Cement Production in Vertical Shaft Kilns in China Status and Opportunities for Improvement Report to the United Nations Industrial Development Organization UNIDO Contract RB-308-D40-8213110-2005 31 January 2006 Page 2 of 189 Table of content Table of content ........................................................................................................................... 2 Acronyms and abbreviations........................................................................................................ 5 Glossary ......................................................................................................................... 10 Executive summary ..................................................................................................................... 12 1. Introduction ......................................................................................................................... 17 1.1 Objective of this study ................................................................................................... 22 2. Cement production .............................................................................................................. 23 2.1 Main processes ............................................................................................................... 23 2.1.1 Quarrying ........................................................................................................ 24 2.1.2 Raw materials preparation .............................................................................. 25 2.1.3 Fuels preparation............................................................................................. 25 2.1.4 Clinker Burning............................................................................................... 27 2.1.5 Cement grinding.............................................................................................. 28 2.1.6 Mineral additions preparation ......................................................................... 29 2.1.7 Cement dispatch.............................................................................................. 29 2.2 Material characteristics .................................................................................................. 30 2.2.1 Main clinker phases ........................................................................................ 30 2.2.2 Raw mix components...................................................................................... 32 2.2.3 Fuels ................................................................................................................ 32 2.2.4 Cement constituents ........................................................................................ 33 2.3 The four main process routes in rotary kiln cement production .................................... 33 2.3.1 The dry process ............................................................................................... 34 2.3.2 The semi-dry process ...................................................................................... 36 2.3.3 The semi-wet process...................................................................................... 38 2.3.4 The wet process............................................................................................... 39 2.3.5 Circulating elements ....................................................................................... 39 2.3.6 Clinker coolers ................................................................................................ 41 2.3.7 Operating characteristics rotary kilns - a summary ........................................ 42 2.4 Cement production using Vertical Shaft Kilns .............................................................. 43 2.4.1 Black meal process.......................................................................................... 44 2.4.2 Process conditions and quality aspects ........................................................... 49 3. Environmental significance of cement production ........................................................... 54 3.1 Dust ......................................................................................................................... 54 3.2 Gaseous atmospheric emissions..................................................................................... 55 3.2.1 Carbon dioxide................................................................................................ 56 3.2.2 Nitrogen oxides ............................................................................................... 56 3.2.3 Sulfur oxides ................................................................................................... 57 3.2.4 Organic compounds ........................................................................................ 59 3.3 PCDD/F emissions ......................................................................................................... 60 3.3.1 Trace elements ................................................................................................ 62 3.4 Other emissions.............................................................................................................. 64 3.5 Normal emission levels from rotary kilns...................................................................... 64 3.6 Air pollution control in cement production.................................................................... 65 3.6.1 Inherent "scrubbing" of exit gases in preheater kiln ....................................... 72 Kåre Helge Karstensen [email protected] Page 3 of 189 3.6.2 Emission control in VSKs............................................................................... 73 4. Resource consumption in cement production ................................................................... 76 4.1 Consumption of raw materials ....................................................................................... 77 4.2 Consumption of energy .................................................................................................. 77 4.3 Options for resource reduction....................................................................................... 79 4.3.1 Use of energy .................................................................................................. 80 4.4 Utilisation of alternative fuels and raw materials in modern cement production .......... 81 5. Cement production in China - general challenges............................................................ 86 5.1 Production ...................................................................................................................... 86 5.2 Geographic location ....................................................................................................... 88 5.3 Raw material consumption............................................................................................. 88 5.4 Energy consumption....................................................................................................... 89 5.5 Emissions ....................................................................................................................... 90 5.6 Comparison of performance........................................................................................... 91 5.7 Health and Safety ........................................................................................................... 93 5.8 Efficiency - a summary .................................................................................................. 94 6. Cement production in China - general opportunities for improvement ....................... 95 6.1 Policy and regulation...................................................................................................... 95 6.1.1 Environmental regulation of the Chinese cement industry............................. 96 6.1.2 Enforcement .................................................................................................... 98 6.1.3 Emissions of persistent organic pollutants POPs............................................ 99 6.2 Technology development ............................................................................................. 102 6.2.1 Best available techniques (BAT) .................................................................. 103 6.2.2 Best available techniques and best environmental practise for controlling and minimising PCDD/F emission............................................................................... 105 6.3 Cleaner production opportunities................................................................................. 106 6.3.1 Emission reduction........................................................................................ 106 6.3.2 Water pollution and dust recovery ................................................................ 108 6.3.3 Energy consumption ..................................................................................... 109 6.3.4 Health and safety........................................................................................... 110 6.3.5 Impacts on land use....................................................................................... 111 6.3.6 Communication............................................................................................. 112 7. Vertical Shaft Kilns ........................................................................................................... 113 7.1 Centralised close-down policy ..................................................................................... 113 7.2 Replacement of VSKs by a combination of market forces and regulation .................. 114 7.2.1 Key economic indicators for VSKs .............................................................. 115 7.3 Demonstration projects for VSK improvement ........................................................... 116 7.3.1 Suggested activities in a VSK demonstration project................................... 120 7.3.2 Exit gas sampling and chemical analysis...................................................... 123 8. Conclusion ....................................................................................................................... 125 9. References and bibliography ............................................................................................ 127 Annex 1 Demonstration project - Improvement of environmental performance and energy efficiency in Vertical Shaft Kilns................................................................................. 137 Annex 2 Emission Standard of Air Pollutants for the ........................................................... 144 Cement Industry in China........................................................................................................ 144 Annex 3 Chinese companies providing equipment to the cement industry ......................... 162 Kåre Helge Karstensen [email protected] Page 4 of 189 Annex 4 Chinese research institutes providing service to the cement industry .................. 178 Kåre Helge Karstensen [email protected] Page 5 of 189 Acronyms and abbreviations AFR Alternative fuel and raw material APCD Air pollution control device ATSDR Agency for Toxic Substances and Disease Registry AWFCO Automatic waste feed cut-off BAT Best available techniques BEP Best environmental practise BHF Bag house filter BIF Boiler and industrial furnace Btu British thermal unit o Degree Celsius C CAA Clean Air Act CEMBUREAU European Cement Association CEMS Continuous emissions monitoring system CEN European Standardisation Organisation CFR Code of Federal Regulations CKD Cement kiln dust Cl2 Molecular chlorine CSI Cement Sustainability Initiative DL Detection limit CO Carbon monoxide CO2 Carbon dioxide DE Destruction efficiency Dioxins A term/abbreviation for polychlorinated dibenzodioxins and polychlorinated dibenzofurans (see also PCDD/Fs) DRE Destruction and removal efficiency Dscm Dry standard cubic meter EC European Commission EF Emission factor e.g. For example EPA Environmental Protection Agency EPER European Pollutant Emission Register Kåre Helge Karstensen [email protected] Page 6 of 189 ESP Electro static precipitator EU European Union FF Fabric filter g Gram GC-ECD Gas chromatography with electron capture detector GC-MS Gas chromatography with mass spectrometry HAPs Hazardous air pollutants HCB Hexachlorobenzene HCI Hydrogen chloride HF Hydrofluoric acid i.e. That is IPPC Integrated Pollution Prevention and Control I-TEF International Toxicity Equivalency Factor I-TEQ International Toxic Equivalent IUPAC International Union of Pure and Applied Chemistry J Joules K (Degree) Kelvin kcal Kilocalorie (1 kcal = 4.19 kJ) kg Kilogramme (1 kg = 1000 g) kJ Kilojoules (1 kJ = 0.24 kcal) kPa Kilo Pascal (= one thousand Pascal) L Litre lb Pound LCA Life cycle analysis LOD Limit of detection LOl Loss of ignition LOQ Limits of quantification 3 m Cubic meter (typically under operating conditions without normalization to, e.g., temperature, pressure, humidity) MACT Maximum Achievable Control Technology MJ Mega joule (l MJ= 1000 kJ) mg/kg Milligrams per kilogram MS Mass spectrometry mol Mole (Unit of Substance) Kåre Helge Karstensen [email protected] Page 7 of 189 Na Sodium NA Not applicable NAAQS National Ambient Air Quality Standards NATO North Atlantic Treaty Organisation ND Not determined/no data (in other words: so far, no measurements available) NESHAP National Emission Standards for Hazardous Air Pollutants ng Nanogram (1 ng = 10-9 gram) Nm3 Normal cubic metre (101.3 kPa, 273 K) NH3 Ammonia NOx Nitrogen oxides (NO+NO2) NR Not reported N-TEQ Toxic equivalent using the Nordic scheme (commonly used in the Scandinavian countries) OECD Organisation for Economic Co-operation and Development O2 Oxygen PAH Polycyclic aromatic hydrocarbons PCA Portland Cement Association (USA) PCB Polychlorinated biphenyls PCDDs Polychlorinated dibenzodioxins PCDFs Polychlorinated dibenzofurans PCDD/Fs Informal term used in this document for PCDDs and PCDFs PIC Product of incomplete combustion pg Picogram (1 pg = 10-12 gram) PM Particulate matter POHC Principal organic hazardous constituent POM Polycyclic organic matter POP Persistent organic pollutants ppb Parts per billion ppm Parts per million ppmv Parts per million (volume basis) ppq Parts per quadrillion ppt Parts per trillion ppt/v Parts per trillion (volume basis) ppm Parts per million Kåre Helge Karstensen [email protected] Page 8 of 189 QA/QC Quality assurance/quality control QL Quantification limit RACT Reasonably Available Control Technology RCRA Resource Conservation and Recovery Act RDF Refuse derived fuel RT Residence time sec Second SINTEF Foundation for Industrial and Scientific Research of Norway SNCR Selective non catalytic reduction SiO2 Silicon dioxide SCR Selective catalytic reduction SO2 Sulfur dioxide SO3 Sulfur trioxide SOx Sulfur oxides SQL Sample quantification limit SRE System removal efficiency t Tonne (metric) TCDD Abbreviation for 2,3,7,8-tetrachlorobidenzo-p-dioxin TCDF Abbreviation for 2,3,7,8-tetrachlorobidenzofuran TEF Toxicity Equivalency Factor TEQ Toxic Equivalent (I-TEQ, N-TEQ or WHO-TEQ) TEQ/yr Toxic Equivalents per year THC Total hydrocarbons TOC Total organic carbon tpa Tonnes per annum (year) TRI Toxics Release Inventory TSCA Toxics Substances Control Act UNDP United Nation Development Programme UK United Kingdom UNEP United Nation Environment Programme UNIDO United Nation Industry Development Organisation US United States of America US EPA United States Environmental Protection Agency VDZ Verein Deutsche Zementwerke Kåre Helge Karstensen [email protected] Page 9 of 189 VOC Volatile organic compounds VSK Vertical shaft kilns WBCSD World Business Council for Sustainable Development WHO World Health Organization y Year % v/v Percentage by volume µg/m3 Micrograms per cubic meter µg Microgram Kåre Helge Karstensen [email protected] Page 10 of 189 Glossary AFR Alternative fuel and raw materials, often wastes or secondary products from other industries, used to substitute conventional fossil fuel and conventional raw materials. Cementitious Materials behaving like cement, i.e. reactive in the presence of water; also compatible with cement. Co-processing Utilisation of alternative fuel and raw materials in the purpose of energy and resource recovery. Dioxins Together with PCDD/Fs used as term/abbreviation for Polychlorinated dibenzodioxins and Polychlorinated dibenzofurans in this document DRE/DE Destruction and Removal Efficiency/Destruction Efficiency. The efficiency of organic compounds destruction under Combustion in the kiln. Kiln inlet/outlet Were the raw meal enters the kiln system and the clinker leaves the kiln system. Pozzolana Pozzolanas are materials that, though not cementitious in themselves, contain silica (and alumina) in a reactive form able to combine with lime in the presence of water to form compounds with cementitious properties. Natural pozzolana is composed mainly of a fine, reddish volcanic earth. An artificial pozzolana has been developed that combines a fly ash and water-quenched boiler slag. Pozzolanic cement Pozzolanic cements are mixtures of Portland cement and a pozzolanic material that may be either natural or artificial. The natural pozzolanas Kåre Helge Karstensen [email protected] Page 11 of 189 are mainly materials of volcanic origin but include some diatomaceous earths. Artificial materials include fly ash, burned clays, and shale’s. Siliceous limestone Limestone that contains silicon dioxide (SiO2) Kåre Helge Karstensen [email protected] Page 12 of 189 Executive summary Cement production in China has grown steadily the last 20 years and increased by more than 10 % yearly. The Chinese cement industry produced 1,060 billion ton cement in 2005, accounting for 808 kg per capita and approximately 50 % of the world production. The cement production will probably reach its saturation point around year 2010 with an annual cement output at the upper limit of 1200 million tonnes. Approximately 60 % of the cement was produced in approximately 4000 Vertical Shaft Kilns (VSKs) in 2005. This part of the cement industry is characterized by its irrational structure, low production efficiency, high energy consumption and heavy environmental pollution. Many VSKs plants have virtually no environmental controls in place; and indeed, the nature of the old technology preclude effective use of modern dust (and other emission) controls. Compared with preheater/precalciner kilns, VSKs seems to consume from 14 % to 105 % more coal pr ton of clinker. Vertical shaft kilns generally produce lower quality (#325 grade or less) cement which is neither suitable for large structures nor for major infrastructure projects such as bridges, airports, etc. It is also not suitable for export to international markets. Improved mechanical shaft kilns have a production capacity of 250-350 tons/day and constituted 1150 and 1240 kilns in 2003 and 2004 respectively. Mechanical shaft kilns have a production capacity of 100-250 tons/day and constituted 9280 and 9060 kilns in 2003 and 2004 respectively. Ordinary shaft kilns have a production capacity of 50-150 tons/day and constituted 3150 and 2400 kilns in 2003 and 2004 respectively. China announced already in 1999 that it would close thousands of small or antiquated cement operations. There have however been many barriers to closure due to worker displacement and retraining costs; potential political instability, and opposition from local leaders who have economic interests in the plants. The key issue is retaining political stability in the face of greater unemployment. The problem is exacerbated compared to similar issues in other developing countries because Chinese cement plants employ up to ten times the labour of plants in developed countries, and because China has a less robust system of Kåre Helge Karstensen [email protected] Page 13 of 189 protective social security. Many of the closed plants will be in rural areas and it is hoped that released workers can fall back on their agricultural jobs or be absorbed in the rapidly growing private sector. Many provincial and local governments are not enthusiastically implementing these centrally planned plant closures. Some VSK will own its position to the disparity in the regional economic development of China still for some years to come, but within the year 2020 it is expected that all ordinary and all mechanised shaft kilns will have been closed down and that less than 10 % of improved mechanical shaft kilns will be in operation. The Chinese government has acknowledged that the replacement of VSKs with modern technology seems to be better off with a combination of economic incentives, regulation, and enforcement and market mechanisms. The new emission standard of Air Pollutants for Cement Industry in China, GB 4915-2004, has been effective for one year only. The standard gives identical emission limits for rotary kiln and shaft kiln for particulate emissions. Low quality cement is currently oversupplied and cheap in China, while high quality cement is rarer and more expensive. Profit margins for most cement producers have decreased and are near zero. Despite the growth in construction, cement prices have fallen the last two years, in some provinces with more than 50 %. New dry preheater/precalciner kilns is more cost-efficient than VSKs, both with regards to the number of labours and fuel costs, and they produce stable high quality cement. Energy prices and cost for labour has been increasing steadily the last years and is forecasted to continue to increase; this will favour dry preheater/precalciner kilns. New and modern dry process production lines with preheater and precalciner constituted 508 units by the end of 2004 and more than 704 will be in operation in the near future. This technology is considered to constitute the best available techniques with regards general cost-efficiency, to energy consumption, emissions and product quality. 1326 limestone quarries are currently known in China containing approximately 56,120 million tonnes of limestone. Taking into account future growth of cement production this deposits can only maintain the need for manufacturing of cement for 59 years (other industry exploitation not taken into account). In addition, cement production usually needs limestone sources of high quality and current quarrying methods are wasting large amounts of non-spec material. The raw material sources is neither uniformly distributed around the country and provinces with high production may not be self-sufficient for a long time. In Kåre Helge Karstensen [email protected] Page 14 of 189 addition, cement is a low profit product and the transportation distance is usually limited to a radius of 200 kilometres. The cement industry consumed about 129 million tons of standard coal, equal to 148 million tons of common coal in 2003. This amounts to approximately 11 % of whole consumption of coal in that year. For 2005 the consumption would be equivalent to approximately 200 million tonnes of common coal. The Chinese energy supply is mainly based on the utilization of coal. In 2002, the geological investigation showed that the storage of coal is about 130,000 million tons and will meet the domestic requirement for another 54 to 81 years. The quality and the distribution of coal are uneven along the country and require long transportation distances in some situations. The electricity consumption in the Chinese cement industry was 94,930 million kWh, amounting to approximately 5 % of the electric consumption in the whole country in 2003. It is estimated that the Chinese cement industry emitted more than 13 million tons of dust, about 27 % of all emissions from the national industry, about 22 % of all CO2 emissions, and about 4.85% of all SO2 emissions in 2003. Data developed the Chinese Enterprise Confederation point to significantly lower efficiencies for Chinese plants with respect to power use (approximately 25 % less efficient), fuel use (approximately 75 % less efficient), and labour (approximately six – thirty times more employees per ton of product) and product losses (nearly 2 % product loss through dust emissions in China). As a general rule, larger facilities have and continue to invest more in energy and process efficiency programs than smaller ones. There were more than 5000 cement producers employing approximately 1.5 million workers by the end of 2004. These companies were owned by the state, by townships, communities, collectives and by private companies. It is not clear if detailed employee accident and incident records are kept, or used to make safety improvements. Health and safety performance information is lacking. There is relatively little use of traditional personal protective equipment, like safety shoes, facemasks (for dust), and safety glasses in Chinese facilities. Kåre Helge Karstensen [email protected] Page 15 of 189 The use of alternative fuels in Chinese plants is almost totally absent, reflecting both the lack of infrastructure to collect and recycle these materials and the inability of vertical shaft kilns to use these materials safely or easily. This is an issue of growing concern, as China faces increasing waste management and disposal challenges. Enforcement of environmental regulations appears uneven, with small or no penalties for violation of environmental standards. Small facilities are frequently excused from compliance for lack of resources. The cement manufacturing process is generally well suited for co-processing byproducts and residues from industrial sources, both as raw materials and fuels substitutes and as mineral additions. There is no doubt that the most effective way of reducing raw material consumption, energy use and emissions from the cement industry is to reduce the clinker content of cement products by using secondary raw materials; then both thermal CO2 from fossil fuels and CO2 from the decarbonation of raw materials are reduced. With the substitution of fossil fuels by alternative fuels, the overall output of thermal CO2 is reduced. Fuel substitution is however not feasible for vertical shaft kilns. VSKs are applying the black-meal process which cannot replace the coal or coke by waste or alternative energy containing materials. The available information in English on the general performance of VSKs doesn't seem to be scientifically well document by real measurements or studies, i.e. there is a need to document the normal baseline conditions. A well documented and thorough knowledge of the normal energy consumption and the normal emission levels from VSKs is a prerequisite for issuing stricter regulation, for reporting statistics, for implementing measures and for measuring improvement. A pilot project is therefore suggested to demonstrate the potential for improvement in energy efficiency and emission reduction of VSKs. No VSKs has been monitored for dioxins and furans and no emission factors have so far been developed for this industry category. China is obliged to provide data on PCDD/F emissions to the Stockholm Convention on Persistent Organic Pollutants (POPs) and to suggest an action plan with reduction targets for PCDD/F emissions from the different source categories. To be able to do this task properly the mechanism for formation of PCDD/Fs in VSKs should be known. The understanding of the formation mechanism will enable the Kåre Helge Karstensen [email protected] Page 16 of 189 environmental authorities to provide measures and strategies for emission reduction and control. Kåre Helge Karstensen [email protected] Page 17 of 189 1. Introduction China is expected to remain the world’s most populous country through year 2040. Its gross domestic product (GDP) has averaged growth of more than 9 percent each year