47E-08 321 2,56E-08 322 4,54E-06 323 7,64E-06 324 1,47E-05 End of the table ξ̂i , mole/g 2,00E-08 2,74E-11 4,99E-11 7,72E-12 2,38E-11 5,47E-12 3,52E-12 3,47E-13 7,20E-13 2,63E-07 1,15E-07 2,98E-08 1,49E-07 6,07E-07 3,91E-07 2,24E-07 2,87E-06 6,35E-06 4,95E-05 i\ j 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 1 2 1 0 1 2 0,75 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 3 0 0 0 0,6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 4 0 0 0 0,2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 5 0 0 0 0,1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6 0 0 0 0,9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 7 0 0 0 2,1 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 8 0 0 0 7 0 7 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 6 10 0 3 3 0 0 4 4 4 0 0 0 0 2 0 0 0 0 0 0 0 9 0 0 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 10 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11 0 0 0 0 0 0,5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 12 0 0 0 0 0 1,5 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 13 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 14 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 15 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 16 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 17 18 19 20 21 22 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Continued on next page . . . 23 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Table A.3: Matrix R0 [324 × 78] (Part 1) 24 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 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0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Continued on next page . . . 62 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 63 64 0 0 0 0 0,4 0 0,4 0 0,5 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0,9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 2 0 3 0 0,6 0 3,75 0 2 0 5 0 1 0 1 0 3,75 0 4 0 1 0 65 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 66 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Table A.4: Matrix R0 [324 × 78] (Part 2). – continued from previous page. 67 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 68 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 69 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 70 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 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4 0 3 0 3 0 1,5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 65 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 66 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Table A.4: Matrix R0 [324 × 78] (Part 2). – continued from previous page. 67 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 68 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 69 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 70 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 71 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 72 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 73 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 74 0 0 0 0 0 0 0 0 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Mineralogical composition of the earth’s crust 373 i\ j 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 41 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 0 3 4 0 42 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 43 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 44 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 45 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 46 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 47 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 48 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 49 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 50 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 51 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 52 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 53 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0,6 54 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 55 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 56 57 58 59 60 61 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0,5 0 0 0 0 Continued on next page . . . 62 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 63 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0,4 64 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 65 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 66 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Table A.4: Matrix R0 [324 × 78] (Part 2). – continued from previous page. 67 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 68 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 69 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 70 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3,6 9 0 71 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 72 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 73 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 74 75 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0,33 0,6 76 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 77 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 78 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 374 ADDITIONAL CALCULATIONS i\ j 315 316 317 318 319 320 321 322 323 324 41 0 0 0 0 0 0 0 0 0 0 42 0 0 0 0 0 0 0 0 0 0 43 0 0 0 0 0 0 0 0 0 0 44 0 0 0 0 0 0 0 0 0 0 45 0 0 0 0 0 0 0 0 0 0 46 0 0 0 0 0 0 0 0 0 0 47 0 0 0 0 0 0 0 0 0 0 48 0 0 0 0 0 0 0 0 0 0 49 0 0 0 0 0 0 0 0 0 0 50 0 0 0 0 0 0 0 0 0 0 51 0 0 0 0 0 0 0 0 0 0 52 0 0 0 0 0 0 0 0 0 0 53 0 0 0 0 0 0 0 0 0 0 54 0 0 0 0 0 0 0 0 0 0 55 0,2 0 0 0 0 0 0 0 0 0 56 0 0 0 0 0 0 0 0 0 0 57 58 59 60 0 0 0,8 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 End of the table 61 0 0 0 0 0 0 0 0 0 0 62 0 0 0 0 0 0 0 0 0 0 63 64 0 0 0,1 0 0 0 0 0 0 0 0 0 0 0 3,75 0 0 0 0 0 65 0 0 0 0 0 0 0 0 0 0 66 0 0 0 0 0 0 0 0 0 0 Table A.4: Matrix R0 [324 × 78] (Part 2). – continued from previous page. 67 0 0 0 0 0 0 0 0 0 0 68 0 0 0 0 0 0 0 0 0 0 69 0 0 0 0 0 0 0 0 0 0 70 0 0 0 0 0 0 0 0 0 0 71 0 0 0 0 0 0 0 0 0 0 72 0 0 0 0 0 0 0 0 0 0 73 0 0 0 0 0 0 0 0 0 0 74 0 0 0 0 0 0 0 0 0 0 75 0 0 0 0 0 0 0 0 0 0 76 0 0 0 0 0 0 0 0 0 0 77 0 0 0 0 0 0 0 0 0 0 78 0 0 0 0 0 0 0 0 0 0 Input data. Mineralogical composition of the earth’s crust 375 376 A.2 ADDITIONAL CALCULATIONS Calculation of average mineral ore grades The average grade of the different mineral deposits analyzed by Cox and Singer [66] is calculated with Eq. 4.4, taking into account the tonnage of each model and the number of deposits (No. dep.) containing the mineral under consideration. Tables A.5 through A.12 show the mean average grade and tonnage of each deposit type. Table 4.9 in chapter 4 shows the final average grade obtained. Table A.5. Summary statistics of grade-tonnage models-1. After [66] Deposit type Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Mean No.dep. Placer Au-PGE 1,07 65 0,03 0,20 16 65 Mean No.dep. Placer PGE-Au 0,13 83 1,50 1588,55 13 83 8,38 10 82,22 21 0,03 23 Mean No.dep. Shoreline Placer 87,50 61 0,03 29 0,27 52 1,27 0,21 0,23 61 50 24 Calculation of average mineral ore grades 377 Table A.6. Summary statistics of grade-tonnage models-2. After [66] Deposit type Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Mean No.dep. Komatiite Ni-Cu 1,72 31 Mean No.dep. Mean No.dep. Dunitic Ni-Cu Synorg-synvolc. Ni-Cu 28,25 22 2,00 32 0,06 1,51 0,14 8 31 21 0,03 0,99 0,04 3 22 12 0,05 0,76 0,48 3 32 29 338,61 201,05 11 5 139,19 5 98,86 31,05 3 2 71,61 9 15,07 5 0,04 10 0,02 5 0,11 3 Major podiform Cu 0,02 174 Carbonatite 59,84 20 0,10 5 0,64 44,03 7,291 3,48 14,32 13,06 78,34 220,80 16 12 14 9 7 W Skarn 1,04 28 Mean No.dep. Minor podiform Cr 0,00 435 42,13 435 4,70 30,83 8,11 65,31 189,67 31 33 69 38 29 Sn Scarn 5,94 4 20 0,66 28 0,31 4 378 ADDITIONAL CALCULATIONS Table A.7. Summary statistics of grade-tonnage models-3. After [66] Deposit type Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Mean No.dep. Replacement Sn 5,25 6 Mean No.dep. Mean No.dep. W veins Sn Veins 0,56 16 0,24 43 0,91 0,80 Mean No.dep. Sn Greisen 7,20 10 16 6 1,27 43 0,28 10 Climax Mo 201,84 9 Porphyry Cu 144,21 208 Porphyry Cu skarn-related 79,62 18 Cu skarn 0,56 64 0,54 0,01 208 103 0,98 0,02 18 4 1,69 64 0,19 1,65 0,12 76 81 4,78 0,33 9 6 21,43 1,78 15 16 9 Calculation of average mineral ore grades 379 Table A.8. Summary statistics of grade-tonnage models-4. After [66] Deposit type Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Mean No.dep. Zn-Pb skarn 1,42 34 Mean No.dep. Fe skarn deposits 7,21 168 49,61 Mean No.dep. Polymet. replacement 1,82 52 Mean No.dep. Replacement Mn 0,02 37 0,03 3 32,54 37 0,88 4 168 0,46 17 0,23 35 114,55 0,45 5,91 22 7 0,2709 193,20 0,71 3,92 45 35 51 3,22 30 5,06 52 Porphyry Cu-Au 101,16 40 Porphyry Cu-Mo 508,16 16 Porphyry Mo, Low -F 94,19 33 0,50 0,00 40 20 0,42 0,02 16 16 0,09 1,59 0,38 27 40 1,22 0,01 16 16 Polymetallic vein 0,01 75 0,19 33 866,96 0,62 2,78 74 54 60 8,97 75 33 380 ADDITIONAL CALCULATIONS Table A.9. Summary statistics of grade-tonnage models-5. After [66] Deposit type Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Mean No.dep. Cyprus massive sulfide 1,27 49 Mean No.dep. Besshi massive sulfide 0,22 44 Mean No.dep. Volcanogenic Mn 0,05 93 0,09 8 38,80 93 Mean No.dep. Creede epith. vein 1,42 27 1,60 49 1,46 44 0,30 19 12,85 0,91 0,79 15 15 16 7,86 0,34 0,56 14 14 6 125,60 2,12 1,88 27 23 26 0,05 3 2,55 24 Comstock epith. vein 0,77 41 Sado epith. vein 0,30 20 Epith. quartz-alunite Au 1,58 8 Volcanogenic U 0,34 21 0,12 0,02 18 0,19 9 0,24 5 114,82 7,46 0,03 41 41 3 37,93 6,86 0,25 20 18 1 17,82 7,81 8 8 0,01 19 0,00 2 21 Calculation of average mineral ore grades 381 Table A.10. Summary statistics of grade-tonnage models-6. After [66] Deposit type Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Mean No.dep. Epithermal Mn 0,02 59 30,59 Mean No.dep. Rhyolite-hosted Sn 0,00 132 Mean No.dep. Volcan.-hosted magnetite 39,99 39 0,40 36 53,72 39 Mean No.dep. Carbonate-hosted Au-Ag 5,08 35 59 21,88 2,57 0,39 Hot-spring Hg 0,01 20 0,34 20 132 Silica-carbonate Hg 0,03 28 0,39 5 34 Sb veins 0,00 81 Disseminated Sb 0,09 23 36,39 5,14 8 9 1,20 0,30 1 2 34,67 81 3,55 23 28 382 ADDITIONAL CALCULATIONS Table A.11. Summary statistics of grade-tonnage models-7. After [66] Deposit type Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Mean No.dep. Kuroko mass. sulfide 1,50 432 Mean No.dep. Algoma and Sup. Fe 165,20 66 0,06 47 50,83 66 Mean No.dep. Sandstone-hosted Pb-Zn 5,36 20 1,26 432 28,77 0,78 2,81 284 238 330 11,22 9 0,59 14 0,75 184 2,15 20 Sedim. Exhal. Zn-Pb 14,69 45 Bedded barite 1,82 25 83,02 Missouri / Appalach. Pb-Zn 34,83 20 Mean No.dep. Sedim.-hosted Cu 21,93 57 0,24 10 2,15 57 Sedimentary Mn 7,28 39 25 0,19 11 43,32 37 4,67 10 5,65 45 4,05 20 2,78 45 1,23 16 0,12 13 31,38 39 Calculation of average mineral ore grades 383 Table A.12. Summary statistics of grade-tonnage models-8. After [66] Deposit type Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Tonnage (Mton) RE2O5 (%) Monazite (%) U3O8 (%) Zircon (% ZrO2) Nb2O5 (%) Barite (%) Al2O3(%) P (%) P2O5 (%) Ilmenite (% TiO2) Rutile (% TiO2) Leucocite (% TiO2) Cr2O3 (%) Mn (%) Fe (%) Co (%) Ni (%) Cu (%) Mo (%) WO3 (%) Pd (ppb) Pt (ppb) Rh (ppb) Ir (ppb) Ru (ppb) Os (ppb) Ag (g/t) Au (g/t) Zn (%) Hg (%) Sn (%) Pb (%) Sb (%) Mean No.dep. Phosphate, upwell. 331,13 60 Mean No.dep. Phosphate, warm current 400,87 18 23,96 24,16 60 Unconformity U-Au 0,23 36 0,52 Mean No.dep. Low-sulfide Au-quartz veins 0,03 313 Mean No.dep. Homestake Au 0,94 116 4,97 15,96 1,62 9,22 18 Lateritic Ni 44,16 71 39 313 52 116 Laterite type bauxite 25,18 122 Karst type bauxite 23,23 41 44,97 49,18 36 0,07 1,36 12 71 122 41 384 ADDITIONAL A.3 CALCULATIONS Calculation of the R.E. Tables A.13, A.14 and A.15, show the variables required for the calculation of the chemical exergy of the elements and the results, according to the assumptions described in section 5.2.3 and the model of the earth’s crust developed in this PhD (chapter 3) for gaseous, liquid and solid reference substances, respectively. Table A.13. Chemical exergies of the elements for gaseous reference substances Element R.S. State Pi0 (kPa) Ar C H2 He Kr N2 Ne O2 Xe Ar CO2 H2 O He Kr N2 Ne O2 Xe g g g g g g g g g 9,06E-03 3,35E-04 2,20E-02 4,85E-06 9,70E-07 7,58E-01 1,77E-05 2,04E-01 8,70E-08 bch,R.S. (kJ/mole) 11,7 19,9 9,5 30,4 34,4 0,7 27,2 4,0 40,3 ∆G f i (kJ/mole) 0,0 -394,4 -228,6 0,0 0,0 0,0 0,0 0,0 0,0 bch j (kJ/mole) 11,7 410,3 236,1 30,4 34,4 0,7 27,2 4,0 40,3 Table A.14: Chemical exergies of the elements for aqueous reference substances Element R.S. State z+ Ag As B Bi Br2 Cd C l2 Cs Cu Hg I2 K Li Mo Na Ni P Pb Rb S Se W Zn Ag C l2− HAsO4−2 B(OH)3 BiO+ Br − C d C l2 C l− Cs+ Cu+2 H g C l4−2 IO3− K+ Li + M oO4−2 N a+ N i +2 H PO4−2 P bC l2 Rb+ SO4−2 SeO4−2 W O4−2 Z n+2 l l l l l l l l l l l l l l l l l l l l l l l -1 -2 0 1 -1 0 -1 1 2 -2 -1 1 1 -2 1 2 -2 0 1 -2 -2 -2 2 γi 0,6 0,138 1 0,52 0,73 1 0,63 0,6 0,2 0,1 0,6 0,62 0,68 0,1 0,65 0,2 0,1 1 0,6 0,12 0,1 0,1 0,2 End of the table mi (mole/kg) 2,70E-09 2,10E-08 3,25E-04 1,00E-10 8,70E-04 6,90E-11 5,66E-01 2,30E-09 7,30E-10 3,40E-10 5,20E-07 1,06E-02 2,50E-05 1,10E-07 4,86E-01 1,20E-07 4,90E-07 4,20E-11 1,40E-06 2,93E-02 1,20E-09 5,60E-10 1,70E-08 ∆G f i -215,5 -714,7 -968,8 -146,4 -104,0 -359,4 -131,3 -282,2 65,5 -446,9 -128,0 -282,4 -294,0 -836,4 -262,1 -45,6 -1089,3 -297,2 -282,4 -744,6 -441,4 -920,5 -147,3 bch j (kJ/mole) 69,7 494,1 628,6 274,8 101,1 293,2 124,2 404,5 134,0 114,8 175,0 366,5 392,9 730,5 336,6 232,5 861,6 232,2 388,8 607,3 346,7 827,7 339,0 Calculation of the R.E. 385 Table A.15: Chemical exergies of the elements for solid reference substances Al Au Ba Be Ca Ce Co Cr Dy Er Eu F2 εj (mole/g) 3,02E-03 7,62E-12 4,57E-06 2,33E-07 6,40E-04 4,50E-07 2,94E-07 1,77E-06 2,40E-08 1,38E-08 6,58E-09 2,93E-05 Fe Ga Gd Ge Hf Ho In Ir La Lu Mg 7,02E-04 2,51E-07 2,03E-08 1,93E-08 2,97E-08 5,03E-09 4,88E-10 1,14E-13 2,23E-07 1,77E-09 6,15E-04 Mn Nb Nd Os Pd Pr Pt Pu Ra Re Rh Ru Sb Sc Si Sm Sn Sr Ta Tb Te 1,41E-05 1,29E-07 1,87E-07 1,63E-13 4,89E-12 5,04E-08 2,56E-12 6,20E-20 4,40E-15 1,06E-12 5,83E-13 3,36E-12 3,29E-09 3,11E-07 1,10E-02 3,13E-08 1,77E-08 3,65E-06 4,97E-09 4,40E-09 3,92E-11 Element 1,60E-03 9,63E-10 4,66E-04 1,09E-06 1,27E-02 1,41E-06 2,31E-07 1,39E-06 7,54E-08 4,33E-08 2,07E-08 2,30E-05 bch,R.S. (kJ/mole) 16,0 51,5 19,0 34,0 10,8 33,4 37,9 33,4 40,7 42,0 43,9 26,5 ∆G f i (kJ/mole) -2441,0 0,0 -1361,9 -2033,3 -1129,0 -1024,8 -1032,6 -1882,3 -1294,3 -1291,0 -1320,1 -12985,3 bch j (kJ/mole) 794,3 51,5 765,5 602,6 723,8 1054,2 308,9 584,4 974,9 973,0 1003,9 556,1 5,95E-04 3,94E-07 6,37E-08 1,52E-07 2,33E-07 1,58E-08 1,92E-09 8,95E-14 7,00E-07 5,56E-09 1,15E-04 18,4 36,6 41,1 38,9 37,9 44,5 49,8 74,5 35,1 47,1 22,5 -742,2 -998,6 -1288,9 -521,5 -1027,4 -1294,8 -830,9 -185,6 -1319,2 -1259,6 -5543,0 376,8 514,6 969,9 556,5 1061,3 979,3 437,4 256,1 994,3 946,6 629,6 24,1 39,9 35,6 73,6 65,2 38,8 66,8 108,5 76,8 69,0 72,2 66,1 54,7 33,8 1,4 40,0 31,9 34,8 48,0 44,9 60,0 -465,2 -1766,4 -1294,3 -305,1 -82,5 -1285,1 -83,7 -995,1 -1364,2 -1067,6 -299,8 -253,1 -829,3 -1819,7 -856,7 -1314,0 -519,6 -1140,1 -1911,6 -1314,2 -270,3 484,6 900,2 969,8 370,8 145,7 963,8 146,5 1099,7 825,8 561,3 183,0 315,2 437,1 923,8 854,2 993,9 547,6 758,8 974,8 999,0 326,4 R.S. State cj xi Al2 SiO5 Au BaSO4 Be2 SiO4 C aCO3 C eO2 C oFe2 O4 K2 C r2 O7 D y(OH)3 E r(OH)3 Eu(OH)3 C aF2 C a9 (PO4 )6 Fe2 O3 Ga2 O3 Gd(OH)3 GeO2 H f O2 H o(OH)3 I n2 O3 I rO2 La(OH)3 Lu(OH)3 M g3 Si4 O10 (OH)2 M nO2 N b2 O3 N d(OH)3 OsO4 P dO P r(OH)3 P tO2 PuO2 RaSO4 Re2 O7 Rh2 O3 RuO2 S b2 O5 Sc2 O3 SiO2 Sm(OH)3 SnO2 S r CO3 Ta2 O5 T b(OH)3 TeO2 s s s s s s s s s s s s 6,75E-03 8,05E-01 6,49E-01 5,95E-02 1,26E-01 0,02 0,005 0,01 0,02 0,02 0,02 0,01 s s s s s s s s s s s 1,08E-02 0,02 0,02 0,05 0,05 0,02 0,05 0,005 0,02 0,02 3,56E-03 s s s s s s s s s s s s s s s s s s s s s 2,66E-02 5,89E-05 0,01 1,01E-07 0,02 5,87E-07 0,005 1,28E-13 0,005 3,84E-12 0,02 1,58E-07 0,005 2,01E-12 0,01 9,73E-20 0,05 3,45E-14 0,01 8,32E-13 0,005 2,29E-13 0,005 2,64E-12 0,001 2,58E-10 0,05 1,22E-06 3,33E-01 5,75E-01 0,02 9,83E-08 9,27E-01 2,58E-06 1,39E-03 7,97E-07 0,01 3,90E-09 0,02 1,38E-08 0,005 3,08E-11 Continued on next page . . . 386 ADDITIONAL CALCULATIONS Table A.15: Chemical exergies of the elements for solid reference substances – continued from previous page. Element Th Ti Tl Tm U V Y Yb Zr A.4 εj (mole/g) 4,53E-08 8,01E-05 4,40E-09 1,78E-09 1,13E-08 1,90E-06 2,36E-07 1,13E-08 2,12E-06 R.S. State cj T hO2 T iO2 T l2 O4 T m(OH)3 UO3 · H2 O V2 O5 Y (OH)3 Y b(OH)3 Z rSiO4 s s s s s s s s s 3,27E-04 2,33E-09 4,15E-02 5,22E-04 0,01 3,45E-09 0,02 5,59E-09 0,01 1,77E-08 0,01 1,49E-06 0,02 7,41E-07 0,02 3,55E-08 9,45E-01 3,15E-04 End of the table xi bch,R.S. (kJ/mole) 49,3 18,7 48,3 47,1 44,2 33,3 35,0 42,5 20,0 ∆G f i (kJ/mole) -1169,1 -889,5 -347,3 -1265,5 -1395,9 -1419,6 -1291,4 -1262,5 -1919,5 bch j (kJ/mole) 1214,5 904,4 193,8 952,5 1196,1 721,5 966,3 944,9 1077,4 Calculation of the chemical exergy of gaseous fuels Table A.16 shows coefficients a1 through a7 for ideal gases required for the calculation of h∗ (T ) and s∗ (T ) in Eqs. 5.43 and 5.45, according to Zelenik and Gordon [413]. Table A.16. Coefficients a1 through a7 [413] C H4 C2 H 6 C3 H 8 C4 H10 C5 H12 N2 CO2 A.5 A.5.1 a1 2,928 1,463 0,8969 1,522 1,878 3,704 2,401 a2 0,002569 0,01549 0,02669 0,03429 0,04122 -0,001422 0,008735 a3 7,844E-06 5,781E-06 5,431E-06 8,101E-06 0,00001253 2,867E-06 -6,607E-06 a4 -4,91E-09 -1,26E-08 -2,13E-08 -2,92E-08 -3,70E-08 -1,20E-09 2,00E-09 a5 2,04E-13 4,59E-12 9,24E-12 1,27E-11 1,53E-11 -1,40E-14 6,33E-16 a6 -10054 -11239 -13955 -17126 -20038 -1064 -48378 a7 4,634 14,43 19,36 18,35 18,77 2,234 9,695 Estimation of the thermodynamic properties of minerals Chermak’s methodology Table A.17 shows the enthalpy and Gibbs free energy of the polyhedral units required for the calculation of silicate minerals. The brackets next to the chemical formulas indicate the coordination number. Estimation of the thermodynamic properties of minerals 387 Table A.17. The g i and hi of each polyhedral type and the standard error (%) of the estimate. Values in kJ/mol. [55] Polyhedral unit [4] Al2 O3 [6] Al2 O3 [6] Al(OH)3 [4] SiO2 M gO[6] [6] M g(OH)2 C aO[6] C aO[8−z] N a2 O[6−8] K2 O[8−12] H2 O FeO[6] [6] Fe(OH)2 [6] Fe2 O3 A.5.2 gi Error hi Error -1631,32 -1594,52 -1181,62 -853,95 -628,86 -851,86 -669,13 -710,08 -672,5 -722,94 -239,91 -266,29 -542,04 -776,07 13,3 15,3 13,2 4,6 10,6 10,2 5,9 7,2 26,0 27,4 5,7 6,8 24,6 33,0 -1716,24 -1690,18 -1319,55 -910,97 -660,06 -941,62 -696,65 -736,00 -683,00 -735,24 292,37 -290,55 -596,07 -939,18 11,0 15,9 12,2 3,2 7,9 9,1 5,2 7,1 18,4 21,1 4,6 5,4 8,2 35,6 Vieillard’s methodology for hydrated clay minerals Table A.18 shows the values for ∆G O−2 M z+ (clay) for ions located in the interlayer (l), octahedral (o), tetrahedral (t) and brucitic (b) sites. These values are required for the calculation of the Gibbs free energy of formation of hydrated clays and phyllosilicates with Eqs 5.65 and 5.66. A.5.3 Estimated values of the enthalpy and Gibbs free energy of minerals Table A.19, shows the estimated standard enthalpy and Gibbs free energy of formation of some of the minerals included in the model of the upper crust developed in chapter 3. The number of the method used to estimate the values are outlined in column “Meth.” (see table 5.8 for the correspondence between methods and numbers). The estimation error ±" is taken as the greatest associated error to the methodologies used for the determination of the mineral’s properties. This means that if there is a substance, for which 2 or more estimation methods were used, only the error associated to the most inaccurate one will be taken into account (the maximum is then ±" = 10%). In the determination of Gibbs free energies of formation from standard entropies (method 1), references [284] and [391] were used for the required standard en- 388 ADDITIONAL CALCULATIONS Table A.18. Values of ∆G O−2 M z+ (clay) for ions located in different sites [382] for hydrated clays and phyllosilicates. Values in kJ/mole Ions K + (l) N a+ (l) Li + (l) M g 2+ (l) C a2+ (l) (N H4 )+ (l) M n+2 (l) Cu+2 (l) C o+2 (l) N i +2 (l) C d +2 (l) Z n+2 (l) Al +3 (l) La+3 (l) Fe2+ (l) Cs+ (l) Rb+ (l) Ba2+ (l) S r 2+ (l) H + (l) Ions Al 3+ (t) Fe3+ (t) Ga3+ (t) Be2+ (t) Si 4+ (t) ∆GO−2 M z+ (hydr. Clays) 425,77 267,19 77,54 -100 -32,34 -28,4 -88 -136,7 -110 -114,8 -102,6 -121 -143,3 -65,6 565,9 528,1 157,6 123,4 -154,2 ∆GO−2 M z+ (hydr. Clays) -197,31 ∆GO−2 M z+ Phyllosil. 