since liberalization and economic reforms began in the late 1970s (Soule et al, 2002). In 1985, China became the world’s leading producer of cement, and today produces almost half of the total global output. While China’s cement industry is relatively insulated from a global perspective, changes are underway to improve product quality, management practices and profitability, including further opening the sector to participation by international players. In 2001, the Chinese government decentralized its industrial ministries and the organizational structure of the cement industry. The Ministry of Building Materials and the State Administration of Building Materials Industry has been changed into several quasigovernmental organisations: China Cement Association, China Building Materials Industry Association, China Building Materials Academy and Institute of Technical Information for Building Materials Industry of China (ITIBMIC). Changes in top officials have also occurred and provincial authorities now exert more control over the industry (Soule et al, 2002). A shrinking number of cement companies remain state-owned, while a growing number are foreign invested enterprises. Collective enterprises account for over 50 percent of companies while 10 percent are privately owned. There also is a trend toward consolidation. The estimated number of Chinese cement producers is approximately 5000, although the actual number is uncertain due to the fragmented nature of the industry, the small size of many plants, the fact that some plants exist illegally, and data reliability issues. About 50 percent of these facilities are rural township enterprises with average annual output of less than 30,000 tonnes. Only about 570 of the 8,500 cement producers had production capacities exceeding 275,000 tonnes per year in 1995, and only ten plants produce more than one million tonnes annually (Soule et al, 2002). For comparison, industrialized cement producing countries average 40 to 50 major producers that manufacture up to four million tonnes annually. China plans to increase the average production capacity at facilities throughout the industry through plant closures and upgrades. The country plans to raise average plant Kåre Helge Karstensen [email protected] Page 18 of 189 production to 200,000 tonnes per year by 2005, 300,000–400,000 by 2010, and 400,000– 500,000 by 2015 (Soule et al, 2002). China announced in 1999 that it would close thousands of small or antiquated cement operations. As many as 6,000 plants are slated to be closed, with 4,000 closures scheduled by the end of 2001. Given current progress, this level of closure by year end 2001 seems unlikely. Initially targeted for closure are 2,000 illegal or improperly licensed cement producers as well as outdated cement operations. China plans to close (through non- recertification) plants that (Soule et al, 2002): • Produce #325 and lower grades (by 2005); • Have vertical kiln diameters smaller than 2.2 meters and/or produce <30,000 tonnes/year, and • Have wet process kilns (either to be closed or converted to dry processes). Cement production in China has grown steadily the last 20 years and increased by more than 10 % yearly. It is estimated that the Chinese cement industry produced 1,060 billion ton cement in 2005 (Cui and Wang, 2005). Approximately 60 % of this cement was produced in approximately 4000 Vertical Shaft Kilns (VSKs). New and modern dry process production lines constituted 508 units by the end of 2004 and as much as 704 will be in full operation within the near future (Cui and Wang, 2005). Today, 138 million tonnes, or one quarter of Chinese cement production comes from rotary kilns; the remaining 433 million tonnes from vertical kilns that will be slowly phased out. Vertical shaft kilns currently contribute 60 percent of production, a number expected to decline only to 50 percent by 2015. Cement production generally tracks well against population density, but there are production concentrations in Shandong and Guangdong provinces and among the coastal provinces generally. The central government is emphasizing the future development of the poorer western provinces to help alleviate regional income differentials that result in migration to the more crowded east. The western provinces account for comparatively little cement production. As urban land development rationalizes (where land uses are determined Kåre Helge Karstensen [email protected] Page 19 of 189 by economic and environmental considerations), local governments are reclaiming land from urban cement plants and replacing them with less noxious and more profitable activities. Companies are being displaced to the urban fringes and also moving closer to limestone deposits, employing conveyer systems to transport limestone over medium distances. Growth in Chinese cement production is due to the construction boom accompanying high GDP growth rates. Only rotary kiln cement can be used legally to build high-rise buildings in China and demand for the higher grade cements increases. Forty percent of China’s cement is now used for basic infrastructure construction (an area regularly neglected during the period of heavy central planning), with about one-third of that used in rural areas. Twenty-five percent is used for maintenance activities. China’s transport sector uses cement in road construction rather than asphalt. As China lacks an adequate national highway system and its rail network is so overburdened, investment can be expected in highways over the medium term. Low quality cement is oversupplied and cheap, while high quality cement is rarer and more expensive. Profit margins for most cement producers hover near zero. Despite the growth in construction, cement prices have fallen, in some provinces with more than 50 %. Because cement is a bulk commodity, transportation costs are a significant component of the industry’s cost structure. The main issue, however, is with the transport of coal because it is an important input into cement production and because it is the primary source of pressure on a strained transport infrastructure network. Cement industry sources indicate that the availability of coal has not constrained the cement industry to date. Unless long-term investment is made to improve the rail network this situation will worsen. Foreign investment in bulk cement storage and transportation facilities is promoted. China is the second leading cement exporter in the world, accounting for about 17 percent of total world cement trade. Shaft kiln cements comprise a significant percentage of total exports. Major exporting regions include Shandong, Jiangsu, Guangdong, Liaoning, Guangxi, and Hebei provinces. The largest exporting companies include Daewoo Shandong Metal and Minerals Import/Export and Taiheiyo Cement. The United States is the largest market for Chinese cement, accounting for 42 percent of trade in 1998 (Soule et al, 2002). Kåre Helge Karstensen [email protected] Page 20 of 189 The cement industry is very energy intensive and China relies almost exclusively on coal to produce cement. Energy accounts for roughly 40 percent of the total manufacturing cost of cement in China. Unlike some industrialized countries, China has not yet moved to alternative energy sources in its cement kilns. If China were to succeed in replacing output from plants that produce #325 cement with more efficient plants, it would save approximately 15 million tonnes of coal each year (Soule et al, 2002). Improving energy efficiency is important to a wide range of stakeholders because it cuts energy costs, improves local environmental quality, and reduces greenhouse gas emissions. China has significant environmental problems. Ambient air levels of total suspended particulates (TSP) and sulfur dioxide (SO2) in Chinese cities are among the highest in the world. In turn these heavy pollutant loads are closely associated with significant respiratory illness and approximately 200,000 premature deaths each year in urban areas (Soule et al, 2002). China’s contribution to global carbon dioxide (CO2) emissions is approximately 14 percent. Cement plants are responsible for over 40 percent of total industrial particulate (dust) emissions (Soule et al, 2002). Chinese cement plants are also responsible for about 6 to 8 percent of the country’s carbon dioxide emissions. These emissions are produced in roughly equal parts from fuel combustion and the calcinations of limestone at high temperature. Carbon dioxide emissions from small Chinese plants are two or more times higher than plants in industrialized nations, because of poor efficiencies requiring more fuel use, etc. (Soule et al, 2002). Increasing the efficiency of cement kilns is one way to reduce carbon dioxide emissions. Cement production is also associated with a number of other environmental problems including possible contamination of local water sources, mercury emissions, excessive noise, erosion surrounding limestone quarries, and nitrogen oxide emissions. Dry rotary kilns, including precalciner kilns, are the most energy efficient technology currently available in China. The associated reduction in coal combustion accompanying the closure of #325 plants would reduce carbon dioxide emissions by about 30 million tonnes, sulfur dioxide by 250,000 tonnes, and solid waste and dust by over 5 million tonnes each year. China has developed a range of environmental laws to deal with air pollution, solid waste, water pollution, etc. In April of 2000, China announced that emission limits would be reduced to 100 milligrams per cubic meter of exhaust. For comparison, cement plants in Kåre Helge Karstensen [email protected] Page 21 of 189 Europe conform to a limit of 50 milligrams. Enforcement of laws is not uniform and remains an issue. Provincial level environmental protection agencies are responsible for enforcing emission limits and can direct capital toward polluters to upgrade their equipment. However, production and profit often supercede enforcement. Environmental regulations tend to be strictly enforced when foreign companies are involved. It is difficult to obtain domestic financing for investment projects within China. Financial needs are many, and sources limited. Chinese stock markets have been an important but insufficient source of low-cost capital for listed enterprises. In recent years, it has become easier for foreign companies to obtain permits for cement projects. But the paperwork, time, and dedication necessary to bring an investment to closure remain daunting, and the sentiment is shared that this situation will only change slowly (Soule et al, 2002). Even with sometimes vicious competition and difficulties in operating in an opaque market, key opportunities are open for both domestic and foreign companies. Promising areas include investment in: • Bulk cement transport and storage infrastructure, • Environmental control equipment, • Precalcinator and dry rotary cement kilns, and • Specialty cements. China is the world’s largest market for cement machinery but with the exception of advanced mills and control system more and more plant are fully Chinese made technology. Foreign investment will be focused on precalcined production lines with capacities of 4,000 tonnes or more using new dry processes for cement clinker. A key ready Chinese built cement plant can now be built in two years at a third of the price of a foreign built plant. Kåre Helge Karstensen [email protected] Page 22 of 189 To address regional income disparities, the western provinces have investment priority during the Eleventh Five-Year Plan. These regions include: Xinjiang, Ningxia, Qinghai, Shaanxi (including Xian), Gansu, Sichuan, Tibet (Xizang), Chongqing City, Guizhou, and Yunnan (including Kunming). Eastern provinces should not expect new plants, but there will be many opportunities for technology upgrades in these areas. China has ambitious plans to prepare for the 2008 Olympic Games. There will be much new construction in Beijing to accommodate the games. Strict environmental measures to improve air and water quality also will be in force in the capital region. 1.1 Objective of this study The objective of this study has been to review and compare Vertical Shaft Kiln (VSKs) cement production technologies with other production technologies and to suggest a pilot project demonstrating the potential for improvement in energy efficiency and emission reduction. A few VSKs have been visited in China and discussion has been carried out with stakeholders on the possibilities for cleaner production options in general and environmental improvement in particular. Interviews have been made with Chinese government officials, cement associations and cement companies. Other sources used for this study include Internet sources, commercial database articles, and statistical compendia. All visits and meetings were arranged by SEPA / FECO. It should be noted however, that data availability limits the ability to conduct in-depth and accurate analysis and there are some conflicting numbers in the text. The available information in English on the general performance of VSKs doesn't seem to be scientifically well document by real measurements or comprehensive studies. The statements made in different documents vary and is even contradictory in some cases. The general impression is that the newest data from 2004 and 2005 is the most reliable, and of course the most updated. The scope of this study has consisted of two weeks of preparation, two weeks visit in China and two weeks reporting. Kåre Helge Karstensen [email protected] Page 23 of 189 2. Cement production The description of the cement production process using rotary kilns is an excerpt from the European Integrated Pollution Prevention and Control document “Reference document on Best Available Techniques in the Cement and Lime Manufacturing Industries” (IPPC, 2001), CEMBUREAUs BAT document (1999), the UK Environment Agency “Integrated pollution prevention and control – Guidance for the Cement and Lime sector" (Environment Agency, 2001) and, from Duda (1985) and Roy (1985). 2.1 Main processes There are four main process routes in the manufacturing of cement using rotary kilns – the dry, semi-dry, semi-wet and wet process. The main features of these processes are described in more detail in the following chapters; the production of cement using Vertical Shaft Kilns is different and dealt with separately in chapter 3. However, common to all processes are the following sub-processes: • Quarrying; • Raw materials preparation; • Fuels preparation; • Clinker burning; • Mineral additions preparation; • Cement grinding; • Cement dispatch. Kåre Helge Karstensen [email protected] Page 24 of 189 Figure 1 Processes identification and system boundaries of cement production using rotary kilns (Environment Agency, 2001) 2.1.1 Quarrying Natural (“primary”) raw materials such as limestone/chalk, marl, and clay/shale are extracted from quarries which, in most cases, are located close to the cement plant. After extraction, these raw materials are crushed at the quarry site and transported to the cement plant for intermediate storage, homogenization and further preparation. “Corrective” materials such as bauxite, iron ore or sand may be required to adapt the chemical composition of the raw mix to the requirements of the process and product specifications. The quantities of these corrective materials are usually low compared to the huge mass flow of the main raw materials. Kåre Helge Karstensen [email protected] Page 25 of 189 To a limited extent, “secondary” (or “alternative”) raw materials originating from industrial sources are used to substitute for natural raw materials and correctives. In the same way as traditional raw materials, they may be fed to the quarry crusher or – more commonly – directly to the cement plant’s raw material preparation system. Today, modern computerised methods are available to evaluate the raw material deposits and to optimise the long-term and short-term production schedule. 2.1.2 Raw materials preparation After intermediate storage and pre-homogenisation, the raw materials are dried and ground together in defined and well-controlled proportions in a raw mill to produce a raw meal for the dry (and semi-dry) process. In the wet (and semi-wet) process, the raw materials are slurried and ground with addition of sufficient water to produce raw slurry. Depending on the technological process applied, additional steps may be required such as preparing raw meal “pellets” from dry meal (semi-dry process) or “filter cake” by dewatering of the slurry in filter presses (semi-wet process). The resulting intermediate product – i.e. raw meal or raw slurry (or their derivatives) – is stored and further homogenised in raw meal silos, storage bins or slurry basins to achieve and maintain the required uniform chemical composition before entering the kiln system. As a rule of thumb, approximately 1.5 – 1.6 tons of (dry) raw materials are required to produce one ton of the burnt product clinker. 2.1.3 Fuels preparation Conventional (fossil) fuels used in the cement industry are mainly coal (lignite and hard coal), petcoke (a product from crude oil refining), and heavy oil (“bunker C”). Natural gas is rarely used due to its higher cost. “Alternative” fuels – i.e. non-fossil fuels derived from industrial (“waste”) sources – are widely used today to substitute in part for the traditional fossil fuels. Kåre Helge Karstensen [email protected] Page 26 of 189 Fuels preparation – i.e. crushing, drying, grinding, and homogenising – usually takes place on site. Specific installations are required such as coal mills, silos and storage halls for solid fuels, tanks for liquid fuels, and the corresponding transport and feeding systems to the kilns. The thermal fuel consumption is largely dependent on the basic process design applied in the burning of clinker. The physical nature of the fuels used in a cement plant – solid, liquid or gaseous – determines the design of the storage, preparation and firing systems – both for conventional fossil fuels and for alternative fuels from industrial sources. The main fuel input has to be delivered in a form that allows uniform and reliable metering as well as easy and complete combustion. This is usually the case with all pulverised, liquid and gaseous fuels. A limited input (up to 35 %) may also be delivered by the addition of coarse materials at specific feed points. Coal and petcoke are ground to fineness similar to raw meal in coal mills (tube mills, vertical roller mills or impact mills). For safety reasons, the whole coal preparation system is designed for protection from fire or explosion. The pulverised fuel may be fed directly to the burner (without intermediate storage and metering system) or – which is common practice today – may be stored in fine coal silos with adequate metering and feeding systems. Fuel oil is stored in large tanks on site. Handling is facilitated by heating up the oil to a temperature of about 80 °C. Metering and combustion are facilitated by additional heating of the oil up to a temperature of 120-140 °C, resulting in a reduction of the viscosity. Natural gas is delivered by national or international distribution systems without onsite storage. Prior to combustion in the kiln, the pressure of the gas has to be reduced to the plant’s network pressure in gas transfer stations where also the fuel metering takes place. Alternative fuels originating from industrial sources may require specific treatment. Gaseous, liquid and pulverised or fine crushed solid fuels can be fed to the kiln system similarly to the fossil fuels mentioned above. Coarsely shredded or even bulky materials can be fed to the preheater/precalciner section or, rarely, to the mid kiln section only. For process Kåre Helge Karstensen [email protected] Page 27 of 189 reasons, the contribution of bulky fuels to the total heat consumption should be limited to about 15 to 30% depending on the kiln system. Alternative fuels are frequently prepared and blended outside the cement plant by specialised companies in facilities specifically designed for this purpose. The cement plant has to provide the storage and feeding systems only on site. Alternative fuel plants are often designed as “multi-purpose plants” in order to handle a variety of different wastes. 2.1.4 Clinker Burning The prepared raw material (“kiln feed”) is fed to the kiln system where it is subjected to a thermal treatment process consisting of the consecutive steps of drying/preheating, calcination (e.g. release of CO2 from limestone), and sintering (or “clinkerisation”, e.g. formation of clinker minerals at temperatures up to 1450 °C). The burnt product “clinker” is cooled down with air to 100-200 °C and is transported to intermediate storage. The kiln systems commonly applied are rotary kilns with or without so-called “suspension preheaters” (and, in more advanced systems, “precalciners”) depending on the main process design selected. The rotary kiln itself is an inclined steel tube with a length to diameter ratio between 10 and 40. The slight inclination (2.5 to 4.5%) together with the slow rotation (0.5–4.5 revolutions per minute) allow for a material transport sufficiently long to achieve the thermal conversion processes required. Exhaust heat from the kiln system is utilised to dry raw materials, solid fuels or mineral additions in the mills. Exhaust gases are dedusted using either electrostatic precipitators or bag filter systems before being released to the atmosphere. Kåre Helge Karstensen [email protected] Page 28 of 189 Clean gas Electrostatic precipitator Raw gas Raw meal Dust recycling Clean gas Mill dryer Cyclone preheater Evaporation cooler Burner Dust collection Rotary kiln Cooling air Clinker Grate cooler Figure 2 2.1.5 Rotary kiln with cyclone preheater and gas dust collection Cement grinding Portland cement is produced by intergrinding cement clinker with a few percent of natural or industrial gypsum (or anhydrite) in a cement mill. Blended cements (or “composite” cements) contain other constituents in addition such as granulated blast-furnace slag, natural or industrial pozzolana (for example, volcanic tuffs or fly ash from thermal power plants), or inert fillers such as limestone. Mineral additions in blended cements may either be interground with clinker or ground separately and mixed with Portland cement. Grinding plants may be located remotely Kåre Helge Karstensen [email protected] Page 29 of 189 from the clinker production facility. The different cement types have to be stored separately in cement silos prior to bagging and dispatch. 2.1.6 Mineral additions preparation Mineral additions from natural or industrial sources intended to be used in blended cements may need to be dried, crushed or ground in separate installations on site. Separate “grinding plants” where mineral additions and blended cements only are produced may also be located remote from the clinker production facility. Mineral additions used in the manufacture of blended cements require separate installations for storage, preblending, crushing, drying and feeding. Commonly used mineral additions include natural materials such as volcanic rocks, limestone or calcined clay, and materials originating from industrial sources such as granulated blast-furnace slag, pulverised fly ash from power stations, or micro silica. Pre-drying may be required for materials with a high moisture content, for example, granulated blast-furnace slag. Rotary tube driers or flash driers make use of the kiln exhaust gases or cooler exhaust air or are operated with a separate hot gas source. Mineral additions may be interground with cement clinker and gypsum in a cement mill or may be ground separately and blended with Portland cement subsequently. Separate grinding and blending is mainly applied in the production of slag cements. For separate grinding of mineral additions, the same installations are used as in cement grinding. 2.1.7 Cement dispatch Cement may be shipped as bulk cement or – usually to a lesser extent – packed into bags and palletised for dispatch. Transport methods used (i.e. road, railway, waterways) depend on local conditions and requirements. Kåre Helge Karstensen [email protected] Page 30 of 189 2.2 Material characteristics Portland cement clinker is produced from a mixture of raw materials containing calcium, silicon, aluminium, and iron as the main elements. When mixed in the correct proportions, new minerals with hydraulic properties – the so-called clinker phases – are formed upon heating up to the sintering (or clinkerisation) temperature as high as 1450 °C. 2.2.1 Main clinker phases The main mineral components in clinker are silicates, aluminates and ferrites of the element calcium. The four main oxides make up four major clinker phases, called alite, belite, aluminate and ferrite. Tri-calcium silicate 3 CaO x SiO2 C3S Alite Di-calcium silicate 2 CaO x SiO2 C2S Belite Calcium aluminate 3 CaO x Al2O3 C3A Aluminate Calcium ferrite 4 CaO x Al2O3 x Fe2O3 C4AF Ferrite In general, C3S contributes to early and late strength (from first day) and increases the heat of hydration; C2S contributes to late strength (from 28 days); C3A also contributes to early strength, heat of hydration and to the resistance to sulphate attack; C4AF mainly affects the clinker colour. The clinker formation process can be divided into 4 steps: Kåre Helge Karstensen [email protected] Page 31 of 189 • Drying and preheating (20 – 900 °C): release of free and chemically bound water; • Calcination (600 – 900 °C): release of CO2: initial reactions with formation of clinker minerals and intermediate phases; • Sintering or clinkerisation (1250 – 1450 °C): formation of calcium silicates and liquid phase; • Kiln internal cooling (1350 – 1200 °C): crystallisation of calcium aluminates and calcium ferrite. Minor mineral constituents in cement clinker include uncombined calcium oxide (“free lime”) and magnesium oxide, as well as alkali sulphates. Additional chemical elements present in the raw materials such as manganese, phosphorus, titanium or heavy metals are mainly incorporated in the mineral structure of the major clinker phases. The properties of clinker (and thus, of the cement produced from it) are mainly determined by its mineral composition and its structure. Some elements in the raw materials such as the alkalis, sulfur and chlorides are volatilised at the high temperatures in the kiln system resulting in a permanent internal cycle of vaporisation and condensation (“circulating elements”). A large part of these elements will remain in the kiln system and will finally leave the kiln with the clinker. A small part will be carried with the kiln exhaust gases and will be mainly precipitated with the particulates in the dedusting system. At a high surplus of volatile elements, the installation of a preheater “bypass” may become necessary where part of the dust laden exhaust gases of the rotary kiln is extracted from the system. Both filter and bypass dust can totally or partially be recycled to the cement manufacturing process. Kåre Helge Karstensen [email protected] Page 32 of 189 2.2.2 Raw mix components A well designed raw mix in clinker manufacturing typically consists of calcareous components rich in calcium, e.g. > 75% of carbonates (limestone, chalk, marble, calcareous marl), argillaceous components rich in aluminium, silicon and iron (marl, marly clay, shale, clay) and corrective components specifically enriched in one of the four main elements (bauxite, iron ore, sand, high-grade limestone, etc.). Correctives are used in small quantities only to adjust the chemical composition of the raw mix to the required quality targets. Depending on availability and chemical composition, both main and corrective raw mix components may also originate from industrial (“non-fossil”) sources (“alternative” raw materials). Examples are coal fly ash from power stations, steel slag, foundry sand, sewage sludge, lime sludge, FCC catalysts from oil refineries, and many more. A proper raw mix design is based on the given raw materials situation, on the process design and process requirements, on the product specifications, and on environmental considerations. A well designed raw mix, adequate fineness of the raw meal and constant chemical composition are essential both for a good product quality and for a smooth kiln operation. Homogeneity and uniformity of the raw mix composition has to be carefully controlled on a permanent basis by adequate sampling and chemical analysis. 