476 280 -110 -52 -76,3 -148,7 562,1 545,1 73,7 18,8 ∆GO−2 M z+ Phyllosil. -196 -261,7 -241,9 -193,9 -169 Ions ∆GO−2 M z+ (hydr. Clays) ∆GO−2 M z+ Phyllosil. -50,71 -112 Li + (o) M g 2+ (o) C a2+ (o) C r +3 (o) M n+2 (o) -158,6 -122,9 -35,2 -103 -74,4 -160,6 -119,1 C o2+ (o) N i +2 (o) -136,8 -132,2 -135,3 Z n+2 (o) Al 3+ (o) -140,3 -161,23 -139,3 -157 Fe2+ (o) Fe3+ (o) Ga3+ (o) T i 4+ (o) -134,4 -164,05 -141 -168,5 -167,6 -180,5 H + (o) Ions M g 2+ (b) Fe2+ (b) Al 3+ (b) Fe3+ (b) Li + (b) M n2+ (b) Z n2+ (b) N i 2+ (b) C o2+ (b) C r +3 (b) C a2+ (b) H + (b) Si 4+ (clay) H + (clay) ∆GO−2 M z+ (hydr. Clays) -220 ∆GO−2 M z+ Phyllosil. -30 -115 -171 -210 70 -87,3 -129,1 -120,8 -114,5 -173,1 4,7 -228 -166,09 -220 tropies of the elements in their reference state, according to Eq. 5.50. Most of the properties of the simple oxides used for the estimations are also recorded in the same references. In column “M.2: Poles”, the poles that compose the mineral under analysis assuming an ideal solid solution (method 2, Eq. 5.53) are given. Estimation of the thermodynamic properties of minerals 389 Column “M.3; 4; 6; 8: Ref. Minerals” includes the reference mineral used to determine the properties of the substance considered. Remember that in method 3, the reference mineral is decomposed either into its sulfides or oxides and the obtained ∆H r and ∆G r is added to the weighted sum of enthalpies and free energies of the simple sulfides or oxides of the mineral under consideration (see Eq. 5.55). In method 4, the same reaction energy involved in a substitution reaction is applied for the mineral under analysis and for an isomorphous one. For methods 6 and 8 (the ∆O−2 method for the same family of compounds, and for different compounds with the same cations, respectively), the reference minerals (at least 2) required for the determination of parameter α in Eqs. 5.62 and 5.66 are given. If not specified, the reference mineral will be used for the determination of both, ∆H 0f and ∆G 0f . The properties of substances approximated with method 4 (the method of Chermak and Rimstidt for silicate minerals) and 7 (the ∆O−2 method for hydrated clay minerals and for phyllosilicates), were obtained with the information provided in tables A.17 and A.18, after decomposing the mineral into its constituent blocks. Column “M.9; 10: Ideal reaction” shows the reaction that takes place to form the mineral under analysis. Remember that in method 9 (assuming ∆S f zero), it is assumed that the entropy of reaction is zero. In method 10 (the element substitution method), the enthalpy and Gibbs free energy of reaction is approximated to zero. If not specified, the reference mineral will be used for the determination of both, ∆H 0f and ∆G 0f . For those substances whose properties were estimated with method 11 (the addition method for hydrated minerals), the weighted enthalpy or Gibbs free energy of liquid water contained in the mineral was added. The properties of minerals estimated with method 12 are obtained through the weighted sum of the simple blocks (either oxides or sulfides) that compose the substance. The properties of the simple compounds are mainly obtained from Faure [94] and Robie [284]. Formula -4586,1 -9006,5 -6079,4 -968,0 -2884,5 -1034,5 -7057,3 Be4 Si2 O7 (OH)2 Be3 Al2 Si6 O18 K(M g2,5 Fe0,5 )(Si3 Al)O10 (OH)1,75 F0,25 Bi2 (CO3 )O2 U0,3 C a0,2 N b0,9 T i0,8 Al0,1 3+ Ta0,5 O6 (OH) Fe0,1 P b5 S b4 S11 C a2,9 C e0,9 T h0,6 La0,4 N d0,2 Si2,7 P0,5 O12 (OH)1,8 F0,2 Bertrandite Beryl Biotite Bismutite Blomstrandite/ Betafite Boulangerite Britholite -6606,9 -6152,6 -2585,3 -17,4 -14136,3 -9894,5 -4300,6 -8500,4 -5706,7 -5317,2 -1527,8 -7180,9 FeAl2 SiO5 (OH)2 K Fe3 (Si3 Al)O10 (F )2 from K M g3 (Si3 Al)O10 (OH)2 and K M g3 (Si3 Al)O10 (F )2 ∆H f C a0,167 Al2,33 Si3,67 O10 (OH)2 SmOH · CO3 · 0, 5H2 O; N dOH · CO3 · 0, 5H2 O C a2 Fe5 Si8 O22 (OH)2 M.3; 4; 6; 8: Ref. Minerals Continued on next page . . . K M g3 (Si3 Al)O10 (OH)2 ; K M g3 (Si3 Al)O10 (F )2 ; K Fe3 (Si3 Al)O10 (OH)2 ; K Fe3 (Si3 Al)O10 (F )2 C a5 (PO4 )3 F ; C a5 (PO4 )3 C l; C a5 (PO4 )3 OH M.2: Poles → P b5 S b4 S11 → 5P bS + 2S b2 S3 C a2,9 C e0,9 T h0,6 La0,4 N d0,2 Si2,7 P0,5 O12 (OH)0,8 F0,2 + 0, 2H2 O → C a2,9 C e0,9 T h0,6 La0,4 N d0,2 Si2,7 P0,5 O12 (OH)2 + 0, 2H F La(CO3 )F + 1, 5H2O → LaOH · CO3 · 0, 5H2 O + H F C a10 (PO4 )6 C l2 +2H F C a10 (PO4 )6 F2 +2H C l Li0,75 N a0,25 Al(PO4 ) F0,75 (OH)0,25 + 0, 75H2 O → Li0,75 N a0,25 Al(PO4 )(OH)2 + 0, 75H F M.9; 10: Ideal reaction 3 1 1 12 12 1; 9 10; 12 12 12 1 1 2; 4 3 1; 8; 10 12 12 ∆H f : 5 3; 10 3 12 10; 12 Meth. [94] [284] [284][94] [284][94] References [94] [284] [136] [136] [284][391] [222][391] [223] [284] [94] [284] 1 0 0 10 10 [94] [284] [309][284] [255] [94] [284][94] 5 [67] [284] 10 [284][94] 10 [284][94] 10 [284][94] 0 0 1 1 5 10 [284][94] 5 10 [284][94] 1 [55] ±", % 1 10 10 ADDITIONAL Chloritoid -2753,4 -19,0 -14980,9 -10499,8 -5691,6 N a0,33 Al2,33 Si3,67 O10 (OH)2 Beidellite M g FeSi2 O6 AuTe2 N a6 C a2 Al6 Si6 O24 (CO3 )2 C e1,7 La1,4 C a0,8 T h0,1 2+ 3+ Fe1,8 M g0,5 T i2,5 Fe0,5 Si4 O22 2+ Fe1,2 M g0,6 M n2+ 0,2 Al4 Si2 O10 (OH)4 -1023,7 -6666,9 -1660,9 La(CO3 )F Bronzite Calaverite Cancrinite Chevkinite -888,7 -2683,8 -7640,4 AxiniteFe Bastnaesite -6386,9 -6773,4 C a5 (PO4 )3 (OH)0,33 F0,33 C l0,33 C a2 Fe2+ Al2 BO3 Si4 O12 (OH) Apatite -1923,1 -4021,0 -2076,8 -4274,4 -10801,5 -7660,9 -282,7 ∆G 0f 2+ C aFe0,6 M g0,3 M n2+ 0,1 (CO3 )2 C aAl2 Si2 O8 -11519,4 -8184,4 -307,1 ∆H 0f Ankerite Anorthite Actinolite C a2 M g3 Fe2 Si8 O22 (OH)2 Aenigmatite N a2 Fe52+ T iSi6 O20 Amblygonite Li0,75 N a0,25 Al(PO4 ) F0,75 (OH)0,25 Mineral Table A.19: Estimations of the standard enthalpy and Gibbs free energy of minerals. Values in kJ/mole 390 CALCULATIONS -2721,2 -2425,4 -11859,9 Y0,7 C a0,2 C e0,12 (Ta0,7 )2 (N b0,2 )2 (T i0,1 )O5,5 (OH)0,5 C a2 (IO3 )2 (C rO4 ) 2+ N a4 C a2 Fe0,7 M n0,3 Z r Si8 O22 (OH)1,5 C l1,5 Delorenzite/ Tanteuxenite Dietzeite Eudyalite Euxenite Y0,7 C a0,2 C e0,1 (Ta0,2 )2 (N b0,7 )2 (T i0,025 )O6 Fergusonite N d0,4 C e0,4 Sm0,1 Y0,1 N bO4 Ferrocolum- Fe2+ N b2 O6 bite -293,7 CuFe2 S3 Cubanite -2506,3 -2631,2 -2631,2 -2671,5 -2808,3 -2172,8 -2148,1 -11062,9 -2549,9 -302,8 -3432,2 -3743,6 -14136,3 N.A. -6277,0 -73,8 -10925,8 -14980,9 -163,1 -6949,7 -79,8 -11600,3 N a6 C a2 Al6 Si6 O24 (CO3 )2 C oAsS C a2 B6 O11 · 5H2 O -7796,6 -8410,0 -8435,5 -8966,4 P t 0,6 P d0,3 N i0,1 S N a2 M g2 Fe2+ Al2 (Si8 O22 )(OH)2 2+ CryptomelaneK8 (M n4+ 7,5 M n0,5 ) O16 Cooperite Crossite Cancrinite Cobaltite Colemanite Chrysocolla Cu2 Si2 O6 (H2 O)4 Clementite Fe32+ M g1,5 Al Fe3+ Si3 AlO12 (OH)6 Clinochlore M g3,75 Fe1,25 Al2 Si3 O10 (OH)8 Clinohumite M g6,75 Fe2,25 Si4 O16 (OH)0,5 F1,5 -4701,4 -2964,6 -7043,1 Chondrodite ∆G 0f -3279,4 -7657,8 -5023,0 2+ (SiO4 )2 M g3,75 Fe1,25 F1,5 (OH)0,5 ∆H 0f Formula Mineral N a12 C a6 Fe32+ Z r3 Si24 O66 (OH)6 ∆H 0f :N a0,033 Al0,02 K0,12 M n0,94 Fe0,0375 Sr0,016 Ba0,012 O2 ; ∆G 0f : M n3 O4 Cu5 FeS4 ∆H 0f :FeAsS 3C aO · B2 O3 ; 2C aO · B2 O3 ; C aO · 2B2 O3 P tS M g5 Al2 Si3 O10 (OH)8 M.3; 4; 6; 8: Ref. Minerals Continued on next page . . . N a2 M g3 Al2 Si8 O22 (OH)2 ; N a2 Fe32+ Al2 Si8 O22 (OH)2 M.2: Poles 2+ N a4 C a2 Fe0,7 M n0,3 Z r Si8 O22 (OH)2 + 1, 5H C l 2+ → N a4 C a2 Fe0,7 M n0,3 Z r Si8 O22 (OH)1,5 C l1,5 + 1, 5H2 O M g6,75 Fe2,25 Si4 O16 (OH)2 + 2, 25M gO → M g9 Si4 O16 (OH)2 + 2, 25FeO; M g6,75 Fe2,25 Si4 O16 (OH)0,5 F1,5 +1, 5H F → M g6,75 Fe2,25 Si4 O16 (OH)2 + 1, 5H2 O ±", References % 5 [55] [284] [94] 12 12 12 12 1; 3; 10 12 3 3 12 3 1; 6; 11 3 1; 2 3 10 [94] [284] [144][284] [97] [94] [284] [94] [284] [120][284] 10 [284][94] 10 [284][94] 10 [284][94] 10 [391] 1 [179][284] 1 [241][226] [284] 10 [284][94] 1 1 1 10 [94] 1 [284][391] 5 [319][284] 1 1 ∆H 0f :12 10 [94] [400] 5 1 [55] 5; 10 2+ M g3,75 Fe1,25 (SiO4 )2 F1,5 (OH)0,5 + 1, 5H2 O 2+ (SiO4 )2 (OH)2 + → M g3,75 Fe1,25 1, 5H F Meth. M.9; 10: Ideal reaction Table A.19: Estimations of the standard enthalpy and Gibbs free energy of minerals. Values in kJ/mole– continued from previous page. Estimation of the thermodynamic properties of minerals 391 Formula Ba0,8 P b0,2 N a0,125 4+ Fe1,3 Al0,2 Si0,1 M n2+ 0,5 M n6 O16 -864,6 -813,2 -12678,2 -13408,5 +1, 75M gO → M g9 Si4 O16 (OH)2 + 1, 75FeO; 2+ M g5,25 Fe1,75 (SiO4 )3 F1,5 (OH)0,5 +1, 5H F → 2+ M g5,25 Fe1,75 (SiO4 )3 (OH)2 +1, 5H2 O 3+ (K0,3 C a0,1 )(M g2,3 Fe0,6 Al0,1 ) (Si2,8 Al1,2 )O10 (OH)1,8 F0,2 ) · 3(H2 O)+ 0, 2H F → 3+ (K0,3 C a0,1 )(M g2,3 Fe0,6 Al0,1 ) (Si2,8 Al1,2 )O10 (OH)2 · 3(H2 O) + 0, 2H2 O N a8 Al6 Si6 O24 C l2 N a8 Al6 Si6 O24 SO4 + 2H2 O → N a8 Al6 Si6 O24 (OH)2 + H2 SO4 1; 2 3, 10 5 1; 7; 10 3; 10 3 M g9 Si4O16 (OH)2 3 12 1 7 12 1; 3; 9 3 12 1; 7; 9 Meth. K0,005 M n0,82 Fe0,165 Ba0,09 P b0,02 O2 · 0, 09H2 O; ∆G 0f : M n3 O4 C a2 M g4 Al(Si7 AlO22 )(OH)2 2+ (SiO4 )3 (OH)2 M g5,25 Fe1,75 M.9; 10: Ideal reaction ∆H 0f :N a0,0125 Al0,029 Si0,01 (N i2 M g)Si2 O5 (OH)4 + 2M gO → M g3 Si2 O5 (OH)4 + 2N iO Ag3 S bS3 C a10 (PO4 )6 F2 M.3; 4; 6; 8: Ref. Minerals Continued on next page . . . T iO2 ; N b2 O5 ; FeO M.2: Poles 1 5 1 5 5 1 [227][94] [284] [187] [55] [382][143] [284] [144] [320][284] [97] [94] [284] 10 [284][94] 0 [144] 0,6 [383] 5 [284] 10 [284][94] 1 [383][143] [284] ±", References % 10 [284][94] 1 [167][391] ADDITIONAL 2+ Ilmenorutile T i0,7 N b0,15 Fe0,225 O2 -5499,1 -5886,2 2+ Hydromusco- K0,6 (H3 O)0,4 Al2 M g0,4 Fe0,1 vite Si3,5 O10 (OH)2 HydrosodaliteN a8 Al6 Si6 O24 (OH)2 -6238,9 -6512,3 -6953,7 -7362,2 -10303,7 -4330,4 -4733,3 -10976,4 -5532,4 -5843,9 -11584,2 -4785,6 -727,5 -4943,3 -3267,1 -2163,9 -5698,1 ∆G 0f 3+ Hydrobiotite (K0,3 C a0,1 )(M g2,3 Fe0,6 Al0,1 )(Si2,8 Al1,2 ) O10 ((OH)1,8 F0,2 ) · 3(H2 O) 3+ Hornblende- C a2 Fe42+ Al0,75 Fe0,25 Fe (Si7 AlO22 )(OH)2 2+ (SiO4 )3 Humite M g5,25 Fe1,75 F1,5 (OH)0,5 Helvine/ Helvite Hollandite -12319,7 -5150,3 M g5 Al2 (Si6 Al2 O22 )(OH)2 3+ (K0,6 N a0,05 )(Fe1,3 Gedrite Glauconite 2+ 3+ Al0,15 ) M g0,4 Fe0,2 (Si3,8 Al0,2 )O10 (OH)2 M n4 Be3 (SiO4 )3 S -703,2 -5220,0 -3494,6 2+ S b3 AsS13 Ag7,2 Cu3,6 Fe1,2 Y2 Fe2+ Be2 (Si2 O10 ) (N i2 M g)Si2 O5 (OH)4 -2319,3 -5984,4 ∆H 0f Freibergite Gadolinite Garnierite Ferrotantalite Fe2+ Ta2 O6 Francolite C a5 (PO4)2,63 (CO3 )0,5 F1,11 Mineral Table A.19: Estimations of the standard enthalpy and Gibbs free energy of minerals. Values in kJ/mole– continued from previous page. 392 CALCULATIONS -3713,1 -3208,3 -11738,2 -2074,0 KC a2 C e3 Si8 O22 (OH)1,5 F0,5 C e0,5 La0,25 N d0,2 T h0,05 (PO4 ) Miserite Monazite (Ce) -557,3 -622,4 N a0,4 C a1,6 Ta2 O6,6 (OH)0,3 F0,1 -80,2 -1721,8 -85,7 -1430,8 FeAs2 N a0,6 C e0,22 La0,11 C a0,1 T i0,8 N b0,2 O3 M nO(OH) Microlite -4642,3 -4995,0 3+ 2+ M g0,5 Fe0,75 K Fe2,5 Al0,25 Si3 O10 (OH)2 Lepidomelane/ Annite Loellingite Loparite (Ce) Manganite -1943,3 -11035,1 -3004,3 -4510,6 -5654,7 -4812,8 -6003,2 C aAl2 Si2 O7 (OH)2 · H2 O K Li2 AlSi4 O10 F (OH) Lawsenite Lepidolite -3925,1 -4191,1 2+ N a1,1 C a0,9 M n2+ 0,5 Fe0,5 Z r0,8 T i0,1 N b0,1 (Si2 O7 ) O0,6 (OH)0,3 F0,1 Lavenite -7865,3 Kernite -2812,1 -3318,7 -8401,2 -4104,9 N a2 O · 2B2 O3 · 4H2 O Jadeite Jarosite -1137,5 -8624,8 -2990,4 -3521,7 3+ (Si2 O6 ) N aAl0,9 Fe0,1 K Fe33+ (SO4 )2 (OH)6 Jacobsite ∆G 0f -9172,9 -1237,4 2+ 2+ M n2+ 0,6 Fe0,3 M g 3+ O M n3+ Fe1,5 0,5 4 Kornerupine M g1,1 Fe0,2 Al5,7 (Si3,7 B0,3 )O17,2 (OH) LamproN a2 Sr BaT i3 Si4 O16 (OH)F phyllite ∆H 0f Formula Mineral C aAl2 Si2 O2 K M g3 (Si3 Al)O10 (OH)2 ; K M g3 (Si3 Al)O10 (F )2 K Fe3 AlSi3 O10 (OH)2 Al6,75 BSi3 O17,25 (OH)0,75 N aAlSi2 O6 M.3; 4; 6; 8: Ref. Minerals Continued on next page . . . M nFe2 O4 ; Fe2 O4 ; FeM n2 O4 ; M g Fe2 O4 ; M nM n2 O4 ; M g M n2 O4 M.2: Poles → N a0,4 C a1,6 Ta2 O6,6 (OH)0,3 F0,1 + 0, 1H2 O → N a0,4 C a1,6 Ta2 O6,6 (OH)0,4 + 0, 1H F KC a2 C e3 Si8 O22 (OH)1,5 F0,5 + 0, 5H2 O → KC a2 C e3 Si8 O22 (OH)2 + 0, 5H F K Li2 AlSi4 O10 F (OH) + H2 O K Li2 AlSi4 O10 (OH)2 + H F N a2 Sr BaT i3 Si4 O16 (OH)F + H2 O → N a2 Sr BaT i3 Si4 O16 (OH)2 + HF 2+ N a1,1 C a0,9 M n2+ 0,5 Fe0,5 Z r0,8 T i0,1 N b0,1 (Si2 O7 ) O0,6 (OH)0,3 F0,1 + 0, 1H2 O 2+ → N a1,1 C a0,9 M n2+ 0,5 Fe0,5 Z r0,8 T i0,1 N b0,1 (Si2 O7 ) O0,6 (OH)0,4 + 0, 1H F N a2 O · 2B2 O3 · 4H2 O → N a2 O + 2B2 O3 + 4H2 O FeM n2 O4 + M nO → M nM n2 O4 + FeO M.9; 10: Ideal reaction Table A.19: Estimations of the standard enthalpy and Gibbs free energy of minerals. Values in kJ/mole– continued from previous page. [135][284] [284][94] 12 10; 12 10 [284][94] 10 [284][94] 10 [284][94] 10 [284] ∆H 0f : 12 10; 12 [94] [284] [284][94] [383][391] 0 [113] 10 [284][94] 1 5 1 10 [284][94] 10 [284][94] 1 5 ±", References % 5 [227][285] [284] [227] [189] [118] 1 [94] [284] 10 [94] [400] 1 12 3 3; 11 7; 4 10; 12 10; 12 3 3 ∆H 0f : 12 10 1; 2; 9 Meth. Estimation of the thermodynamic properties of minerals 393 N a0,75 K0,25 Al(SiO4 ) 2+ M n2+ K N a2 LiFe1,5 0,5 T i2 Si8 O24 N a0.3 Fe23+ (Si3,7 Al0,3 )O10 (OH)2 · 4(H2 O) N a2,8 M n2+ 0,2 Sr0,5 C a0,5 La0,33 C e0,6 Z n0,6 M g0,4 Si6 O17 N a8 Al6 Si6 O24 SO4 2+ (SiO4 ) M g1,6 Fe0.4 Nepheline Neptunite Nontronite Olivine M g1,35 Fe0,55 C a0,1 (Si2 O6 ) Pyrargirite C a2 M gAl2 (SiO4 ) (Si2 O7 )(OH)2 · H2 O Ag3 S bS3 -3752,1 -5939,9 -766,2 -5902,2 -3977,5 -6477,8 -778,3 -6292,8 -2347,2 -2569,1 -131,5 -142,2 -6672,5 -2681,3 -2847,7 -7148,6 -3074,2 -3297,1 -1448,8 -967,9 -6055,4 -1044,5 -6481,6 -1535,4 -2904,3 -1925,0 -3075,5 -2083,3 -13131,5 -7532,2 -8020,8 -13936,7 -1972,4 -10061,3 -5447,7 -5616,6 -2087,6 -10724,6 -6841,0 -5991,3 -9096,6 -5354,5 -5523,8 -9804,0 ∆G 0f ∆H 0f M gSi2 O6 ; Fe2 Si2 O6 ; C a4 M gAl5 Si6 O21 (OH)7 4+ ∆H 0f :Ba0,4 M n2+ 0,4 M n0,6 O2 0, 4H2 O; ∆G 0f : M n3 O4 K M g3 (Si3 Al)O10 (OH)2 ; K M g3 (Si3 Al)O10 (F )2 C a2 (Al2 Fe3+ )Si3 O12 (OH) N aAlSiO4 K M g3 (Si3 Al)O10 (OH)2 ; K M g3 (Si3 Al)O10 (F )2 M.3; 4; 6; 8: Ref. Minerals Continued on next page . . . C aSi2 O6 ; M gSi2 O6 ; N aFeSi2 O6 ; C aSi2 O6 ; N aAlSi2 O6 C a0,167 Al2,33 Si3,67 O10 (OH)2 ; N a0,33 Al2,33 Si3,67 O10 (OH)2 M.2: Poles · Ag3 S bS3 → 3 Ag2 S 2 + 1 S b2 S3 2 K M g3 AlSi3 O10 F (OH)+H2 O K M g3 AlSi3 O10 (OH)2 +H F N a8 Al6 Si6 O24 SO4 + 2H C l N a8 Al6 Si6 O24 C l2 + H2 SO4 → → KAl3 Si3 O10 (OH)1,8 F0,2 +0, 2H2 O → KAl3 Si3 O10 (OH)2 +0, 2H F M.9; 10: Ideal reaction 1 9 3 3 12 12 2 1 5 12 4 [284] [55] [187] [284] 5 1 1 [284] [144][284] [97] [94] [284] 10 [284][94] 10 [284][94] 1 5 1 [284] [144][284] [94] 0 [25] 1 [55] 10 [284][94] 1 [391][284] 1 5 5 2 11 3 [391][284] 1 [94] [284] 10 [284][94] 0,6 [382][143] [284] 10 [284][94] 1 10 [284][94] ±", References % 1 [94] ∆H 0f : 10 12 3 12 1; 7 4 12 2 Meth. ADDITIONAL Pumpellyte Pollucite Cs0,6 N a0,2 Rb0,1 Al0,9 Si2,1 O6 · (H2 O) Polycrase Y0,5 C a0,1 C e0,1 U0,1 (Y) T h0,1 T i1,2 N b0,6 Ta0,2 O6 4+ Psilomelane Ba2 M n2+ 2 M n3 O10 · 2H 2 O Pigeonite C a0,6 N a0,4 M g0,6 Al0,3 Fe0,1 Si2 O6 Opal SiO2 · 0, 5H2 O OrthiteC a(C e0,4 C a0,2 Y0,133 ) Allanite (Al2 Fe3+ )Si3 O12 (OH) Orthoclase KAlSi3 O8 Palygorskite M gAlSi4 O10 (OH) · 4(H2 O) 2+ N i4,5 S8 Pentlandite Fe4,5 Phlogopite K M g3 AlSi3 O10 F (OH) Omphacite Nosean Nordite Muscovite N a0,165 C a0,084 Al2,33 Si3,67 O10 (OH)2 N a4 T i3,6 N b0,4 (Si2 O7 )2 O4 4(H2 O) KAl3 Si3 O10 (OH)1,8 F0,2 Montmorillonite Murmanite · Formula Mineral Table A.19: Estimations of the standard enthalpy and Gibbs free energy of minerals. Values in kJ/mole– continued from previous page. 394 CALCULATIONS Chamosite Titanite Todorokite C aT iSiO5 3+ N a2 M n4+ 4 M n2 O12 · 3H 2 O 3+ 3+ (Fe3 M g2 Fe0,5 Al0,5 ) (Si3 Al)O10 (OH)2 -2597,1 -4037,4 -7596,0 -3740,2 Thortveitite Sc1,5 Y0,5 Si2 O7 Thuringite- -1999,6 -100,6 -1939,7 -11543,9 -2048,8 -1968,6 -100,2 -1909,5 -12413,7 -2160,5 -2455,1 -3576,5 -6981,9 -3540,6 -4035,4 -184,5 -15197,0 -4363,4 -166,1 -16655,5 -7788,2 -463,5 -3715,9 -11504,2 -8429,2 -444,9 -3860,7 -12197,4 (M g3,75 Fe1,25 Al) (Si3 Al)O10 (OH)2 (OH)6 Ag4 M nS b2 S6 K0,75 N a0,25 AlSi3 O8 N a4 Al3 Si9 O24 C l -4103,9 -132,7 -1821,9 -9399,5 -8808,5 -2687,3 ∆G 0f Samsonite Sanidine ScapoliteMarialite Serpentine M g3 Si2 O5 (OH)4 Stephanite Ag5 S bS4 StilplomelaneK0 , 8Fe8 Al0,8 5Si11,1 O21 (OH)8 · 6H2 O Tennantite Cu10 Fe2 As4 S13 Tetradymite Bi2 Te2 S Tetrahedrite Cu10 Fe2 S b4 S13 Thomsonite N aC a2 Al5 Si5 O20 · 6H2 O Thorite T hSiO4 Ripidolite -4360,1 -140,3 -1964,9 -10087,1 -9415,1 -2897,9 N aC aN b2 O6 (OH)0,75 F0,25 Pyrochlore Ramsayite N a2 T i2 Si2 O9 Realgar As4 S4 RhabdophaneC e0,75 La0,25 (PO4 ) · H2 O Riebeckite N a2 Fe32+ Fe23+ (Si8 O22 )(OH)2 Rinkolite/ N a2 C a3 C e1,5 Y0,5 MosanT i0,4 N b0,5 Z r0,1 (Si2 O7 )2 O1,5 F3,5 drite ∆H 0f Formula Mineral ∆H 0f :M g0,19 M n3+ 0,38 ∆H 0f :Ag3 S bS3 KAlSi3 O8 ∆H 0f :Ag3 S bS3 M.3; 4; 6; 8: Ref. Minerals 0 M n4+ 0,62 O2 · 0, 75H 2 O; ∆G f : M n3 O4 Continued on next page . . . Y2 Si2 O7 ; Sc2 Si2 O7 Bi2 Te3 ; Bi2 S3 LaPO4 ; C ePO4 M.2: Poles → Sc2 Si2 O7 + Al2 O3 → Al2 Si2 O7 + Sc2 O3 ; s0f :Y2 Si2 O7 + Al2 O3 → Al2 Si2 O7 + Y2 O3 T hSiO4 + UO2 → USiO4 + T hO2 N a2 C a3 C e1,5 Y0,5 T i0,4 N b0,5 Z r0,1 (Si2 O7 )2 O1,5 F3,5 + 3, 5H2 O N a2 C a3 C e1,5 Y0,5 T i0,4 N b0,5 Z r0,1 (Si2 O7 )2 O5 + 3, 5H F N aC aN b2 O6 (OH)0.75 F0.25 + 0, 25H2 O → N aC aN b2 O6 (OH) + 0, 25H F M.9; 10: Ideal reaction Table A.19: Estimations of the standard enthalpy and Gibbs free energy of minerals. Values in kJ/mole– continued from previous page. 1 3 7 2; 9 1 2 1 5 1; 9 1 3 1 3 3 1 7 12 1 2 1 10; 12 10; 12 Meth. [284][94] [312] [364][388] [94] [312] [284][94] [284] [94] [284] [186][284] 0 1 0 5 0 [94] [312] [97] [284] [94] [25] [284] [210][210] [284] 0 [303][284] 1 [226][94] 0 [303][284] 1 [55] 5 [298][192] [284] 5 [62] [269] [213] [391] [284] 0,6 [383] 5 1 0 0,6 [383] 10 0 1 0 10 ±", References % 10 [284][94] Estimation of the thermodynamic properties of minerals 395 -6151,5 -1392,9 -5957,2 -14401,4 -6762,2 -1489,4 -7018,8 -637,8 -378,0 -4608,4 -4439,7 -1246,2 N aFe32+ Al6 (BO3 )3 Si6 O18 (OH)4 N aC a(B5 O6 (OH)6 )· 5H2 O T iFe22+ O4 M g3 Si4 O10 (OH)2 · 2(H2 O) 3+ M n4+ 0,6 Fe0,2 C a0,2 N a0,1 O1,5 (OH)0,5 · 1, 4(H2 O) Fe2+ N i2 S4 Fe3 (PO4 )2 (H2 O)8 Y PO4 N aC a2 Z r0,6 N b0,4 Si2 O8,4 (OH)0,3 F0,3 2+ M n0,5 W O4 Fe0,5 TourmalineSchorl Ulexite Ulvöspinel Vermiculite Vernadite Violarite Vivianite Weinschenkite Wohlerite Wolframite -1987,7 -13453,5 -3044,4 Al2 (SiO4 )F1,1 (OH)0,9 Topaz -1146,4 -4170,0 -1871,1 -4428,2 -368,9 -571,4 -2875,2 ∆H 0f Formula Mineral ∆G 0f FeW O4 ; M nW O4 M.2: Poles End of the table M n4+ 0,6 O2 · 0, 4H 2 O; M n3 O4 ∆G 0f : ∆H 0f :Ba0,13 M nO2 · 0, 27H2 O M.3; 4; 6; 8: Ref. Minerals FeS 2 N i3 S4 + 13 3 Fe2 S3 + N aC a2 Z r0,6 N b0,4 Si2 O8,4 (OH)0,3 F0,3 + 0, 3H2 O → N aC a2 Z r0,6 N b0,4 Si2 O8,4 (OH)0,6 + 0, 3H F 1 3 Fe2+ N i2 S4 → Al2 (SiO4 )F1,1 (OH)0,9 +0,9H F → Al2 SiO4 F2 +0,9H2 O M.9; 10: Ideal reaction Table A.19: Estimations of the standard enthalpy and Gibbs free energy of minerals. Values in kJ/mole– continued from previous page. 2 10; 12 ∆H 0f : 12 1 1; 9 1 12 ∆H 0f : 12 3 1 10 Meth. [107][284] [255][79] [241] [284][94] 1 0 [284] [364][345] [284] [391] 10 [284][94] 10 [284] 1 1 0 [293][284] 10 [284][94] 10 [284] 0 ±", References % 5 [94] 396 ADDITIONAL CALCULATIONS Exergy calculation of the mineral resources A.6 397 Exergy calculation of the mineral resources Table A.20 and A.21 show the chemical Bch and concentration Bc exergy, as well ∗ as their corresponding exergy cost (Bch and Bc∗ ), of the world’s mineral production in 2006, the reserve, base reserve and world’s resources, collected from the USGS [362]. The specific chemical exergies of the substances bch are calculated with Eq. 5.1. The concentration exergies bc are calculated as the difference between the concentration exergies obtained with the average mineral concentration in the deposits (x m ) and with the average concentration in the earth’s crust (x c ), both are calculated with Eq. 5.10. The exergy costs are obtained with Eq. 5.46, and the unit exergy costs kch and kc from table 5.7. The average mineral concentration in the crust and in the mineral deposits are expressed as x c and x m , respectively. Aluminium Antimony Arsenic Barite Beryllium Bismuth Boron oxide Bromine Cadmium Cesium Chromium Cobalt Copper Feldspar Fluorspar Gallium Germanium Gold Graphite Gypsum Hafnium Helium Indium Iodine Iron Lead Lithium Magnesium Manganese Mercury Molybdenum Nickel Niobium Phosphate rock (as fosforite) PGM Potash (K2 O) REE (as C e2 O3 ) Rhenium Selenium Silver Strontium bch [kJ/mol] 794,30 437,10 494,10 18,40 24,30 274,80 84,12 50,56 293,15 404,46 584,40 308,89 134,03 35,02 112,64 514,61 556,48 51,50 410,25 17,92 1061,31 30,37 437,36 87,48 376,84 232,18 392,92 629,60 484,64 114,77 730,50 232,48 900,20 360,45 146,52 416,26 408,21 561,34 346,70 69,73 758,76 kch [-] 8 10 10 N.A. 1 10 N.A. N.A. 10 1 1 10 80 N.A. N.A. 1 1 1 N.A. N.A. 1 1 10 N.A. 5 25 1 1 1 10 1 58 1 1 N.A. 1 N.A. 10 1 10 N.A. Production Reserves ∗ ∗ Bch Bch Bch Bch 2,38E+04 1,91E+05 3,20E+06 2,57E+07 1,15E+01 1,15E+02 1,80E+02 1,80E+03 9,42E+00 9,42E+01 1,88E+02 1,88E+03 1,50E+01 N.A. 3,58E+02 N.A. 4,15E-03 4,15E-03 N.A. N.A. 1,79E-01 1,79E+00 1,01E+01 1,01E+02 1,23E+02 N.A. 4,91E+03 N.A. 8,24E+00 N.A. N.A. N.A. 1,20E+00 1,20E+01 3,05E+01 3,05E+02 N.A. N.A. 5,09E+00 5,09E+00 1,57E+03 1,57E+03 N.A. N.A. 8,45E+00 8,45E+01 8,77E+02 8,77E+03 8,20E+02 6,58E+04 2,66E+04 2,13E+06 4,63E+01 N.A. N.A. N.A. 1,84E+02 N.A. 8,27E+03 N.A. 1,29E-02 1,29E-02 N.A. N.A. 1,65E-02 1,65E-02 N.A. N.A. 1,54E-02 1,54E-02 2,62E-01 2,62E-01 8,40E+02 N.A. 7,02E+04 N.A. 1,74E+02 N.A. 0,00E+00 N.A. N.A. N.A. 8,64E+01 8,64E+01 5,09E+00 5,09E+00 N.A. N.A. 5,29E-02 5,29E-01 1,00E+00 1,00E+01 4,12E-01 N.A. 2,47E+02 N.A. 1,40E+05 7,41E+05 1,18E+07 6,25E+07 9,29E+01 2,36E+03 2,11E+03 5,37E+04 4,50E+02 4,50E+02 5,54E+03 5,54E+03 4,26E+02 4,26E+02 N.A. N.A. 2,51E+03 2,51E+03 9,69E+04 9,69E+04 2,02E-02 2,02E-01 6,29E-01 6,29E+00 3,35E+01 3,35E+01 1,56E+03 1,56E+03 1,49E+02 8,70E+03 6,34E+03 3,69E+05 1,03E+01 1,03E+01 6,25E+02 6,25E+02 1,21E+03 1,21E+03 1,54E+05 1,54E+05 9,29E-03 N.A. 1,27E+00 N.A. 3,07E+03 3,07E+03 8,76E+05 8,76E+05 3,65E+00 N.A. 2,61E+03 N.A. 3,40E-03 3,40E-02 1,80E-01 1,80E+00 1,62E-01 1,62E-01 8,60E+00 8,60E+00 3,12E-01 3,12E+00 4,17E+00 4,17E+01 1,21E+02 N.A. 1,41E+03 N.A. Continued on next page . . . Reserve base ∗ Bch Bch 4,10E+06 3,29E+07 3,69E+02 3,69E+03 2,83E+02 2,83E+03 1,66E+03 N.A. N.A. N.A. 2,14E+01 2,14E+02 1,18E+04 N.A. N.A. N.A. 7,48E+01 7,48E+02 8,00E+00 8,00E+00 N.A. N.A. 1,63E+03 1,63E+04 5,11E+04 4,09E+06 N.A. N.A. 1,65E+04 N.A. N.A. N.A. N.A. N.A. 5,62E-01 5,62E-01 1,71E+05 N.A. 0,00E+00 N.A. 1,56E+02 1,56E+02 1,17E+03 1,17E+03 1,46E+00 1,46E+01 4,45E+02 N.A. 2,58E+07 1,37E+08 4,55E+03 1,15E+05 1,49E+04 1,49E+04 N.A. N.A. 1,10E+06 1,10E+06 3,28E+00 3,28E+01 3,46E+03 3,46E+03 1,42E+04 8,26E+05 6,94E+02 6,94E+02 4,27E+05 4,27E+05 1,44E+00 N.A. 1,90E+06 1,90E+06 4,46E+03 N.A. 7,20E-01 7,20E+00 1,78E+01 1,78E+01 8,80E+00 8,80E+01 2,48E+03 N.A. Table A.20: The chemical exergy and exergy cost of the 2006 world’s mineral production, mineral reserves, base reserve and world resources. Values are expressed in ktoe if not specified World resources ∗ Bch Bch 9,61E+06 7,72E+07 N.A. N.A. 1,73E+03 1,73E+04 3,77E+03 N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. 