2.2.3 Fuels Main fossil fuels (“primary” fuels) in the cement industry are coal, petcoke, heavy oil, and – to a lesser extent – natural gas. Non-fossil “alternative” fuels derived from industrial sources such as tyres, waste oil, plastics, solvents and many more are commonly used as substitute fuels today. The chemical components of the ash of solid fuels combine with the raw materials and will be fully incorporated in the clinker produced. Thus, the chemical composition of the ash has to be considered in the raw mix design. In the same way as the major elements, metals which may be introduced with liquid or solid fuels will also be incorporated into the clinker structure to a large extent. Exceptions are Kåre Helge Karstensen [email protected] Page 33 of 189 metals which are partly or completely volatilised in the kiln system such as mercury, thallium or cadmium. These elements will be captured in the kiln (filter) dust or may to some extent escape with the stack emissions (mercury and thallium) if not managed appropriately. 2.2.4 Cement constituents Portland cement is produced by intergrinding clinker with a few percent of natural or industrial gypsum or anhydrite (calcium sulphate) acting as a set regulator. In many countries, the addition of up to 5% of “minor constituents” such as raw meal, limestone or filter dust is allowed. In blended (or “composite”) cements, part of the cement consists of mineral additions originating from natural or industrial sources. These mineral additions may have hydraulic (granulated blast furnace slag), pozzolanic (volcanic rocks, coal fly ash, micro silica, calcined clay) or filler properties (limestone). The composition of blended cements is specified in the national cement standards. The standards usually also includes quality specifications for the individual mineral additions used. 2.3 The four main process routes in rotary kiln cement production Historically, the development of the clinker manufacturing process was characterised by the change from “wet” to “dry” systems with the intermediate steps of the “semi-wet” and “semi-dry” process routes. The first rotary kilns – introduced around 1895 – were long wet kilns. “Wet” kilns allowed for an easier handling and homogenisation of the raw materials, especially in cases when the raw materials are wet and sticky or exhibit large fluctuations in the chemical composition of the individual raw mix components. With more advanced modern technology however, it is possible to prepare a homogeneous raw meal using the “dry” process, i.e. without addition of water to prepare raw slurry. The main advantage of a Kåre Helge Karstensen [email protected] Page 34 of 189 modern dry process over a traditional wet system is the far lower fuel consumption and thus, lower fuel cost. Today, the selection of the wet process is only feasible under very specific raw material and process conditions. The four different basic processes can be briefly characterised as follows: • Dry process: Dry raw meal is fed to a cyclone preheater or precalciner kiln or, in some cases, to a long dry kiln with internal chain preheater. • Semi-dry process: Dry raw meal is pelletised with water and fed to a travelling grate preheater prior to the rotary kiln or in some cases, to a long kiln equipped with internal cross preheaters. • Semi-wet process: Raw slurry is first dewatered in filter presses. The resulting filter cake is either extruded into pellets and fed to a travelling grate preheater or fed directly to a filter cake drier for (dry) raw meal production prior to a preheater/precalciner kiln. • Wet process: The raw slurry is fed either directly to a long rotary kiln equipped with an internal drying/preheating system (conventional wet process) or to slurry drier prior to a preheater/precalciner kiln (modern wet process). All processes have in common that the kiln feed is first dried, then calcined by dissociation of carbon dioxide (CO2) from the CaCO3 in the feed material, and finally sintered to clinker at temperatures between 1,400 ºC and 1,450 ºC. During this process the feed loses approximately one third of its original dry mass. The hot clinker is cooled by air to 100-200 ºC in a clinker cooler. The heated air is used as secondary combustion air in the kiln. 2.3.1 The dry process Kåre Helge Karstensen [email protected] Page 35 of 189 For dry and semi-dry kiln systems, raw meal is prepared by drying and grinding of the raw material components in tube mills or vertical roller mills, making use of the hot kiln exhaust gases or cooler exhaust air for drying. Prior to being fed to the kiln, the raw meal is homogenised and/or blended either in batch type or in continuously operating homogenising silo systems. In suspension preheater kilns, the raw meal is fed to the top of a series of cyclones passing down in stepwise counter-current flow with hot exhaust gases from the rotary kiln thus providing intimate contact and efficient heat exchange between solid particles and hot gas. The cyclones thereby serve as separators between solids and gas. Prior to entering the rotary kiln, the raw meal is heated up to a temperature of approximately 810-830 °C where the calcination (i.e. the release of CO2 from the carbonates) is already about 30% complete. The exhaust gases leave the preheater at a temperature of 300-360 °C and are further utilised for raw material drying in the raw mill. 4-stage preheater kilns are susceptible to blockages and build-ups caused by excessive input of elements such as sulfur, chlorides or alkalis which are easily volatilised in the kiln system. This input has to be carefully controlled. Excessive input may require the installation of a system which allows part of the rotary kiln gases to bypass the preheater. Thereby part of the volatile compounds are extracted together with the gas. A bypass system extracts a portion (typically 5-15 %) of the kiln gases from the riser pipe between the kiln and preheater. This gas has a high dust burden. It is cooled with air, volatile compounds are condensed onto the particulates and the gas then passes through a dust filter. Modern suspension preheater kilns usually have 4 cyclone stages with a maximum capacity limited to approximately 4000 t/d. In some cases, 2-stage cyclone preheaters or 1stage preheaters supported by internal chain heat exchangers are still in operation. A considerable capacity increase can be obtained with precalciner kilns with a second combustion device between the rotary kiln and the preheater section. In the precalciner, up to 60 % of the total fuel of the kiln system can be burnt. At an exit temperature of about 880 °C, the hot meal is calcined to a degree of around 90 % when entering the rotary kiln. Kåre Helge Karstensen [email protected] Page 36 of 189 Kiln systems with 5 to 6 stage cyclone preheater and precalciner are considered standard technology for new plants today, as the extra cyclone stages improve thermal efficiency. In some cases, the raw meal is fed directly to a long dry kiln without external preheater. A system of chains in the inlet part of the rotary kiln provides the heat exchange between the hot combustion gases from the hot zone of the kiln and the kiln feed. Long dry kilns have high heat consumption and high dust cycles requiring separate dedusting cyclones. Figure 3 2.3.2 Production of cement by the dry process (CEMBUREAU, 1999) The semi-dry process In the semi-dry process, dry raw meal is pelletised with 10-12 % of water on an inclined rotating table (“granulating disc”) and fed to a horizontal travelling grate preheater Kåre Helge Karstensen [email protected] Page 37 of 189 in front of the rotary kiln (“Lepol” system). The pelletised material is dried, pre-heated and partly calcined on the two-chamber travelling grate making use of the hot exhaust gases from the kiln. A higher degree of calcination can be achieved by burning part of the fuel in the hot chamber of the grate preheater. The hot exhaust gases from the kiln first pass through a layer of preheated pellets in the hot chamber. After intermediate dedusting in cyclones, the gases are drawn once again through a layer of moist pellets in the drying chamber of the grate. As much of the residual dust is precipitated on the moist pellet bed, the total dust load of the exhaust gases at the preheater outlet is low. Figure 4 Production of cement by the semi-dry process (CEMBUREAU, 1999) As a drawback of the semi-dry process, kiln exhaust gases cannot be utilised in the raw meal drying and grinding system due to the low temperature level. The maintenance costs of grate preheaters are high. Modern installations rarely use the semi-dry process. Kåre Helge Karstensen [email protected] Page 38 of 189 2.3.3 The semi-wet process In the semi-wet process the raw slurry is dewatered in filter presses. Typically, modern chamber filtration systems produce filter cakes with a residual moisture content of 1621 %. In the past, filter cakes were further processed in extruders to form pellets which were then fed to grate preheater kilns with three chambers. With modern cement plants, slurry filtration is applied only where raw materials have a very high natural moisture content, i.e. chalk. Filter cake coming from the filter presses is kept in intermediate storage bins before it is fed to heated crushers or dryers where a dry raw meal is produced which is fed to a modern preheater or precalciner kiln. With the dryers/crushers operating full time in parallel with the kiln (compound operation), these systems have a very good energy recovery by making full use of the kiln exhaust gases and the cooler exhaust air. Figure 5 Production of cement by the semi-wet process (CEMBUREAU, 1999) Kåre Helge Karstensen [email protected] Page 39 of 189 2.3.4 The wet process Conventional wet process kilns are the oldest type of rotary kilns to produce clinker. Wet kiln feed (raw slurry) typically contains 28 to 43 % of water which is added to the raw mill (slurry drums, wash mills and/or tube mills). Batch blending and homogenisation is achieved in special slurry silos or slurry basins where compressed air is introduced and the slurry is continuously stirred. The slurry is pumped into the rotary kiln where the water has to be evaporated in the drying zone at the kiln inlet. The drying zone is designed with chains and crosses to facilitate the heat exchange between the kiln feed and the combustion gases. After having passed the drying zone, the raw material moves down the kiln to be calcined and burnt to clinker in the sintering zone. Conventional wet kiln technology has high heat consumption and produces large volumes of combustion gases and water vapour. Wet rotary kilns may reach a total length of up to 240 m compared to short dry kilns of 55 to 65 m length (without the preheater section). In modern wet kiln systems, the raw slurry is fed to slurry drier where the water is evaporated prior to the dried raw meal entering a cyclone preheater/precalciner kiln. Modern wet kiln systems have a far lower specific heat consumption compared to conventional wet kilns. 2.3.5 Circulating elements Volatile components such as alkalis, sulfur and chlorine introduced with raw materials and fuels may give rise to problems in kiln operation when present in high concentrations. Build-up formation in the preheater cyclones or rings in the rotary kiln inlet zone may lead to reduced kiln availability and productivity. Thus, the input of these volatile components is Kåre Helge Karstensen [email protected] Page 40 of 189 carefully controlled for operational and economic reasons. Input control is also required to achieve and maintain the required quality of clinker and cement. Figure 6 Production of cement by the wet process (CEMBUREAU, 1999) Depending on their volatility, alkalis, sulfur and chlorides evaporate in the sintering zone of the rotary kiln and recondense at cooler parts of the system either on the raw meal particles or on the surrounding walls. With the raw meal, they are reintroduced to the sintering zone again thus establishing a permanent "internal cycle” of volatile “circulating” elements. By reaching equilibrium between input and output, a major part of the volatile components will finally leave the system incorporated in the clinker. Part of the volatile components however, may form new compounds such as alkali chlorides or alkali sulphates and other intermediate phases such as spurrite which will then contribute to the build-up phenomena mentioned above by producing a “sticky” raw meal adhesive to the walls of the cyclones, the ducts or the kiln tube. A small part only of the Kåre Helge Karstensen [email protected] Page 41 of 189 circulating elements leaves the kiln with the exhaust gas dust and is precipitated in the dedusting device of the system. With excessive input of volatile elements, the installation of a kiln gas bypass system may become necessary in order to extract part of the circulating elements from the kiln system. This bypass dust which is usually highly enriched in alkalis, sulfur or chlorides is cooled down and then passed through a dust collector before being discharged. 2.3.6 Clinker coolers Clinker leaving the rotary kiln at a temperature around 1200-1250 °C has to be cooled down rapidly to allow further transport and handling. This process also recovers heat from the clinker back to the kiln by preheating the air used for combustion in the main burner and in any secondary firing. In addition, rapid cooling prevents undesired chemical reactions in the clinker which may negatively affect the quality and the grindability of the clinker. Three main types of clinker coolers are used: • Rotary (tube) coolers • Planetary (satellite) coolers, and • Grate coolers Tube coolers placed underneath the kiln outlet make use of the same principle as the rotary kiln for clinker burning, but for reverse heat exchange with cooling air drawn through the tube in counter-current flow to the hot clinker. This cooler type is rarely used in the cement industry nowadays. In a planetary (or satellite) cooler, 9 to 11 tubes are arranged peripherally at the discharge end of the rotary kiln. Hot clinker enters the tubes through inlet ports and passes through the tubes in cross counter-current to the cooling air. Due to their design, planetary coolers are susceptible to comparatively high wear and to thermal shock effects, and – similarly to tube coolers – clinker exit temperatures may still be high without additional Kåre Helge Karstensen [email protected] Page 42 of 189 cooling by water injection. Planetary coolers are not suited for precalciner kilns as exhaust air cannot be extracted for combustion in the secondary firing. Grate coolers are preferably used in modern installations. Cooling is achieved by cross-flow air blown through a clinker layer travelling slowly on a reciprocating grate which consists of perforated plates. The whole cooling zone includes a “recuperation zone” and an “aftercooling zone”. From the recuperation zone, preheated air is recovered for combustion of the main burner fuel (“secondary air”) and of the precalciner fuel (“tertiary air”). The hot air from the aftercooling zone can be used for drying of raw materials or coal. Grate coolers thus provide the most efficient and most flexible heat recovery system for modern dry process kilns. 2.3.7 Operating characteristics rotary kilns - a summary A summary of the operating characteristics of the four main process routes is given in the figure below. Figure 7 Operating characteristics of kiln processes (CEMBUREAU, 1999) Kåre Helge Karstensen [email protected] Page 43 of 189 2.4 Cement production using Vertical Shaft Kilns The raw materials used for cement production in Vertical Shaft Kilns (VSKs) are exactly the same as in any other production process, i.e. limestone/chalk, marl, and clay/shale. These raw materials are extracted from quarries which, in most cases, are located close to the cement plant. After extraction, these raw materials are crushed at the quarry site and transported to the cement plant for intermediate storage, homogenization and further preparation. “Corrective” materials such as bauxite, iron ore or sand may be required to adapt the chemical composition of the raw mix to the requirements of the process and product specifications. The quantities of these corrective materials are usually low compared to the huge mass flow of the main raw materials. Figure 8 Limestone transport from a nearby quarry (Chinese cement plant) Kåre Helge Karstensen [email protected] Page 44 of 189 2.4.1 Black meal process After intermediate storage and pre-homogenisation, the raw materials are dried and ground together solid fuel, approximately 13 % of coal or coke, in defined and well-controlled proportions, usually in a vertical roller mill, with a sieve residue of 16 % R 90 µm (depend on the burnability and reactivity of raw meal) and ~ 0.5 to 0.8 % R 200 µm (representing quartz grain). The ratio of fuel and raw meal will depend of the lower calorific value of the fuel. It may be possible to grind separately raw meal and solid fuel and then mix them together but this may influence the homogeneity of the final raw meal and subsequently the clinker quality. The black meal is nodulised, (as in Lepold kiln) on an inclined rotary plate, by addition of water, about 12%, before fed to the top of the kiln. The kiln is fed from the top and air is blown from the bottom. The material goes through the same process steps as other production processes, i.e. evaporation of water, calcination of CaCO3 and production of CaO and CO2, and clinker formation as it goes down the kiln in counter current with the combustion air coming from bottom. The limestone must be mixed with clay which have some plasticity properties, if not the nodules will not have enough strength and will turn back to powder in the kiln. This will again influence the air flow through the kiln and consequently the combustion and production of clinker. The uniformity of the nodule size is important both for air circulation and nodule mechanical resistance, as well as burning. A big nodule will hardly be burned in its centre, even if the combustion air can easily flow through the kiln. On the contrary, small nodule may be overburnt even if combustion air may encounter more resistance to go up the kiln. The size of nodule is determined by visual control done by the operator, usually the size is around 10 to 14 mm (~fingernail size). Kåre Helge Karstensen [email protected] Page 45 of 189 Figure 9 Black meal preparation and feeding from an inclined rotary plate at the top of the Vertical Shaft Kiln Shaft kilns consist of a refractory-lined, vertical cylinder 2-3 meter in diameter and 810 meter high. They are fed from the top with a raw material and fuel mix called black meal. The material travels through a short sintering zone in the upper, slightly enlarged part of the kiln, where free and chemically bound water are released through drying and preheating at a temperature of 20 – 900 °C. Calcination releases of CO2 at a temperature of 600–900 °C and the formation of calcium silicates and liquid phase, clinkerisation at a temperature of 1250 – 1450 °C. The clinker is then cooled by the combustion air blown in from the bottom and leaves the lower end of the kiln on a discharge grate in the form of clinker. Kåre Helge Karstensen [email protected] Page 46 of 189 Figure 10 Black meal nodules entering the top of the Vertical Shaft Kiln The material flows through the kiln in about 8 hours and the retention time above 1200 °C is around 30 to 40 minutes. The peak material temp is 1450 0C as in other kilns and tricalcium silicate, or C3S is formed at this temperature (see figure below). The temperature inside the kiln, or 1 to 2 meter under the surface at the top of the kiln, is checked by the operator by using a long 3 meter iron stick which is put it inside the kiln bed surface. If the colour of the end of the stick is red after a while, the temperature is satisfactory. Vertical shaft kilns produce usually less than 300 tonnes of clinker per day. They are only economic for small plants, and for this reason their number has been diminishing. The best demonstrated practice is a production capacity of 190~200 t/d. Kåre Helge Karstensen [email protected] Page 47 of 189 Figure 12 Formation of the four major clinker phases as a function of temperature Figure 11 Controlling the process at the top of the Vertical Shaft Kiln Kåre Helge Karstensen [email protected] Page 48 of 189 Figure 13 Three vertical shaft kilns in parallel Kåre Helge Karstensen [email protected] Page 49 of 189 Figure 14 2.4.2 Bottom of the three parallel kilns Process conditions and quality aspects The normal air flow pr ton clinker is approximately 750 Nm3/t, i.e. for a clinker production of 8 t/h, approximately 6000 Nm3/h of air is fed from the bottom. Additional air can be blown in the middle of the kiln if necessary, usually <20 % of the total volume. The gas flow at stack will be approximately ~20 000 Nm3/h, additional volume coming from the release CO2 and H2O vapour. Increasing the air flow would increase the production rate and the quality of the clinker. The position where to input this additional air (for combustion and cooling effect) may be of particular effect on the result. The air flow is probably not constant through the whole section of the kiln, if the centre of the kiln is compared with the wall. This would imply that the burning conditions are Kåre Helge Karstensen [email protected] Page 50 of 189 slightly different in the centre compared to wall as well as the temperature, and the bigger the diameter the bigger the difference may be. The incoming air at the bottom performs also the cooling effect to crystallize C3S (alite) and C2S (belite). Calculating the chemical composition is the same for VSKs as other kiln processes; the ash from the fuel will be absorbed by the clinker and this chemical composition must be taken into account when proportionate the raw meal composition. The final chemical composition will influence the lime saturation factor (LS), the alumina ratio (AR) and the silicate ratio (SR). The resulting clinker is discharged at the bottom of the kiln through a triple gate device to ensure air tightness. Figure 15 The shape of the VSK clinker is more irregular than the round nodules formed in rotary kilns Kåre Helge Karstensen [email protected] Page 51 of 189 A rotary kiln will ensure that the material is always agitated, witch improve the heat transfers and the chemical reaction between CaO, SiO2, Al2O3 and Fe2O3. In a VSK this is not the case, no CaO molecule in excess inside one single nodule will move to the neighbour nodule to combine with any "free" molecules of SiO2, Al2O3 and Fe2O3 present here. It is a static process and each nodule can be considered as one single ”independent kiln”, i.e. the homogenisation is really of primary importance in a VSK process. Pre-blending and raw meal homogenizing silos after grinding can improve homogenisation. Figure 16 Raw meal and gypsum storage at a VSK in China The free lime (unreacted CaO) of the clinker will depend on the lime saturation factor (LSF) and kiln operation but usually the free lime will be between 1,5 % at the best to 5 % at the worse. The LSF is a measure to which extent the CaO-richest compounds C3S, C3A and C4AF can be formed without the necessary presence of free lime. If the LSF is 100 % this Kåre Helge Karstensen [email protected] Page 52 of 189 means that you have exact stoicheiometric amount of CaO needed combine with SiO2, Al2O3 and Fe2O3. If your LSF is 104 %, this means that you have 4 % of CaO in excess and it will not be combined with the other molecules, i.e. at least 4 % free lime in the clinker. Free lime in the clinker is very dependant on the combustion conditions and the temperature in the kiln (see figure 12). The strength of the clinker is related to the mineral composition but also to the final grinding (blaine) and to the mineral component (pozolana). Figure 17 Quality control at the VSK laboratory In a modern rotary kiln the thermal energy is coming from the main burner 40 % and the precalciner burner 60 %. The operator can adjust the thermal energy in the process to control the final product, which is impossible in a VSK. The black meal is defined at an early Kåre Helge Karstensen [email protected] Page 53 of 189 stage, and cannot be modified during the burning process. It is not possible to adjust the thermal input and what you get out the kiln is what you have fed in. Kåre Helge Karstensen [email protected] Page 54 of 189 3. Environmental significance of cement production The main environmental impacts of the manufacture of cement in general are related to the following categories: • Dust from stack emissions and fugitive sources; • Gaseous atmospheric emissions of CO2, NOx, SO2, VOC and others; • Other emissions like noise and vibrations, odour, process water, production waste, etc. 3.1 Dust Historically, the emission of dust – particularly from kiln stacks – has been the main environmental concern in cement manufacture. “Point source” dust emissions originate mainly from the raw mills, the kiln system, the clinker cooler, and the cement mills. A general feature of these process steps is that hot exhaust gas or exhaust air is passing through pulverised material resulting in an intimately dispersed mixture of gas and particulates. Primary reduction measures are therefore hardly available. The nature of the particulates generated is linked to the source material itself, i.e. raw materials (partly calcined), clinker or cement. Dust emissions in the modern cement industry have been reduced considerably in the last 20 years, and state-of-the-art abatement techniques now available (electrostatic precipitators, bag filters) result in stack emissions which are insignificant in a modern and well managed cement plant. Dust from dispersed sources in the plant area (“fugitive dust”) may originate mainly from materials storage and handling, i.e. transport systems, stockpiles, crane driving, bagging, etc., and from traffic movement on unpaved roads. Techniques for control and containment Kåre Helge Karstensen [email protected] Page 55 of 189 of fugitive dust include dedusting of material transfer points, closed storage installations with proper ventilation, or vacuum cleaning equipment, etc. As the chemical and mineralogical composition of dust in a cement plant is similar to that of natural rocks, it is commonly considered as a “nuisance”. Reduction and control of dust emissions in a modern cement plant requires both investments and adequate management practices but is not a technical problem. Kiln dust collected from the gas cleaning devices is highly alkaline and may contain trace elements such as heavy metals corresponding to the contents in the source materials. Usually, kiln dust is completely returned to the process – either to the kiln system or to the cement mill. In rare cases, it is not possible to recycle kiln dust or bypass dust completely in the process. This residual dust is disposed of on site (or in controlled landfills) or is treated and sold to other industries, i.e. as binder for waste stabilisation or even as fertiliser. Heavy metals delivered by either conventional raw materials and fuels or by alternative raw materials and fuels from industrial sources will be mainly incorporated in clinker or – to a lesser extent – in kiln dust. Bypass dust extracted from the kiln system may be highly enriched in alkalis, sulphates and chlorides and – similarly to filter dust – in some cases cannot be completely recycled to the process. For both types of dust, conditioning and safe disposal avoiding contamination of groundwater or soil is a site-specific requirement. 3.2 Gaseous atmospheric emissions Gaseous emissions from the kiln system released to the atmosphere are the primary environmental concern in cement manufacture today. Major gaseous emissions are CO2, NOx and SO2. Other emissions of less significance are VOCs (volatile organic compounds), CO, ammonia, and heavy metals. CO2 as the main greenhouse gas is released in considerable quantities. Kåre Helge Karstensen [email protected] Page 56 of 189 Other gaseous emissions such as hydrochloric acid or hydrofluoric acid are nearly completely captured by the inherent and efficient alkaline scrubber effect of the preheater cement kiln system. Natural raw materials used for clinker production may contain volatile components in small quantities. These components will be volatilised and partly emitted under the conditions prevailing in the preheater section of a dry process cement kiln or in the drying/preheating zone of a VSK or before entering the burning zone of the long wet or long dry rotary kiln. 3.2.1 Carbon dioxide Carbon dioxide emissions arise from the calcination of the raw materials and from the combustion of fossil fuels. CO2 resulting from calcination can be influenced to a very limited extent only. Emissions of CO2 resulting from fuel combustion have generally been reduced due to the strong economic incentive for the cement industry to minimise fuel energy consumption. CO2 reduction of some 30% in the last 25 years – arising mainly from the adoption of more fuel efficient kiln processes – leaves little scope for further improvement. Potential is mainly left to the increased utilisation of renewable alternative fuels or other waste derived fuels and to the production of blended cements with mineral additions substituting clinker. 3.2.2 Nitrogen oxides NOx formation is an inevitable consequence of the high temperature combustion process, with a smaller contribution resulting from the chemical composition of the fuels and raw materials. Nitrogen oxides are formed by oxidation of molecular nitrogen in the combustion air (“thermal” NOx is the sum of nitrogen oxides; in cement kiln exhaust gases, NO and NO2 are dominant, > 90% NO, < 10% NO2). Thermal NOx formation is strongly dependent on the combustion temperature with a marked increase above 1400 °C. “Hard” Kåre Helge Karstensen [email protected] Page 57 of 189 burning required by certain raw mixes – i.e. at a higher temperature profile – increases NOx formation. While thermal NOx is the dominant contribution to total NOx generation, a smaller part may also result from nitrogen compounds contained in the fuels which are oxidised in the flame as well (“fuel NOx”). In the main burner flame, the contribution of fuel NOx is much lower than that of thermal NOx. In the secondary firing of a preheater/precalciner kiln with a flame temperature of not more than 1200 °C, the formation of thermal NOx is much lower compared to the main burner flame. Therefore, in precalciner kilns where up to 60% of the total fuel can be burnt in the calciner flame, fuel NOx may be a higher proportion of the reduced total NOx emissions. Natural raw materials such as clays or shale’s may also contain nitrogen compounds. Part of these compounds may be released and oxidised upon heating in the kiln system and may thus in certain cases considerably contribute to the total NOx emissions. NOx formation is reduced if fuel is burnt in a more “reducing” atmosphere with low oxygen content. Operation under reducing conditions is limited due to process requirements in order to maintain good clinker quality and undisturbed kiln operation. NOx emissions in cement kilns (expressed as NO2) typically vary between 500 and 2000 mg/m3. There is no information available on the formation mechanism and emissions of NOx in vertical shaft kilns. 3.2.3 Sulfur oxides Sulfur compounds enter the kiln system either with the fuels or with the raw materials. Sulfur compounds in raw materials are present mainly as sulphates (for example, calcium sulphate CaSO4) or as sulphides (i.e. pyrite or marcasite FeS2). Kåre Helge Karstensen [email protected] Page 58 of 189 Sulphates in the raw materials are thermally stable up to temperatures of 1200 °C, and will thus enter the sintering zone of the rotary kiln where they are decomposed to produce SO2. Part of the SO2 combines with alkalis and is incorporated into the clinker structure. The remaining part of SO2 is carried back to the cooler zones of the kiln system where it reacts either with calcined calcium oxide or with calcium carbonate thus being reintroduced to the sintering zone again (“chemical SO2 absorption”). Inorganic and organic sulfur compounds introduced with the fuels will be subject to the same internal cycle consisting of thermal decomposition, oxidation to SO2 and reaction with alkalis or with calcium oxide. With this closed internal cycle, all the sulfur which is introduced via fuels or via raw material sulphates will leave the kiln chemically incorporated in clinker, and will not give rise to gaseous SO2 emissions. Sulphides (and also organic sulfur compounds) in raw materials however, are decomposed and oxidised at moderate temperatures of 400 to 600 °C to produce SO2 when the raw materials are heated by the exhaust gases. At these temperatures, not enough calcium oxide is available to react with the SO2. Therefore, in a dry preheater kiln about 30% of the total sulphide input may leave the preheater section as gaseous SO2. During direct operation – i.e. with the raw mill off – most of it is emitted to the atmosphere. During compound operation – i.e. with the raw mill on-line – typically between 30 and 90% of that remaining SO2 is additionally adsorbed to the freshly ground raw meal particles in the raw mill (“physico-chemical absorption”). In grate preheater kilns SO2 absorption is also good because the gas is passing through the turbulent flow of material from grate to kiln and then passing at low velocities firstly through the bed of material which is partly calcined and then through the moist calcium carbonate in the drying chamber. In long dry and long wet kilns, the chemical absorption capacity for SO2 is generally less efficient due to the reduced contact between kiln exhaust gas and raw materials. In these kiln systems, all kinds of sulfur input may partially contribute to SO2 emissions, and the general emission level may be higher than in dry preheater kilns. Kåre Helge Karstensen [email protected] Page 59 of 189 In VSKs systems, all kinds of sulpur input may partially contribute to SO2 emissions, and the general emission level may be higher than in dry preheater kilns. Gaseous emissions such as SO2 or VOC are to a large extent determined by the chemical characteristics of the raw materials used, and not by the fuel composition. Emissions are lowest with raw materials low in volatile components. 3.2.4 Organic compounds Natural raw materials such as limestone’s, marls and shale’s may also contain up to 0.8 % w/w of organic matter (“kerogene”) – depending on the geological conditions of the deposit. A large part of this organic matter may be volatilised in the kiln system even at moderate temperatures between 400 and 600 °C. Kiln tests with raw meals of different origin have demonstrated that approximately 85 to 95% of the organic matters in the raw materials are converted to CO2 in the presence of 3% excess oxygen in the kiln exhaust gas, and 5 to 15% are oxidised to CO. A small proportion – usually less than 1% – of the total organic carbon (“TOC”) content may be emitted as volatile organic compounds (“VOC”) such as hydrocarbons. The emission level of VOC in the stack gas of cement kilns is usually between 10 and 100 mg/Nm3, with a few excessive cases up to 500 mg/Nm3. The CO concentration in the clean gas can be as high as 1000 mg/Nm3, even exceeding 2000 mg/Nm3 in some cases. The carbon monoxide and hydrocarbon contents measured in the stack gas of cement kiln systems are essentially determined by the content of organic matter in the raw materials, and are therefore not an indicator of incomplete combustion of conventional or alternative fuels. Organic matter introduced to the main burner and to the secondary firing will be completely destroyed due to the high temperatures and the long retention time of the combustion gases. Kåre Helge Karstensen [email protected] Page 60 of 189 There is currently no information available on the emissions of VOC in vertical shaft kilns. VOC release may function as a precursor for the formation of dioxins and furans in the air pollution control device of a VSK and needs to be investigated further. 3.3 PCDD/F emissions The Stockholm Convention requires Parties to take measures to reduce or eliminate releases of persistent organic pollutants (POPs) from intentional production and use, from unintentional production and from stockpiles and wastes. The chemicals intentionally produced and currently assigned for elimination under the Stockholm Convention are the pesticides aldrin, chlordane, dieldrin, endrin, heptachlor, hexachlorobenzene (HCB), mirex and toxaphene, as well as the industrial chemical Polychlorinated Biphenyls (PCBs). The Convention also seeks the continuing minimisation and, where feasible, elimination of the releases of unintentionally produced POPs such as the by-products from wet chemical and thermal processes, polychlorinated dibenzo-p-dioxins/-furans (PCDD/Fs) as well as HCB and PCBs. Cement kilns co-processing hazardous waste are explicitly mentioned in the Stockholm Convention as an “industrial source having the potential for comparatively high formation and release of these chemicals to the environment”. The World Business Council for Sustainable Development initiated a study where the objective was to compile data on the status of POPs emissions from the cement industry, to share state of the art knowledge about PCDD/F formation mechanisms in cement production processes and to show how it’s possible to control and minimise PCDD/F emissions from cement kilns utilising integrated process optimisation, so called primary measures. This is the most comprehensive study available on POPs emission from the cement industry. (Karstensen, 2006). Around 2200 PCDD/F measurements, many PCB measurements and a few HCB measurements made from the 1970s until recently was. The data represents emission levels from large capacity processing technologies, including wet and dry process cement kilns, Kåre Helge Karstensen [email protected] Page 61 of 189 performed under normal and worst case operating conditions, with and without the coprocessing of a wide range of alternative fuel and raw materials and with wastes and hazardous wastes fed to the main burner, to the rotary kiln inlet and to the preheater/precalciner. Vertical shaft kilns was not dealt with due to lack of emission data. The PCDD/F data evaluated shows that: • Most cement kilns can meet an emission level of 0.1 ng TEQ/Nm3 if primary measures are applied; • Co-processing of alternative fuels and raw materials, fed to the main burner, kiln inlet or the precalciner does not seem to influence or change the emissions of POPs; • Data evaluated from dry preheater and precalciner cement kilns in developing countries show very low emission levels, much lower than 0.1 ng TEQ/Nm3. • The emissions from modern dry preheater/precalciner kilns seem generally to be slightly lower than emissions from wet kilns. Emission data from US cement kilns in the 1980s and first part of the 1990s indicated that cement kilns co-processing hazardous waste as a co-fuel had much higher PCDD/F emissions than kilns co-processing non-hazardous wastes or using conventional fuel only. In recent documents however, the US EPA has explained the most probable cause for these findings, namely that cement kilns burning hazardous waste were normally tested under “worst” scenario trial burn conditions, i.e. typically high waste feeding rates and high temperatures in the air pollution control device, conditions today known to stimulate PCDD/F formation. Cement kilns burning non-hazardous waste or conventional fossil fuel only were however tested under normal conditions, no “worst” scenario conditions, making a comparison between hazardous waste burning and non-hazardous waste burning kilns dubious. Reducing the temperature at the inlet of the air pollution control device is one factor which has shown to limit dioxin formation and emissions at all types of cement kilns, independent of waste feeding, as lower temperatures are believed to prevent the post- Kåre Helge Karstensen [email protected] Page 62 of 189 combustion catalytic formation of PCDD/Fs. The US EPA concluded in 1999 in the new Maximum Achievable Control Technology regulation that hazardous waste burning in cement kilns does not have an impact on PCDD/F formation because they are formed postcombustion, i.e. in the air pollution control device. The study also provides a large number of measurements of PCDD/F in products and residues from the cement industry. The levels are normally low and in the same magnitude as found in foods like fish, butter and breast milk as well as soil, sediments and sewage sludge. For new cement plants and major upgrades the best available techniques for the production of cement clinker is a dry process kiln with multi-stage preheating and precalcination. A smooth and stable kiln process, operating close to the process parameter set points is beneficial for all kiln emissions as well as for the energy use. The most important primary measures to achieve compliance with an emission level of 0.1 ng TEQ/Nm3 is quick cooling of the kiln exhaust gases to lower than 200oC in long wet and long dry kilns without preheating. Modern preheater and precalciner kilns have this feature already inherent in the process design. Feeding of alternative raw materials as part of raw-material-mix should be avoided if it includes organic material and no alternative fuels should be fed during start-up and shut down. Since PCDD/F is the only group of POPs commonly being regulated up to now, there are fewer measurements available for HCB and PCBs. However, the more than 50 PCB measurements referred to in this report show that all values are below 0.4 µg PCB TEQ/m3, many at a few nanogram level or below the detection limit. 10 HCB measurements show a concentration of a few nanograms per cubic meter or concentrations below the detection limit. 3.3.1 Trace elements During the clinker burning process, all mineral input delivered by the raw materials – be it natural or alternative raw materials sources – is converted into the clinker phases at the high temperatures prevailing in the sintering zone of the kiln. Kåre Helge Karstensen [email protected] Combustion ashes from Page 63 of 189 conventional and alternative fuels used in rotary kilns are also completely incorporated into the clinker minerals. Therefore cement kiln systems do not generate combustion ashes which require separate disposal. Consequently, the fuel ashes substitute for part of the (natural) raw materials input. In order to maintain a good clinker quality, the ash composition of the fuels has to be taken into account in the raw mix design. Trace elements such as heavy metals are naturally present in low concentrations in the raw materials and fuels used for the manufacture of cement clinker. The behaviour of these metals in the burning process depends largely on their volatility. • Non-volatile metals remain completely within the product and leave the kiln system fully incorporated in the mineral structure of the clinker – similarly to the main elements. Most of the common metals are non-volatile. • Semi-volatile elements such as cadmium or lead may in part be volatilised with the high temperature conditions in the sintering zone of the kiln system. They condense on the raw materials in cooler parts of the kiln system and are reintroduced to the hot zone again. A major part of cadmium and lead will be incorporated in clinker; the remaining part will precipitate with the kiln dust and will be collected in the filter systems. • Volatile metals such as mercury and thallium are more easily volatilised and condense on raw material particles at lower temperatures in the kiln system (thallium at approximately 300-350 °C, mercury at 120-150 °C). Whereas thallium is nearly completely precipitated onto the kiln dust particles, only part of the mercury will be collected within the filter system. Volatile metals are retained in the clinker minerals to a very small extent only. Being the only metal which can be emitted with the clean gas in gaseous form, the input of mercury with raw materials and fuels has to be carefully controlled. There is currently no information available on the emissions of volatile metals in vertical shaft kilns and should to be investigated further. Kåre Helge Karstensen [email protected] Page 64 of 189 3.4 Other emissions Heavy machinery and large fans used in the cement manufacture may give rise to emissions of noise and vibrations. Odour emissions are seldom a problem with a well operated plant, but may be mainly related to emissions from handling and storage of conventional or alternative fuels. In exceptional cases, nitrogen compounds in the raw materials may lead to ammonia emissions which – even at low concentrations – may give rise to odour. Process water in cement manufacturing will usually be completely evaporated or recycled in the process. Filtrate water from filter presses used in the semi-wet process is fairly alkaline and contains suspended solids requiring site-specific treatment and/or disposal options. Emergencies such as fire, explosions or spillage/leakage are extremely rare in the modern cement industry but minor explosions can be experienced in VSKs if the coal/coke in the black meal contains high concentrations of volatile matters. Potential consequences for the environment are minimised by adequate prevention and protection measures such as fire and explosion proof design of machinery and emergency response schemes. 3.5 Normal emission levels from rotary kilns Average emission data (long term average values) from European rotary cement kilns in operation are summarised in the table below. The figures given are representative of the ranges within which kilns normally operate. Due to the age and design of the plant, the nature of the raw materials, etc., individual kilns may operate outside these ranges. Kåre Helge Karstensen [email protected] Page 65 of 189 Table 1 Long term average emission values from European cement kilns (CEMBUREAU, 1999) mg per standard cubic meter [mg/Nm3] Emission Dust 20 – 200 NOx 500 – 2000 SO2 10 – 2500 Total organic carbon (TOC) 10 – 100 CO 500 – 2000 Fluorides <5 Chlorides < 25 PCDD/F < 0.1 [ng/Nm3] Heavy metals: 3.6 - class 1 (Hg, Cd, Tl) < 0.1 - class 2 (As, Co, Ni, Se, Te) < 0.1 - class 3 (Sb, Pb, Cr, Cu, Mn, V, Sn) incl. Zn < 0.3 Air pollution control in cement production Particulate matter, commonly called dust, is the primary emission in the manufacture of cement. For the control of dust the cement industry employs mechanical collectors, i.e. cyclone collectors and to a lesser degree small size gravity settling chambers, further fabric type dust collectors, gravel bed filters and finally electrostatic precipitators. To meet the emission standards, sometimes combinations of these collectors are employed, depending on the intensity and temperature of the effluents. In all modern kiln systems, the exhaust gases are finally passed through an air pollution control device for separation of the dust before being released to the atmosphere via stacks. Today, two types of dust separators are most commonly used in the modern cement industry, electrostatic precipitators and bag filters. Kåre Helge Karstensen [email protected] Page 66 of 189 Gravity settling chambers will always be of importance for pre-cleaning of high dust laden gases; they work on the principle of removing the dust by reducing the velocity of the gas or air stream. The gas is directed from the dust generating equipment into the large volume of settling chambers, where velocity drops low enough to let large dust particles drop out by gravity. Dust settling chambers are sometimes equipped with deflectors, to change the direction of gas flow and so to shorten the settling path of the particles, improving collection efficiency. Because of the simple construction, gravity settling chambers are the lowest in cost, but at the same time also the least effective dust collection devices. Only relatively coarse particles are removed. For removing of fine dust particles, e.g. in the range of 20 microns, large size gravity settling chambers would be required, with a length of about 35 m. Therefore settling chambers are used only to reduce the dust load ahead of more efficient dust collectors such as bag filters or electric precipitators. The efficiency of gravity settling chambers is in the range of 30-70% when handling typical dust of a cement plant. The gas velocity in the settling chambers should not exceed 0.5 m/sec (Duda, 1985). Cyclones as dust collection devices were in use long before their mode of operation was theoretically explained and calculable. A cyclone consists essentially of two sections; a cylindrical and a conical one. At the top of the cylindrical section the gas enters tangentially and spirals along the walls downward into the conical section (outside vortex); from here it starts to occupy the center space of the cyclone, and spirals upward (inside vortex) to the outlet thimble. Centrifugal forces push the dust particles toward the wall where they accumulate and descend down by gravity as well as under the influence of the outer vortex. Most of the particles fall down to the bottom into a hopper from where they are removed by rotary valves or screw conveyors. The ascending gas vortex represents the clean gas, but it always contains a certain amount of fine particulates. The inside vortex occupies only a small part of the cyclone’s cross-section, and along its axis there is the so-called neutral sector; if the size of this sector is taken away with the escaping gases. From this it results that the longer distance a dust particle has to cover for reaching the boundary gas layer, the less particles are separated in the cyclone; therefore it can be said that the efficiency of a cyclone diameters of 225, 400, 600 and 3150 mm, the corresponding efficiencies equal 96.7, 92.6, 88.2, and 57.5% (Duda, 1985). In the cement industry, cyclones are for application with rotary kilns, great clinker coolers, crushers, dryers, grinding mills, conveyors, etc. They are low cost dust collectors, Kåre Helge Karstensen [email protected] Page 67 of 189 without moving parts, and can be furnished with refractory linings for high temperatures up to 975°C. Cyclones can be designed for high pressure drop as well as for medium throughput, and high dust collection efficiency. Cyclones are built with diameters from 300 to 2300 mm in arrangements of one, two, four or six units combinations. The size of the particular cyclones depends (besides the required throughput and collection efficiency) also on the dust load, the particle size as well as on the properties of the dust. Units of cyclones may be installed in parallel for large gas volumes, and in series for higher efficiencies, or in combinations of series and parallel for high throughput and high efficiency. It was learn from practical experience that the diameters of cyclones with the best efficiency are in the range of 50 to 300 mm. However, the capacity of such cyclones is low and in the range of about 25 m3/min (Duda, 1985). Therefore for higher gas volumes a multitude of small diameter cyclones are combined into groups of cyclones, commonly called multicyclones. Multicyclones are enclosed units and arranged in banks of parallel flow with feed gas from a plenum chamber and with a common dust discharge hopper; multicyclones units can contain up to 400 individual cyclones. The efficiency of multicyclone dust collectors is in the range of 85-94%, collecting dust particles of 15 to 20 micron diameter an up, with a pressure drop of 130-180 mm of water column. A disadvantage of multicyclones is occasional plugging of the small tubes. In country with less stringent air pollution regulations, the multicyclone is in the cement industry a major component in collection of dust from kiln gases, grate clinker coolers, dryers, grinding mills, etc. However, in countries with stricter dust control regulations, the multicyclone serves mostly as a primary dust collector ahead of high efficiency dust collectors. Fabric filters used in the cement industry are generally of the bag type, e.g. tubes with 300 mm diameter or less, and up to 10 m high; they consist of woven or felted cloth, made from natural or synthetic fibers. Fabric filters can handle small particles in the submicron range at high efficiencies of 99.95%. Depending on the kind of fabric, these filters can be applied to gas temperatures up to 285°C. The dust laden gas flows through a porous medium – the filter fabric – and deposits particles in the voids. After filling the voids, a cake starts to build up on the fabric’s surface, which does most of the filtering. During the precoating period which lasts only moments, the efficiency may drop. When the dust layer on the fabric Kåre Helge Karstensen [email protected] Page 68 of 189 becomes too thick, an increase in pressure drop results; this requires cleaning of the fabric. Depending on the characteristic of the dust and the type of the fabric, there are generally four methods of filter cleaning in use: • Bag swinging; this is a method which imparts a gentle oscillating motion to the tops of the filter bags; this helps to dislodge the dust cake. • Reverse air; this method collapses the filter tube by differential air pressure, thus releasing the filter cake. • Pulse pressure; the plenum chamber of the isolated compartment is for about 300 milliseconds supplied with a burst of compressed air of about 7 kg/cm. This pulse of air expands rapidly and sets up a shock wave which flexes the fabric, thus dislodging the dust cake. For the pulse air a small separate compressor is required. • Sonic cleaning; this method employs sound generators which produce a low frequency sound (<200 Hz/sec., intensity 100-150 dB), causing the filter bags to vibrate. These vibrations combined with reversed air loosen dust particles from the surface of the fabric. Cleaning is accomplished periodically, mostly in response to a timer. Sometimes two different cleaning methods are applied to one filter for a better cleaning. During cleaning action there is no airflow through the filer bag in the normal direction; this requires that the period of cleaning, the particular dust collector compartment most be taken off-stream. Therefore for continuous automatic dust collection a fabric dust type collector must have one compartment in excess of the capacity required by the gas volume. Bag filter performance is not susceptible to process disturbances or “CO peaks”. Kåre Helge Karstensen [email protected] Page 69 of 189 Figure 18 Principle of bag filter (Duda, 1985) Electrostatic precipitators use electrostatic forces to separate the dust from the exhaust gas. By means of discharge electrodes, the dust particles are negatively charged and can be separated on corresponding collecting electrodes. The particles are then discharged from the collecting electrodes to dust hoppers by electrode rapping. In contrast to bag filters, the design of electrostatic precipitators allows the separate collection of coarse and fine particles. ESP's are susceptible to process changes such as CO peaks. The dedusting efficiency can be increased by making use of more than one electric “field” operating in series. Dust collectors are evaluated by their efficiencies. The efficiencies of dust collection equipment are the ratio of the quantity of precipitated dust to the total quantity of dust introduced into the dust collection device, expressed in percent. Thus, if from an introduced dust quantity of 100 g, the dust collector retains 95 g, the efficiency of the dust collector is 95%. With a dedusting efficiency of up to 99.99% in modern control devices, it is possible to achieve a dust emission level from the stack below 20 mg per cubic meter of gas. Kåre Helge Karstensen [email protected] Page 70 of 189 In the dry process, the kiln exhaust gases have relatively high temperature and low humidity. Therefore, they can be utilised for drying of the raw materials in the raw mill during “compound operation”, i.e. when the raw mill is in operation. During “direct operation” (with the raw mill off), the hot exhaust gases have to be cooled down by means of water injection in a conditioning tower to a temperature suitable to the dust collector. With this procedure the gas volume is reduced, too, and the precipitation characteristics of the dust in the filter system are improved. Figure 19 Principle of electrostatic precipitators The dust collected in the filter devices can be fed back to the process, either by reintroducing it to the raw materials preparation system (dry process), by insufflations into the sintering zone (wet kilns), or by feeding the dust to the cement mill (if allowed in the cement standards). Kåre Helge Karstensen [email protected] Page 71 of 189 Figure 20 Schematic of an electric precipitator (dust-type) (Duda, 1985) In certain cases where the level of alkali elements is limited in cement clinker (“low alkali” clinker), not all the kiln dust can be returned to the system. Whereas an electrostatic precipitator allows the high alkali part of the dust to be separated and rejected, such a separation cannot be achieved with a bag filter and all the dust would have to be rejected. The other main sources of dust in the cement manufacturing process which require dedusting are the clinker cooler, the raw mill and the cement mills. temperature, exhaust air from cement mills does not require cooling. Kåre Helge Karstensen [email protected] Due to its low Page 72 of 189 Depending on the process stage where it is extracted, the chemical and mineralogical composition of the dust corresponds respectively to that of the raw meal, the clinker or the cement, or their intermediate products. 