3,74E+02 3,74E+03 N.A. N.A. 1,02E+06 1,02E+06 1,88E+03 1,88E+04 1,63E+05 1,31E+07 N.A. N.A. 1,72E+04 N.A. 1,76E+02 1,76E+02 N.A. N.A. N.A. N.A. 6,53E+05 N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. 5,60E+02 N.A. 3,71E+07 1,97E+08 4,02E+04 1,02E+06 1,76E+04 1,76E+04 N.A. N.A. N.A. N.A. 8,20E+00 8,20E+01 2,36E+03 2,36E+03 N.A. N.A. N.A. N.A. N.A. N.A. 1,79E+00 N.A. 2,64E+07 2,64E+07 N.A. N.A. 7,92E-01 7,92E+00 N.A. N.A. N.A. N.A. 2,07E+05 N.A. 398 ADDITIONAL CALCULATIONS Tantalum Tellurium Thorium Tin Titanium (T iO2 ) Vanadium Wolfram Zinc Zircon (Z rO2 ) Sum bch [kJ/mol] 974,85 326,36 1214,50 547,58 18,84 721,48 827,70 339,02 46,21 kch [-] 1 1 N.A. 1 1 1 1 13 1 Production Reserves ∗ ∗ Bch Bch Bch Bch 2,97E-01 2,97E-01 2,78E+01 2,78E+01 8,07E-03 8,07E-03 1,28E+00 1,28E+00 0,00E+00 N.A. 1,32E+02 N.A. 3,33E+01 3,33E+01 6,72E+02 6,72E+02 3,27E+01 3,27E+01 4,11E+03 4,11E+03 1,90E+01 1,90E+01 4,40E+03 4,40E+03 9,77E+00 9,77E+00 3,12E+02 3,12E+02 1,24E+03 1,64E+04 2,23E+04 2,94E+05 1,06E+01 1,06E+01 3,40E+02 3,40E+02 1,77E+05 1,03E+06 1,63E+07 9,22E+07 End of the table Reserve base ∗ Bch Bch 3,85E+01 3,85E+01 2,87E+00 2,87E+00 1,54E+02 N.A. 1,21E+03 1,21E+03 8,45E+03 8,45E+03 1,29E+04 1,29E+04 6,78E+02 6,78E+02 5,95E+04 7,85E+05 6,45E+02 6,45E+02 3,37E+07 1,79E+08 Table A.20: The chemical exergy and exergy cost of the 2006 world’s mineral production, mineral reserves, base reserve and world resources. Values are expressed in ktoe if not specified.– continued from previous page. World resources ∗ Bch Bch N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. 1,13E+04 1,13E+04 2,13E+04 2,13E+04 N.A. N.A. 2,35E+05 3,11E+06 N.A. N.A. 7,55E+07 3,19E+08 Exergy calculation of the mineral resources 399 Aluminium Antimony Arsenic Barite Beryllium Bismuth Boron oxide Bromine Cadmium Cesium Chromium Cobalt Copper Feldspar Fluorspar Gallium Germanium Gold Graphite Gypsum Hafnium Helium Indium Iodine Iron Lead Lithium Magnesium Manganese Mercury Molybdenum Nickel Niobium Phosphate rock (as fosforite) PGM Potash (K2 O) REE (as C e2 O3 ) Rhenium Selenium Silver Strontium x m [g/g] 4,60E-01 3,78E-02 1,00E-02 8,30E-01 1,00E-02 2,00E-03 2,00E-01 5,00E-03 1,00E-04 2,33E-01 4,35E-01 1,08E-03 5,80E-03 4,50E-01 2,50E-01 2,30E-05 5,00E-05 2,20E-07 5,00E-01 8,00E-01 6,00E-05 7,00E-02 1,40E-04 1,60E-04 5,11E-01 2,05E-02 4,00E-04 4,50E-01 3,15E-01 3,83E-03 3,10E-04 1,30E-02 6,38E-03 1,10E-03 8,02E-07 2,50E-01 9,70E-04 2,23E-04 2,50E-02 4,30E-06 3,40E-01 x c [g/g] 8,15E-02 4,00E-07 4,80E-06 4,13E-06 2,10E-06 1,60E-07 1,70E-05 5,00E-03 9,00E-08 4,90E-06 9,20E-05 1,73E-05 2,80E-05 1,45E-01 1,32E-06 1,75E-05 1,40E-06 1,50E-09 1,99E-03 1,08E-04 5,30E-06 7,00E-02 5,60E-08 1,40E-06 3,92E-02 1,70E-05 2,40E-05 1,50E-02 7,74E-04 5,00E-08 1,10E-06 4,70E-05 1,20E-05 4,03E-04 5,00E-10 2,32E-02 6,30E-05 1,98E-10 9,00E-08 5,30E-08 3,20E-04 kc [-] 2250 28 80 N.A. 112 90 N.A. N.A. 804 N.A. 37 1262 343 N.A. N.A. N.A. N.A. 422879 N.A. N.A. N.A. N.A. N.A. N.A. 97 219 158 1 284 1707 947 432 N.A. 44 N.A. 39 N.A. 1939 N.A. 7042 0 Production Reserves Bc Bc∗ Bc Bc∗ 1,46E+02 3,28E+05 1,97E+04 4,42E+07 7,48E-01 2,12E+01 1,17E+01 3,33E+02 3,61E-01 2,89E+01 7,23E+00 5,78E+02 2,60E+01 N.A. 6,19E+02 N.A. 3,59E-03 4,01E-01 N.A. N.A. 1,52E-02 1,37E+00 8,56E-01 7,69E+01 3,44E+01 N.A. 1,37E+03 N.A. N.A. N.A. N.A. N.A. 7,13E-02 5,73E+01 1,81E+00 1,45E+03 N.A. N.A. 3,40E-01 N.A. 5,81E+01 2,13E+03 N.A. N.A. 2,80E-01 3,54E+02 2,91E+01 3,67E+04 8,10E+01 2,78E+04 2,63E+03 9,01E+05 4,34E+00 N.A. N.A. N.A. 4,97E+01 N.A. 2,24E+03 N.A. 1,69E-05 N.A. N.A. N.A. 2,63E-04 N.A. N.A. N.A. 3,69E-03 1,56E+03 6,30E-02 2,66E+04 2,96E+01 N.A. 2,47E+03 N.A. 2,28E+02 N.A. N.A. N.A. N.A. N.A. 4,89E-01 N.A. N.A. N.A. N.A. N.A. 2,34E-03 N.A. 4,44E-02 N.A. 5,53E-02 N.A. 3,32E+01 N.A. 2,63E+03 2,56E+05 2,22E+05 2,16E+07 7,05E+00 1,54E+03 1,60E+02 3,51E+04 N.A. N.A. 9,84E+01 1,56E+04 6,15E+00 6,15E+00 N.A. N.A. 7,93E+01 2,25E+04 3,07E+03 8,71E+05 4,91E-03 8,39E+00 1,53E-01 2,61E+02 6,41E-01 6,07E+02 3,00E+01 2,84E+04 8,97E+00 3,87E+03 3,80E+02 1,64E+05 1,78E-01 N.A. 1,08E+01 N.A. 8,34E+00 3,66E+02 1,06E+03 4,64E+04 1,16E-03 N.A. 1,59E-01 N.A. 4,58E+01 1,77E+03 1,31E+04 5,04E+05 6,07E-02 N.A. 4,34E+01 N.A. 2,09E-04 4,06E-01 1,11E-02 2,15E+01 1,45E-02 N.A. 7,72E-01 N.A. 4,88E-02 3,43E+02 6,52E-01 4,59E+03 2,83E+00 0,00E+00 3,29E+01 0,00E+00 Continued on next page . . . Reserve base Bc Bc∗ 2,52E+04 5,66E+07 2,40E+01 6,82E+02 1,08E+01 8,67E+02 2,87E+03 N.A. N.A. N.A. 1,82E+00 1,63E+02 3,31E+03 N.A. N.A. N.A. 4,43E+00 3,56E+03 5,34E-01 N.A. N.A. N.A. 5,40E+01 6,81E+04 5,04E+03 1,73E+06 N.A. N.A. 4,47E+03 N.A. N.A. N.A. N.A. N.A. 1,35E-01 5,71E+04 6,04E+03 N.A. N.A. N.A. 8,83E-01 N.A. N.A. N.A. 6,46E-02 N.A. 5,97E+01 N.A. 4,86E+05 4,73E+07 3,45E+02 7,55E+04 2,64E+02 4,18E+04 N.A. N.A. 3,47E+04 9,84E+06 7,97E-01 1,36E+03 6,62E+01 6,26E+04 8,51E+02 3,68E+05 1,20E+01 N.A. 2,94E+03 1,29E+05 1,79E-01 N.A. 2,83E+04 1,09E+06 7,40E+01 N.A. 4,43E-02 8,59E+01 1,60E+00 N.A. 1,38E+00 9,69E+03 5,81E+01 0,00E+00 Table A.21: The concentration exergy and exergy cost of the 2006 world’s mineral production, mineral reserves, base reserve and world resources. Values are expressed in ktoe if not specified World resources Bc Bc∗ 5,90E+04 1,33E+08 N.A. N.A. 6,65E+01 5,32E+03 6,52E+03 N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. 2,22E+01 1,78E+04 N.A. N.A. 3,77E+04 1,38E+06 6,23E+01 7,86E+04 1,61E+04 5,52E+06 N.A. N.A. 4,66E+03 N.A. 2,32E-01 N.A. N.A. N.A. N.A. N.A. 2,30E+04 N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. 7,52E+01 N.A. 6,98E+05 6,80E+07 3,05E+03 6,66E+05 3,12E+02 4,93E+04 N.A. N.A. N.A. N.A. 1,99E+00 3,40E+03 4,53E+01 4,29E+04 N.A. N.A. N.A. N.A. N.A. N.A. 2,24E-01 N.A. 3,93E+05 1,52E+07 N.A. N.A. 4,87E-02 9,45E+01 N.A. N.A. N.A. N.A. 4,84E+03 N.A. 400 ADDITIONAL CALCULATIONS Tantalum Tellurium Thorium Tin Titanium (T iO2 ) Vanadium Wolfram Zinc Zircon (Z rO2 ) Sum x m [g/g] 6,50E-03 1,00E-06 3,00E-02 4,80E-03 6,90E-03 2,00E-02 7,17E-03 4,06E-02 2,69E-03 x c [g/g] 9,00E-07 5,00E-09 1,05E-05 2,10E-06 3,84E-03 9,70E-05 1,90E-06 6,70E-05 1,93E-04 kc [-] 12509 N.A. N.A. 1493 348 572 3105 126 7744 Production Reserves Bc Bc∗ Bc Bc∗ 6,71E-03 8,39E+01 6,28E-01 7,86E+03 3,25E-04 N.A. 5,16E-02 N.A. N.A. N.A. 2,15E+00 N.A. 1,17E+00 1,74E+03 2,35E+01 3,52E+04 2,53E+00 8,80E+02 3,18E+02 1,11E+05 3,49E-01 2,00E+02 8,07E+01 4,61E+04 2,41E-01 7,48E+02 7,70E+00 2,39E+04 5,82E+01 7,33E+03 1,05E+03 1,32E+05 1,49E+00 1,16E+04 4,81E+01 3,73E+05 3,51E+03 6,69E+05 2,70E+05 6,92E+07 End of the table Reserve base Bc Bc∗ 8,70E-01 1,09E+04 1,16E-01 N.A. 2,50E+00 N.A. 4,25E+01 6,34E+04 6,53E+02 2,28E+05 2,36E+02 1,35E+05 1,67E+01 5,19E+04 2,79E+03 3,52E+05 9,12E+01 7,06E+05 6,04E+05 1,19E+08 Table A.21: The concentration exergy and exergy cost of the 2006 world’s mineral production, mineral reserves, base reserve and world resources. Values are expressed in ktoe if not specified.– continued from previous page. World resources Bc Bc∗ N.A. N.A. N.A. N.A. N.A. N.A. N.A. N.A. 8,71E+02 3,03E+05 3,91E+02 2,24E+05 N.A. N.A. 1,11E+04 1,39E+06 N.A. N.A. 1,26E+06 2,25E+08 Exergy calculation of the mineral resources 401 402 A.7 A.7.1 ADDITIONAL CALCULATIONS Australian fossil fuel production Coal Table A.22 shows the Australian coal production from 1913 to 2006. The data has been obtained from the British Geological Survey’s historical statistics [159], [157], [52], [250], [154], [155], [30], [31] and [29]. Table A.22: Evolution of the Australian coal production. Values in ktons Year 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 Anthrac. Bitum. 12619 12657 11600 9971 10398 11126 10695 13178 13087 12498 12720 13980 13850 13465 13742 12032 10533 9686 8537 8725 9239 9734 11064 11555 12270 11869 14443 14612 14423 13944 13020 14000 14901 15022 14336 16816 Subbit. Lign. Year Anthrac. 1960 51 1961 60 1962 70 1963 62 1964 74 1965 71 1966 47 1967 39 1968 30 1969 15 1970 119 1971 130 1972 891 1973 973 1974 1479 1975 1618 1976 1769 1977 1861 1978 2230 1979 2655 1980 2622 1981 2660 1982 2257 1983 3094 1984 3449 1985 3735 1986 1987 1988 4640 1989 2 5014 1990 5174 1991 35 5098 1992 42 5533 1993 138 5799 1994 196 6240 1995 6801 1996 7495 1997 7446 1998 Continued on next page . . . Bitum. 20975 22347 22362 22629 24840 28685 30568 31806 37350 42349 46063 45841 59389 57355 66474 62417 69676 72679 74094 72679 76794 93405 99109 99828 116018 158256 170067 178399 176604 190085 162957 167472 179144 180045 182553 193534 198638 216690 222040 Subbit. 1908 1988 2433 2568 2891 3191 3297 3425 3542 3735 3482 3161 3300 3298 3975 3300 5008 5529 5733 5529 6365 7190 7992 8998 8288 Lign. 15210 16543 17415 18756 19341 20993 22136 23763 23346 23282 24175 23382 23697 24676 27303 23697 28178 29250 32860 29250 32597 32990 37821 34191 35166 36985 37604 44877 43450 48252 47725 52124 50228 48458 48582 50751 53604 58160 65600 Australian fossil fuel production 403 Table A.22: Evolution of the Australian coal production. Values in ktons– continued from previous page. Year 1951 1952 1953 1954 1955 1956 1957 1958 1959 A.7.2 Anthrac. 58 55 Bitum. 16373 18084 17119 18212 17979 18050 18596 18917 18877 Subbit. 1521 1635 1590 1871 1608 1536 1645 1798 1695 Lign. Year Anthrac. 7963 1999 8235 2000 8391 2001 9482 2002 10276 2003 10731 2004 10915 2005 11832 2006 13246 End of the table Bitum. 232860 244840 266710 272560 280700 294810 308000 316000 Subbit. Lign. 65820 67363 64958 66661 66809 66343 67152 67737 Oil Table A.23 shows Australian oil production from 1913 to 2006. The data has been obtained from the British Geological Survey’s historical statistics [159], [157], [52], [250], [154], [155], [30], [31] and [29]. For the period between 1931 to 1940, oil data corresponds only to the region of Victoria. Until 1964, the statistics include crude petroleum plus oil shale. Table A.23: Evolution of the Australian oil production. Values in ktons Year 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 ktons 5,52 16,26 5,03 5,66 10,27 10,52 10,15 8,12 0,08 0,08 Year ktons Year ktons 1937 0,04 1961 1938 0,03 1962 1939 0,02 1963 1940 0,02 1964 278 1941 1965 334 1942 1966 432 1943 1967 993 1944 1968 1818 1945 1969 2065 1946 1970 8541 1947 1971 14803 1948 0,12 1972 15685 1949 0,14 1973 20635 1950 0,16 1974 24559 1951 0,27 1975 21738 1952 1976 22122 1953 1977 22793 1954 1978 22976 1955 1979 23141 1956 1980 19451 Continued on next page . . . Year 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 ktons 30447 27151 29076 27493 25908 30548 28835 28326 26300 28505 27031 28407 30000 28000 27000 37000 34000 33000 27000 20748 404 ADDITIONAL CALCULATIONS Table A.23: Evolution of the Australian oil production. Values in ktons.– continued from previous page. Year 1933 1934 1935 1936 A.7.3 ktons 0,08 0,02 0,02 0,02 Year 1957 1958 1959 1960 ktons Year 1981 1982 1983 1984 End of the table ktons 19799 18839 21209 26377 Year 2005 2006 ktons 21439 20831 Natural gas Table A.24 shows Australian natural gas production from 1961 to 2006. The data has been obtained from the British Geological Survey’s historical statistics [154], [155], [155], [30], [31] and [29]. Table A.24: Evolution of the Australian natural gas production. Values in millions of cubic meters Year 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 A.8 A.8.1 M m3 0,34 1,6 2,7 3,0 4,0 4,0 4,3 6,1 265 1502 2274 3188 Year 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 M m3 4099 4677 5026 5929 6728 7320 8381 9567 11260 11565 11581 12600 Year 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 M m3 13470 14714 15023 15383 17806 20620 21694 23462 24457 28147 29761 29799 Year 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 M m3 29876 30361 30755 31165 32482 32606 33180 35224 37129 38883 World’s fuel production Uranium Table A.25 shows the production of uranium in western countries and the world production from 1945 to 2006. Approximate data about uranium production in western countries is extracted from the World Nuclear Association [408]. For world production data, it has been assumed that western countries contribute to about 69 World’s fuel production 405 % of total world production. From 2002 to 2006, world production information is directly provided by the WNA [408]. Table A.25: Production of uranium in western countries and in the world. Values are expressed in tons Year 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 A.8.2 Production w. countries [408] 500 500 500 1500 1500 3000 3000 2000 4500 6500 7500 10300 20000 30000 34000 32000 28000 25500 23000 22500 15300 15000 15400 17000 17000 18300 19000 20000 20000 19000 20000 World production Year 725 725 725 2174 2174 4348 4348 2899 6522 9420 10870 14928 28986 43478 49275 46377 40580 36957 33333 32609 22174 21739 22319 24638 24638 26522 27536 28986 28986 27536 28986 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Production w. countries [408] 24000 29000 35000 39000 45000 45000 42000 36000 38000 35000 36500 34500 36000 33000 27500 26000 23000 22500 22500 25000 27500 28000 26500 22500 26500 27500 26000 25000 28000 World production 34783 42029 50725 56522 65217 65217 60870 52174 55072 50725 52899 50000 52174 47826 39855 37681 33333 32609 32609 36232 39855 40580 38406 32609 38406 39855 36063 35613 40251 41702 39429 Coal Table A.26 shows the world’s coal production from 1900 to 2006. The data from 1981 to 2006 has been extracted from BP [35]. From 1900 to 1912 the information has been obtained from the estimations done by Ortiz [253]. From 1913 to 1981, 406 ADDITIONAL CALCULATIONS the data was obtained from the British Geological Survey’s historical statistics [159], [157], [52], [250], [154]. Table A.26: Evolution of the world’s coal production Year 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 A.8.3 Mt coal 800,0 820,0 850,0 900,0 920,0 1000,0 1100,0 1080,0 1100,0 1190,0 1200,0 1210,0 1320,1 1160,0 1175,3 1258,7 1310,4 1234,3 1084,7 1302,0 1118,0 1210,0 1340,0 1340,0 1350,0 1340,0 Year 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 Mt coal 1450,0 1440,0 1540,0 1390,0 1240,0 1110,0 1150,0 1260,0 1310,0 1420,0 1510,0 1420,0 1550,0 1660,0 1745,0 1756,0 1770,0 1420,0 1324,0 1445,0 1622,0 1698,0 1670,0 1792,0 1570,0 1900,0 1930,0 Year 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 Mt coal 1940,0 2100,0 2220,0 2300,0 2400,0 2480,0 2590,0 2440,0 2510,0 2610,0 2710,0 2760,0 2790,0 2677,0 2702,0 2826,0 2944,0 2950,0 3041,0 3065,0 3107,0 3253,0 3349,0 3510,0 3558,0 3719,0 3806,0 Year 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Mt coal 3831,1 3980,1 3986,8 4191,5 4420,8 4528,8 4629,9 4735,7 4818,5 4718,6 4538,8 4500,2 4382,5 4470,5 4592,5 4667,7 4702,1 4555,7 4544,5 4606,6 4819,2 4852,3 5187,6 5585,3 5886,7 6195,1 Oil Table A.27 shows the world’s oil production from 1900 to 2006. The data from 1965 to 2006 has been extracted from BP [35]. Until 1912, the information has been obtained from the estimations done by Ortiz [253]. Between 1913 and 1965, the data was obtained from the British Geological Survey’s historical statistics [159], [157], [52], [250], [154]. World’s fuel production 407 Table A.27: Evolution of the world’s oil production Year 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 A.8.4 Mt oil 0,0 4,5 9,0 13,6 18,1 22,6 27,1 31,7 36,2 40,7 45,2 49,8 54,3 56,0 59,0 62,7 67,4 71,8 69,1 79,3 99,8 113,1 124,1 146,9 146,1 154,1 157,4 Year 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 Mt oil Year 181,7 1954 183,8 1955 207,0 1956 197,0 1957 190,5 1958 180,8 1959 199,1 1960 207,3 1961 228,6 1962 249,9 1963 283,5 1964 279,4 1965 289,9 1966 299,0 1967 310,6 1968 290,6 1969 320,6 1970 342,0 1971 361,9 1972 383,4 1973 423,2 1974 477,5 1975 475,1 1976 530,2 1977 600,9 1978 632,6 1979 668,5 1980 End of the table Mt oil 699,0 774,5 842,7 888,4 910,8 984,0 1053,6 1131,8 1208,0 1303,5 1403,1 1500,6 1700,6 1824,7 1990,9 2141,2 2355,2 2492,6 2636,6 2866,6 2875,2 2734,4 2969,0 3073,2 3103,1 3233,1 3087,9 Year 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 Mt oil 2910,0 2795,6 2759,2 2814,6 2792,1 2935,9 2947,1 3069,0 3102,9 3170,6 3160,5 3190,0 3188,6 3237,2 3281,0 3376,5 3480,5 3548,3 3482,9 3618,1 3602,7 3575,6 3701,3 3862,6 3896,8 3914,1 Natural gas Table A.28 shows the world’s natural gas production from 1900 to 2006. The data from 1970 to 2006 has been extracted from BP [35]. Until 1920, the information has been estimated from US natural gas production, which is a compilation of data from the “Espasa” encyclopedia [87] between years 1900 -1921. Between 1921 and 1970, the data was obtained from the British Geological Survey’s historical statistics [159], [157], [52], [250], [154]. For years 1945-1947, a linear increasing rate has been assumed, because of lack of data. 408 ADDITIONAL CALCULATIONS Table A.28: Evolution of the world’s natural gas production. Data in billion of cubic meters Year 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 A.9 World Prod. 3,5 5,0 5,9 6,7 7,3 7,5 10,8 11,5 11,2 13,4 14,6 14,7 15,8 16,2 16,5 17,6 21,0 22,1 20,3 21,0 22,4 19,8 22,8 29,8 33,7 35,3 38,9 42,7 45,6 56,4 57,6 49,3 47,0 47,4 54,6 Year 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 World Prod. 57,5 65,5 72,5 75,2 80,5 80,4 112,2 91,1 98,9 106,6 121,1 135,6 150,1 164,6 175,6 184,1 239,0 257,1 270,1 295,9 323,6 351,8 386,3 388,6 432,4 472,9 511,8 558,5 609,8 663,8 706,9 759,8 821,5 889,1 955,1 Year 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 World Prod. 1009,3 1073,8 1125,3 1180,2 1201,5 1203,3 1252,9 1301,5 1347,3 1438,0 1448,5 1475,8 1478,0 1483,2 1614,9 1666,7 1713,6 1798,7 1882,4 1943,3 1991,8 2023,7 2037,0 2073,1 2093,6 2134,7 2227,9 2231,5 2279,5 2343,7 2425,2 2482,1 2524,6 2614,3 2703,1 2779,8 2865,3 The Hubbert peak applied to world production of the main non-fuel minerals Figures A.1, A.2, and A.3 show the Hubbert model applied to the exergy costs of world iron, aluminium and copper production. It is assumed that the total world The Hubbert peak applied to world production of the main non-fuel minerals 409 5 x 10 15 2068 Bt* 10 5 8 0 x 10 2.5 Integral Bt* 2 1.5 1 0.5 0 1900 1950 2000 2050 2100 2150 2200 2250 Figure A.1. The Hubbert peak applied to the exergy cost of world’s iron production, based on the world resources. Data in ktoe 6 2 x 10 2089 Bt* 1.5 1 0.5 8 0 x 10 2.5 Integral Bt* 2 1.5 1 0.5 0 1900 1950 2000 2050 2100 2150 2200 2250 2300 Figure A.2. The Hubbert peak applied to the exergy cost of world’s aluminium production, based on the world resources. Data in ktoe mineral reserves are equal to the world resources of each mineral in 2006 published by the USGS [362] plus the irreversible exergy distance D∗ from 1900 to 2006. 