3.6.1 Inherent "scrubbing" of exit gases in preheater kiln In all kiln systems, the finely ground raw material moves in counter-current flow to the hot combustion gases. Thus, it acts perfectly as an integrated multi-stage exhaust gas cleaning system very similar to the operating principle of a circulating fluidised bed absorber or "dry scrubber". Components resulting from the combustion of the fuels or from the transformation of the raw materials remain in the exhaust gas only until they are absorbed by the fresh raw meal flowing in counter-current. The raw meal with its large specific surface and its high alkalinity provides an excellent medium to retain gas components within the kiln system. For instance, calcined or partly calcined raw meal with its high content of reactive calcium oxide has a high absorption capacity for acid gases such as sulfur dioxide and hydrochloric or hydrofluoric acid, but also for other pollutants such as heavy metals. Wet kilns and long dry kilns provide intimate contact between gas and solid particles mainly at the kiln inlet with its chain system for heat exchange. Semi-dry and semi- wet kilns provide this “scrubber effect” mainly in the grate preheater section of the kiln system, and also in heated crushers or dryers when these are used. Suspension preheater kilns with 4 to 6 cyclone stages are especially well suited to achieve a “multi-stage” scrubber effect especially when operating together with the raw mill (compound operation). At least 5 scrubber stages operate in series at different temperature levels between 100 and 800 °C consuming roughly 1 kg of absorbent (i.e. raw meal/hot meal) per Nm3 of exhaust gas. Kåre Helge Karstensen [email protected] Page 73 of 189 Figure 21 Schematic diagrams of preheaters (IPPC, 2001) No studies have been conducted to evaluate if there is any absorbing effect of the raw meal layers in a vertical shaft kiln. 3.6.2 Emission control in VSKs All emissions from a VSK are ducted from the top of the kiln and the main emissions are dust and CO (due to incomplete combustion/reductive conditions). Emission data from Chinese VSK is absent but dusts concentrations of 2000 to 4000 mg/Nm3 have been measured from VSK stack other places (Viacroze, 2005). The dust emissions can be very variable depending on kiln operations; stable kiln conditions will reduce the emissions. Air pollution control devices used by vertical shaft kilns is usually cyclones and bag filters. Dust collected in these devices is easy to recycle back to the process. Kåre Helge Karstensen [email protected] Page 74 of 189 Also common in China is the wet-membrane dust collection equipment. These filter systems seems to have low efficiency and high moisture content of the exit gas, which makes it difficult to recover the dust back to the production. Gas cleaning devices which utilize water as an active element to precipitate dust particles, are no longer employed in the modern cement industry, since reprocessing of the wet dust is troublesome, and handling the collected material generates additional dust problems. Electro static precipitators are not commonly used by vertical shaft kilns due to risks of explosions (difficult to control CO levels) and due to the humid exit gas. VOC is mainly related to raw meal and will change from one plant to another. Picture 22 Bag filters used for exit gas cleaning in VSKs Kåre Helge Karstensen [email protected] Page 75 of 189 Picture 23 Cyclone and filter used for exit gas cleaning in VSK Kåre Helge Karstensen [email protected] Page 76 of 189 4. Resource consumption in cement production Cement manufacturing is a “high volume process” and correspondingly requires large quantities of resources, i.e. raw materials, thermal fuels and electrical power. The average flow of raw materials, fuels and electricity needed for the production of one ton of cement and the subsequent emissions of CO2 is depicted in the figure below. Figure 24 Production flow for cement (US Geological Survey, 2004) Kåre Helge Karstensen [email protected] Page 77 of 189 4.1 Consumption of raw materials A “medium-sized” modern rotary kiln with a clinker production of 3000 tons per day or 1 million tons per year corresponds to a cement production of 1.23 million tons per year (based on average figures for the clinker content in cement in Europe). Table 2 Consumption of raw materials in cement production (IPPC, 2001) Conservation of natural resources can be achieved through increased substitution of natural raw materials and fossil fuels by industrial by-products and residues in the manufacturing process. 4.2 Consumption of energy Cement manufacturing is an energy intensive process. The specific thermal energy consumption of a cement kiln varies between 3000 and 7500 MJ per ton of clinker, depending on the basic process design of the plant. Kåre Helge Karstensen [email protected] Page 78 of 189 The dominant use of energy in cement manufacture is as fuel for the kiln. The main users of electricity are the mills (raw grinding, finish grinding, cement mills and coal mills) and the exhaust fans (kiln/raw mill and cement mill) which together account for more than 80% of electrical energy usage. On average, energy costs, in the form of fuel and electricity, represent 50% of the total production cost involved in producing a tonne of cement. Electrical energy represents approximately 20% of this overall energy requirement (IPPC, 2001). The theoretical energy use for the burning process (chemical reactions) is about 1700 to 1800 MJ/tonne clinker (IPPC, 2001). The actual fuel energy use for different kiln systems is in the following ranges (MJ/tonne clinker): • about 3000 for dry process, multi-stage cyclone preheater and precalciner kilns; • 3100-4200 for dry process rotary kilns equipped with cyclone preheaters; • 3300-4500 for semi-dry/semi-wet processes; • up to 5000 for dry process long kilns; • 5000-6000 for wet process long kilns; • 3100-4200 for vertical shaft kilns. The actual use of energy for the production of one ton of clinker is from 70 to 250 percent higher than the theoretical energy need. This clearly shows the potential for improvement of energy use through upgrades and process optimisation. The specific electrical energy consumption ranges typically between 90 and 130 kWh per ton of cement. Kåre Helge Karstensen [email protected] Page 79 of 189 4.3 Options for resource reduction A technique to reduce energy use and emissions from the cement industry, expressed per unit mass of cement product, is to reduce the clinker content of cement products. This can be done by adding fillers, for example sand, slag, limestone, fly-ash and pozzolana, in the grinding step. In Europe the average clinker content in cement is 80-85 %. Many manufacturers of cement are working on techniques to further lower the clinker content. One reported technique claims to exchange 50% of the clinker with maintained product quality/performance and without increased production cost. Cement standards define some types of cement with less than 20 % clinker, the balance being made of blast furnace slag (IPPC, 2001). Table 3 Clinker factor in various cement types (European Standard (EN197)) Cement Designation Type I II Notation Clinker GGBFS S - Silica fume D - Pozzolana Natural Industrial P Q - Fly ashes Silic. Calcar. V W - Burnt Shale T - Limestone L - Minor additional constit. 0-5 I K 95-100 Portland Slag Cement II/A-S II/B-S 80-94 65-79 6-20 21-35 - - - - - - - 0-5 0-5 Portland Silica Fume Cement II/A-D 90-94 - 6-10 - - - - - - 0-5 Portland Pozzolana Cement II/A-P II/B-P II/A-Q II/B-Q 80-94 65-79 80-94 65-79 - - 6-20 21-35 - 6-20 21-35 - - - - 0-5 0-5 0-5 0-5 Portland Fly Ash Cement II/A-V II/B-V II/A-W II/B-W 80-94 65-79 80-94 65-79 - - - - 6-20 21-35 - 6-20 21-35 - - 0-5 0-5 0-5 0-5 Portland Burnt Shale Cement II/A-T II/B-T 80-94 65-79 - - - - - - 6-20 21-35 - 0-5 0-5 Portland Limestone Cement II/A-L II/B-L 80-94 65-79 - - - - - - - 6-20 21-35 0-5 0-5 Portland Composite Cement II/A-M II/B-M 80-94 65-79 Portland Cement <- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 6 - 20 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -> <- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - 21 - 35 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -> III Blastfurnace Cement III/A III/B III/C 35-64 20-34 5-19 35-65 66-80 81-95 IV Pozzolanic Cement IV/A IV/B 65-89 45-64 - V Composite Cement V/A V/B 40-64 20-39 18-30 31-50 - - - - - 0-5 0-5 0-5 < - - - - - - - - - - 11 - 35 - - - - - - - - - - -> < - - - - - - - - - - 36 - 55 - - - - - - - - - - -> - - - 0-5 0-5 < - - - - - - - - 18 - 30 - - - - - -> < - - - - - - - - 31 - 50 - - - - - -> - - - 0-5 0-5 Kåre Helge Karstensen [email protected] - Page 80 of 189 As can be seen from table 3, ordinary Portland cement is composed of 95-100 % of Clinker. Portland pozzolana cement II B-P however contains only 65-79 % of clinker, i.e. to produce 1 ton of II/B-P you need 650 kg of clinker compared to 950 kg of clinker for the ordinary Portland cement. This is not only saving raw materials but also reduces the CO2 emission which will related to the same ratio, i.e. 950/650 = 1.46 times more CO2 emission for the production of ordinary Portland cement compared to the II/B-P cement. Recycling of collected dust to the production processes lowers the total consumption of raw materials. This recycling may take place directly into the kiln or kiln feed (alkali metal content being the limiting factor) or by blending with finished cement products. The use of suitable wastes as raw materials can reduce the input of natural resources, but should always be done with satisfactory control on the substances introduced to the kiln process. 4.3.1 Use of energy Kiln systems with 5 cyclone preheater stages and precalciner are considered standard technology for ordinary new plants, such a configuration will use 2900-3200 MJ/tonne clinker (IPPC, 2001). To optimise the input of energy in other kiln systems it is a possibility to change the configuration of the kiln to a short dry process kiln with multi stage preheating and precalcination. This is usually not feasible unless done as part of a major upgrade with an increase in production. The application of the latest generation of clinker coolers and recovering waste heat as far as possible, utilising it for drying and preheating processes, are examples of methods which cut primary energy consumption. Electrical energy use can be minimised through the installation of power management systems and the utilisation of energy efficient equipment such as high-pressure grinding rolls for clinker comminution and variable speed drives for fans. Kåre Helge Karstensen [email protected] Page 81 of 189 Energy use will be increased by most type of end-of-pipe abatement. Some reduction techniques will also have a positive effect on energy use, for example process control optimisation. 4.4 Utilisation of alternative fuels and raw materials in modern cement production In the burning of cement clinker it is necessary to maintain material temperatures of up to 1450 °C in order to ensure the sintering reactions required. This is achieved by applying peak combustion temperatures of about 2000 °C with the main burner flame. The combustion gases from the main burner remain at a temperature above 1200 °C for at least 5-10 seconds. An excess of oxygen – typically 2-3 % – is also required in the combustion gases of the rotary kiln as the clinker needs to be burned under oxidising conditions. These conditions are essential for the formation of the clinker phases and the quality of the finished cement. The retention time of the kiln charge in the rotary kiln is 20-30 and up to 60 minutes depending on the length of the kiln. The figure below illustrates the temperature profiles for the combustion gases and the material for a preheater/precalciner rotary kiln system. While the temperature profiles may be different for the various kiln types, the peak gas and material temperatures described above have to be maintained in any case. The burning conditions in kilns with precalciner firing depend on the precalciner design. Gas temperatures from a precalciner burner are typically around 1100 °C, and the gas retention time in the precalciner is approximately 3 seconds. Under the conditions prevailing in a cement kiln – i.e. flame temperatures of up to 2000 °C, material temperatures of up to 1450 °C and gas retention times of up to 10 seconds at temperatures between 1200 and 2000 °C – all kinds of organic compounds fed to the main burner with the fuels are reliably destroyed. The combustion process in the main flame of the rotary kiln is therefore complete. No (hydrocarbon type) products of incomplete combustion can be identified in the combustion gases of the main burner at steady-state conditions. The cement manufacturing process is an industrial process where large material volumes are turned into commercial products, i.e. clinker and cement. Cement kilns operate Kåre Helge Karstensen [email protected] Page 82 of 189 continuously all through the year – 24 hours a day – with only minor interruptions for maintenance and repair. A smooth kiln operation is necessary in a cement plant in order to meet production targets and to meet the quality requirements of the products. Consequently, to achieve these goals, all relevant process parameters are permanently monitored and recorded including the analytical control of all raw materials, fuels, intermediate and finished products as well as environmental monitoring. With these prerequisites – i.e. large material flow, continuous operation and comprehensive process and product control, the cement manufacturing process seems to be well suited for co-processing by-products and residues from industrial sources, both as raw materials and fuels substitutes and as mineral additions. The selection of appropriate feed points is essential for environmentally sound co- processing of alternative materials, i.e.: • Raw materials: mineral waste free of organic compounds can be added to the raw meal or raw slurry preparation system. Mineral wastes containing significantly quantities of organic components are introduced via the solid fuels handling system, i.e. directly to the main burner, to the secondary firing or, rarely, to the calcining zone of a long wet kiln (“mid-kiln”). • Fuels: alternative fuels are fed to the main burner, to the secondary firing in the preheater/precalciner section, or to the mid-kiln zone of a long wet kiln. Kåre Helge Karstensen [email protected] Page 83 of 189 Figure 25 Gas and material profiles in cyclone preheater/precalciner system in compound operation (CEMBUREAU, 1999) • Mineral additions: mineral additions such as granulated blast furnace slag, fly ash from thermal power plants or industrial gypsum are fed to the cement mill. In Europe, the type of mineral additions permitted is regulated by the cement standards. In addition to regulatory requirements, the cement producers have set up selflimitations such as • To prevent potential abuse of the cement kiln system in waste recovery operations • To assure the required product quality • To protect the manufacturing process from operational problems • To avoid negative impacts to the environment, and Kåre Helge Karstensen [email protected] Page 84 of 189 • To ensure workers’ health and safety. The cement manufacturing process is a large materials throughput process with continuous operation and comprehensive operational control. Therefore, it has a large potential for co-processing a variety of materials from industrial sources. Wastes and hazardous wastes in the environment represent a challenge for many countries, but cement kiln co-processing can constitute a sound and affordable recovery option. Cement kilns can destroy organic hazardous wastes in a safe and sound manner when properly operated and will be mutually beneficial to both industry, which generates such wastes, and to the society who want to dispose properly of such wastes in a safe and environmentally acceptable manner. The added benefit of non renewable fossil energy conservation is important, since large quantities of valuable natural fuel can be saved in the manufacture of cement when such techniques are employed. Since the early 70s, and particularly since the mid 80s, alternative – i.e. non-fossil – raw materials and fuels derived mainly from industrial sources have been beneficially utilised in the cement industry for economic reasons. Since that time, it has been demonstrated both in daily operations and in numerous tests that the overall environmental performance of a cement plant is not impaired by this practice in an appropriately managed plant operation. Cement kilns make full use of both the calorific and the mineral content of alternative materials. Fossil fuels such as coal or crude oil are substituted by combustible materials which otherwise would often be landfilled or incinerated in specialised facilities. The mineral part of alternative fuels (ashes) as well as non-combustible industrial residues or by-products can substitute for part of the natural raw materials (limestone’s, clay, etc.). All components are effectively incorporated into the product, and – with few exceptions – no residues are left for disposal. The use of mineral additions from industrial sources substituting clinker saves both raw material resources and energy resources as the energy intensive clinker production can be reduced. With the substitution of fossil fuels by (renewable) alternative fuels, the overall output of thermal CO2 is reduced. A thermal substitution rate of 40% in a cement plant with an Kåre Helge Karstensen [email protected] Page 85 of 189 annual production of 1 million tons of clinker reduces the net CO2 generation by about 100,000 tons. Substitution of clinker by mineral additions may be more important as both thermal CO2 from fossil fuels and CO2 from the decarbonation of raw materials is reduced. Since only moderate investments are needed, cement plants can recover adequate wastes at lower costs than would be required for landfilling or treatment in specialised incinerators. In addition, public investment required for the installation of new specialised incinerators would also be reduced. Substitute materials derived from waste streams usually reduce the production cost in cement manufacturing, thus strengthening the position of the industry particularly with regard to imports from countries with less stringent environmental legislation. It will also facilitate the industry’s development of technologies to further clean up atmospheric emissions. Kåre Helge Karstensen [email protected] Page 86 of 189 5. Cement production in China - general challenges The Chinese cement market is the largest in the world, and continuing to grow driven by strong demand. The industry is highly fragmented, characterized by a large number of small, vertical shaft-kilns, operated at the village and township level, along with a smaller number of modern rotary-kiln facilities using modern, dry-process technology. Counterparts in the US and Europe and Japan rely exclusively on rotary kilns, of large capacities. While many still use an older, less efficient wet process, new plants use dry processes exclusively. 5.1 Production Cement production in China has grown steadily the last 20 years and increased by more than 10 % yearly (Soule et al, 2002). It is estimated that the Chinese cement industry produced 1,060 billion ton cement in 2005, accounting for 808 kg per capita and approximately 50 % of the world production (Cui and Wang, 2005). It is estimated that the cement production will reach its saturation point around year 2010 with an annual cement output at the upper limit of 1200 million tonnes (Cui and Wang, 2005). Approximately 60 % of this cement was produced in approximately 4000 Vertical Shaft Kilns (VSKs). New and modern dry process production lines constituted 508 units by the end of 2004 and as much as 704 will be in full operation within the near future (Cui and Wang, 2005). By the end of 2004, there were 5027 cement producers in China employing 1,422,100 workers (Cui and Wang, 2005). These companies were owned by the state, by townships, communities, collectives and by private companies. Chinese cement industry is characterized by its irrational structure, low production efficiency, high energy consumption and heavy environmental pollution, which will curb its further development (Cui and Wang, 2005). Kåre Helge Karstensen [email protected] Page 87 of 189 While some 3200 of these smaller facilities have been closed under government orders, many remain in operation, or have restarted operation. Over 300 vertical kilns were constructed in China in 2000. Zhejiang Provincial officials have recently declined to issue permits for any cement facility smaller that 2000 tonnes/day (Chinese Enterprise Confederation, 2003). Government efforts have turned to building larger cement groups. Considerable progress has been made in these larger cement groups in improving technology and efficiency, with concomitant reductions in environmental impacts. Major air pollutants (dust, SOX and NOX) are nevertheless generally discharged at levels above (sometimes far above) EU and US facilities. For example, average dust emissions in Chinese plants are more than five times current European standards (Chinese Enterprise Confederation, 2003). Figure 26 World and Chinese cement production growth in the period 1950-2003 (US Geological Survey, 2004) In 1995, the domestic production was 476 million tonnes, were approximately 81 % was made in Vertical Shaft Kilns (Cui and Wang, 2005). It is anticipated that the Chinese Kåre Helge Karstensen [email protected] Page 88 of 189 cement industry will finish its restructuring target within the next 20 years, which would involve phasing out the VSKs and replace by modern dry processes. This will reduce the overall emissions, reduce the fossil fuel consumption and improve the cement quality. 5.2 Geographic location Most of the cement plants are located in the dense population areas along the east cost of China, on the middle or down-stream banks of the Yangtze River, and are near large and medium-size cities. In 2002, cement industries located in ten provinces accounted for about 70% of the total sales. These provinces are (in descending order) Shangdong, Zhejiang, Guangdong, Jiangsu, Hebei, Henan, Sichuan, Hubei, Anhui and Hunan (Wang, 2005). It is expected that new dry process kilns will be spread from coast developed areas to developing areas, such as Northeast, Southwest, Central and Northwest China, and the outmoded production technology such as mini cement works with shaft kilns will be expeditiously eliminated or only left a small proportion in mountain areas (Cui and Wang, 2005). The demand for high-quality cement, especially high grade cement and special cement will be growing further. 5.3 Raw material consumption 1326 limestone quarries are currently known in China containing approximately 56,120 million tonnes of limestone (Cui and Wang, 2005). Taking into account future growth of cement production this deposits can only maintain the need for manufacturing of cement for 59 years (other industry exploitation not taken into account). In addition, cement production usually needs limestone sources of high quality and current quarrying methods are wasting large amounts of non-spec material (Cui and Wang, 2005). The raw material sources is neither uniformly distributed around the country and provinces with high production may not be self-sufficient for a long time. In addition, cement is a low profit product and the transportation distance is usually limited to a radius of 200 Kåre Helge Karstensen [email protected] Page 89 of 189 kilometres. Certain provinces will have limestone sources for a maximum 40 years production at current level (Cui and Wang, 2005). Many VSKs plants have virtually no environmental controls in place; and indeed, the nature of the old technology precludes effective use of modern dust (and other emission) controls. 5.4 Energy consumption In 2003, the cement industry consumed about 129 million tons of standard coal, equal to 148 million tons of common coal. This amounts to approximately 11 % of whole consumption of coal in that year (Cui and Wang, 2005). This consumption would be equivalent to approximately 200 million tonnes of common coal for 2005. The Chinese energy supply is mainly based on the utilization of coal. In 2002, the geological investigation showed that the storage of coal is about 130,000 million tons and will meet the domestic requirement for another 54 to 81 years (Cui and Wang, 2005). The quality and the distribution of coal are uneven along the country and requires long transportation distances in some situations. In 2003, the electricity consumption in the Chinese cement industry was 94,930 million kWh, amounting to approximately 5 % of the electric consumption in the whole country (Cui and Wang, 2005). There is very little use of alternative fuels in Chinese plants, reflecting both the lack of infrastructure to collect and recycle these materials and the inability of vertical shaft kilns to use these materials safely or easily (Chinese Enterprise Confederation, 2003). This is an issue of growing concern, as China faces increasing waste management and disposal challenges. Enforcement of environmental regulations appears uneven, with small or no penalties for violation of environmental standards. Small facilities are frequently excused from compliance for lack of resources. Kåre Helge Karstensen [email protected] Page 90 of 189 5.5 Emissions Based on the current technical level in China, the production of 1 ton of cement will lead to an emission of 20 kg of dust, 1 ton of CO2, 2 kg of SO2 and 4 kg of NOx. It is estimated that the Chinese cement industry in 2003 emitted more than 13 million tons of dust (about 27 % of all emissions from the national industry), 660 million tons of CO2 (about 22 % of all emissions), 1.31 million tons of SO2 (about 4.85% of all emissions) and 2.62 million tons of NOx (Cui and Wang, 2005). Figure 27 CO2 emissions 2004 (US Geological Survey, 2004) No VSKs has been monitored for dioxins and furans and no emission factors have so far been developed for this industry category (UNEP, 2005). The facilities employing modern technology often have a smaller average size than international counterparts, but produce products meeting international standards, and employ varying degrees of environmental controls. Kåre Helge Karstensen [email protected] Page 91 of 189 5.6 Comparison of performance The consumption of coal and electricity between the various productions technologies used in China in 2002 is given in the table below (Cui and Wang, 2005). The number of VSKs has been reduced since then, but it can be expected that the relative differences in coal consumption and electricity consumption is unchanged. Table 3 Performance of various process technology in China in 2002 (Cui and Wang, 2005). Electricity Process Number technology Capacity Coal consumption (million tonnes) consumption (kWh/ton (kg/ton clinker) cement) Rotary kilns 1428 187.5 157 105 precalciner 257 110.0 107-125 105-115 preheater 82 2.5 130-140 115-130 preheater (shaft) 295 10.0 165-170 120-130 wet process 254 30.0 190-210 95-105 other 540 35.0 -200 -115 VSKs 6000 670 160-220 95-125 Kåre Helge Karstensen [email protected] Page 92 of 189 Compared with preheater/precalciner kilns, VSKs seems to consume from 14 % to 105 % more coal pr ton of clinker. The difference in electricity consumption seems to be slightly in favour of VSKs, basically because VSKs are not using much electric equipment like ESP's and drivers; the electricity consumption is mainly due to mills and fans. In the table below Cui and Wang (2005) compare what they call "advanced technical level of foreign and domestic cement industry". The year of comparison is unclear. Table 4 Comparison of "advanced technical level of foreign and domestic (Chinese) cement industry" (Cui and Wang, 2005). Item Foreign advanced level Domestic advanced level The capacity of large plants up to 98.3% of whole about 32% of whole capacity with precalcining systems capacity 95% 85% Heat consumption 2888 kJ/kg-clinker 3350 kJ/kg-clinker Coal consumption 100 kg standard coal/ton- 120 kg standard coal/ton- clinker clinker Availability Electricity consumption 92 kWh/ton-cement 110 kWh/ton-cement Dust emission 15 mg/Nm 100 mg/Nm3 SO2 emission 300 mg/Nm3 800 mg/Nm3 NOx emission 200 mg/Nm3 400 mg/Nm3 150,00 tons/ per person, per 4000 tons/ per person, per year year Labour efficiency 3 Kåre Helge Karstensen [email protected] Page 93 of 189 The comparison by Cui and Wang (2005) seems to be in favour of what is called foreign advanced level. If compared with average emission data from European cement kilns, the difference may not be that great (see table 1), especially on the emissions to air. Vertical shaft kilns generally produce lower quality (#325 grade or less) cement which is neither suitable for large structures nor for major infrastructure projects such as bridges, airports, etc. It is also not suitable for export to international markets. Figure 28 5.7 New modern Chinese cement plant with limestone quarry nearby Health and Safety The Chinese cement industry employs nearly one and half million people. It is not clear if detailed employee accident and incident records are kept, or used to make safety Kåre Helge Karstensen [email protected] Page 94 of 189 improvements. Health and safety performance information is lacking. There is relatively little use of traditional personal protective equipment, like safety shoes, facemasks (for dust), and safety glasses in Chinese facilities. 5.8 Efficiency - a summary It is not clear that benchmarking and operational efficiency assessments are made on a routine basis. Data developed the Chinese Enterprise Confederation (2003) point to significantly lower efficiencies for Chinese plants with respect to power use (approximately 25 % less efficient), fuel use (approximately 75 % less efficient), and labour (approximately six – thirty times more employees per ton of product) and product losses (nearly 2 % product loss through dust emissions in China). As a general rule, larger facilities have and continue to invest more in energy and process efficiency programs than smaller ones. Vertical shaft kilns, which still dominate cement production, are limited to about 300-tonnes/day capacities. Kåre Helge Karstensen [email protected] Page 95 of 189 6. Cement production in China - general opportunities for improvement Major opportunities exist to improve overall industry efficiency by closing the least efficient small facilities and consolidating processing in larger, more efficient units (Chinese Enterprise Confederation, 2003). Medium sized plants could be offered some time period for making improvements up to a specified level of environmental and product quality performance. Failing to reach this level would then ultimately lead to closure. Larger facilities can gain the economies of scale, use advanced process control technologies, and environmental control equipment. This could help make a substantial reduction in dust emissions (and the accompanying long term respiratory health problems) as well as workplace exposure. Some portions of existing smaller facilities could possibly be retained for use in grinding, blending, bagging and distribution of cement, allowing some local employment to be retained as well. Employee health and safety can be quickly improved providing relatively inexpensive personnel protective equipment, such as dust masks, safety shoes, etc. 6.1 Policy and regulation The Chinese government has set up a series of policies and regulations to stimulate the sustainable development of the cement industry, the largest of that sector in the world. It has continued to grow well, driven by strong demand for construction and new housing in many urban areas. The industry is highly fragmented, characterized by very large numbers of small, vertical shaft-kiln type facilities which operate at village and township levels. The Chinese government has imposed the macro economic control measures for some overheated industries, and cement manufacturing is one of them. In accordance with the control measures announced in 2004, the National Development and Reform Commission (NDRC), one of the nation’s leading industrial watchdogs, announced that full implementation of control would be strengthened by restrictions on land use and bank loans to prevent a repeat of overheated investment in that sector (Wang, 2004). Kåre Helge Karstensen [email protected] Page 96 of 189 NDRC considers that future investment in cement industries should be directed to the improvement of production facilities to reduce the cost of unit production, to meeting the challenges of energy efficiency and the shortage of raw materials including coal and electricity as well as water, and to the implementation of Cleaner Production (CP) and the Circular Economy (CE) in that industrial sector (Wang, 2004). Because of the seriousness of the production and environmental problems, industrial consolidation has become a necessity. By the end of 2000, China had closed down a total of 3,200 small plants with small size cement kilns and decreased production capacity by more than 80 million tons (Wang, 2004). However, over 300 vertical kilns, with the blessing of local government policy to boost the economy and employment, were built with this out-ofdate technology, with an annual production of 30 million tons (Wang, 2004). Since 2003, the central government has issued executive regulations to cool down several overheated and rapidly expanding industries (including the cement sector) by denying construction permits for new plants and by restricting bank loans and financing from the stock market, but still encouraging funding for facility upgrades (Wang, 2004). 6.1.1 Environmental regulation of the Chinese cement industry The emission standard of Air Pollutants for Cement Industry in China was issued 29 December 2004 and was effective from 1 January 2005. The regulation GB 4915-2004 was issued by the State Environmental Protection Administration of China, General Administration of Quality Supervision, Inspection, and Quarantine of China. The standard was proposed by the Science & Technology Department of State Environmental Protection Administration and drafted by Environmental Standard Institute of Chinese Research Academy of Environmental Science, Hefei Cement Research & Design Institute of China Building Material Group and China National Materials Industry Group. The Standard is established to carry out the Law of the People’s Republic of China on Prevention and Control of Atmospheric Pollution, to control the air pollutants emission of the Kåre Helge Karstensen [email protected] Page 97 of 189 cement industry, and to promote structural readjustment of the cement industry. The Standard is a substitute for Emission Standard of Air Pollutants for Cement plant GB 4915-1996 and is considerably strengthen compared to the previous standard (see Annex 2). Figure 29 Humid and dusty VSK emissions The application of the Standard has been expanded to cover the entire process of cement industry production, including grinding plant, mine exploitation and field crusher system. The new Standard gives particulate emission requirements and the emission limits for rotary kiln and shaft kiln are identical. There is no longer any different emission limits for different functional regions of ambient air quality or different emission limits for different existing production lines. However, a transitional period to meet the standard is set but the mission limits of newly established production lines are stricter. The new Standard also gives Kåre Helge Karstensen [email protected] Page 98 of 189 emission requirement for cement kiln incinerating hazardous wastes, as well as regulations of environmental conservation and regulations on synchronous running rate and height of exhaust funnel. The new Standard also requires installing continuous monitoring of the exit gas emissions. 6.1.2 Enforcement Wang (2004) recommends the following with regards to regulation and enforcement: (1) For a new plant, build the necessity for CP implementation into the EIA (Environmental Impact Assessment) and make it compulsory. Any dust emission control equipment must be designed, constructed, and operational simultaneously with the main plant body. (2) For existing plants which are emitting dust concentrations over the national or local standards, CP audits are mandatory in accordance with the CP Law. Guide the plants on means to reduce the emissions to within the limits. (3) Increasing the pollution taxes for overall dust emissions. At present, the tax rate is set at 0.28 RMB per kg, and it represents only about 40% of the operational cost for the dust control process. The result is a lack of initiative and reluctance by industry to install the control devices. It is suggested that governments should raise the fee/tax rates higher than the capital and operational costs in order to stimulate the willingness of enterprise to use such devices, (4) Managers/administrators of national or local scientific and technical institutions should include overall planning and on environment and technology research and development in their yearly programs. For the cement industry, expanding CP areas and subjects for using waste substances as tires, plastics and other alternative raw materials for the substitutions of virgin fuel (materials.) To enhance further CP plans, provide technical support. Kåre Helge Karstensen [email protected] Page 99 of 189 (5) National and local Development and Reform Commissions should negotiate and consult the finance and taxation departments to formulate financial support for those plants with noticeable achievements in benefits to the economy and the environment. For other action plans without any clear economic benefit, the comprehensive utilization of wastes should be encouraged with defined and favourable financial policies and support, in order that the CP implementation can be realized in the cement industry as well as other related enterprises. (6) The size structure and changes to the sector organization plan (privatization) as announced by the State Council must be conducted and carried out for the purpose of improving the environment, economic viability, and for the capability of competing on the world market by reduced costs. 6.1.3 Emissions of persistent organic pollutants POPs China is a signatory to the Stockholm Convention, which requires Parties to take measures to reduce or eliminate releases of persistent organic pollutants (POPs) from intentional production and use, from unintentional production and from stockpiles and wastes. The chemicals intentionally produced and currently assigned for elimination under the Stockholm Convention are the pesticides aldrin, chlordane, dieldrin, endrin, heptachlor, hexachlorobenzene (HCB), mirex and toxaphene, as well as the industrial chemical Polychlorinated Biphenyls (PCBs). The Convention also seeks the continuing minimisation and, where feasible, elimination of the releases of unintentionally produced POPs such as the by-products from wet chemical and thermal processes, polychlorinated dibenzo-p-dioxins/-furans (PCDD/Fs) as well as HCB and PCBs. Cement kilns co-processing hazardous waste are explicitly mentioned in the Stockholm Convention as an “industrial source having the potential for comparatively high formation and release of these chemicals to the environment” (see chapter 3.3). Kåre Helge Karstensen [email protected] Page 100 of 189 The regulation GB 4915-2004 of Air Pollutants for Cement Industry requires that the "emission concentration of dioxin should not exceed 0.1ng TEQ/m3". See also Annex 2. 6.1.3.1 Regulatory framework to control POPs emissions in the European Union In all EU Directives the principles of integrated pollution prevention and control (IPPC), specifically laid down in Directive 96/61/EC, covering all aspects of environmental performance in an integrated manner, shall be taken into account. Also Best Available Technique Reference Documents (BREFs) established by the European IPPC Bureau have to be taken into account by the authorities for issuing permits. Also the Protocol on persistent organic pollutants signed by the EU within the framework of the United Nations Economic Commission for Europe (UN-ECE) Convention on long-range transboundary air pollutions sets a legally binding PCDD/F emission limit value of 0.1 ng TEQ/m3 for incinerating more than 3 tonnes per hour of municipal solid waste and 0.5 ng TEQ/m3 for installations burning more than 1 ton per hour of medical waste, and 0.2 ng TEQ/m3 for installations incinerating more than 1 ton per hour of hazardous waste. Gaseous emissions from cement kiln using conventional fuels are regulated within the EU under the so-called Air Framework Directive 84/360/EEC (Eduljee, 1998). A technical note defining Best Available Techniques (BAT) for the manufacture of cement was published in 2001 (IPPC) and includes the emission levels achievable when using conventional fuels within the kiln, but does not identify BAT achievable emission levels using secondary or substitute fuels. The European cement industry has argued that prescriptive regulations designed to ensure combustion in dedicated waste incinerators are inappropriate for the regulation of fuel substitution in industrial furnaces such as cement kilns. The nature of the thermal processes governing cement manufacture is such that emissions arising from the combustion of the alternative fuel should be treated separately to emissions arising from the raw materials feeding the kiln. Kåre Helge Karstensen [email protected] Page 101 of 189 This principle has been accepted by the EU and applied in Directive 2000/76/EC on the incineration of waste, regulating the use of hazardous waste as a alternative fuel in cement kilns, by recognising and providing for the practice of ”co-incineration”. Individual Member States have also accepted the need to take account of emissions from raw materials in setting emission controls on exhaust gases from cement kilns. For example, in France emission limits for sulfur dioxide are set according to the sulfur content in the raw materials. In Germany the national waste incineration regulation 17.BimSchV makes specific provision for the exemption of carbon monoxide and total organic carbon emissions from cement plants burning waste supplementary fuels on the grounds that the emission of these substances is not a function of the fuel used or the amount of waste burnt, and is also not a relevant parameter for ensuring the safe combustion of secondary fuels in such plants. In general, the European cement industry has argued that regulatory decisions concerning the use of secondary fuels in cement plants are best taken at national level, thereby allowing regulators to take into account specific local conditions in writing permits. This position has been endorsed by the EU in Directive 96/61/EC on IPPC, in which national regulatory authorities are requested to base operating permits on BAT, while taking into account the technical characteristics of processes, their geographic location and local environmental conditions. As a safeguard, permits must not allow any EU environmental quality standards to be breached. Notwithstanding the derogations on emissions of substances such as sulfur dioxide and carbon monoxide, the cement industry has accepted the emission standard for dioxins of 0.1 ng TEQ/m3 generally applied throughout EU to regulate dioxin emissions from municipal and hazardous waste incineration. Emission levels shall be corrected to 273 K, 101.3 kPa, 10% O2 and dry gas. 6.1.3.2 Regulatory framework to control POPs emissions in the US Under the authority of the Clean Air Act, the US Environmental Protection Agency (EPA) promulgated national emission standards for new and existing cement kilns burning non-hazardous waste in May 1999 (Federal Register, 1999a; 2004). The regulations are Kåre Helge Karstensen [email protected] Page 102 of 189 specific to the I-TEQ concentration in the combustion gases leaving the stack. Existing and new cement kilns either combusting or not combusting hazardous waste as auxiliary fuel cannot emit more than 0.2 ng I-TEQ/m3 (corrected to 250C, 7% O2 and dry gas). In addition, the temperature of the combustion gases measured at the inlet to the air pollution control device cannot exceed 232 °C. The rule requires owners or operators of facilities to test for PCDD/Fs every 2½ years and the Office of Air Quality Planning and Standards (OAQPS) expects this rule to reduce I-TEQ PCDD/Fs emissions from existing and new facilities by 36 % over the next few years (Federal Register, 1999a, 2004). 6.2 Technology development Technological advancement of the Chinese cement industry will concentrate on the further development of new technology, on the utilization of secondary materials and other supplementary cementitious materials. In recent years, improvement of cement production lines with precalcining systems includes the new homogenization technology, new preheating and precalcining systems with the capacity of up to ten thousand tons of cement per day, various new types of crushing and grinding systems, new operation and management systems, new environmental protection measures such as the use of new bag dust collector and low NOx burner (Cui and Wang, 2005). The utilization of secondary materials and supplementary cementitious materials may save huge amounts of natural resources. The use of secondary fuels for cement manufacturing is just starting slowly in China but alternative cementitious materials such as fly ash has been used for cement manufacturing for a long time. It is estimated that the production of fly ash and coal gangue is near 300 million tons/year each. If all of these materials can be used for cement and concrete manufacturing, then the output of clinker can be reduced by 50% with the need of burning process (Cui and Wang, 2005). Dry preheater/precalciner kilns are regarded to be the best available techniques (BAT) and to constitute the Best Environmental Practise (BEP). These technologies are also the most economically feasible option, which constitutes a competitive advantage and thereby contributes to gradually phase out older, polluting and less competitive technologies. Kåre Helge Karstensen [email protected] Page 103 of 189 6.2.1 Best available techniques (BAT) For new plants and major upgrades the best available techniques for the production of cement clinker is a dry process kiln with multi-stage preheating and precalcination. A smooth and stable kiln process, operating close to the process parameter set points, is beneficial for all kiln emissions as well as the energy use. This can be obtained by applying: - Process control optimisation, including computer-based automatic control systems. - The use of modern fuel feed systems. • Minimising fuel energy use by means of: - Preheating and precalcination to the extent possible, considering the existing kiln system configuration. • Careful selection and control of substances entering the kiln can reduce emissions and when practicable, homogenous raw materials and fuels with low contents of sulfur, nitrogen, chlorine, metals and volatile organic compounds should be selected. Kåre Helge Karstensen [email protected] Page 104 of 189 Figure 30 New modern Chinese cement plant with preheater and precalciner Kåre Helge Karstensen [email protected] Page 105 of 189 In the Best Available Technique Reference (BREF) document, techniques and possible emission levels associated with the use of BAT are presented that are considered to be appropriate to the sector as a whole (IPPC, 2001). In some cases it may be technically possible to achieve better emission levels but due to the costs involved or cross media considerations, they are not considered to be appropriate as BAT for the sector as a whole. The concept of “levels associated with BAT” is to be distinguished from the term “achievable level”. Where a level is described as “achievable” using a particular technique or combination of techniques, this should be understood to mean that the level may be expected to be achieved over a substantial period of time in a well maintained and operated installation or process using those techniques. Actual cost of applying a technique will depend strongly on the specific situation regarding, for example, taxes, fees, and the technical characteristics of the installation concerned. It is not possible to evaluate such site-specific factors fully. It is intended that the general BAT could be used to judge the current performance of an existing installation or to judge a proposal for a new installation and thereby assist in the determination of appropriate “BAT-based” conditions for that installation. It is foreseen that new installations could be designed to perform at or even better than the general “BAT” levels. It is also considered that many existing installations could reasonably be expected, over time, to move towards the general “BAT” levels or do better. While the BAT and BEP levels do not set legally binding standards, they are meant to give information for the guidance of industry, States and the public on achievable emission levels when using specified techniques. 6.2.2 Best available techniques and best environmental practise for controlling and minimising PCDD/F emission The following primary measures are considered to be most critical in avoiding the formation and emission of PCDD/F from modern cement kilns and seems in most cases to be sufficient to comply with an emission level of 0.1 ng PCDD/F I-TEQ/Nm3: Kåre Helge Karstensen [email protected] Page 106 of 189 9 Quick cooling of kiln exhaust gases to lower than 200 oC in long wet and long dry kilns without preheating. In modern preheater and precalciner kilns this feature is already inherent in the process design. 9 Limit or avoid alternative raw material feed as part of raw-material-mix if it includes organics. 9 No alternative fuel feed during start-up and shut down. 9 Monitoring and stabilisation of critical process parameters, i.e. homogenous raw mix and fuel feed, regular dosage and excess oxygen. 6.3 Cleaner production opportunities It has been long realized that in controlling industrial pollution and lowering production costs, it is important to have cooperation between enterprises and government, and to make full use of market influences to stimulate industries to take positive measures for improving the environment and thus the economy. In cement industrial sector, though it has made progress recently in these areas, performance is still far from desirable to reach sustainable development goals (Wang, 2004). 