410 ADDITIONAL CALCULATIONS 5 2 x 10 2066 Bt* 1.5 1 0.5 7 0 x 10 2.5 Integral Bt* 2 1.5 1 0.5 0 1900 1950 2000 2050 2100 2150 2200 2250 Figure A.3. The Hubbert peak applied to the exergy cost of world’s copper production, based on the world resources. Data in ktoe A.10 Fuel consumption in the 21st century Tables A.29 through A.34 show the primary energy consumption and cumulative resources production assumed in each of the SRES scenarios. Table A.29. Primary energy consumption and cumulative resources production in the IPCC’s B1 scenario [160] Year Coal Oil Gas 1990 105 129 62 2000 109 141 71 2010 120 176 108 Coal Oil Gas 0,0 0,0 0,0 1,1 1,3 0,6 2,2 2,9 1,5 Primary Energy, EJ 2020 2030 2040 2050 2060 134 163 181 167 133 206 230 236 228 199 138 153 166 173 168 Cumulative Resources Production, ZJ 3,5 4,9 6,7 8,5 10,0 4,8 7,0 9,3 11,6 13,8 2,8 4,2 5,8 7,5 9,2 2070 101 167 154 2080 76 143 136 2090 58 119 121 2100 44 99 103 11,1 15,6 10,8 12,0 17,2 12,3 12,7 18,5 13,6 13,2 19,6 14,7 Fuel consumption in the 21st century 411 Table A.30. Primary energy consumption and cumulative resources production in the IPCC’s A1T scenario [160] Year Coal Oil Gas 1990 91 128 71 2000 106 155 87 2010 125 172 124 Coal Oil Gas 0,0 0,0 0,0 0,9 1,4 0,8 2,0 3,0 1,6 Primary Energy, EJ 2020 2030 2040 2050 2060 151 180 153 119 87 193 223 241 250 236 166 231 288 324 344 Cumulative Resources Production, ZJ 3,2 4,7 6,5 8,1 9,3 4,7 6,6 8,9 11,3 13,8 2,9 4,5 6,8 9,7 13,0 2070 60 205 324 2080 53 143 291 2090 40 113 240 2100 25 77 196 10,1 16,1 16,4 10,7 18,2 19,6 11,3 19,6 22,6 11,7 20,8 25,0 Table A.31. Primary energy consumption and cumulative resources production in the IPCC’s B2 scenario [160] Year Coal Oil Gas 1990 91 128 71 2000 91 168 84 2010 98 195 107 Coal Oil Gas 0,0 0,0 0,0 0,9 1,4 0,7 1,8 3,1 1,6 Primary Energy, EJ 2020 2030 2040 2050 2060 98 96 93 86 91 214 240 238 227 201 150 194 251 297 356 Cumulative Resources Production, ZJ 2,8 3,8 4,7 5,7 6,5 5,1 7,2 9,6 12,0 14,3 2,7 4,2 6,1 8,6 11,6 2070 119 146 390 2080 170 101 402 2090 231 72 385 2100 300 52 336 7,4 16,3 15,1 8,6 17,7 19,0 10,3 18,7 23,1 12,6 19,5 26,9 Table A.32. Primary energy consumption and cumulative resources production in the IPCC’s A1B scenario [160] Year Coal Oil Gas 1990 93 143 73 2000 99 167 91 2010 134 209 147 Coal Oil Gas 0,1 0,1 0,1 1,1 1,7 0,9 2,2 3,6 2,1 Primary Energy, EJ 2020 2030 2040 2050 2060 163 179 182 186 165 238 239 226 214 188 196 298 372 465 519 Cumulative Resources Production, ZJ 3,7 5,4 7,0 9,1 10,5 5,8 8,2 10,2 12,7 14,4 3,8 6,3 9,3 13,9 18,2 2070 148 166 578 2080 126 149 604 2090 103 136 590 2100 84 125 576 12,2 16,3 23,9 13,6 18,0 29,8 14,7 19,4 35,5 15,9 20,8 42,2 412 ADDITIONAL CALCULATIONS Table A.33. Primary energy consumption and cumulative resources production in the IPCC’s A2 scenario [160] Year Coal Oil Gas 1990 92 134 71 2000 90 172 74 2010 106 220 89 Coal Oil Gas 0,0 0,0 0,0 1,0 1,7 0,8 2,0 3,6 1,6 Primary Energy, EJ 2020 2030 2040 2050 2060 129 184 239 294 415 291 270 249 228 148 126 176 225 275 297 Cumulative Resources Production, ZJ 3,2 4,7 6,9 9,5 13,1 6,2 9,0 11,6 13,9 15,7 2,7 4,2 6,2 8,7 11,6 2070 536 69 319 2080 658 23 330 2090 781 12 331 2100 904 0 331 17,9 16,7 14,7 31,1 17,0 17,9 38,3 17,2 21,3 46,8 17,2 24,6 Table A.34. Primary energy consumption and cumulative resources production in the IPCC’s A1FI scenario [160] Year Coal Oil Gas 1990 88 131 70 2000 115 136 85 2010 150 150 129 Coal Oil Gas 0,1 0,1 0,1 1,2 1,5 0,9 2,6 2,9 2,1 Primary Energy, EJ 2020 2030 2040 2050 2060 193 299 393 475 448 173 165 202 283 353 203 268 333 398 494 Cumulative Resources Production, ZJ 4,2 7,0 10,4 14,6 19,1 4,5 6,2 8,1 10,4 13,8 3,6 6,1 9,2 12,7 17,4 2070 432 416 573 2080 429 471 634 2090 518 359 606 2100 607 248 578 23,6 17,7 22,8 27,9 22,0 28,7 32,9 25,8 34,8 37,9 29,6 40,9 Nomenclature, Figures, Tables and References 413 Nomenclature Symbols a1 − a7 : Experimental coefficients for the calculation of h∗ (T ) and s∗ (T ) [-] a i : Effective diameter of the ion [m] a j 1 : Intercept of the learning curve with the vertical axes for material’s use [-] ae1 : Intercept of the learning curve with the vertical axes for energy’s use [-] a j 2 : Parameter relating material inputs per unit output at time period t [-] ae2 : Parameter relating energy inputs per unit output at time period t [-] A1 : Constant in the Debye- Huckel equation with the value 0,51 kg1/2 mole−1/2 for water at 25o C A2 : Constant in the Debye- Huckel equation with the value 3,287 * 109 kg1/2 m−1 mole−1/2 for water at 25o C b : Specific exergy [kJ/mole] b0 : Full width at half maximum of the Gaussian peak [-] bch : Specific chemical exergy [kJ/mole] bc : Specific concentration exergy [kJ/mole] B : Absolute exergy [kJ] B∗ : Absolute exergy replacement cost (also named actual exergy) [kJ] Bc : Absolute concentration exergy [kJ] Bch : Absolute chemical exergy [kJ] B t : Absolute total exergy [kJ] c j : Fraction of the j-th element appearing in the form of reference species [-] ∆C p : Heat capacity [kJ/mole] d1 : Moles of C contained in the fuel [mole/g] D : Minimum exergy distance, equivalent to the exergy difference between two situations of the planet [kJ] D ∗ : Actual exergy distance, equivalent to the difference of the exergy replacement costs of two situations of the planet [kJ] 415 416 NOMENCLATURE Ḋ : Minimum exergy degradation velocity [kW] Ḋ ∗ : Actual degradation velocity in terms of exergy replacement costs [kW] e 0 : Standard energy [kJ/mole] e1 − e5 : Exponentials used to calculate the contribution of the entropy change for gaseous reference substances [-] e(t ) : Flow of energy used to perform a certain process [kJ] f j : Elements of the atomic composition vector of the fuel f = [1, h, o, n, s]0 [-] F : Fractal relationship of the deposit [-] F1 − F7 : Coefficients for estimating x H2 O,00 [-] gi : Free energy contribution of one mole of each oxide or hydroxide component of the substance, according to the method of Chermak and Rimstid [55] [kJ/mole] ∆G f : Gibbs free energy of formation [kJ/mole] ∆Gm : Gibs free energy of mixing [kJ/mole] 0 ∆Ghyd : hydration Gibbs free energy [kJ/mole] r ∆G O −2 : Gibbs free energy of formation of a generic oxide M Ox (c) from its aqueous ion [kJ/mole] 0 : Gibbs free energy of formation of a given compound as determined from the constituent oxides ∆Gox [kJ/mole] ∆G r : Gibs free energy of the reaction [kJ/mole] h : Moles of hydrogen per mole of carbon in the fuel [mole/mole] hi : Enthalpy contribution of one mole of each oxide or hydroxide of the substance, according to the method of Chermak and Rimstid [55] [kJ/mole] h∗ (T ) : Enthalpy of Zelenik and Gordon [413] [kJ/mole] H j,00 : Enthalpy of the elements in the dead state [kJ/mole] ∆H : Enthalpy change [kJ/mole] ∆H f : Enthalpy of formation [kJ/mole] ∆Hm : Enthalpy of mixing [kJ/mole] 0 ∆Hhyd : Hydration enthalpy [kJ/mole] r ∆H O −2 : Enthalpy of formation of a generic oxide M Ox (c) from its aqueous ion [kJ/mole] 0 : Gibbs free energy of formation of a given compound as determined from the constituent oxides ∆Hox [kJ/mole] ∆H r : Enthalpy of the reaction [kJ/mole] I : Ionic strength of the electrolyte [mole/kg] j(t ) : Flow of material used to perform a certain process [kg] k c : Unit concentration exergy replacement cost [-] k ch : Unit chemical exergy replacement cost [-] l j : Number of the atoms of j-th element in the molecule of the reference species [-] m : Mass [kg] Nomenclature 417 m i : Conventional standard molarity of the reference substance i in seawater [mole/kg] M : Tonnage of the deposit [k g] Mc : Tonnage of the piece of land under consideration [kg] M W : Molecular weight [mol e/g] n : Moles of nitrogen per mole of carbon in the fuel [mole/mole] n i : Number of moles of substance i [mole]. In section 5.4.5, the number of oxygen ions linked to the Miz+ cations [-]. n s : Number of cations located in different sites of the hydrated clay mineral or phyllosilicate [-]. n w : Number of molecules of water [-] N : Number of oxygens linked to the molecular structure of the double oxide [-] o : Moles of oxygen per mole of carbon in the fuel [mole/mole] ∆O −2 : Enthalpy ∆H O−2 or Gibbs free energy ∆G O−2 of formation of a generic oxide M Ox (c) from its aqueous ion [kJ/mole] P : Pressure [kPa] and Production of a mineral commodity [ktoe/year] P0i : Conventional mean ideal gas partial pressure of substance i in the atmosphere [kPa] p H : Exponent of the concentration of hydrogen ion in seawater (pH=8,1) [-] Q : Heat loss escaping the crust [W /m3 ] Q B : Heat input at the base of the lithosphere due to mantle convection [W /m3 ] QC : Radiogenic heat production of the crust [W /m3 ] Q L : Radiogenic heat production in the mantle part of the lithosphere [W /m3 ] Q M : Mantle heat flow [W /m3 ] Q T : Long-term heat production transient due to cooling after a major tectonic or magmatic perturbation [W /m3 ] r j,i : Amount of moles of element j in substance i [mole j/mole i] rk,i : Number of molecules of additional elements k present in the molecule of reference substance i [mole k/mole i] R : Available reserves [ktoe] R[ j × i] : Stoichiometric coefficient matrix between species i and elements j of dimensions [ j × i] R̄ : Universal gas constant [8,314E-3 kJ/(mole K)] RF : Regression factor of the fit [-] R/P : Resources to production ratio [-] s : Moles of sulphur per mole of carbon in the fuel [mole/mole] s 0 : Standard entropy [kJ/mole] s ∗ (T ) : Entropy of Zelenik and Gordon [413] [kJ/(mole K)] ∆S : Entropy change [kJ/(mole K)] t : time [s, years] t0 : Year where the peak of production is reached [yr] 418 NOMENCLATURE T : Temperature [K] t Me : Exergy content of one ton of mineral in a certain time and place [kJ] t Me ∗ : Exergy replacement cost of one ton of mineral in a certain time and place [kJ] w : Moles of water per mole of carbon in the fuel [mole/mole] W : Moles of liquid water (moisture) in the fuel [mole] x : Molar fraction [mole/mole]. In section 5.4.5, the number of oxygen atoms combined with one atom M in the oxide [-]. x c : Concentration of the mineral in the earth’s crust [g/g] x m : Concentration of the mineral deposit [g/g] X : The molar fraction of oxygen related to the cations of a hydrated clay mineral or phyllosilicate [-] y0 : Height of the Gaussian peak [-] z : Moles of ashes per mole of carbon in the fuel [mole/mole] z + : Number of elementary positive charges [-] Z : Moles of ashes in the fuel [mole] Greek letters 0 [-] αG : Empirical coefficient variable for estimating ∆Gox 0 αH : Empirical coefficient variable for estimating ∆H ox [-] δ : Thickness of the crust [m] γ : Activity coefficient (molarity scale) of the reference substance in seawater [-] Γ(t ) : Cumulative production in period t [kg] ε : Relative error [%] ε j : Mean molar concentration of element j contained in the atmosphere, hydrosphere or continental crust [mole/g] µ j,00 : Chemical potential of the elements in the dead state [kJ/mole] ρ15 : Density of the fuel at 15◦ C [kg/m3 ] τ : Temperature [◦ C] ξi : Mean molar concentration of substance i contained in the atmosphere, hydrosphere or continental crust [mole/g] Abbreviations BGS : British Geological Survey BP : British Petroleum EWG : Energy Watch Group HHV : High Heating Value Nomenclature IGU : International Gas Union IPCC : Intergovernmental Panel on Climate Change IWP&DC : The International Water Power & Dam Construction LHV : Low Heating Value PV : Photovoltaic energy R.B. : Reserve Base R.E. : Reference Environment RE2 O5 : Rare earth’s oxides R.S. : Reference Substances in the Reference Environment RW : Renewable Energies SRES : Special Report on Emission Scenarios THC : Thermohaline Circulation USBM : U.S. Bureau of Mines USGS : U.S. Geological Survey WEC : World Energy Council W.R. : World Resources Subscripts 0 : Conditions of the environment 00 : Conditions of the reference environment or dead state at m: Atmosphere bk : The number of brucitic cations c r : Upper continental crust e: Electrical consumption g l: Glaciers g w : Groundwater h yd r : Hydrosphere j : Index of the considered element. In section 5.4.5, also the index of the considered cation i : Index of the considered species. In section 5.4.5, also the index of the considered cation k : Index of the additional element appearing in the reference substance of element j l i : The number of interlayer atom L : Liquid fuel F : Clean solid fuel o : The octahedral site t : The tetrahedral site 419 420 NOMENCLATURE r w : River water s p he r e: Considered sphere of the earth, either atmosphere, hydrosphere or upper continental crust s w : Seawater t : Total t h: Thermal consumption W : Moisture Z : Ashes Superscripts ∧ : Property calculated in this study − : Average of the property 0 : Standard conditions List of Figures 1.1 Conceptual diagram of the terms exergoecology and thermo-ecology . 11 2.1 The atmospheric layers. Source: http://www.atmosphere.mpg.de (Max Plank Institute) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Earth’s cutaway. Source: USGS [397] . . . . . . . . . . . . . . . . . . . . . 22 38 2.2 Energy flow sheet for the surface of the earth [317] . . . . . . . . . . . . The hydrologic cycle. Source: http://www.ec.gc.ca/water (Environment Canada) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 A simplified summary of the path of the Thermohaline Ocean Circulation [274] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.4 Primary world energy consumption by fuel type at the end of 2006. Values in Mtoe [35]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 Coal proved reserves at the end 2006. Values in thousand millions tonnes (share of anthracite and bituminous coal in brackets) [35]. . . . 4.6 Coal production and consumption at the end of 2006. Elaborated from data included in [35]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 Oil proved reserves at the end 2006. Values in thousand millions of barrels [35]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.8 Oil production and consumption at the end of 2006. Elaborated from data included in [35]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9 Natural gas proved reserves at the end 2006. Values in trillion cubic meters [35]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.10 Natural gas production and consumption at the end of 2006. Elaborated from data included in [35]. . . . . . . . . . . . . . . . . . . . . . . . 4.11 A classification of mineral resources and reserves [141]. . . . . . . . . . 4.12 Two possible relationships between ore grade and the metal, mineral, or energy content of the resource base [316]. . . . . . . . . . . . . . . . . 4.1 4.2 5.1 Exergy required for separating a substance from a mixture, according to Eq. 5.10. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 421 107 115 117 120 122 123 125 125 126 126 130 131 160 422 7.1 7.2 7.3 7.4 7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 7.14 7.15 7.16 7.17 7.18 7.19 7.20 7.21 7.22 7.23 7.24 7.25 7.26 7.27 7.28 7.29 7.30 7.31 LIST OF FIGURES Conceptual diagram for the terms exergy distance and exergy degradation velocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Hubbert’s bell shape curve of the production cycle of any exhaustible resource [146]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Hypothetical processes involved in obtaining the mineral of copper from the reference environment . . . . . . . . . . . . . . . . . . . . . . . . Yearly chemical exergy consumption in the US of pure copper due to copper production throughout the 20th century . . . . . . . . . . . . . . Cumulative chemical exergy decrease of copper mines in the US throughout the 20th century . . . . . . . . . . . . . . . . . . . . . . . . . . Yearly concentration exergy consumption in the US of pure copper due to copper production throughout the 20th century . . . . . . . . . . . . . Cumulative concentration exergy decrease of copper mines in the US throughout the 20th century . . . . . . . . . . . . . . . . . . . . . . . . . . The Hubbert peak applied to US copper production. Best fitting curve. Values in ktoe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Hubbert peak applied to US copper base reserves. Values in ktoe. . Ore grade and cumulated exergy consumption of Australian gold mines The Hubbert peak applied to Australian gold reserves. Values in toe. . Ore grade and cumulated exergy consumption of Australian copper mines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Hubbert peak applied to Australian copper reserves. Values in ktoe. Ore grade and cumulated exergy consumption of Australian nickel mines The Hubbert peak applied to Australian nickel reserves. Values in ktoe. Ore grade and cumulated exergy consumption of Australian silver mines The Hubbert peak applied to Australian silver reserves. Values in toe. . Ore grade and cumulated exergy consumption of Australian lead mines The Hubbert peak applied to Australian lead reserves. Values in ktoe. . Ore grade and cumulated exergy consumption of Australian zinc mines The Hubbert peak applied to Australian zinc reserves. Values in ktoe. . Ore grade and cumulated exergy consumption of Australian iron mines The Hubbert peak applied to Australian iron reserves. Values in ktoe. . The exergy loss of Australian coal reserves. Values in ktoe. . . . . . . . . The Hubbert peak applied to Australian coal reserves. Values in ktoe. . The exergy loss of Australian oil reserves. Values in ktoe. . . . . . . . . . The Hubbert peak applied to Australian oil reserves. Values in ktoe. . . The exergy loss of Australian natural gas reserves. Values in ktoe. . . . The Hubbert peak applied to Australian natural gas reserves. Values in ktoe. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Irreversible exergy consumption of the main non-fuel minerals in Australia in the period from 1884 to 1906 . . . . . . . . . . . . . . . . . . . . Irreversible exergy consumption of the main non-fuel minerals in Australia in the period from 1907 to 1964 . . . . . . . . . . . . . . . . . . . . 231 233 236 239 239 240 241 243 245 248 249 251 251 253 253 255 256 257 258 259 260 261 262 264 265 266 266 268 268 270 271 List of Figures 7.32 Irreversible exergy consumption of the main non-fuel minerals in Australia in the period from 1965 to 2004 . . . . . . . . . . . . . . . . . . . . 7.33 Irreversible exergy consumption of the main fuel and non-fuel minerals in Australia in the period of 1914 to 1968 . . . . . . . . . . . . . . . . . . 7.34 Irreversible exergy consumption of the main fuel and non-fuel minerals in Australia in the period of 1969 to 2004 . . . . . . . . . . . . . . . . . . 7.35 Relative contribution of the extraction of fuel and non-fuel minerals to the global exergy degradation of Australia in the period of 1914 to 2004 7.36 Exergy countdown of the main consumed minerals in Australia . . . . . 7.37 Exergy countdown of metals copper, zinc, nickel, lead and silver in Australia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.10 8.11 8.12 8.13 8.14 8.15 8.16 8.17 8.18 8.19 8.20 The exergy loss of the main non-fuel mineral commodities on earth in the twentieth century . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The actual exergy loss of the main non-fuel mineral commodities on earth in the twentieth century . . . . . . . . . . . . . . . . . . . . . . . . . The actual exergy loss of the main 15 non-fuel mineral commodities on earth in the twentieth century, excluding iron and aluminium . . . . Depletion degree in % of the main non-fuel mineral commodity reserves The Hubbert peak applied to world iron production. Data in ktoe . . . The Hubbert peak applied to world aluminium production. Data in ktoe The Hubbert peak applied to world copper production. Data in ktoe . . Actual exergy consumption of the world’s fuel and non-fuel minerals throughout the 20th century . . . . . . . . . . . . . . . . . . . . . . . . . . The Hubbert peak applied to world coal production. Data in Mtoe . . . The Hubbert peak applied to world natural gas production. Data in Mtoe The Hubbert peak applied to world oil production. Data in Mtoe . . . . The Hubbert peak applied to the world’s conventional fossil fuel production. Data in Mtoe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The Hubbert peak applied to the world’s main minerals production. Data in Mtoe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The exergy countdown of the main minerals extracted on earth . . . . Schematic presentation of the global carbon cycle as estimated by Post et al. [270] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scenarios for GHG emissions from 2000 to 2100 and projections of surface temperatures [160] . . . . . . . . . . . . . . . . . . . . . . . . . . . CO2 emissions and equilibrium temperature increases for a range of stabilization levels [162] . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exergy loss of the different types of coal as a function of the CO2 concentration in the atmosphere . . . . . . . . . . . . . . . . . . . . . . . . . . Exergy loss of the different types of fuel-oils as a function of the CO2 concentration in the atmosphere . . . . . . . . . . . . . . . . . . . . . . . . Exergy loss of natural gas as a function of the CO2 concentration in the atmosphere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423 271 272 273 273 275 276 286 287 288 288 289 290 290 292 293 293 294 295 296 296 298 300 301 303 304 305 424 LIST OF FIGURES 8.21 Actual exergy consumption of the main minerals in the 21st century based on the Hubbert peak model. Values in Gtoe . . . . . . . . . . . . . 8.22 Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s B1 scenario. Values in Gtoe . . . . . . . . . . . . . . 8.23 Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s A1T scenario. Values in Gtoe . . . . . . . . . . . . . 8.24 Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s B2 scenario. Values in Gtoe . . . . . . . . . . . . . . 8.25 Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s A1B scenario. Values in Gtoe . . . . . . . . . . . . . 8.26 Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s A2 scenario. Values in Gtoe . . . . . . . . . . . . . . 8.27 Actual exergy consumption of the main minerals in the 21st century based on the IPCC’s A1FI scenario. Values in Gtoe . . . . . . . . . . . . . 8.28 Summary of the actual exergy degradation of the main extracted minerals in the period between years 1900 and 2100 based on the Hubbert and the IPCC’s SRES scenarios . . . . . . . . . . . . . . . . . . . . . . . . . A.1 The Hubbert peak applied to the exergy cost of world’s iron production, based on the world resources. Data in ktoe . . . . . . . . . . . . . . . . . A.2 The Hubbert peak applied to the exergy cost of world’s aluminium production, based on the world resources. Data in ktoe . . . . . . . . . . A.3 The Hubbert peak applied to the exergy cost of world’s copper production, based on the world resources. Data in ktoe . . . . . . . . . . . . . . 308 310 312 313 314 316 317 319 409 409 410 List of Tables 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 3.1 3.2 3.3 3.4 3.5 Composition of the main envelopes derived from direct sampling or from a chemical translation of a direct measurement (density), in the case of the core, and the corresponding whole earth composition [169]. Gaseous chemical composition of the atmosphere [272]. . . . . . . . . . Inventory of water at the earth’s surface [263]. . . . . . . . . . . . . . . . Volume of Oceans and Seas. Adapted from [85] . . . . . . . . . . . . . . The composition of average seawater. Adapted from [224] . . . . . . . Predicted Mean Oceanic Concentrations. Adapted from [273]. . . . . . Renewable water resources and potential water availability by continents [311]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mean chemical contents of world river water [197] . . . . . . . . . . . . The average concentrations of elements in filtered river water. Concentration in ppb. Adapted from Li [196]. . . . . . . . . . . . . . . . . . . Constituents of ground waters from different rock types. Concentrations in µg/g [405]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Area of land surface covered by glaciers in different regions of the world, together with estimates of volume and the equivalent sea level rise that the volume implies [185]. . . . . . . . . . . . . . . . . . . . . . . The concentration of major ions in glacial runoff from different regions of the world. Concentrations are reported in mg/l. Adapted from [43] Average composition of the upper continental crust according to different studies. Elements in g/g. . . . . . . . . . . . . . . . . . . . . . . . . . Mineral classification based on Dana’s New Mineralogy [103] . . . . . . Crustal abundance of minerals. Data in percent volume. . . . . . . . . . Average mineralogical composition of the upper continental crust according to Grigor’ev [127]. Results are given in mass percentage. . . . Comparison of Rudnick and Gao’s [292] chemical composition of the upper earth’s crust and the one generated by Grigor’ev [127] according to Eq. 3.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mineralogical composition of the earth’s crust according to the calculations of this study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425 21 24 25 26 27 28 31 31 32 34 35 36 39 44 47 47 55 92 426 3.6 LIST OF TABLES Crustal abundance of minerals according to this and Grigor’ev’s model in mass % [127] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 World energy use in 1984 [130] . . . . . . . . . . . . . . . . . . . . . . . . Estimates of bulk continental crust heat production from heat flow data [168]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.3 Estimated uranium resources in ores rich enough to be mined for use in 235 U power plants [317], together with estimated rates of production for 2005 according to the BGS [139]. Data reported as ktons of metal content. No distinctions are drawn between reserves and resources, and no data for resources are reported by the former URSS countries. . 4.4 Specific exergy on a dry basis of representative biomass samples [138] 4.5 Rank of coal according to the norm ASTM D388. . . . . . . . . . . . . . . 4.6 Rank of oil according to the British standard BS2869:1998 . . . . . . . 4.7 Physical properties of different compositions of natural gas [34] . . . . 4.8 Available energy, potential energy use and current consumption of natural resources on earth. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.9 Summary statistics of grade-tonnage models. After [66] . . . . . . . . . 4.10 Mineral world reserves, reserve base and world resources in 2006 . . . 4.1 4.2 5.1 5.4 5.5 5.6 5.7 5.8 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 Exergy difference of selected elements considering either as reference species the most abundant or the most stable substances in the R.E. [367] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Standard chemical exergies of the elements . . . . . . . . . . . . . . . . . Composition of the three R.E. proposed . . . . . . . . . . . . . . . . . . . Calculation of the chemical potential of the elements according to three different R.E. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exergy costs of selected substances [371] & [207] . . . . . . . . . . . . . Summary of the methodologies used to predict the thermodynamic properties of minerals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 109 111 118 121 122 123 128 132 136 144 154 164 166 170 184 Thermodynamic properties of the atmosphere. Values of ∆H 0f i , ∆G 0f i , 0 bch in kJ/mole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . i Thermodynamic properties of seawater. Values in kJ/mole . . . . . . . . Thermodynamic properties of average rivers. Values in kJ/mole . . . . Thermodynamic properties of glacial runoff. Values in kJ/mole . . . . . Thermodynamic properties of groundwaters. Values in kJ/mole . . . . Summary of the thermodynamic properties of the hydrosphere. Values in kJ/mole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Thermodynamic properties of the upper continental crust . . . . . . . . The standard chemical exergy of the earth’s outer layers . . . . . . . . . High heating value and elementary analysis (% by weight) considered in the study of Valero and Arauzo [366] to define different types of coal. 189 190 191 192 193 194 196 205 208 List of Tables 6.10 Thermodynamic properties of the different types of coal. Values in kJ/kg, except for s0 (kJ/kgK) . . . . . . . . . . . . . . . . . . . . . . . . . 6.11 The exergy of the world’s coal proven reserves reported in [401]. Values in million tonnes if not specified . . . . . . . . . . . . . . . . . . . . . 6.12 High heating value and elementary analysis (% by weight) of the different types of oil, according to the British standard BS2869:1998 . . . 6.13 Thermodynamic properties of the different types of oil. Values in kJ/kg, except for s0 (kJ/kgK) . . . . . . . . . . . . . . . . . . . . . . . . . 6.14 The exergy of the world’s oil proven reserves reported in [35]. Values in thousand million tonnes if not specified . . . . . . . . . . . . . . . . . . 6.15 Standard volumetric composition of natural gas considered in [366] . 6.16 Thermodynamic properties of natural gas. Values in kJ/N m3 , except for ∆H f (kJ/kg) and s0 (kJ/kgK) . . . . . . . . . . . . . . . . . . . . . . . 6.17 The exergy of the world’s natural gas proven reserves reported in [35] 6.18 The exergy and exergy cost of the mineral reserves, base reserve and world resources. Values are expressed in ktoe . . . . . . . . . . . . . . . . 6.19 Available exergy, potential exergy use and current exergy consumption of natural resources on earth. Letter e denotes electrical consumption, while th thermal consumption. . . . . . . . . . . . . . . . . . . . . . . . . Summary of the results of the exergy distance of US copper mines during the 20th century. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.2 Summary of the results of the exergy distance of Australian gold mines. 7.3 Summary of the results of the exergy distance of Australian copper mines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.4 Summary of the results of the exergy distance of Australian nickel mines. 7.5 Summary of the results of the exergy distance of Australian silver mines. 7.6 Summary of the results of the exergy distance of Australian lead mines. 7.7 Summary of the results of the exergy distance of Australian zinc mines. 7.8 Summary of the results of the exergy distance of Australian iron mines. 7.9 Summary of the results of the exergy assessment of the main Australian minerals. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.10 Monetary costs of the main mineral reserves depletion suffered in Australia due to mineral production in year 2004 . . . . . . . . . . . . . . . . 427 208 209 213 213 213 215 216 216 219 224 7.1 8.1 8.2 8.3 8.4 8.5 The exergy loss of the main mineral commodities in the world. Values are expressed in ktoe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The exergy loss of coal, oil and natural gas in the 20th century. . . . . . Projected global averaged temperature change (◦ C at 2090-2099 relative to 1980-1999) at the end of the 21st century. After [160] . . . . . Characteristics of stabilization scenarios and resulting long-term equilibrium global average temperature rise above pre-industrial at equilibrium from thermal expansion only. After [162] . . . . . . . . . . . . . Temperature rise and CO2 concentration in the SRES scenarios . . . . . 246 250 252 254 256 258 260 263 269 276 284 291 300 301 302 428 8.6 8.7 8.8 8.9 8.10 8.11 8.12 8.13 8.14 8.15 8.16 8.17 8.18 8.19 LIST OF Specific exergy (b in kJ/kg) and Exergy loss (%) of anthracite, bituminous, subbituminous, and lignite coal according to the different SRES scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Specific exergy (b) and Exergy loss (%) of fuel-oil 1, fuel-oil 2 and fuel-oil 4, according to the different SRES scenarios. . . . . . . . . . . . Specific exergy (b) and Exergy loss (%) of natural gas according to the different SRES scenarios. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Exergy loss of the 2006 coal reserves due to the increase of GHG emissions, according to the different SRES scenarios. Values in Mtoe . . . . Exergy loss of the 2006 fuel-oil reserves due to the increase of GHG emissions, according to the different SRES scenarios . . . . . . . . . . . Exergy loss of the 2006 natural gas reserves due to the increase of GHG emissions, according to the different SRES scenarios . . . . . . . . . . . Actual exergy degradation of the main extracted minerals in the 21st century based on the Hubbert peak model . . . . . . . . . . . . . . . . . . Actual exergy degradation of the main extracted minerals in the 21st century based on the B1 scenario . . . . . . . . . . . . . . . . . . . . . . . Actual exergy degradation of the main extracted minerals in the 21st century based on the A1T scenario . . . . . . . . . . . . . . . . . . . . . . Actual exergy degradation of the main extracted minerals in the 21st century based on the B2 scenario . . . . . . . . . . . . . . . . . . . . . . . Actual exergy degradation of the main extracted minerals in the 21st century based on the A1B scenario . . . . . . . . . . . . . . . . . . . . . . Actual exergy degradation of the main extracted minerals in the 21st century based on the A2 scenario . . . . . . . . . . . . . . . . . . . . . . . Actual exergy degradation of the main extracted minerals in the 21st century based on the A1FI scenario . . . . . . . . . . . . . . . . . . . . . . Summary of the actual exergy degradation of the main extracted minerals in the period between years 1900 and 2100 based on the Hubbert and the IPCC’s SRES scenarios . . . . . . . . . . . . . . . . . . . . . . . . . A.1 Vector ε̂ j [78 × 1], according to Rudnick and Gao [292] and vector ε j [78 × 1], obtained from Grigor’ev [127]. Values in mole/g . . . . . . . A.2 Vector ξi [324 × 1], according to Grigor’ev [127] and vector ξ̂i [324 × 1] obtained in this study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.3 Matrix R0 [324 × 78] (Part 1) . . . . . . . . . . . . . . . . . . . . . . . . . . A.4 Matrix R0 [324 × 78] (Part 2) . . . . . . . . . . . . . . . . . . . . . . . . . . A.5 Summary statistics of grade-tonnage models-1. After [66] . . . . . . . . A.6 Summary statistics of grade-tonnage models-2. After [66] . . . . . . . . A.7 Summary statistics of grade-tonnage models-3. After [66] . . . . . . . . A.8 Summary statistics of grade-tonnage models-4. After [66] . . . . . . . . A.9 Summary statistics of grade-tonnage models-5. After [66] . . . . . . . . A.10 Summary statistics of grade-tonnage models-6. After [66] . . . . . . . . A.11 Summary statistics of grade-tonnage models-7. After [66] . . . . . . . . TABLES 302 303 304 306 306 306 309 311 312 313 315 316 318 318 351 352 360 367 376 377 378 379 380 381 382 List of Tables A.12 A.13 A.14 A.15 A.16 A.17 A.18 A.19 A.20 A.21 A.22 A.23 A.23 A.24 A.25 A.26 A.27 A.28 A.29 A.30 A.31 A.32 A.33 A.34 Summary statistics of grade-tonnage models-8. After [66] . . . . . . . . Chemical exergies of the elements for gaseous reference substances . . Chemical exergies of the elements for aqueous reference substances . . Chemical exergies of the elements for solid reference substances . . . . Coefficients a1 through a7 [413] . . . . . . . . . . . . . . . . . . . . . . . . The g i and hi of each polyhedral type and the standard error (%) of the estimate. Values in kJ/mol. [55] . . . . . . . . . . . . . . . . . . . . . Values of ∆G O−2 M z+ (clay) for ions located in different sites [382] for hydrated clays and phyllosilicates. Values in kJ/mole . . . . . . . . . Estimations of the standard enthalpy and Gibbs free energy of minerals. Values in kJ/mole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . The chemical exergy and exergy cost of the 2006 world’s mineral production, mineral reserves, base reserve and world resources. Values are expressed in ktoe if not specified . . . . . . . . . . . . . . . . . . . . . The concentration exergy and exergy cost of the 2006 world’s mineral production, mineral reserves, base reserve and world resources. Values are expressed in ktoe if not specified . . . . . . . . . . . . . . . . . . . . . Evolution of the Australian coal production. Values in ktons . . . . . . . Evolution of the Australian oil production. Values in ktons . . . . . . . . Evolution of the Australian oil production. Values in ktons.– continued from previous page. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Evolution of the Australian natural gas production. Values in millions of cubic meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Production of uranium in western countries and in the world. Values are expressed in tons . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Evolution of the world’s coal production . . . . . . . . . . . . . . . . . . . Evolution of the world’s oil production . . . . . . . . . . . . . . . . . . . . Evolution of the world’s natural gas production. Data in billion of cubic meters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Primary energy consumption and cumulative resources production in the IPCC’s B1 scenario [160] . . . . . . . . . . . . . . . . . . . . . . . . . . Primary energy consumption and cumulative resources production in the IPCC’s A1T scenario [160] . . . . . . . . . . . . . . . . . . . . . . . . . Primary energy consumption and cumulative resources production in the IPCC’s B2 scenario [160] . . . . . . . . . . . . . . . . . . . . . . . . . . Primary energy consumption and cumulative resources production in the IPCC’s A1B scenario [160] . . . . . . . . . . . . . . . . . . . . . . . . . Primary energy consumption and cumulative resources production in the IPCC’s A2 scenario [160] . . . . . . . . . . . . . . . . . . . . . . . . . . Primary energy consumption and cumulative resources production in the IPCC’s A1FI scenario [160] . . . . . . . . . . . . . . . . . . . . . . . . . 429 383 384 384 385 386 387 388 390 398 400 402 403 404 404 405 406 407 408 410 411 411 411 412 412 References [1] Abare. Energy update 2006. Technical report, The Australian Bureau of Agricultural and Resource Economics, 2006. Online under: http://www.abareconomics.com/publications_html/ energy/energy_06/ energyupdate _06.pdf. [2] Y. Ahmad, S. El Serafy, and E. Lutz, editors. Environmental accounting. The World Bank, Washington, D.C., 1989. [3] J. Ahrendts. The exergy of chemically reacting systems. Technical report, VDI Forschungsheft 579, Düsseldorf, 1977. In German. [4] J. Ahrendts. Reference states. Energy, 5:667–677, 1980. [5] A. Alchian. Reliability of progress curves in airframe production. Econometrica, 31:679–693, 1963. [6] C. Allègre, J.-P. Poirier, E. Humler, and A. Hofmann. The chemical composition of the earth. Earth and Planetary Science Letters, 134:515–526, 1995. [7] C. J. Allègre, E. Lewin, and B. Dupré. A coherent crustal mantle model for the uranium-thorium-lead isotopic system. Chem. Geol., 70:211–234, 1988. [8] C. J. Allègre, G. Manhès, and E. Lewin. Chemical composition of the earth and the volatility control on planetary genetics. Earth and Planetary Science Letters, 185:46–69, 2001. [9] C. L. Archer and M. Z. Jacobson. Evaluation of global wind power. Journal of Geophysical Research - Atmospheres, 110(D12, D12110), June 2005. [10] R. Aringhoff, C. Aubrey, G. Brakmann, and S. Teske. Solar thermal power 2020. Technical report, Greenpeace International/European Solar Thermal Power Industry Association, Netherlands, 2003. [11] Ashrae. Ashrae Handbook. Fundamentals. Ashrae, 2005. [12] AusIMM. History of coal mining in Australia. Number No. 21 in Monograph Series. Australasian Institute of Mining and Metallurgy, 1993. 