6.3.1 Emission reduction Major emissions from cement manufacturing plants traditionally are airborne pollutants and powered dust from the kiln and its emissions. Pollutants are mainly particulates from a number of solid processing and handling operations, CO2, SO2 and NO2. Relatively speaking, SO2 and NO2.emissions from cement industries are small, and they represent less than 2% of the total emitted of these compounds in USA and Europe. In recent years, as a result of advanced control technology and equipment design, such as electro Kåre Helge Karstensen [email protected] Page 107 of 189 static precipitator and bag filter facilities, significant progress has been reached in reducing air emissions from the cement industrial sector. For a new plant today, air pollution emissions are at least 90% less than those from typical facilities built 30-40 years ago (Wang, 2004). "In developed countries, the cement industry has reduced substantially emissions of SO2, NO2 and particulates through a combination of improved technology and specific regulatory standards. This is often not so in China, especially for those old and small size plants. Particulate emissions from the cement industry accounted for 40% of the total estimated 25 million tons emitted in 1998. In the public’s mind, the industry was and continuous to be the worst dust emitter" (Wang, 2004). World wide, the cement industry produces about 5 % of global manmade CO2 (Worrell et al, 2001). Cement is a low value-added product, and the average price has been of 50-60 $ US/ton since 2000 however, in China it skyrocketed to about 200 $ early in 2004 (Wang, 2004). "As the industry produces an equal weight of CO2 and clinker, any cost imposed on the reduction of CO2 emission to the atmosphere and any management plan can have a significant impact on the industry’s financial performance. At the present rate of many CO2 management expenses on the market - in the range of $ 10 to $ 25/ton and expected to rise as the public demand its treatment - most Chinese cement enterprises will not be able to foot the bill, unless their production capacities are increased and are big enough to bear the cost" (Wang, 2004). Increasing the use of alternative fuels and raw materials can reduce the use of virgin materials including limestone and petroleum products, and can reduce CO2 emission and production costs. Alternative and substituted materials as fly ash from power plants, steel mill slugs, and pozzolanic substances can be used in cement to replace some of the limestone, and the quality of the product is not affected in applications. In China the governmental standard-setting organizations have slowly changed the strict composition criteria into that of cement performance, and as a result a much wider use of blended products can be witnessed (Wang, 2004). The following measures are recommended for China with regards to achieve emission reduction (Wang, 2004): Kåre Helge Karstensen [email protected] Page 108 of 189 (1) A well defined emission inventory and reporting process with emission reduction cost estimates; (2) A program for effective communication with the local stakeholders including regulatory personnel. Reporting to the public on emissions and reduction progress is important to engagement in the program; (3) A program to define the emission reduction targets and timetables. This is of vital importance and of deep concern to the public, and accounts for the economic forecast of the plant, and current and pending regulatory requirements; (4) In order to win confidence, the industry needs an effective way of monitoring and reporting emissions which can address the safety concerns of the public and product quality concerns of the users. 6.3.2 Water pollution and dust recovery Water pollution is not generally an important issue for cement production. On the other hand, close attention must be paid to deal the problems of solid waste, especially cement kiln dust. Chinese cement operations produced more than 8 billion tons of dusts in 2000, of which about 7 billion tons were collected and recycled with an estimated cost saving from materials of 35 hundred million RMBs (Wang, 2004). Dust collected by control devices can be recycled internally as raw material to lower the production cost. In China, specific regulations issued by government for cement industries do exist, but often compromises take place, especially by the local authorities, between economic benefit and environmental deterioration (Wang, 2004). Through technical innovation and improvement, and industrial restructuring, powdered dust has been collected and returned to the process, replacing fresh raw materials. Such inner recycling within the plant with different types of dust collection equipment through CP implementation has greatly reduced air pollution and increased energy/resource savings (Wang, 2004). Kåre Helge Karstensen [email protected] Page 109 of 189 One example from Nan Xin Cement plant in Suzhou, Jiangsu province illustrates this potential (Wang, 2004). "By using CP order to control dust emission and to implement recycling as well as production expansion, the Company invested more than 2 million RMBs to convert wet- membrane collection equipment, the low efficiency type, into a bag house with high efficiency. From the process, the local emission standard for dust has been reached, and in addition, it obtained remarkable economic benefits. The dust collected with the membrane had a high moisture content and was difficult for raw material substitution. With the bag house technique, dust can be recycled and reused. The estimated annual amount of dust collected is more than 8,000 tons. If the original material costs about 100 RMB per ton, an annual saving is of 800,000 RMB, with an addition of 300,000 RMB from the deduction in discharge/emission fees, a total benefit of one million RMB is realized. Extra operation cost and labor amounts to about 700,000 RMB, so the net economic benefit is 300,000 BMB and the amortized capital investment for the equipment can be repaid within eight years. The provincial authorities have used this example to publicize benefits, and to encourage other plants in the sector to adopt CP/CE principles to fit their individual needs for dust collectors, and to include the recycling unit into the production process management with regular inspection and maintenance to assure its proper operation". By CP implementation, the waste minimization/recycling/reuse process is not limited to powdered dust recovery generated by the cement sector. It also extends to wastes from other industries including slugs from steel mills, powdered coal dust from power plants, sulfate gypsum from chemical industries and coal residue from industrial boilers (Wang, 2004). 6.3.3 Energy consumption The average coal used per ton of cement production has been decreased from 190 kg in 1990 to 166 in 2000 (Wang, 2004). For a production of 5.79 billion tons during this period, this has saved 139 million tons of coal. Chinese industries however will on average consume 47% more energy and emit 13 times more dust than those in developed countries which have kilns with much larger production capacities (Wang, 2004). Vertical kilns produce the lowest Kåre Helge Karstensen [email protected] Page 110 of 189 rate of dust compared with other types, the technology is out-of-date since the quality of the product is poor and unstable, and energy consumption is high (Wang, 2004). Figure 31 6.3.4 Dusty environment at the top of the VSK Health and safety The Chinese cement industry can and must reduce the number of injuries and fatalities for production, and it should be as good as that of the petroleum and chemical sectors. Techniques for safety and health performance are well known and established, and have been applied successfully. The key factors are (Wang, 2004): (1) Incorporating safety into the working culture of the enterprise through continuous reinforcement and education about safe working practices and Kåre Helge Karstensen [email protected] Page 111 of 189 conditions; establishing safety awards; and awareness-raising of senior management; (2) A systematic program for tracking, reporting, and analyzing all safety related incidents, including those “near-miss” cases; (3) Communication and dissemination systems within enterprises or groups to expedite the distribution and sharing all safety-related information to avoid repeated instances; and (4) Ongoing analysis of incidents, responses, and progress to provide information on continuous improvement. 6.3.5 Impacts on land use Efforts to exercise and use environmental and social impact assessments of the plant must be strengthened, including the publication of quarry management plans, its influence on biodiversity protection, and the handling of plant and quarry closures in a responsible way, environmentally and socially. In China, the government would like to establish following factors for best practice (Wang, 2004): (1) Apply EIA (environmental impact assessment) and social impact assessment for all new cement projects; (2) In consultation with local communities, develop land use management plans for all such plants; (3) Share the quarry rehabilitation plans provided by the plants in writing with those communities. Update plans as needed to reflect the current technology and the changing community’s requirement; Kåre Helge Karstensen [email protected] Page 112 of 189 (4) Develop the necessary advanced planning for plant closures. Dialogues with community leaders should be held at the regular intervals. 6.3.6 Communication The Chinese cement industry has had a low profile and a history of limited engagement with stakeholders outside the area of that industry. "In many cases, this reflects the tradition of long-established private enterprises that were often owned and dominated by families" (Wang, 2004). Learning from developed countries, the Chinese government has encouraged cement plants in the need for communications to the public, and announced that this represents a key element for a “license to operate”. In fact, effective ways to communicate must be tailored to the particular audience at the local level. They include (Wang, 2004): (1) Identify what needs to be communicated, the background extent of understanding, biases, and public opinion on these issues; (2) Identify and work together with the decision makers that affect the local facilities; (3) Understand the local circumstances, environment, and other critical issues; (4) Engagement with the community on a regular and on-going basis both from a business perspective and by personal contacts through interactions of individual employees. Kåre Helge Karstensen [email protected] Page 113 of 189 7. Vertical Shaft Kilns VSKs constitute the majority of process technologies and make up about 60% of current total output of cement in China. Unfortunately, most of the VSKs suffer severe shortcomings through cement quality fluctuations and heavy pollution (Cui and Wang, 2005). In recent years, restructure of cement industry has been carried out and numerous VSK plants with poor operating conditions has been closed, creating sufficient market space for the development of key cement plants in favourable business environments and accelerating the advance of modern cement manufacturing technology. Improved mechanical shaft kilns have a production capacity of 250-350 tons/day and constituted 1150 and 1240 kilns in 2003 and 2004 respectively. Mechanical shaft kilns have a production capacity of 100-250 tons/day and constituted 9280 and 9060 kilns in 2003 and 2004 respectively. Ordinary shaft kilns have a production capacity of 50-150 tons/day and constituted 3150 and 2400 kilns in 2003 and 2004 respectively (Cement Sub Sector Survey, 2004). Some VSK will own its position to the disparity in the regional economic development of China still for some years to come, but within the year 2020 it is expected that all ordinary and all mechanised shaft kilns will have been closed down and that less than 10 % of improved mechanical shaft kilns will be in operation (Cement Sub Sector Survey, 2004). 7.1 Centralised close-down policy China announced already in 1999 that it would close thousands of small or antiquated cement operations. There have however been many barriers to closure due to: • Worker displacement and retraining costs; • Potential political instability, and Kåre Helge Karstensen [email protected] Page 114 of 189 • Opposition from local leaders who have economic interests in the plants. The key issue is retaining political stability in the face of greater unemployment. The problem is exacerbated compared to similar issues in other developing countries because Chinese cement plants employ up to ten times the labour of plants in developed countries, and because China has a less robust system of protective social security. Many of the closed plants will be in rural areas and it is hoped that released workers can fall back on their agricultural jobs or be absorbed in the rapidly growing private sector. Many provincial and local governments are not enthusiastically implementing these centrally planned plant closures. 7.2 Replacement of VSKs by a combination of market forces and regulation The Chinese government has recently acknowledged that the replacement of VSKs with modern technology seems to be better off with a combination of economic incentives, regulation, and enforcement and market mechanisms. The four most important aspects in replacing the VSKs seem to be the following: 1. Different Ministries, Councils, Bureaus, Commissions, Banks etc. has issued executive regulations to cool down several overheated and rapidly expanding industries, including the cement sector, by denying construction permits for new plants but still encouraging funding for facility upgrades. Since 1984 there has been issued 34 Circulars and Notices from the Chinese government in an effort to regulate and administer the growth of the cement industry (Cement Sub Sector Survey, 2004). The National Development and Reform Commission (NDRC) has announced that full implementation of control would be strengthened by restrictions on land use and bank loans to prevent a repeat of overheated investment in the cement sector (Wang, 2004). Future investment in cement industries should be directed to the improvement of production facilities to reduce the cost of unit production, to meeting the challenges of energy efficiency and the shortage of raw materials including coal and electricity as well as water. No new plant is allowed to be built with a production capacity less than 4000 tons a day, and it must employ the best available technology and required Kåre Helge Karstensen [email protected] Page 115 of 189 equipment for pollution control and prevention. This policy will favour new dry preheater/precalciner kilns. 2. The new emission standard of Air Pollutants for Cement Industry in China, GB 49152004, has been effective for one year only. The standard gives identical emission limits for rotary kiln and shaft kiln for particulate emissions and even if a transitional period has been given to meet the standard for plants in operation, the mission limits of new production lines are stricter than previous standards (see Annex 2). When this standard is effectively enforced it will favour new dry preheater/precalciner kilns; they will "automatically" comply with the standard without any need for further investment in air pollution control device. 3. Low quality cement is currently oversupplied and cheap in China, while high quality cement is rarer and more expensive. Profit margins for most cement producers have decreased and are near zero. Despite the growth in construction, cement prices have fallen the last two years, in some provinces with more than 50 %. New dry preheater/precalciner kilns is more cost-efficient than VSKs, both with regards to labour and fuel costs, and they produce stable high quality cement. 4. Energy prices and cost for labour has been increasing steadily the last years and is forecasted to continue to increase; this will favour dry preheater/precalciner kilns. 7.2.1 Key economic indicators for VSKs In addition to the four important aspects mentioned in the previous chapter, the China Cement Association has set up a list of key economic indicators which should be fulfilled when building new or refurbishing older VSKs (Digital Cement, 2005). These requirements and recommendations aim to improve the economic performance as well as quality, energy efficiency and emission reductions by requiring that new or refurbished VSKs need to comply with the following: Kåre Helge Karstensen [email protected] Page 116 of 189 1. The diameter should be 3.8 meter and the height 8.5 meter; each line should produce 25 ton clinker per hour (two lines, 1200 ton clinker per day); i.e. improved mechanical shaft kilns. 2. The concrete strength should be minimum 30 MPa after 3 days and 55 MPa after 28 days. 3. The energy use should be limited to 800 kcal per kg of clinker. 4. The electricity use should be limited to 60 kWh per ton of clinker. 5. The plant must comply with the SEPA Air Pollution standard for Cement Production (see Annex 2). 6. The employee efficiency should be equivalent to 2000 ton cement per employee per year. If these recommendations are implemented and followed, it would definitely mean a significant improvement in general cost and energy efficiency, as well as on the emissions and the cement quality. There is no reason to believe that these recommendations are not followed if new VSKs are built. It is however doubtful that it will be economic feasible to refurbished older plants with the current frame- and market conditions; if a market for cement is present, a new preheater/precalciner kiln may be more economic attractive. 7.3 Demonstration projects for VSK improvement Even if the number of VSKs seems to diminish dramatically the coming years, a considerable number will still be in operation for the next fifteen years or so and the potential in decreasing the emissions and reducing the need for energy is great. A pilot project is therefore suggested to demonstrate the potential for improvement in energy efficiency and Kåre Helge Karstensen [email protected] Page 117 of 189 emission reduction of VSKs. Such a project is also needed to establish reliable data on PCDD/F emissions from VSKs. China is obliged to provide data on PCDD/F emissions to the Stockholm Convention on Persistent Organic Pollutants (POPs). In the absence of such data, the UNEP Standardized Toolkit for Identification and Quantification of Dioxin and Furan Releases (UNEP, 2005) has assigned an emission factor of 5 µg PCDD/F TEQ per ton of cement to vertical shaft kilns. This is the same emission factor applied for wet kilns with ESP temperature over 300 oC, whereas an emission factor of 0.05 µg TEQ/t is applied to all dry kilns and wet kilns where dust collector temperatures are held below 200 oC. China is also obliged to suggest an action plan with reduction targets for PCDD/F emissions from the different source categories to the Stockholm Convention. To be able to do this task properly the mechanism for formation of PCDD/Fs in VSKs should be known. The understanding of the formation mechanism will enable the environmental authorities to provide measures and strategies for emission reduction and control. The available information in English on the performance of VSKs, i.e. the alleged energy inefficiency, environmental pollution and inferior cement quality, doesn't seem to be scientifically well document by real measurements or comprehensive studies. The statements made in different documents vary and is even contradictory in some cases (Sino-US Workshop on Environmental Management and Technologies in Cement Industry, 2005; Cui and Wang, 2005; Cement Sub Sector Survey, 2004; Wang, 2004; US Geological Survey, 2004; Chinese Enterprise Confederation, 2003; Nordqvist and Somesfalean, 2003; Soule et al, 2002; Nordqvist and Nilsson, 2001; Price et al, 2000). It is impossible to measure the improvement in energy efficiency or emission reduction without having a thorough and exact understanding of the baseline or normal performance. The establishment of basic knowledge has to be done as the first priority activity in a demonstration project. Taking into consideration that most VSKs seems to be replaced "naturally" within year 2020 the scope of a demonstration project should give priority to aspects of VSKs operation which is considered most important from a short term environmental point of view, i.e. Kåre Helge Karstensen [email protected] Page 118 of 189 emissions and energy efficiency of improved and mechanical shaft kilns. Aspects like consolidation, privatisation, regulation, cement quality, socio-economic considerations etc. are not considered. As mentioned several times in the report, cement manufacturing process is generally well suited for co-processing by-products and residues from industrial sources, both as raw materials and fuels substitutes and as mineral additions. There is no doubt that the most effective way of reducing the raw material consumption, energy use and emissions from the cement industry is to reduce the clinker content of cement products by using secondary raw materials; then both thermal CO2 from fossil fuels and CO2 from the decarbonation of raw materials are reduced. Substitution of fossil fuels by alternative fuels will reduce effectively the overall output of the thermal fossil origin of CO2. Such substitution is however not feasible for vertical shaft kilns. VSKs are applying the black-meal process which cannot replace the coal or coke by waste or alternative fuels (with the exception of petcoke). Other options to reduce the energy consumption in vertical shaft kilns have to be explored. The Institute of Technical Information for Building Materials Industry (ITIBMI) suggested in 2004 the following 17 "technologies" for energy saving in the VSK industry (Cement Sub Sector Survey, 2004): 1. Prehomogenization technology of raw materials and fuel 2. Homoginization techniques of raw mix and cement 3. Improvement and selection technique of feed proportioning scheme of raw mix 4. Feed proportioning in accordance with rate value and heat distribution technique of block raw mix 5. Pre-grinding technique Kåre Helge Karstensen [email protected] Page 119 of 189 6. Technique of application of grinding aid 7. Energy saving technique in drying 8. New mill application technique 9. High-efficiency separator application technique 10. Pre-watering nodulization and small nodule firing technology 11. Dust disposing technique in shaft kiln enterprise 12. Quality control and management technique in the production process 13. Automatic control technique of the production process of shaft kiln enterprises 14. Chemical instrument analysis and physical testing technique 15. Frequency converting and speed regulating technique for energy saving 16. Comprehensive utilization technique of resources 17. Energy saving type lining mating technique It is a complex task to assess the potential of these proposed measures and to assign priorities among them; the suitability will also clearly depend on the starting conditions. It seems however reasonable to draw attention to number 7, 11, 16 and 17 above. Kåre Helge Karstensen [email protected] Page 120 of 189 7.3.1 Suggested activities in a VSK demonstration project It is recommended to focus on mechanical shaft kilns and improved mechanical shaft kilns in the demonstration project. In 2004 these two categories of shaft kilns had an output of 38 and 16 percent of the produced cement respectively. Ordinary shaft kilns had an output of 5 % in 2004 but all these units are expected to be closed own in a few years time (Cement Sub Sector Survey, 2004). 1. The first activity in a demonstration project will be to establish and document the energy consumption and the normal emission levels of pollutants from a representative selection of VSKs. Dust, VOC, HCl and PCDD/F should be the first priority among the air pollutants; NOx, SO2 and CO the second priority and heavy metals, PCBs and PAHs the third priority. It is important that these studies are designed in a way that uncovers optimal knowledge of factors of influence and possibilities for reduction and control. 2. The second activity will be to uncover the mechanism for formation of PCDD/Fs in VSKs, to understand the factors of influence and subsequent measures for emission reduction and control, and to provide reliable emissions factors. This activity will systematically evaluate all parameters known to induce formation of PCDD/Fs, i.e. sources and levels of hydrocarbons, organics and chloride; temperature window post combustion (in the air pollution control device); particulate surfaces which can catalyse the formation and residence time. 3. The third activity will be to investigate the cost-benefit of replacing wet-membrane dust collection equipment with dry bag-house filter. Wet-membrane filter systems seem to have low efficiency and the humid dust makes it difficult to recover the dust back to the production. It is not known how widespread and common this system is among the VSKs and this need to be investigated before initiating this activity. It is anticipated that replacement of wet systems with a dry system will have a good effect on reducing the dust emissions as well as on saving raw materials by recovery of dust. 4. The fourth activity will be to investigate the potential for fuel and cost savings using waste heat from the VSK for drying purpose. Drying of raw materials and fuel is very Kåre Helge Karstensen [email protected] Page 121 of 189 important in achieving a homogenous raw mix, which again will be important in achieving an optimal fuel to raw material ratio, stable "burning" and sintering conditions and subsequent even and low emissions and lastly, a predictable and high quality product. Drying of raw materials and fuel are currently done as a separate preparation step using auxiliary fuel for heating. There is a considerable potential for fuel savings and emission reductions by utilising waste heat gas from the VSK but the challenge is closely connected to being able to recover heat from the low temperature exit gas, approximately 200 0C. 5. The fifth activity will be to investigate the potential of replacing high volatile coal/coke with low volatile coal. Fuel with a high concentration of volatiles will be quickly consumed high up in the kiln, cause quality problems with the clinker and may also represent a security problem as small explosion of material can be experienced. A VSK in Madagascar used a charcoal with 27 % volatiles and consumed 5800-5900 J/kg clinker. The charcoal was replaced by a coal with 13 % volatiles and the kiln reduced it's consumption to 3300 to 3400 J/Kg clinker (810 kcal/kg) (Viacroze, 2005). Such energy saving can be achieved by a combination of switching to low volatile coal, by improving the raw meal homogeneity, by decreasing the coal ratio in the black meal, and by optimise the air flow through the kiln. Coal used in the cement industry usually has a lower heating value of 6500–7000 kcal/kg, an ash content of 12–15 %, a volatile matter of 18–22 % and moisture content up to 12 %. The carbon content of mineral coal is 60-92 % and 80-90 % in coke. The combustible components are carbon, hydrogen, and sulfur; when burning, these constituents combine with oxygen from air and generate heat. When drying coal it should be noted that completely dry coal is difficult to ignite. As is known, carbon does not react directly with atmospheric oxygen; the combustion to CO and CO 2 proceeds by way of chain reactions where carbon reacts first with the more active OHradical. The presence of small quantities of water vapour is required for the ignition of fuel. Thus, the drying process of coal should not go too far. A moisture content of approximately 1–1.5 % in the pulverized coal promotes combustion. The content of volatile matter is important for the rating of coals. The loss in weight as the result of carbonization of coal under exclusion of air represents the total of volatile matter. Coal from younger geological formations contains more parts of oxygen, hydrogen, and nitrogen than coals from older geological formations. During combustion, these Kåre Helge Karstensen [email protected] Page 122 of 189 elements and their compounds generate more volatile matter than coals from older geological formations. The standard content of volatile matter for coals used in the combustion of pulverized coal is about 18 – 22 %. However, when applying proper grinding, it is now possible to utilize also low gaseous coals in rotary kilns. To insure economic kiln operation, the heating value of the coal should be about 7000 kcal/kg. Coal with lower heating value increases the specific heat consumption for clinker burning, decreasing simultaneously the specific kiln throughput. 