431 432 REFERENCES [13] R. Ayres. Optimal investment policies with exhaustible resources: An information based model. Journal of Environmental Economics and Management, 15:439–461, 1988. [14] R. Ayres, L. Ayres, and A. Masini. Sustainable Metals Management, chapter An application of exergy accounting to five basic metal industries, pages 141– 194. Springer, 2006. [15] R. Ayres, L. Ayres, and B. Warr. Exergy, power and work in the US economy, 1900 to1998. Energy, 28:219–273, 2003. [16] R. Ayres and S. Miller. The role of technical change. Journal of Environmental Economics and Management, 7:353–371, 1980. [17] R. Ayres and I. Nair. Thermodynamics and economics. Physics Today, 35:62– 71, 1984. [18] U. Bardi. The mineral economy: a model for the shape of oil production curves. Energy Policy, 33(1):53–61, Jan. 2005. [19] I. Barin. Thermochemical Data of Pure Substances. VCH Verlagsgesellschaft GmbH, Weinheim, Germany, 1993. [20] H. Barnett and C. Morse. Scarcity and Growth. John Hopkins, Baltimore, 1963. [21] D. Barthelmy. Mineralogy database, http://www.webmineral.com, 2007. [22] A. Bartlett. An Analysis of U.S. and World Oil Production Patterns Using Hubbert-Style Curves. Mathematical Geology, 32(1):1–17, 2000. [23] R. J. Beichner, J. W. Jewett, and R. A. Serway. Physics For Scientists and Engineers. Saunders College, New York, 2000. [24] R. Bentley. Global oil & gas depletion. Energy Policy, 30:189–205, 2002. [25] R. Berman. Thermodynamic databases used by various versions of TWQ. Unpublished documentation accompanying the TWQ software package, 1992. [26] R. A. Berner. The long-term carbon cycle, fossil fuels and atmospheric composition. Nature, 426(6964):323–236, 2003. [27] A. N. Berzina, V. I. Sotnikov, M. Economou-Eliopoulos, and D. G. Eliopoulos. Distribution of rhenium in molybdenite from porphyry Cu-Mo and Mo-Cu deposits of Russia (Siberia) and Mongolia. Ore Geology Reviews, 26(1-2):91– 113, 2005. [28] BGS. World mineral production 2001-2005. Technical report, BGS, 2005. webmineral. Online under 433 [29] BGS. Minerals - what makes a mine? http://www.mineralsuk.com/britmin/mm5.pdf, 2006. [30] BGS. World Mineral Statistics. British Geological Survey, Various years (1982 - 2002). [31] BGS. World Mineral Production. British Geological Survey, Various years (2002 - 2006). [32] L. S. Borodin. Estimated chemical composition and petrochemical evolution of the upper continental crust. Geochem. Int., 37:723–734, 1999. [33] F. Bosjankovic. Reference level of exergy of chemically reacting systems. Forschung im Ingenieurwesen, 21:151–152, 1963. [34] E. Botero. Valoración exergética de recursos naturales, minerales, agua y combustibles fósiles. PhD thesis, Universidad de Zaragoza, 2000. [35] BP. Statistical review of world energy. Technical report, British Petroleum, 2007. Online under: http://www.bp.com/ productlanding.do ?categoryId=6848&contentId=7033471. [36] G. P. Brasseur, J. J. Orlando, and G. S. Tyndall. Atmospheric Chemistry and Global Change. Oxford University Press, Oxford, 1999. [37] P. G. Brewer. Chemical Oceanography, volume 1, chapter Minor elements in sea water, pages 415–496. Academic Press, 1975. [38] K. A. Brik, B. B. Mureni, L. O. Kiseleva, L. H. Masinkova, and G. A. Kvasov. Gold distribution according to its structure and volume fraction in the sands of gold deposits. Mineral balance of chemical elements in rocks and deposits of the Urals, pages 29–36, 1989. In Russian. [39] V. Brodianski. Earth’s available energy and the sustainable development of life support systems. Theories and Practices for Energy Education, Training, Regulation and Standards, from Encyclopedia of Life Support Systems (EOLSS), Developed under the Auspices of the UNESCO. Eolss Publishers, Oxford, UK; Online encyclopedia: http://www.eolss.net, Retrieved May 19, 2005. [40] W. S. Broecker. The great ocean conveyor. Oceanography, 4(2):79–89, 1991. [41] D. B. Brooks and P. W. Andrews. Mineral resources, economic growth and world population. Science, pages 13–20, 1974. [42] M. Brown and R. Herendeen. Embodied energy analysis and emergy analysis: a comparative view. Ecological Economics, 19:219–235, 1996. [43] S. Brown. World Energy Resource. Springer, 2002. Online under: 434 REFERENCES [44] A. Caille and others. Deciding the Future: Energy Policy Scenarios to 2050. World Energy Council, London, UK, 2007. Online under: http://www.worldenergy.org/documents/scenarios_study_online_1.pdf. [45] C. Campbell. Better understanding urged for rapidly depleting reserves. Oil and Gas Journal, 7:51–54, April 1997. [46] C. Campbell. The Essence of Oil & Gas Depletion. Multiscience Publishing, Brentwood, 2003. [47] C. Campbell and J. Laherrère. The end of cheap oil. Scientific American, pages 60–65, March 1998. [48] S. M. Cargill, D. H. Root, and E. H. Bailey. Resource estimation from historical data: mercury, a test case. Internat. Assoc. Math. Geologists Jour., 12:489–522, 1980. [49] R. Carmichael. Practical handbook of Physical Properties of Rocks and Minerals. CRC Press, Boca Raton, Florida, 1990. [50] O. Carpintero. El metabolismo de la economía española. Recursos naturales y la huella ecológica (1955-2000). Economía vs Naturaleza, Madrid, 2005. In Spanish. [51] D. D. Carr, editor. Industrial Minerals and Rocks. Society for Mining, Metallurgy, and Exploration, Inc., Littleton, Colorado, 1994. [52] CGS. Statistical Summary. Colonial Geological Surveys, Various years (19481955). [53] P. Chapman and F. Roberts. Metal Resources and Energy. Butterworths, 1983. [54] R. H. Charlier and J. R. Justus. Elsevier Oceanographic Series, chapter Ocean Energies: Environmental, economic, and technological aspects of alternative power sources, page pp. 534. Elsevier, 1993. [55] J. A. Chermak and D. Rimstidt. Estimating the thermodynamik properties (∆G 0f and ∆H 0f ) of silicate minerals at 298 K from the sum of polyhedral contributions. American Mineralogist, 74:1023–1031, 1989. [56] CIA. The world factbook. Technical report, Central Intellilgence Agency, 2005. Online under: https://www.cia.gov/library/publications/the-worldfactbook/. [57] S. Ciriacy-Wantrup. Resource Conservation, Economics and Policies. University of California Press, California, 1952. [58] F. Clarke. The relative abundance of the chemical elements. Phil. Soc. Washington Bull., XI:131–142, 1889. 435 [59] C. Cleveland and M. Ruth. When, where, and by how much do biophysical limits constrain the economic process? Ecological Economics, 22:203–223, 1997. [60] K. C. Condie. Plate Tectonics and Crustal Evolution. Pergamon, London, 1993. [61] L. Connelly and C. Coshland. Exergy and industrial ecology. Part 2: A nondimensional analysis of means to reduce resource depletion. Exergy Int. J., 1(4):234–255, 2001. [62] E. H. P. Cordfunke, A. S. Booij, and R. R. Vanderlaan. The thermochemical properties of Y2 Si2 O7 and D y2 Si2 O7 . J Chem Thermodyn, 30(2):199–205, 1998. [63] R. L. Cornelissen and G. G. Hirs. The value of the exergetic life cycle assessment besides the LCA. Energy Conversion and Management, 43:1417–1424, 2002. [64] R. Costanza, editor. Ecological Economics-The Science and Management of Sustainability, chapter Part II: Accounting, Modeling and Analysis. Columbia University Press, New York, 1991. [65] R. Costanza and H. E. Daly. Natural capital and sustainable development. Conservation Biology, 6(1):37–46, March 1992. [66] D. P. Cox and D. A. Singer, editors. Mineral Deposit Models, volume US Geological Survey Bulletin 1693. US Geological Survey, 1992. Online under: hhtp://pubs.usgs.gov/bul/b1693/. [67] J. Craig and P. Barton. Thermochemical approximations for sulfosalts. Economic Geology, 68:493–506, 1973. [68] J. Craig, D. Vaughan, and B. J. Skinner. Resources of the earth: origin, use and environmental impact. Prentice Hall, 3rd edition, 2001. [69] F. Culkin. Chemical Oceanography, volume 1, chapter The major constituents of seawater, pages 121–161. Academic Press, London, 1965. [70] H. Daly and J. Cobb. For the common good: redirecting the economy toward community, the environment, and a sustainable future. Beacon Press, Boston, Massachussets, 1989. [71] A. G. Darnley. Resources and World Development, chapter Resources for Nuclear Energy, pages 187–210. John Wiley and Sons Limited, 1987. [72] K. Deffeyes. The Impending World Oil Shortage. Princeton University Press, Princeton, 2001. 436 REFERENCES [73] J. H. DeYoung and D. A. Singer. Physical factors that could restrict mineral supply. Economic Geology, 75th Anniversary Volume:939–954, 1981. [74] D. Diederichsen. Referenzumgebungen zur Berechnung der chemischen Exergie. Technical report, Technical Report, Fortschr.-Ber.VDI Reihe 19, Düsseldorf, 1999. In German. [75] W. V. Dieren, editor. Taking Nature into Account. Copernicus, 1995. [76] I. Dincer. Thermodynamics, exergy and environmental impact. Sources, 22:723–732, 2000. [77] R. Duda and L. Reijl. Minerals of the World. Spring Books, 1986. [78] K. Dunham. Non-renewable mineral resources. Resources Policy, pages 3–13, 1974. [79] L. Duro, M. Grivé, C. Domenech, X. Gaona, J. Bruno, and E. Giffaut. Réferentiel de comportements des redionucléides et des toxiques chimiques, chapter Chemical thermodynamic data base thermochimie. Andra, 2005. [80] K. E. Eade and W. Fahring. Regional, lithological and temporal variation in the abundances of some trace elements in the canadian shield. Geol. Sur. Canada Paper, pages 72–46, 1973. [81] K. E. Eade and W. F. Fahring. Geochemical evolutionary trends of continental plates, a preliminary study fo the Canadian Shield. Geol. Surv. Canada Bull., 179(1-59), 1971. [82] EIA. International Energy Annual 2004. Technical report, Energy Information Administration, 2004. Online under: http://www.eia.doe.gov/ emeu/cabs/ Australia/Oil.html. [83] W. Eisermann, P. Johnson, and W. Conger. Estimating thermodynamic properties of coal, char, tar and ash. Fuel Processing Technology, 3:39–53, 1980. [84] EITI. Extractive Industries Transparency Iniciative. Report of the International Advisory Group. Technical report, Department for International Development, London, UK, 2006. [85] Encyclopaedia-Britannica. Table 1: Surface area, volume, and average depth of oceans and seas. Online under: http://www.britannica.com/eb/article9116157, 2007. [86] eParliament. Climate, Energy, Forests. Creating a virtual parliament of legislators to protect our planet. http://www.eparl.net/eparliament/upload/Why_an_e-Parliament.pdf, 2003-2006. Energy 437 [87] ESPASA, editor. Enciclopedia Universal Ilustrada, volume 25. Espasa-Calpe, 1986. pp. 938-939. [88] EU. Towards a thematic strategy on the sustainable use of natural resources. Technical Report COM(2003) 572 final, European Union, 2003. [89] EWG. Coal: resources and future production. Technical Report EWG-Paper No. 1/07, Energy Watch Group, 2007. [90] M. Faber. Energy and time in economic and physical resources, chapter A biophysical approach to the economy entropy, environment and resources, pages 315–337. Elsevier Science Publishers, Amsterdam, 1984. [91] M. Faber and J.L.Proops. Ecological Economics: The Science and Management of Sustainability, chapter National Accounting, Time and the Environment, pages 214–233. Columbia University Press, New York, 1991. [92] M. Faber, H. Niemes, and G. Stephan. Entropy, Environment and Resources. Springer-Verlag, Berlin, Heidelberg, New York, 1987. [93] W. F. Fahring and K. E. Eade. The chemical evolution of the Canadian Shield. Geochim. Cosmochim. Acta, 5:1247–1252, 1968. [94] G. Faure. Principles and applications of Inorganic Chemistry. MacMillan, 1991. [95] A. Fisher. Measures of Natural Resource Scarcity, chapter Measures of Natural Resource Scarcity, pages 249–275. John Hopkins University Press for Resources for the Future, Baltimore, 1979. [96] J. W. Forrester. World Dynamics. Wright Allen Press, INC., 1971. [97] S. Fritsch, J. Post, S. Suib, and A. Navrotsky. Thermochemistry of framework and layer manganese dioxide related phases. Chemistry of Materials, 10(474479), 1988. [98] L. Fulton and T. Howes. Biofuels for transport: An international perspective. Technical report, IEA/EET, 2004. [99] R. B. Fulton and G. Montgomery. Industrial Minerals and Rocks, chapter Fluorspar, pages 509–522. Society for Mining, Metallurgy, and Exploration, Inc., 1994. [100] W. S. Fyfe. Geochemistry. Clarendon Press, Oxford, 1974. [101] R. Gaggioli and P. Petit. Second law analysis for pinpointing the true inefficiencies in final conversion systems. A.C.S. Division of Fuel Chemistry, 21(2), 1976. 438 REFERENCES [102] J. Gaillardet, J. Viers, and B. Dupré. Treatise on Geochemistry, volume 5, chapter Trace Elements in River Waters, pages 225–272. Elsevier Pergamon Ltd, 2004. [103] R. V. Gaines, H. C. W. Skinner, E. E. Foord, B. Mason, and A. Rosenzweig. Dana’s New Mineralogy. John Wiley & Sons, Inc., 1997. [104] S. J. G. Galer, S. L. Goldstein, and R. K. O’Nions. Limits on chemical and convective isolation in the earth’s interior. Chem. Geol., 75:257–290, 1989. [105] R. Ganapathy and E. Anders. Bulk compositions of the moon and earth, estimated from meteorites. In Proc. 5th Lunar Sci. Conf, pages 1181–1206, 1974. [106] S. Gao, T.-C. Luo, B.-R. Zhang, Y.-W. Han, Z.-D. Zhao, and Y.-K. HU. Chemical composition of the continental crust as revealed by studies in East China. Geochimica et Cosmochimica Acta, 62(11):1959–1975, Jun 1998. [107] P. Garofalo, A. Audétat, D. Günther, C. Heinrich, and J. Ridley. Estimation and testing of standard molar thermodynamic properties of tourmaline endmembers using data of natural samples. American Mineralogist, 85:78–88, 2000. [108] L. Gartner. Relations entre enthalpies et enthalpies libres de formation des ions, des oxydes de formule Mn Nm O2 . Utilization des frequences de vibration dans l’infra-rouge. PhD thesis, Université de Strasbourg, 1979. [109] K. Gawell, M. Reed, and P. M. Wright. Geothermal energy, the potential for clean power from the earth. Technical report, Geothermal Energy Association, 1999. Online under: http://www.geoenergy.org/publications/reports/PRELI-MINARY%20REPORT.pdf. [110] Y. Genç. Genesis of the Neogene interstratal karst-type Pöhrenk fluorite-barite (+-lead) deposit (Kirsehir, Central Anatolia, Turkey). Ore Geology Reviews, 29(2):105–117, 2006. [111] N. Georgescu-Roegen. The Entropy Law and the Economic Process. Harvard University Press, Cambridge Massachussets, London England, 1971. [112] Geoscience. Australia’s identified mineral resources. Technical report, Australian Government. Geoscience Australia, 2005. [113] Geoscience-Australia. Virtual centre for geofluids and thermodynamic data. Online under: https://www.ga.gov.au/rural/projects/thermo/calculator/search.jsp. [114] GERM. Geochemical earth http://earthref.org/GERM. reference model. Online under: 439 [115] P. H. Gleick. The world’s water 2000-2001, the biennial report on freshwater resources. Island Press, Washington D.C., 2000. [116] V. M. Goldschmidt. The principles of distribution of chemical elements in minerals and rocks. J. Chem. Soc., 1937. [117] V. M. Goldschmidt. Geochemistry. Clarendon Press, Oxford, 1954. [118] Y. V. Golikov, V. P. Barkhatov, V. F. Kostitsyn, E. G.and Balakirev, and G. I. Chufarov. Thermodynamic of phase equilibria in the Mg-Mn-O system. Russ. J. Phys. Chem., 57(8):1983–1985, 1983. [119] L. G. Goroshenko. Some peculiarities of the mineralogy of granulitic forming rocks in the Kola peninsule in relation with its origin. Problems of the sedimentary geology of the precambrian, 3:56–79, 1971. In Russian. [120] M. Gottschalk. Internally consistent thermodynamic data for rock-forming minerals in the system SiO2-TiO2-Al2O3-Fe2O3-CaO-MgO-FeO-K2O-Na2OH2O-CO2. European Journal of Mineralogy, 9(1):175–223, 1997. [121] J. Govett and M. Govett. The concept and measurement of mineral reserves and resources. Resources Policy, pages 46–55, 1974. [122] N. N. Greenwood and A. Earnshaw. Chemistry of the Elements. Pergamon Press, 1984. [123] K. Gregory and H. Rogner. Energy resources and conversion technologies for the 21st century. Mitigation and Adaptation Strategies for Global Change, 3((2-4)):171–229, 1998. [124] N. Grigor’ev. The average contents minerals of the major groups of magmatic rocks; granite-metamorphic layers. Uralian Geological Journal, 1:47– 58, 2000. [125] N. Grigor’ev. The average mineralogical composition of the upper continental crust. Uralian Geological Journal, 3:3–21, 2000. In Russian. [126] N. A. Grigor’ev. Andesitic magmatism and its place in geological history in the Oljon area (West Baikal). Litosphera, pages 113–122, 2006. In Russian. [127] N. A. Grigor’ev. Average composition of the upper continental crust and dimensions of the maximum concentration of chemical elements. Geology of the Ural and neighbouring territories. Summary materials 2002-2006. Uralian Geological Journey, October 2007. In Russian. [128] A. Grubler, N. Nakiecenvic, and A. McDonald. Global Energy Perspectives. Cambridge University Press, Cambridge (MA), 1998. 440 REFERENCES [129] U. Haack. On the content and vertical distribution of K, Th, and U in the continental crust. Earth Planet. Sci. Lett., 62:360–366, 1983. [130] D. O. Hall, M. Slesser, D. K. L. Betz, D. J. McLaren, P. F. Burollet, P. C. Roberts, A. G. Darnley, H. D. Schilling, J. Diekmann, D. A. White, W. U. Ehrmann, R. H. Williams, and H. W. Levi. Resources and World Development, chapter Assessment of Renewable and Nonrenewable Energy Resources, pages 4854– 506. John Wiley & Sons Limited, 1987. [131] M. J. Harris. Flotation Concentration of a Low Grade Fluorite Ore from Southwestern New Mexico: A Preliminary Study. Technical Report 321, New Mexico Bureau of Mines and Mineral Resources, November 1987. Online under: http://geoinfo.nmt.edu/publications/. [132] C. Harvie and J. Moller, N.and Weare. The prediction of mineral solubilities in natural waters: The Na-K-Mg-Ca-H-Cl-SO4-OH-HCO3-CO3-CO2-H2O system to high ionic strengths at 25o C. Geochim. Cosmochim. Acta, 48:723–751, 1984. [133] C. Hatfield. Oil back on the global agenda. Nature, 387:121, 1997. [134] H. C. Helgeson, J. M. Delany, H. W. Nesbitt, and D. K. Bird. Summary and critique of the thermodynamic properties of the rock-forming minerals. American Journal of Science, 278-A:1–229, 1978. [135] B. Hemingway, L. M. Anovitz, R. Robie, and J. J. McGee. The thermodynamic properties of dumortierite. American Mineralogist, 75:1370–1375, 1990. [136] B. Hemingway, M. Barton, R. Robie, and H. Haselton. Heat capacities and thermodynamic functions for beryl, Be3Al2Si6O18, phenakite, Be2SiO4, euclase, BeAlSiO4(OH), bertrandite, Be4Si2O7(OH)2, and chrysoberyl, BeAl2O4. American Mineralogist, 71:557–568, 1986. [137] P. Henderson. Inorganic Geochemistry. Pergamon Press, 1982. [138] W. A. Hermann. Quantifying global exergy resources. Energy, 31:1685–1702, 2006. [139] L. E. Hetherington, T. J. Brown, A. J. Benham, P. A. J. Lusty, and N. E. Idoine. World mineral production. Technical report, British Geological Survey, Keyworth, Nottingham (UK), 2007. [140] M. H. Hey. An index of mineral species & varieties arranged chemically: with an alphabetical index of accepted mineral names and synonyms. British Museum (Natural History), 1975. [141] D. E. Highley, G. R. Chapman, and K. A. Bonel. The Economic Importance of Minerals to the UK. Report CR/04/070N, British GEological Survey Commissioned, 2004. 441 [142] R. Höll, M. Kling, and E. Schroll. Metallogenesis of germanium-a review. Ore Geology Reviews, 30(3-4):145–180, March 2007. [143] T. J. B. Holland. Dependance of entropy on volume for silicate and oxide minerals. A review and a predicture model. Amer. Miner., 74:5–13, 1989. [144] T. J. B. Holland and R. Powell. An internally consistent thermodynamic data set for phases of petrological interest. Journal of Metamorphic Geology, 16:309–343, 1998. [145] H. Hotelling. The economics of exhaustible resources. Journal of Political Economy, 1931. [146] M. K. Hubbert. Nuclear energy and the fossil fuels. Technical Report Publicaton No. 95, Shell develpment Company. Exploration and Production Research Division, 1956. [147] M. K. Hubbert. Energy resources: a report to the Committee on Natural Resources of the National Academy of Sciences. Technical Report PB-222401, National Academy of Sciences - National Research Council, Washington, D.C. (USA), 1962. [148] C. P. Idyll, editor. The Science of the Sea. Nelson, 1970. [149] IEA. Technology innovation, development and diffusion. Information paper, International Energy Agency, OECD, Paris, 2003. [150] IEA. World Energy Outlook 2004. Technical report, International Energy Agency, OECD, Paris, 2004. [151] IEA. World Energy Outlook 2005, Middle East and North Africa Insights. Technical report, International Energy Agency, OECD, Paris, 2005. [152] IEA. World Energy Outlook. International Energy Council, Paris, France, 2006. [153] IEA. Key World Energy Statistics. IEA, 2007. Online under: http://www.iea.org/textbase/nppdf/free/2007/key_stats_2007.pdf. [154] IGS. Statistical Summary of the Mineral Industry. Institute of Geological Sciences, Various years (1965 - 1971). [155] IGS. World Mineral Statistics. Institute of Geological Sciences, Various years (1972 - 1981). [156] IGU. World gas prospects, strategies and economics. In Proceedings of the 20th World Gas Conference, Copenhagen, Denmark, 1997. International Gas Union. [157] II. Statistical Summary. Imperial Institute, Various years (1924 - 1947). 442 REFERENCES [158] S. Ikumi, C. Luo, and C. Y. Wen. A method of estimating entropies of coals and coal liquids. The Canadian journal of chemical engineering, 60:551–555, 1982. [159] IMRB. Statistical Summary. Imperial Mineral Resources Bureau, Various years (1913-1923). [160] IPCC. Special Report on Emissions Scenarios: A Special Report of Working Group III of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, U.K., 2000. Online under: http://www.grida.no/climate/ipcc/emission/index.htm. [161] IPCC. Climate Change 2001 (Mitigation). Contribution of Working Group III to the Third Assessment Report of the Intergovernmental Panel on Climate Change, chapter Technological and Economic Potential of Greenhouse Gas Emissions Reduction. Cambridge Univ. Press, 2001. [162] IPCC. Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, chapter Summary for Policymakers. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA., 2007. Online under: http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf. [163] IPCC. IPCC Working group III fourth assessment report, chapter Energy supply. Netherlands Environmental Assessment Agency, 2007. [164] ISR. Australia’s Export Coal Industry. Dept. of Industry, Science & Resources Energy Minerals Branch, 6th edition, 2001. [165] L. Ivanhoe and G. Leckie. Global oil, gas fields, sizes tallied, analyzed. Oil and Gas Journal, 91(7):87–91, 1993. [166] IWP&DC. International Water Power and Dam Construction Handbook. Reed Business Pub. Ltd., Sutton, Surrey, England, 1996. [167] R. Jahnke. The synthesis and solubility of carbonate fluoroapatite. American Journal of Science, 284:58–78, January 1984. [168] C. Jaupart and J. C. Mareschal. Treatise on Geochemistry. The Crust, volume 3, chapter Constraints on Crustal Heat Production from Heat Flow Data, pages 65–84. Elsevier Pergamon, 2004. [169] M. Javoy. Chemical earth models. C.R. Acad. Sci. Paris, Sciences de la terre et des planètes / Earth & Planetary Sciences, 329:537–555, 1999. [170] T. Johansson, K. McCormick, L. Neij, and W. Turkenburg. The potentials of renewable energy. Thematic background paper for renewables, 2004. Online under: http://www.renewables2004.de. 443 [171] K. S. Johnson. Industrial Minerals and Rocks, chapter Iodine, pages 583–588. Society for Mining, Metallurgy, and Exploration, Inc., 6th edition, 1994. [172] R. Jolyon. Mindat.org-the mineral and locality database. Online under: http://www.mindat.org, 2007. [173] I. W. Jones, G. Munhoven, M. Tranter, P. Huybrechts, and M. J. Sharp. Modelled glacial and non-glacial HCO3, Si and Ge fluxes since the LGM: little potential for impact on atmospheric CO2 concentrations and the marine Ge:Si ratio. Global Planet Change, 33:139–153, 2002. [174] D. B. Jorgensen. Industrial Minerals and Rocks, chapter Gypsum and Anhydrite, pages 571–581. Society for Mining, Metallurgy, and Exploration, Inc, 1994. [175] S. Jorgensen. Eco-Exergy as Sustainability. WIT Press, UK, 2006. [176] S. Jorgensen and Y. Svirezhe. Towards a Thermodynamic Theory for Ecological Systems. Elsevier, 1st edition, 2004. [177] H. Kameyama, K. Yoshida, S. Yamauchi, and K. Fueki. Evaluation of reference exergy for the elements. Applied Energy, 11:69–83, 1982. [178] V. K. Karzhavin. Amphiboles: thermodynamic properties. 12:1724–1732, 1991. Geokhimiya, [179] V. K. Karzhavin. Thermodynamic properties of eudialyte. 31(6):77–80, 1994. Geoch. Int., [180] R. A. Kauffman and D. V. Dyk. Industrial Minerals and Rocks, chapter Feldspar, pages 473–481. Society for Mining, Metallurgy, and Exploration, Inc., 1994. [181] R. Keeling, editor. Treatise on Geochemistry. The Atmosphere, volume 4. Elsevier Pergamon, 2004. [182] H. M. Kendall, R. M. Glendinning, C. H. MacFadden, and R. F. Logan. Introduction to Physical Geography. Harcourt Brace Jovanovich, Inc, New York, 2nd edition, 1974. [183] R. Kerr. The Next Oil Crisis Looms Large-And Perhaps Close. 281:1128–1131, 1998. Science, [184] N. Khan, Z. Saleem, and A. Wahid. Review of natural energy sources and global power needs. Renewable and Sustainable Energy Reviews, 12(7):1959– 1973, September 2008. [185] P. G. Knight. Glaciers. Cheltenham, Stanley Thornes, 1999. 444 REFERENCES [186] N. Komada, D. Moecher, E. Westrum, B. Hemingway, M. Zolotov, Y. Semenov, and I. Khodakovsky. Thermodynamic properties of scapolites at temperatures ranging from 10 K to 1000 K. J. Chem. Thermodynamics, 28:941–973, 1996. [187] N. Komada, E. F. Westrum, M. Y. Hemingway, B. S.and Zolotov, Y. V. Semenov, I. L. Khodakovsky, and M. Anovitz. Thermodynamic properties of sodalite at temperatures from 15 K to 1000 K. J Chem Thermodyn, 27(10):1119–1132, 1995. [188] J. Krautkraemer. Scarcity and Growth Revisited, chapter Economics of Scarcity, pages 54–77. Resources for the Future, Washington DC, USA, 2005. [189] O. Kubaschewski. The thermodynamic properties of double oxides (A review), volume 4. High Temp., High Press, 1972. [190] J. Laherrere. Published figures and political reserves. World Oil, 33, January 1994. [191] D. Langmuir. Uranium solution-mineral equilibria at low temperatures with applications to sedimentary ore deposits. Geochim. et Cosmoch. Acta, 42(6):547–565, 1978. [192] D. Langmuir and K. Applin. Short Papers of the U.S. Geological Survey Uranium Thorium Symp., chapter Refinement of the thermodynamic properties of uranium minerals and dissolved species with applications to the chemistry of ground waters in sandstone-type uranium deposits, pages 57–66. U. S. Geol. Survey Circ., 1977. [193] S. Lasky. How tonnage and grade relations help predict ore reserves. Eng. Mining Jour., 151:81–85, 1950. [194] W. Latimer. The oxidation states of the elements and their potentials in aqueous solutions. Prentice-Hall, New York, 1952. [195] L. D. Leet, S. Judson, and M. E. Kauffman. Physical Geology. Prentice-Hall, Inc, 6th edition, 1982. [196] Y. H. Li. A brief discussion on the mean oceanic residence time of elements. Geochimica et Cosmochimica Acta, 46:2671–2675, 1982. [197] D. A. Livingstone. Data of Geochemistry, chapter Chemical composition of rivers and lakes. US Geological Survey, 6th edition, 1963. [198] W. G. Lloyd and D. A. Davenport. Applying thermodynamics to fossil fuel. Journal of chemical education, 57:56–60, 1980. [199] J. Lovelock. Gaia: A new look at life on Earth. Oxford University Press, 1979. 445 [200] J. Lovelock. The revenge of Gaia: Why the Earth Is Fighting Back - and How We Can Still Save Humanity. Penguin Press, 2006. [201] M. Lozano. Metodología para el análisis exergético de calderas de vapor en centrales térmicas. PhD thesis, Universidad de Zaragoza, Septiembre 1989. [202] M. Lozano and A. Valero. Methodology for calculating exergy in chemical processes. In W. Wepfer, G. Tsatsaronis, and R. Bajura, editors, ASME. AES, volume 4, 1988. [203] P. Lujula. Classification of natural resources. In 2003 ECPR Joint Session of Workshops,, Edinburgh, UK, March 2003. Department of Economics. Norwegian University of Science and Technology, Dragvoll. NO-7491 Trondheim, Norway. [204] M. I. L’vovich. World Water Resources and their Future. LithoCrafters, Inc., Chelsea, Michigan, 1979. [205] D. Lynch. Standard free energy of formation of NiAs. Metallurgical and Materials Transactions B, 13(2):285–288, 1982. [206] T. R. Malthus. An Essay on the Principle of Population. Methuen and Co., Ltd. 1904. Ed. Edwin Cannan. Library of Economics and Liberty., 1798. Retrieved May 18, 2006 from the World Wide Web: http://www.econlib.org/library/Malthus/malPop1.html. [207] A. Martinez, A. Valero, A. Valero D., and I. Arauzo. Accounting the Earth’s mineral capital for the most demanded minerals in the industry. The case of bauxite, alumina and aluminium and limestone. In Biennial international workshop. Advances in energy studies, Porto Venere, Italy, 12-16 September 2006. [208] E. Martinot. Renewables. Global status report. 2006 update. Technical report, Renewable Energy Policy Network for the 21st Century, 2006. Online under: http://www.ren21.net/. [209] B. Mason. Principles of Geochemistry. Wiley, 3rd edition, 1966. [210] H. J. Massonne and Z. Szpurka. Thermodynamic properties of white micas on the basis of high-pressure experiments in the systems K2O-MgO-Al2O3SiO2-H2O and K2O-FeO-Al2O3-SiO2-H2O. Lithos 4, 1(1-3):229–250, 1997. [211] C. Masters, E. Attanasi, and D. Root. World petroleum assessment and analysis. In Proceedings of the 14th World Petroleum Congress, pages 1–13, Stavanger, Norway, 1994. John Wiley. [212] W. McDonough and S.-s. Sun. The composition of the earth. Chemical Geology, 120:223–253, 1995. 446 REFERENCES [213] O. P. Mchedlov-Petrossyan. The chemistry of Inorganic Building Materials. Moscow Stryizdat, 1971. [214] V. E. McKelvey. Mineral resources estimates and public policy. American Scientist, 60(1):32–40, 1972. [215] S. M. McLennan. Relationships between the trace element composition of sedimentary rocks and upper continental crust. Geochemistry geophysics geosystems, 2:2000GC000109, April 2001. [216] S. M. McLennan and S. R. Taylor. Heat flow and the chemical composition of continental crust. Journal of Geology, 104:369–377, 1996. [217] D. H. Meadows, D. L. Meadows, and J. Randers. Beyond the Limits: Confronting Global Collapse, Envisioning a Sustainable Future. Chelsea Green Publishing Company, 1993. [218] D. H. Meadows, D. L. Meadows, J. Randers, and W. W. Behrens. The Limits to Growth. Universe Books, 1972. [219] D. H. Meadows, J. Randers, and D. L. Meadows. Limits to Growth: The 30Year Update. Chelsea Green Publishing Company, White River Junction, Vt, 2004. [220] F. Melcher, T. Oberthür, and D. Rammlmair. Geochemical and mineralogical distribution of germanium in the Khusib Springs Cu-Zn-Pb-Ag sulfide deposit, Otavi Mountain Land, Namibia. Ore Geology Reviews, 28(1):32–56, 2006. [221] W. D. Menzie, D. A. Singer, and J. H. Deyoung. Scarcity and Growth Revisited, chapter Mineral Resources and Consumption in the Twenty-First Century, pages 33–53. Resources for the Future, 2005. [222] L. Merli and J. Fuger. Thermochemistry of selected lanthanide and actinide hydroxycarbonates and carbonates. Radiochim Acta, 74:37–43, 1996. [223] L. Merli, B. Lambert, and J. Fuger. Thermochemistry of lanthanum, neodymium, samarium and americium trihydroxides and their relation to the corresponding hydroxycarbonates. J Nucl Mater, 247:172–176, 1997. [224] F. Millero. Chemical Oceanography. CRC Press, 2nd edition, 1996. [225] F. Millero. Physical Chemistry of Natural Waters. Wiley-Interscience Series in Geochemistry, 2001. [226] K. Mills. Thermodynamic data for inorganic sulphides , selenides and tellurides. Butterworths, London, 1974. 447 [227] T. Miyano and N. J. Beukes. Physicochemical environments for the formation of quartz free manganese oxide ores from the early proterozoic formation Kalahari manganese field, South Africa. Econ. Geol., 82:706–718, 1987. [228] G. E. Moore. Structure and metamorphism of the Keene-Brattle-boro Area, New Hampshire-Vermont. Geoch. et Cosmoch. Acta, 65(12):2007–2016, 2001. [229] J. R. Moreira. Can Renewable Energy Make Important Contribution to GHG Atmospheric Stabilization? Third project workshop, LAMNET, Brasilia, Brazil, December 2002. [230] D. Morse and A. Glover. Events Affecting the U.S. Nonfuel Minerals Industry 1900-2000. Technical report, U.S. Geological Survey (USGS), 2000. http://minerals.usgs.gov/minerals/pubs/commodity/timeline/ 20th_century_review.pdf. [231] M. Mottl. Composition of seawater: Salinity of the major ions. Chemocal Oceanography (OC 623); www.soest.hawaii.edu. [232] G. M. Mudd. Sustainable mining: An evaluation of changing ore grades and waste volumes. In International Conference on Sustainability Engineering & Science. Auckland, New Zealand. 6-9 July, Auckland, New Zealand, 6-9 July 2004. [233] G. M. Mudd. The Sustainability of Mining in Australia: Key Production Trends and Their Environmental Implications. Joint research report, Mineral Policy Institute (MPI) and Department of Civil Engineering, Monash University, Australia, 2006. [234] G. M. Mudd. An analysis of historic production trends in Australian base metal mining. Ore Geology Reviews, 32(1-2):227–261, 2007. [235] W. Munk and C. Wunsch. Abyssal recipes II: energetics of tidal and wind mixing. Deep-Sea Research, Part I (Oceanographic Research Papers), 45(12):1977– 2010, 1998. [236] S. Murao, M. Deb, and M. Furuno. Mineralogical evolution of indium in high grade tin-polymetallic hydrothermal veins-A comparative study from Tosham, Haryana state, India and Goka, Naegi district, Japan. Ore Geology Reviews, 33(3-4):490–504, June 2008. [237] J. Naredo. La economía en evolución. Historia y perspectivas de características básicas del pensamiento económico. Ediciones Siglo XXI, Madrid, 1987. [238] J. Naredo. El final de la era del petróleo, chapter El conflicto entre eficacia y sostenibilidad utilizar el capital mineral de la tierra o el flujo solar y sus derivados renovables, pages 185–199. Icaria editorial, 2008. 448 REFERENCES [239] J. Naredo and A. Valero, editors. Desarrollo económico y deterioro ecológico. Fundación Argentaria, Madrid, 1999. [240] NASA. Surface meteorology and solar energy (release 5). Technical report, Earth Science Enterprise Program. NASA Langley Research Center, Langley, VA, 2004. Online under: http://eosweb.larc.nasa.gob/sse/. [241] G. B. Naumov, B. N. Ryzhenko, and I. L. Khodakovsky. Handbook of thermodynamic Data. Moscou Atomizdat, 1971. In Russian. [242] H. W. Nesbitt and G. M. Young. Prediction of some weathering trends of plutonic and volcanic rocks based on thermodynamic and kinetic considerations. Geochim. Cosmochim. Acta, 48(7):1523–1534, 1984. [243] H. E. Newson, K. W. W. Sims, P. D. Noll, W. L. Jaeger, S. A. Maehr, and T. B. Beserra. The depletion of tungsten in the bulk silicate earth: constraints on core formation. Geochim. Cosmochim. Acta, 60:1155–1169, 1996. [244] J. A. Ober. Industrial Minerals and Rocks, chapter Strontium minerals, pages 1003–1009. Society for Mining, Metallurgy, and Exploration, Inc., 6th edition, 1994. [245] H. Odum. System Ecology: An Introduction. John Wiley and Sons, New York, 1983. [246] H. T. Odum. Environmental Accounting. Emergy and Environmental Decision Making. John Wiley & Sons, inc., 1st edition, 1996. [247] OECD. Uranium 2003: resources, production and demand. Joint report, OECD Nuclear Energy Agency and the International Atomic Energy Agency, Paris, 2004. [248] OECD. Uranium 2005 - Resources, Production and Demand. Technical report, OECD Nuclear Energy Agency (NEA) and the IAEA, 2005. Online under: http://www.nea.fr/html/ndd/reports/ 2006/uranium2005-english.pdf. [249] OECD. Advanced nuclear fuel cycles and radioactive waste management. Number ISBN: 92-64-02485-9. OECD/NEA, 2006. [250] OGS. Statistical Summary. Overseas Geological Surveys, Various years (1956 - 1964). [251] R. K. O’Nions, N. M. Evensen, and P. J. Hamilton. Geochemical modeling of mantle differentiation and crustal growth. J. Geophys. Res., 84:6091–6101, 1979. [252] Oroya. Third qarter activities and cash flow report for the period ended 31 march 2006. Technical report, Oroya Mining Limited, 2006. Online under: http://www.oroya.com.au. 449 [253] A. Ortiz. Desarrollo económico y deterioro ecológico, chapter Cuantificación de la extracción de rocas y minerales de la corteza terrestre, pages 103–154. Fundación Argentaria, 1999. [254] G. Ottonello. Principles of geochemistry. Columbia University Press, New York, 1997. [255] G. Ottonello, A. Della G., A. Dal. N., and F. Baccaarin. Thermodynamic Data, chapter A structure Energy model for C2/c Pyroxenes in the system Na-MgCa-Mn-Fe-Al-Cr-Ti-Si-O, pages 194–238. Springer Verlag, 1990. [256] S. Pacala and R. Socolow. Stabilization wedges: Solving the climate problem for the next 50 years with current technologies. Science, 305:968–972, 2004. [257] W. S. B. Paterson. The Physics of Glaciers. Pergamon, Oxford, 3rd edition, 1994. [258] R. Perry and C. Chilton. Manual del Ingeniero Químico. McGraw-Hill de México, México, 2nd edition, 1992. [259] R. Perry and D. Green, editors. Perry’s Chemical Engineers Handbook. McGraw Hill, New York, 1984. [260] W. C. Peters. Exploration and mining geology. John Wiley and Sons, 1978. [261] C. Philibert. Case study 1: concentrating solar power technologies. International energy technology collaboration and climate change mitigation, OECD Environmental Directorate, International Energy Agency, Paris, 2004. [262] A. Philpotts. Igneous and Metamorphic Petrology. Prentice Hall, Englewood Cliffs, 1990. [263] M. Pidwirny. Fundamentals of physical geography. Online under: http://www.physicalgeography.net/fundamentals/contents.html, 2006. [264] M. Pilson. An Introduction to the Chemistry of the Sea. Prentice Hall, New Jersey, 1998. [265] G. Pinaev. Standard reference exergies of chemical elements in the oceanic reference medium. I. Consideration of modern hydrochemical data on the concentrations of elements in the oceanic medium and the deviation of their reactivity from the neutral one. Journal of Engineering Physics and Thermophysics, 79(5):1028–1038, 2006. [266] G. Pinaev. Standard reference exergies of chemical elements in the oceanic reference medium. II. Estimation of the equilibrium of ecospecies in the oceanic medium. Journal of Engineering Physics and Thermophysics, 79(5):1039– 1049, 2006. 450 REFERENCES [267] T. Plank and C. Langmuir. The geochemical composition of subducting sediment and its consequences for the crust and mantle. Chemical Geology, 145:325–394, 1998. [268] A. Polanski and K. Smulikowski. Geochemia. Wydawnictwa Geologicne, Warsaw, 1969. In Polish. [269] L. D. Polyachenok, K. Nasarov, and O. G. Polyachenok. The interaction of scandium trichloride with quartz. Russ. J. Phys. Chem., 52:1021–1022, 1978. [270] W. M. Post, T. Peng, W. R. Emanuel, A. W. King, V. H. Dale, and D. L. DeAngelis. The global carbon cycle. American Scientist, 78(310-326), 1990. [271] R. Prinn, R. Weiss, P. Fraser, P. Simmonds, D. Cunnold, F. Alyea, S. O’Doherty, P. Salameh, B. Miller, J. Huang, R. Wang, D. Hartley, C. Harth, L. Steele, G. Sturrock, P. Midgley, and A. McColloch. A history of chemically and radiatively important gases in air deduced from ale/gage/agage. J. Geophys. Res., 105:17751–17792, 2000. [272] R. G. Prinn. Treatise on Geochemistry, volume 4, chapter Ozone, Hydroxyl Radical, and Oxidative Capacity, pages 1–19. Elservier Pergamon, 2004. [273] M. S. Quinby-Hunt and K. K. Turekian. Distribution of elements in sea water. EOS Trans, AGU 64:130–132, 1983. [274] S. Rahmstorf. Encyclopedia of Quaternary Sciences, chapter Thermohaline Ocean Circulation. Elsevier, Amsterdam, 2006. [275] Z. Rant. Zur Bestimmung der spezifischen Exergie von Brennstoffen. Allgem. Waermetechn., 10(172-176), 1961. In German. [276] L. Ranz. Análisis de los costes exergéticos de la riqueza mineral terrestre. Su aplicación para la gestión de la sostenibilidad. PhD thesis, Universidad de Zaragoza, Abril 1999. [277] D. Reynolds. The mineral economy. How prices and costs can falsely signal decreasing scarcity. Ecological Economics, 31:155–166, 1999. [278] L. Riekert. The efficiency of energy utilization in chemical processes. Chem. Eng. Sci, 29:1613–1620, 1974. [279] S. Ringen, J. Lanum, and F. P. Miknis. Calculating heating values from elemental composition of fossil fuels. Fuel, 58(69-71), 1979. [280] A. E. Ringwood. Advances in Earth Sciences, chapter The chemical composition and origin of the earth, pages 287–356. MIT Press, 1966. 451 [281] R. Rivero and M. Garfias. Standard Chemical Exergy Updated. Part II. In R. Rivero, L. Monroy, R. Pulido, and G. Tsatsaronis, editors, Energy-Efficient, Cost-Effective, and Environmentally-Sustainable Systems and Processes, volume 2, pages 773–785, 2004. [282] R. Rivero, G. Montero, and M. Garfias. The effect of environmental temperature on the chemical exergy of hydrocarbons. In Proceedings of ECOS 2002, volume 1, pages 69–78, Berlin, 3-5 July 2002. [283] F. Roberts and I. Torrens. Analysis of the life cycle of non-ferrous minerals. Resources Policy, pages 14–28, 1974. [284] R. A. Robie and B. S. Hemingway. Thermodynamic properties of minerals and related substances at 298.15 K and 1 bar (105 Pascals) pressure and higher temperature. U.S. Geological Survey Bulletin 2131, 1995. [285] R. A. Robie, B. S. Hemingway, and J. R. Fisher. Thermodynamic properties of minerals and related substances at 298.15 K and 1 bar (105 Pascals) pressure and at higher temperatures. U.S. Geological Survey Bulletin 1452, 1978. [286] D. H. Roemmich and C. Wunsch. Two transatlantic sections: Meridional circulation and heat flux in the subtropical North Atlantic Ocean. Deep Sea Research, 32:619–664, 1985. [287] A. B. Ronov and A. A. Yaroshevsky. Earth’s Crust and Upper Mantle, chapter Chemical Composition of the Earth’s Crust. American Geophysical Union, Washington D.C., 1969. [288] A. B. Ronov, A. A. Yaroshevsky, and A. A. Migdisov. Chemical structure of the earth’s crust and geochemical balance of the major elements. M. Nauka, Moscow, 1990. [289] M. Rosen. Can exergy help us understand and address environmental concerns? Exergy, 2:214–217, 2002. [290] M. Rosen. Energy, culture and standard of life. Theories and Practices for Energy Education, Training, Regulation and Standards, from Encyclopedia of Life Support Systems (EOLSS), Developed under the Auspices of the UNESCO. Eolss Publishers, Oxford ,UK, [http://www.eolss.net], Retrieved May 19, 2005. [291] R. L. Rudnick. Nature and composition of the continental crust: a lower crustal perspective. Reviews of Geophysics, 33(3):267–309, August 1995. [292] R. L. Rudnick and S. Gao. Treatise on Geochemistry. The Crust, volume 3, chapter Composition of the Continental Crust, pages 1–64. Elsevier Pergamon, 2004. 452 REFERENCES [293] C. Ruoyu, L. Jun, X. Shuping, and G. Shiyang. Thermochemistry of ulexite. Thermochimica Acta, 306(1-2):1–5, 1997. [294] M. Ruth. Integrating Economics, Ecology and Thermodynamics, volume 3 of Ecology, Economy & Environment. Kluwer Academic Publishers, 1993. [295] M. Ruth. Thermodynamic constraints on optimal depletion of copper and aluminum in the United States: a dynamic model of substitution and technical change. Ecological Economics, 15:197–213, 1995. [296] R. Sadourny. Global Change of Planet Earth, chapter Modelling the Physical Ocean-Atmosphere System and Its Response to External Radiative Perturbations. OECD, 1994. [297] R. N. Schock. Energy Technologies for the 21st Century. The Roles of Renewable Energy. In World Federation of Scientists International Seminars on Planetary Emergencies, Erice, Italy, August, 20-23 2005. Center for Global Security Research, Lawrence Livermore National Laboratory, University of California. [298] R. D. Schuiling, L. Vergouwen, and H. Van d. Rijst. Gibbs energies of formation of zircon (ZrSiO4), thorite (ThSiO4), and phenacite (Be2SiO4). Amer. Mineralogist, 61:161–168, 1976. [299] E. Sciubba. Cost analysis of energy conversion systems via a novel resourcebased quantifier. Energy, 28:457–477, 2003. [300] E. Sciubba. Extended exergy accounting applied to energy recovery from waste: The concept of total recycling. Energy, 28:1315–1334, 2003. [301] D. M. Scotford. Petrology of the Cincinnatian Series. Shales and Environmental Implication. Geol. Soc. Am. Bull., 76(2):193–222, 1965. [302] A. Scott and P. Pearse. Natural resources in a high-tech economy. Resources Policy, pages 154–166, September 1992. [303] R. R. I. Seal, E. J. Essene, and W. C. Kelly. Tetrahedrite and tennantite: Evaluation of thermodynamic data and phase equilibria. Canadian Mineralogist, 28(725-738), 1990. [304] E. Serova and V. Brodianski. The concept "environment" in exergy analysis (some special cases). In Proceedings of ECOS 2002, volume 1, pages 79–82, Berlin, 2002. [305] F. Seymour and S. Zadek. Accountability Forum Issue 9, chapter Governing Energy: The Global Energy Challenge, pages 6–15. Greenleaf Publishing and Accountability, 2006. 453 [306] D. Shaw, G. Reilly, J. Muysson, G. Pattenden, and F. Campbell. An estimate of the chemical composition of the Canadian Precambrian shield. Can. J. Earth Sci., 4:829–853, 1967. [307] D. M. Shaw, A. P. Dickin, H. Li, R. H. McNutt, H. P. Scharcz, and M. G. Truscott. Crustal geochemistry in the Wawa-Foleyet region, Ontario. Can. J. Earth Sci, 31:1104–1121, 1994. [308] D. M. Shaw, J. Dostal, and R. R. Keays. Additional estimates of continental surface Precambrian shield composition in Canada. Geochim. Cosmoch. Acta, 40:73–83, 1976. [309] P. F. Shi, S. K. Saxena, and B. Sundman. Sublattice solid solution model and its application to orthopyroxene (Mg,Fe)Si2O6. Phys. Chem. Miner., 18(6):393– 405, 1992. [310] J. Shieh and L. Fan. Estimation of energy (enthalpy) and exergy (availability) contents in structurally complicated materials. Energy Sources, 6(1):1–46, 1982. [311] I. A. Shiklomanov. World Water Resources: Modern Assessment and Outlook for 21-st Century. Federal Service of Rusia for Hidrometeorology & Environment Monitoring. State Hydrological Institute, St. Peterburg, 1999. [312] Y. Shvarov, M. Borisov, D. Grichuk, and E. Bastrakov. Default unitherm database for the hch package for geochemical modelling. Unpublished computer file, 1999. [313] J. L. Simon. The Ultimate Resource 2. Princeton University Press, 1998. [314] K. W. W. Sims, H. E. Newson, and E. S. Gladney. Origin of the Earth, chapter Chemical fractionation during formation of the Earth’s core and continental crust: clues from As, Sb, W and M., and In., pages 291–317. Oxford University Press, Oxford, 1990. [315] C. Skidmore. Zirconium and Hafnium (chapter). In Mining Journal Review. Technical report, Minor Metals Trade Association, 2006. Online under: http://www.mmta.co.uk/economicsFacts/miningJournalReview.aspx. [316] B. J. Skinner. A second iron age ahead? May-June 1976. American Scientist, 64:258–269, [317] B. J. Skinner. Earth resources. Prentice-Hall, London, 1986. [318] B. J. Skinner, S. C. Porter, and D. B. Botkin. The Blue Planet. An introduction to earth system science. Wiley, 2nd edition edition, 1999. 454 REFERENCES [319] W. Slough and G. P. Jones. A compilation of thermodynamic data for borate systems. Technical report, National Physics Laboratory Division Chemical Standards, 1974. [320] E. A. Smelik, D. M. Jenkins, and A. Navrotsky. A calorimetric study of synthetic amphiboles along the tremolite-tschermakite join and the heats of formation of magnesiohorneblende and tschermakite. Amer Mineral, 79(12):1110–1122, 1994. [321] A. Smith. An Inquiry into the Nature and Causes of the Wealth of Nations. Methuen and Co., Ltd. 1904. Ed. Edwin Cannan. Library of Economics and Liberty., 1904. Retrieved May 18, 2006 from the World Wide Web: http://www.econlib.org/LIBRARY/Smith/smWN4.html. [322] J. V. Smith. Mineralogy of the planets: a voyage in space and time. Mineral. Mag., 43(1-89), 1979. [323] L. K. Smith and W. J. Bruckard. The separation of arsenic from copper in a northparkes copper-gold ore using controlled-potential flotation. International Journal of Mineral Processing, 2007. Article in Press. [324] N. Smith and G. Robinson. Technology pushes reserves "crunch" date back in time. Oil and Gas Journal, pages 43–50, April 7 1997. [325] V. K. Smith, editor. Scarcity and Growth Reconsidered. John Hopkins University Press for Resources for the Future, 1979. [326] R. Solow. The economics of resources or the resources of economics. American Economic Review, 66:1–114, 1974. [327] J. A. Souza-Neto, P. H. Sonnet, J. M. Legrand, and M. Volfinger. The Bonfim W-Au-Bi-Te Skarn deposit, northeastern Brazil: a polymetallic ore revealed by emp and pixe analyses. Technical report, Universidad Federal de Pernambuco, retrieved 17 July 2007. Online under: http://www.ufpe.br/geologia/docentes/publicacoes/. [328] W. Stanek. Thermo-ecology analysis of the influence of mettalurgy upon the depletion of non-renewable natural resources. In L. Rivero, L. Monroy, R. Pulido, and G. Tsatsaronis, editors, Energy-Efficient, Cost-Effective, and Environmentally-Sustainable Systems and Proceses. Instituto Mexicano del Petróleo, 2004. [329] H. Staudigel, F. Albarède, J. Blichert-Toft, J. Edmond, B. McDonough, S. Jacobsen, R. Keeling, C. H. Langmuir, R. Nielsen, T. Plank, R. Rudnick, H. F. Shaw, S. Shirey, J. Veizer, and W. White. Geochemical Earth Reference Model (GERM): description of the initiative. Chemical Geology, 134:515–526, 1998. 455 [330] V. Stepanov. Chemical energies and exergies of fuels. Energy, 20(3):235–242, 1995. [331] A. N. Strahler. Physical Geography. John Wiley and Sons, Inc., 4th edition, 1975. [332] M. Sussman. Choosing a reference environment-state for available-energy computations. In 72nd Annual Meeting. American Institute of Chemical Engineers, San Francisco (USA), November 1979. [333] J. Szargut. Energy potential balance in chemical processes. Archiwum Budowy Maszyn, 4(11):89–117, 1957. In Polish. [334] J. Szargut. Exergy balance of metallurgical processes. Archiwum Hutnictwa, 6(1):23–60, 1961. In Polish. [335] J. Szargut. Standard chemical exergy of some elements and their compounds, based upon te concentration in earth’s crust. Geochemistry International, 35(1-2):53–60, 1987. [336] J. Szargut. Chemical exergies of the elements. Applied Energy, 32:269–286, 1989. [337] J. Szargut. Anthropogenic and natural exergy losses (exergy balance of the earth’s surface and atmosphere). Energy, 28:1047–1054, 2003. [338] J. Szargut. Exergy method: technical and ecological applications. WIT-press, Ashurst, UK, 2005. [339] J. Szargut. Global implications of the second law of thermodynamics. Exergy, Energy System Analysis, and Optimization., from Encyclopedia of Life Support Systems (EOLSS), Developed under the Auspices of the UNESCO Eolss Publishers, Oxford, UK; Online encyclopedia: http://www.eolss.net, Retrieved May 19, 2005. [340] J. Szargut and D. Morris. Calculation of standard chemical exergy of some elements and their compounds based upon seawater as the datum level substance. Bulletin of the Polish Academy of Sciences. Techical Sciences., 33(56):293–305, 1985. [341] J. Szargut, D. Morris, and F. Steward. Exergy analysis of thermal, chemical, and metallurgical processes. Hemisphere Publishing Corporation, 1988. [342] J. Szargut and T. Styrylska. Approximate evaluation of the exergy of fuels. Brennst. Waerme Kraft, 16(12):589–596, 1964. In German. [343] J. Szargut, A. Valero, W. Stanek, and A. Valero D. Towards an international legal reference environment. In Proceedings of ECOS 2005, pages 409–420, Trondheim, Norway, June 2005. 456 REFERENCES [344] J. Szargut, A. Ziebik, and W. Stanek. Depletion of the non-renewable natural exergy resources as a measure of the ecological cost. Energy Conversion and Management, (43):1149–1163, 2002. [345] I. V. Tananaev, V. P. Orlovskii, K. M. Kourbanov, B. S. Khalikov, S. O. Osmanov, and V. I. Bulgakov. Evolution of the enthalpy at 298K and entropy at 298K of scandium, yttrium and lanthanide orthophosphates. Doklady Akademia Nauk Tadzhirghistan S.S.S.R, 17(42-44), 1974. [346] E. J. Tarbuck and F. K. Lutgens. The Earth. An introduction to physical geology. Charles E. Merrill, 1984. [347] Y. Tardy. Relationship among Gibbs energies of formation of compounds. Amer. Jour. Sci., 279:217–224, 1979. Referencia del libro Ottonello1997. [348] Y. Tardy and R. M. Garrels. A method of estimating the Gibbs energies of formation of layer silicates. Geochim. Cosmochim. Acta, 38:1101–1116, 1974. [349] Y. Tardy and R. M. Garrels. Prediction of Gibbs energies of formation: IRelationships among Gibbs energies of formation of hydroxides, oxides and aqueous ions. Geochim. Cosmochim. Acta, 40:1015–1056, 1976. [350] Y. Tardy and R. M. Garrels. Prediction of Gibbs energies of formation of compounds from the elements, II: Monovalent and divalent metal silicates. Geochim. Cosmochim. Acta, 41:87–92, 1977. [351] Y. Tardy and L. Gartner. Relationships among Gibbs energies of formation of sulfates, nitrates, carbonates, oxides and aqueous ions. Contrib. Mineral. Petrol., 63:89–102, 1977. [352] Y. Tardy and P. Viellard. Relationships among Gibbs energies of formation of phosphates, oxides and aqueous ions. Contrib. Mineral. Petrol., 63:75–88, 1977. [353] S. Taylor and S. McLennan. The Continental Crust: Its Composition and Evolution. Blackwell, London, 1985. [354] S. Taylor and S. McLennan. The geochemical evolution of the continental crust. Rev. Geophys., 33:241–265, 1995. [355] F. Teng, W. F. McDonough, R. L. Rudnick, C. Dalpé, P. B. Tomascak, B. W. Chapell, and S. Gao. Lithium isotopic composition and concentration of the upper continental crust. Geochim. Cosmoch. Acta, 68(20):4167–4178, October 2004. [356] T. B. Thomson. Geology and uranium-thorium mineral deposits of the Bokan Mountain Granite Complex, southeastern Alaska. Ore Geology Reviews, 3(13):193–210, April 1998. 457 [357] M. Tranter. Treatise on Geochemistry, volume 5, chapter Geochemical Weathering in Glacial and Proglacial Environments, pages 189–205. Elsevier Pergamon, 2004. [358] D. L. Turcotte. A fractal approach to the relationship between ore grade and tonnage. Economic Geology and the Bulletin of the Society of Economic Geologists, 81(6):1528–1532, October 1986. [359] K. K. Turekian. Handbook of Geochemistry, volume 1, chapter The Oceans, Streams, and Atmosphere, pages 297–320. Springer-Verlag, Berlin, 1969. [360] USGS. United states geological survey fact sheet. Fact sheet, United States Geological Survey, December, 2 2004. Online under: http://marine.usgs.gov/fact40sheets/gas-hydrates/title.html. [361] USGS. Historical statistics for mineral and material commodities in the United States. Report, US Geological Survey, 2006. Online under: http://minerals.usgs.gov/ds/2005/140/. [362] USGS. Mineral commodity summaries. Technical report, US Geological Survey, 2007. Online under: http://minerals.usgs.gov/minerals/pubs/mcs. [363] USGS. Minerals yearbook. Technical report, USGS, Various years. Online under: http:minerals.usgs.gov/minerals/pubs/myb.html/. [364] S. Ushakov, K. Helean, A. Navrotsky, and L. Boatner. Thermochemistry of rare-earth orthophosphates. Journal of Materials Research, 16(9):2623–2633, 2001. [365] A. Valero. Thermoeconomics as a conceptual basis for energy-ecological analysis. In S. Ulgiati, editor, Advances in Energy Studies. Energy Flows in Ecology and Economy, pages 415–444, Musis, Roma, 1998. [366] A. Valero and I. Arauzo. Exergy outcomes associated with the greenhouse effects. In G. Reistad, M. Moran, W. Wepfer, and N. Lior, editors, AES, Second Analysis-Industrial and Environmental Applications, volume 25, pages 63–70. The American Society of Mechanical Engineers, 1991. [367] A. Valero and E. Botero. An assessment of the earth’s clean fossil exergy capital based on exergy abatement costs. Energy System Analysis, and Optimization., from Encyclopedia of Life Support Systems (EOLSS), Developed under the Auspices of the UNESCO. [368] A. Valero, E. Botero, and A. Valero D. Exergy accounting of natural resources. Exergy, Energy System Analysis, and Optimization., from Encyclopedia of Life Support Systems (EOLSS), Developed under the Auspices of the UNESCO Eolss Publishers, Oxford, UK; Online encyclopedia: http://www.eolss.net, Retrieved May 19, 2005. 458 REFERENCES [369] A. Valero and M. Lozano. Curso de Termoeconomía. Universidad de Zaragoza, 1994. [370] A. Valero, M. Lozano, and M. Muñoz. A general theory of exergy saving. I. On the exergetic cost. In R. Gaggioli, editor, Computer-Aided Engineering and Energy Systems. Second Law Analysis and Modelling, volume 3, pages 1–8, 1986. [371] A. Valero, L. Ranz, and E. Botero. Exergetic Evaluation of Natural Mineral Capital (1) Reference Environment Methodology. In G. Tsatsaronis, M. Moran, F. Cziesla, and T. Bruckner, editors, ECOS 2002, volume 1, pages 54–61, Berlin, July 2002. [372] A. Valero, J. Uche, A. Valero D., A. Martínez, and J. Escriu. Physical Hydronomics: application of the exergy analysis to the assessment of environmental costs of water bodies. The case of the Inland Basins of Catalonia. In Proceedings of ECOS 2007, volume I, pages 683–692, 2007. [373] A. Valero, A. Valero D., and C. Torres. Exergy and the Hubbert peak. An extended analysis for the assessment of the scarcity of minerals on earth. In Proceedings of IMECE 2008, Boston, USA, 31 October - 6 November 2008. ASME. [374] A. Valero D. Assessing world mineral deposits through the second law of thermodynamics. In Inproceedings of the Mineral Deposit Studies Group (MDSG) conference, Nottingham (UK), 2-4 January 2008. [375] A. Valero D., A. Valero, and I. Arauzo. Exergy as an indicator for resources scarcity. The exergy loss of Australian mineral capital, a case study. In Proceedings of IMECE2006, Chicago, USA, 5-10 November 2006. ASME. [376] A. Valero D., A. Valero, and I. Arauzo. Evolution of the decrease in mineral exergy throughout the 20th century. The case of copper in the US. Energy, 33(2):107–115, 2008. [377] A. Valero D., A. Valero, and A. Martinez. Exergy evaluation of the mineral capital on Earth. Influence of the reference environment. In Proceedings of IMECE 2005, Orlando, USA, 5-11 November 2005. ASME. [378] A. Valero D., A. Valero, A. Martínez, and G. Mudd. A physical way to assess the decrease of mineral capital through exergy. The Australian case. In Proceedings of ISEE 2006, New Delhi, India, 15-18 December 2006. Ninth Biennial Conference on the International Society for Ecological Economics (ISEE). “Ecological Sustainability and Human Well-being”. [379] W. van Gool. Thermodynamics of chemical references for exergy analysis. Energy Conversion and Management, 39(16-18):1719–1728, 1998. 459 [380] P. Vieillard. Modèle de calcul des énergies de formation des mineraux bati sur la connaisance affinée des structures cristallines. CNRS Memoirs 69, Université Louis Pasteur, Strasbourg, 1982. [381] P. Vieillard. Prediction of enthalpy of formation based on refined cyrstal structures of multisite compounds. 1. Theories and examples. Geochimica et Cosmochimica Acta, 58:4049–4063, 1994. [382] P. Vieillard. A new method for the prediction of Gibbs free energies of formation of hydrated clay minerals base on the electronegativity scale. Clays & Clay Minerals, 48(4):459–473, 2000. [383] P. Vieillard. A new method for the prediction of Gibbs free energies of formation of phyllosilicates (10 A and 14 A) based on the electronegativity scale. Clays and Clay Minerals, 50(3):352–363, 2002. [384] P. Vieillard and H. D. B. Jenkins. Empirical relationships for estimation of enthalpies of formation of simples hydrates. Part 2. Hydrates of alkaline-earth metal cations. Journal Chemical Research (Synopsis), pages 446–447, 1986. [385] P. Vieillard and H. D. B. Jenkins. Empirical relationships for estimation of enthalpies of formation of simples hydrates. Part 3. Hydrates of transitionmetal cations (C r 2+ , Fe2+ , C o2+ , N i 2+ , Cu2+ , Z n2+ , C d 2+ and UO22+ ). Journal Chemical Research (Synopsis), pages 448–449, 1986. [386] P. Vieillard and H. D. B. Jenkins. Empirical relationships for estimation of enthalpies of formation of simples hydrates. Part I Hydrates of alkali- metal cations, of hydrogen and of monovalent cations. Journal Chemical Research (Synopsis), pages 444–445, 1986. [387] P. Vieillard, L. Richard, and M. Boiron. Prediction of enthalpies of formation of sulfides and sulfosalts minerals. In Colloque Bilan et prospective de GDR Transmet, Nancy, 6-7 juillet 2006, 2006. [388] P. Vieillard and Y. Tardy. Phosphate Minerals, chapter Thermochemical properties of phosphates. Springer Verlag, New York, 1984. [389] P. Vieillard and Y. Tardy. Estimation of enthalpies of formation of minerals based on their refined crystal structures. American Journal of Science, 288:997–1040, 1988. [390] P. Vieillard and Y. Tardy. Prediction of enthalpy of formation based on refined crystal structures of multisite compounds. 2. Application to minerals belonging to the system Li2 O − N a2 O − K2 O − BeO − M gO − C aO − M nOFeO − Fe2 O3 − Al2 O3 − SiO2 − H2 O. Results and discussion. Geochimica et Cosmochimica Acta, 58(4064-4107), 1994. 460 REFERENCES [391] D. Wagman, H. William, V. Parker, R. Schumm, I. Halow, S. Bailey, K. Churney, and R. Nuttall. The NBS tables of chemical thermodynamic properties: Selected values for inorganic and C1 and C2 organic substances in SI units. American Chemical Society and the American Institute of Physics for the National Bureau of Standards, New York, 1982. [392] G. Wall. Exergy - a useful concept within resource accounting. report 77-42, Institute of Theoretical Physics, Göteborg, 1977. [393] G. Wall. Exergetics. Eolss Publishers, Oxford ,UK, [http://www.eolss.net], Retrieved May 19, 2005. [394] G. Wall. National exergy accounting of natural resources. Eolss Publishers, Oxford, UK, [http://www.eolss.net], Retrieved May 19, 2005. [395] G. Wall and M. Gong. On exergy and sustainable development-part 1: Conditions and concepts. Exergy Int. J., 1(3):128–145, 2001. [396] W. Wang and R. X. Huang. Wind energy input to the surface waves. Journal of Physical Oceanography, 34(5):1276–1280, 2004. [397] J. Watson. Inside the earth. Technical report, USGS, 1999. Online under: http://pubs.usgs.gov/publications/text/inside.html. [398] WCED. Our Common Future (The Brundtland Report). Oxford University Press, 1987. [399] R. Weast, editor. CRC Handbook of Chemistry and Physics. CRC Press, 1975. [400] R. C. Weast, W. J. Astle, and W. H. Beyer. CRC Handbook of Chemistry and Physics. CRC Press, 1986. [401] WEC. Survey of energy resources 2007. Technical report, World Energy Council, 2007. Online under: http://www.worldenergy.org/publica tions/ survey_of_energy_resources_2007/ default.asp. [402] K. H. Wedepohl, editor. Handbook of Geochemistry, volume 1. Springer-Verlag, Berlin, 1969. [403] K. H. Wedepohl. Geochemistry. Holt, Rinehart and Winston, Inc., 1971. [404] K. H. Wedepohl. The composition of the continental crust. Geochimica et Cosmochimica Acta, 59(7):1217–1232, 1995. [405] D. E. White, J. D. Hem, and G. A. Waring. Data of Geochemistry, chapter Chemical composition of sub-surface waters. Bull. 440-F. U.S. Geological Survey, 6th edition, 1963. 461 [406] M. J. Wilhelm and K. C. Williams. Industrial Minerals and Rocks, chapter Bromine Resources, pages 187–189. Society for Mining, Metallurgy, and Exploration, Inc., 1994. [407] S. C. Williams-Stroud, J. P. Searls, and R. J. Hite. Industrial Minerals and Rocks, chapter Potash resources, pages 783–802. Society for Mining, Metallurgy, and Exploration, Inc., 6th edition, 1994. [408] WNA. World uranium mining. Technical report, World Nuclear Association, 2007. Online under: http://www.world-nuclear.org/info/inf23.html. [409] T. J. Wolery and S. A. Daveler. A software package for geochemical modeling of aqueous systems. Lawrence Livermore National Laboratory, 1992. [410] WRI. World resources 2000-2001. World Resources Institute, Washington, DC, 2000. [411] C. Yoder. Global Earth Physics: A handbook of physical constants, chapter Astrometic and geodetic properties of the Earth and Solar system, pages 1– 31. Amercian geophysical union, 1995. [412] A. Zaleta, L. Ranz, and A. Valero. Towards a unified measure of renewable resources availability: the exergy method applied to the water of a river. Energy Conversion and Management, 39(16-18):1911–1917, 1998. [413] F. Zelenik and S. Gordon. Simultaneous least-square approximation of a function and its first integrals with application to thermodynamic data. Technical Report TN D-767, NASA, 1961. [414] J. Zwartendyk, P. Abelson, H. Baumann, J. Clark, M. Dalheimer, J. Darmstadter, P. Demeny, R. Gordon, D. Harris, H. Krupp, J. Tilton, and F. Wiedenbein. Resources and World Development, chapter Human factors influencing resource availability and use, pages 532–546. John Wiley and Sons Limited, 1987.
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