6. The sixth activity will be to investigate the potential for fuel and cost savings using better thermal isolation linings of the kiln. Better lining material will reduce heat consumption and save energy, lower the surface temperature of kiln body, increase the clinker output, improve the quality of the clinker and extend the life of the VSK (Cement Sub Sector Survey, 2004). "The difference in the investment between energy saving type lining and ordinary lining is small. If the reduction of heat consumption of clinker is 150 kcal/kg, a mechanical shaft kiln of φ3×10m (output 12 t/d) can save 1851 tons of standard coals annually, corresponding to 2356 tons of substantial coals (calorific power 5500 kcal/kg) worth 0.353 mil. Yuan (the price of coal 150 Yuan/t); a cement factory that manufactures 0.2 million ton of clinker per year can annually save 4294 ton of standard coal valued at 0.818 million Yuan. In addition, if the kiln can increase production with 1 ton of clinker every hour and increase the production with 7200 t clinker annually and 8470 tons of ground ordinary Portland cement more which are valued at 1.69 million Yuan". (Cement Sub Sector Survey, 2004) 7. The seventh activity will be to demonstrate the potential for reducing the raw material consumption, energy use and emissions by reducing the clinker content of the cement by using secondary raw materials. This will reduce both thermal CO2 from fossil fuels and CO2 from the decarbonation of raw materials. The utilisation of secondary materials and supplementary cementitious materials has been practised in China for some years already (Cui and Wang, 2005) and the purpose of this activity is to document the potential by carrying out a practical demonstration project where secondary raw materials from a nearby industry is used in a VSK plant. The activity will carry out the necessary quality testing and establish the specifications, documentation and limitations for future practise. Kåre Helge Karstensen [email protected] Page 123 of 189 Figure 32 7.3.2 Dusty emissions from a VSK Exit gas sampling and chemical analysis According to the conclusions of the Regional Workshop and Capacity Building Needs to Analyse POPs in Developing Countries held in Beijing 13-16 December 2006 there should be currently 11 laboratories in China which are equipped to carry out PCDD/F and PCB analysis with High Resolution Gas Chromatography Mass Spectrometer (HR GC-MS). The workshop was organised by UNEP, the Basel Convention, Tsinghua University and the Office for Stockholm Convention Implementation at the State Environmental Protection Administration. The activity 1 and 2 mentioned above will need to be carried out in accordance with international standards for flue gas sampling and analysis. The sampling for PCDD/F should Kåre Helge Karstensen [email protected] Page 124 of 189 be in accordance with one of the three methods established in EN 1948 (1996) or US Method 23 (1995). Analysis of all stack and residue samples for PCDD/F and dioxin-like PCBs should be in accordance with EN 1948, US Method 23(A) or l613. Kåre Helge Karstensen [email protected] Page 125 of 189 8. Conclusion The Chinese cement industry produced 1,060 billion ton cement in 2005, accounting for 808 kg per capita and approximately 50 % of the world production. Approximately 60 % of the cement was produced in approximately 4000 Vertical Shaft Kilns (VSKs). This part of the cement industry is characterized by its irrational structure, low production efficiency, high energy consumption and heavy environmental pollution. Compared with preheater/ precalciner kilns, VSKs seems to consume from 14 % to 105 % more coal pr ton of clinker. Vertical shaft kilns generally produce lower quality (#325 grade or less) cement which is neither suitable for large structures nor for major infrastructure projects such as bridges, airports, etc. VSKs seem to be replaced naturally with modern and more efficient technology with a combination of economic incentives, regulation, and enforcement and market mechanisms. The new emission standard of Air Pollutants for Cement Industry in China, GB 4915-2004, has been effective for one year only. The standard gives identical emission limits for rotary kiln and shaft kiln for particulate emissions. Low quality cement is currently oversupplied and cheap in China, while high quality cement is rarer and more expensive. Profit margins for most cement producers have decreased and are near zero. Despite the growth in construction, cement prices have fallen the last two years, in some provinces with more than 50 %. New dry preheater/precalciner kilns is more cost-efficient than VSKs, both with regards to the number of labours and fuel costs, and they produce stable high quality cement. Energy prices and cost for labour has been increasing steadily the last years and is forecasted to continue to increase; this will favour dry preheater/precalciner kilns. New and modern dry process production lines with preheater and precalciner is considered to constitute the best available techniques with regards general cost-efficiency, to energy consumption, emissions and product quality and new is built every year. The cement industry consumed about 129 million tons of standard coal, equal to 148 million tons of common coal in 2003. The electricity consumption in the Chinese cement industry was 94,930 million kWh, amounting to approximately 5 % of the electric Kåre Helge Karstensen [email protected] Page 126 of 189 consumption in the whole country in 2003. It is estimated that the Chinese cement industry emitted more than 13 million tons of dust, about 27 % of all emissions from the national industry, about 22 % of all CO2 emissions, and about 4.85% of all SO2 emissions in 2003. The cement manufacturing process is generally well suited for co-processing byproducts and residues from industrial sources, both as raw materials and fuels substitutes and as mineral additions. There is no doubt that the most effective way of reducing raw material consumption, energy use and emissions from the cement industry is to reduce the clinker content of cement products by using secondary raw materials; then both thermal CO2 from fossil fuels and CO2 from the decarbonation of raw materials are reduced. With the substitution of fossil fuels by alternative fuels, the overall output of thermal CO2 is reduced. Fuel substitution is however not feasible for vertical shaft kilns. VSKs are applying the black-meal process which cannot replace the coal or coke by waste or alternative energy containing materials. The available information in English on the general performance of VSKs doesn't seem to be scientifically well document by real measurements or studies, i.e. there is a need to document the normal baseline conditions. A well documented and thorough knowledge of the normal energy consumption and the normal emission levels from VSKs is a prerequisite for issuing stricter regulation, for reporting statistics, for implementing measures and for measuring improvement. A pilot project is therefore suggested to demonstrate the potential for improvement in energy efficiency and emission reduction of VSKs. No VSKs has been monitored for dioxins and furans and no emission factors have so far been developed for this industry category. China is obliged to provide data on PCDD/F emissions to the Stockholm Convention on Persistent Organic Pollutants (POPs) and to suggest an action plan with reduction targets for PCDD/F emissions from the different source categories. To be able to do this task properly the mechanism for formation of PCDD/Fs in VSKs should be known. The understanding of the formation mechanism will enable the environmental authorities to provide measures and strategies for emission reduction and control. Kåre Helge Karstensen [email protected] Page 127 of 189 9. References and bibliography Begg, K.G., T. Jackson, and S. Parkinson. 2001. “Beyond Joint Implementation — Designing Flexibility into Global Climate Policy.” Energy Policy 29 (1): 17-27. CEMBUREAU, 1999. “Best available techniques for the cement industry". The European Cement Association. Rue d’Arlon 55 - B-1040 Brussels. http://www.cembureau.be. Cement Sub Sector Survey, 2004. 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World Development Indicators 2000. Washington, D.C.: WB. World Bank, 2000. World Development Report 2000/2001: Attacking Poverty. 23rd ed. Oxford: Oxford University Press. Worrell, E. and Galitsky, C., 2004. "Energy Efficiency Improvement Opportunities for Cement Making". An ENERGY STAR Guide for Energy and Plant Managers. Worrell, E., R. van Berkel, Zhou F.Q., C. Menke, R. Schaeffer, and R.O. Williams, 2001. “Technology Transfer of Energy Efficient Technologies in Industry: A Review of Trends and Policy Issues.” Energy Policy 29 (1): 29-43. Kåre Helge Karstensen [email protected] Page 136 of 189 Wu B.Z., Fan Y.S., He K.B., and Zhao W.J., 1998. “The Status and Trend of China’s Policies on Climate Change.” Energizing China. Reconciling Environmental Protection and Economic Growth: 541-54. Ed. M.B. McElroy, C.P. Nielsen, and P. Lydon. Cam- bridge, Mass.: Harvard University Press. Kåre Helge Karstensen [email protected] Page 137 of 189 Annex 1 Demonstration project - Improvement of environmental performance and energy efficiency in Vertical Shaft Kilns Project Identification 1. Improvement of environmental performance Project Title: and energy efficiency in Vertical Shaft Kilns 2. Country: China 3. Sector: Cement production in Vertical Shaft Kilns 4. Estimated total cost (USD) 1,100,000 5. Requesting/implementing agency SEPA - State Environmental Protection Administration, Beijing. Project Objectives and Activities 6. Goal To document the energy use and the normal baseline emissions of selected pollutants like dust and PCDD/Fs for selected VSKs and to demonstrate the potential for improvement in energy efficiency and emission reduction, as well as associated costs. 7. Project context Kåre Helge Karstensen [email protected] Page 138 of 189 7.1 Background Chinese cement industry produced 1,060 billion ton cement in 2005, accounting for approximately 50 % of the world production. 60 % of this cement was produced in 4000 Vertical Shaft Kilns (VSKs). In 2003, the cement industry consumed about 129 million tons of standard coal, equal to 148 million tons of common coal. This amounts to approximately 11 % of whole consumption of coal in that year. This consumption would be equivalent to approximately 200 million tonnes of common coal for 2005. In 2003, the electricity consumption in the Chinese cement industry was 94,930 million kWh, amounting to approximately 5 % of the electric consumption in the whole country. Based on the current technical level in China, the production of 1 ton of cement will lead to an emission of 20 kg of dust, 1 ton of CO2, 2 kg of SO2 and 4 kg of NOx. It is estimated that the Chinese cement industry in 2003 emitted more than 13 million tons of dust (about 27 % of all emissions from the national industry), 660 million tons of CO2 (about 22 % of all emissions), 1.31 million tons of SO2 (about 4.85% of all emissions) and 2.62 million tons of NOx. No VSKs has been monitored for dioxins and furans and no emission factors have so far been developed for this industry category (UNEP, 2005). 7.2 Significance With these consumption and emission volumes, even small improvements can contribute significantly to reduce consumption of raw materials and energy, to reduce emission of pollutants and to improve the quality of the product. 8. Project objectives The main objectives of the project are: Kåre Helge Karstensen [email protected] Page 139 of 189 • To document the normal energy consumption and the normal emission levels of pollutants from a representative selection of VSKs. • To uncover the mechanism for formation of PCDD/Fs in VSKs and to provide reliable emissions factors for quantification of annual release from the sector.. • To investigate the cost-benefit and feasibility of replacing wet-membrane dust collection equipment with dry bag-house filter. . • To investigate the potential for fuel and cost savings using waste heat from the VSK for drying of the raw material and fuel. • To investigate the effect of replacing high volatile coal/coke with low volatile coal. • To investigate the potential for fuel and cost savings using better thermal isolation linings of the kiln. • To carry out a practical demonstration project where secondary raw materials from a nearby industry is used in a VSK plant. 9. Expected outputs The outputs will be: • A well documented and thorough knowledge of the normal energy consumption and the normal emission levels from VSKs. This is a prerequisite for issuing stricter regulation, for reporting statistics, for implementing improvement strategies and for measuring improvement. Kåre Helge Karstensen [email protected] Page 140 of 189 • Understanding of the dominating factors influencing the formation of PCDD/Fs in VSKs. This is a prerequisite for issuing reliable emissions factors, for quantification of annual release and for implementing measures for reduction and control. • A feasibility study documenting the potential for emission reduction and for the recovery of dust by replacing wet-membrane dust collection equipment with dry baghouse filter. . • A feasibility study documenting the potential for fuel and cost savings using waste heat from the VSK for drying of the raw material and fuel. • A feasibility study documenting the effect of fuel saving and improved product quality by replacing high volatile coal/coke with low volatile coal. • A feasibility study documenting the potential for fuel savings and improved product quality by using better thermal isolation linings of the kiln. • A feasibility study documenting the potential for fuel and raw material savings, for emission reduction and for solving a waste problem by using secondary raw materials from other industry to reduce the clinker content. 10. Activities It is recommended to focus on mechanical shaft kilns and improved mechanical shaft kilns in the demonstration project. See also chapter 7.3.1. 1. The first activity will be to establish and document the energy consumption and the normal emission levels of pollutants from a representative selection of VSKs. Dust, VOC, HCl and PCDD/F should be the first priority among the air pollutants; NOx, SO2 and CO the second priority and heavy metals, PCBs and PAHs the third priority. Kåre Helge Karstensen [email protected] Page 141 of 189 2. The second activity will be to uncover the mechanism for formation of PCDD/Fs in VSKs, to understand the factors of influence and subsequent measures for emission reduction and control and to provide reliable emissions factors for quantification of annual release from the sector. 3. The third activity will be to investigate the cost-benefit of replacing wet-membrane dust collection equipment with dry bag-house filter. . 4. The fourth activity will be to investigate the potential for fuel and cost savings using waste heat from the VSK for drying of the raw material and fuel. 5. The fifth activity will be to investigate the effect of replacing high volatile coal/coke with low volatile coal. 6. The sixth activity will be to investigate the potential for fuel and cost savings using better thermal isolation linings of the kiln. 7. The seventh activity will be to carry out a practical demonstration project where secondary raw materials from a nearby industry are used in a VSK plant. The activity will carry out the necessary quality testing and establish the specifications, documentation and limitations for future practise. 11. Activity and time schedule To ensure ample time for capacity building, awareness raising and information dissemination, as well as enough time for demonstration tests, the project should be executed over a period of minimum two and a half year. The first year will be allocated to start up and information gathering on baseline conditions and previous experiences; the second year will mainly focus on pilot tests and local training; the last half year will be used for preparation of documentation, information material and the final report with all finding, recommendations and results from the project. Kåre Helge Karstensen [email protected] Page 142 of 189 Table 1 Activity distribution and time schedule Activity Duration (months) Completed (months after start) Inception, planning, contracting, mobilisation etc. 3 3 Compilation of previous experiences and data/ visits 6 8 Selection of VSKs and Provinces. Contracting Test house 2 9 Baseline study (energy use and emissions) 4 13 Supplementary investigations PCDD/F formation 3 15 Replacing wet-membrane dust collection equipment 4 17 Waste heat for drying of the raw material and fuel 4 20 Replacing high volatile coal/coke with low volatile coal 4 20 Thermal isolation linings of the kiln 6 24 Secondary raw materials from a nearby industry 6 24 Training and information dissemination 5 29 Evaluation, reporting and termination of project 1 30 Total 48 30 12. Project inputs Table 2 Cost and budget estimates No. Subject m/m Budget in USD 1 1 International expert with technical cement kiln experience (CTA) 15 300,000 2 1 International expert on cement kiln emissions 10 200,000 3 1 National expert in VSKs (Project Manager) 30 60,000 4 3 National experts experienced in VSK and emissions 3 x 20 120,000 5 Administrative support, interpretation, translation 6 Sampling, analysis and equipment 7 Local travel 30,000 8 Computers and office equipment 25,000 30,000 200,000 Contingencies 135,000 Total 1,100,000 Kåre Helge Karstensen [email protected] Page 143 of 189 13. Budget distribution & financing Financial contribution should be sought among organisations like the Office for Stockholm Convention Implementation at the State Environmental Protection Administration, by GEF and UNIDO. 14. Involved organisations The Office for Stockholm Convention Implementation and the Solid Waste & Toxic Chemicals Management Division under the State Environmental Protection Administration (SEPA) in Beijing, China Building Materials Industry Association, Institute of Technical Information for Building Materials Industry of China, China Building Materials Academy, China Cement Association, Tsinghua University, the Chinese Research Academy of Environmental Sciences and other relevant research institutions. Kåre Helge Karstensen [email protected] Page 144 of 189 Annex 2 Emission Standard of Air Pollutants for the Cement Industry in China Emission Standard of Air Pollutants for Cement Industry GB4915-2004 as substitute for GB4915-1996 State Environmental Protection Administration of China General Administration of Quality Supervision, Inspection, and Quarantine of China Issued on Dec.29th, 2004 Effective from Jan.1st, 2005 Previous versions substituted for by this Standard are: GB4915-85, GB4915-1996. This standard is proposed by the Science & Technology Department of State Environmental Protection Administration. Units committed to draft this standard are: Environmental Standard Institute of Chinese Research Academy of Environmental Science, Hefei Cement Research & Design Institute of China Building Material Group and China National Materials Industry Group. This standard was approved by State Environmental Protection Administration on Dec.29th, 2004. This standard comes into effect on Jan.1st, 2005. Kåre Helge Karstensen [email protected] Page 145 of 189 This standard is to be interpreted by State Environmental Protection Administration. 1. Range This Standard prescribes emission limits of air pollutants for various production equipments, unorganized emission limits of particulates in the workplace, and relevant administrative regulations on environmental protection of the cement industry. This standard also sets particulates emission requirement of cement products production. This standard applies to: air pollutants emission administration of existing cement producers and cement products manufacturers; environmental impact assessment, design, completion, examination and acceptance of newly-constructed, expanded and rebuilt cement mines, cement and its products production lines, as well as their pollutants emission administration after their construction is finished. 2. Cited Normative Documents Cited by this standard, clauses of the following documents became clauses of this standard. For the cited documents without date indicated, their latest edition applies to this standard. • Integrated Emission Standard of Air Pollutants, GB16297-1996; • Pollution Control Standard for Hazardous Wastes Incineration, GB 18484; Kåre Helge Karstensen [email protected] Page 146 of 189 • Methods of Determination of Particulates and Sampling of Gaseous Pollutants Emitted from Exhaust Gas of Stationary Source, GB/T16157; • Ambient Air - Determination of Total Suspended Particulates - Gravimetric Method, GB/T15432; • Determination of Nitrogen Oxides from Exhausted Gas of Stationary Source Ultraviolet Spectrophotometric Method, HJ/T 42; • Determination of Nitrogen Oxides - N (1-naphtye from Exhausted Gas of Stationary Source) - Ethylenediamine Dihydrochloride Spectrophotometric Method, HJ/T 43; • Technical Guidelines for Unorganized Emission Monitoring of Air Pollutants, HJ/T55; • Determination of Sulfur Dioxide from Exhausted Gas of Stationary Source - Iodine Titration Method, HJ/T56; • Determination of Sulfur Dioxide from Exhausted Gas of Stationary Source Potential Electrolysis Method, HJ/T 57; • Determination of Fluoride of Stationary Ambient Pollution Source Ion-Selective Electrode Analysis, HJ/T 67; Kåre Helge Karstensen [email protected] Page 147 of 189 • Technical Requirement and Test Method of Continuous Emissions Monitoring System of Exhausted Gas of Stationary Source, HJ/T 76; • Determination of Poly-o-Chlorinated Dibenzo Dioxin and Poly-o-chlorinated Dibenzo Furan -- Isotope Dilution High Resolution Capillary Gas Chromatography/ High Resolution Mass Spetrometry, HJ/T77. The new Standard refers to normal conditions, which for temperature is 370C and air pressure 101 325 Pa. The emission concentration of air pollutants prescribed in this standard means value of dry flue gas under normal conditions. 3.2 Maximum acceptable emission concentration It means maximum limits of any 1-hour average concentration of pollutants from exhaust funnel of treatment facilities; or in places where there are no treatment facilities, maximum limits of any 1-hour average concentration of pollutants from exhaust funnel. 3.3 Unit product emission quantity It indicates the quantity of noxious substance emitted by various equipment for the production of 1 ton of product, with the unit of kg/t product. Output is calculated based on the actual hourly output of equipment during pollutants monitoring time. For example, output of cement Kåre Helge Karstensen [email protected] Page 148 of 189 kiln and cooler is calculated based on output of clinker; output of raw mill based on raw meal; cement mill on cement; coal mill on coal powder, and dryer as well as drying mill on dry material. For in-line kiln/raw mill, when kiln and mill are running jointly, output should be calculated based on material quantity produced by the mill, and when cement kiln is running alone, it should be calculated based on clinker quantity produced by the cement kiln. 3.4 Unorganized emission It indicates irregular emission of air pollutants without exhaust funnel, mainly including material pile in the operational field, dust of open transport, and dusty gas leakage from the pipe and equipment. Emission through low exhaust funnels belongs to controlled emission, but it can bring about the same outcome as the unorganized emission. Therefore, when the Concentration Limits of Unorganized Emission Monitoring Spot is carried out, the increase of pollutants concentration at the monitoring spot resulted from low exhaust funnels should not be deducted. 3.5 Concentration Limit of Unorganized Emission Monitoring Spot It indicates maximum limits of any 1-hour average concentration of pollutants at the monitoring spot. Kåre Helge Karstensen [email protected] Page 149 of 189 3.6 Height of Exhaust Funnel Height from the ground level where the exhaust funnel (or its main structure) lays to outlet of the exhaust funnel. 3.7 Cement Kiln The equipment calcining clinkers, often including rotary kiln and shaft kiln. 3.8 In-Line Kiln/Raw Mill The system where the kiln and mill run jointly. It leads the exhaust gas to material milling system, to dry the material by its residual heat, and treats exhaust gas from the kiln and mill by one dust collector. 3.9 Dryer, Drying Mill, Coal Mill and Cooler. The dryer means various types of material drying equipments; the drying mill refers to material drying and milling equipment; the coal mill indicates various types of coal powder Kåre Helge Karstensen [email protected] Page 150 of 189 manufacture equipments; and the cooler indicates various types (cylinder, grate and so on) of clinker cooling equipments. 3.10 Crusher, Mill, Packing Machine and other Ventilated Production Equipments. The crusher indicates various types of equipment crushing bulk materials; the mill indicates various equipment systems of material milling (drying mill and coal mill exclusive); the packing machine indicates various equipment packing cement (including cement silo); other ventilated production equipment indicates production equipment besides the main production equipments mentioned above, which requires ventilation, including material transport equipment, material silo and various types of storage, etc. 3.11 Cement Product Production It indicates production of ready-mixed concrete and precast concrete, excluding the process of concrete mixing on construction sites. 3.12 Existing production line, Newly-established Production Line The existing production line indicates production line of cement mine, cement manufacture and cement products which had been founded and operated or whose environmental impact report had been approved before the date of enforcement of this standard (Jan.1st 2005). Kåre Helge Karstensen [email protected] Page 151 of 189 The newly-established production line indicates newly built, revamped and expanded production line of cement mine, cement manufacture and cement products whose environmental impact report is approved on or after the date of enforcement of this standard (Jan.1st 2005). 4. Emission Limits 4.1 Limits of Air Pollutants Emission From Exhaust Funnel of Production Equipments 4.1.1 Before July 1st 2006, air pollutants emission from exhaust funnels of production equipment (facilities) of existing cement plants(pulverizing mill inclusive) should still be regulated by GB 4915-1996; and existing cement mines and cement products plants should execute GB 16297-1996. From Jul.1st 2006 to Dec.31st 2009, the maximum acceptable emission concentration and unit product emission quantity of particulates and gaseous pollutants from the exhaust funnels of production equipments (facilities) of existing production line should not exceed the limits set in table 1. From Jan.1st 2010, the maximum acceptable emission concentration and unit product emission quantity of particulates and gaseous pollutants from the exhaust funnels of production equipments (facilities) of existing production line should not exceed limits set in table 2. Kåre Helge Karstensen [email protected] Page 152 of 189 4.1.2 From Jan. 1st 2005, the maximum acceptable emission concentration and unit product emission quantity of particulates and gaseous pollutants from the exhaust funnels of production equipments (facilities) of newly-established production line should not exceed limits set in table 2. 4.1.3 When hazardous wastes are incinerated in the cement kiln, particulates, sulfur dioxide, nitrogen oxide and fluoride in exhaust gas are respectively subject to the emission limits set in table 1 and table 2 based on construction date of the cement kiln; other pollutants to the emission limits set in Pollution Control Standard for Hazardous Wastes Incineration GB 18484, but the emission concentration of dioxin should not exceed 0.1ng TEQ/m3. 4.2 Unorganized Emission Limit of Particulates in Operational field The unorganized particulate emission of existing cement plant (pulverizing mill inclusive) should be regulated by GB4915-1996 before Jul.1st 2006, while that of existing cement products plant should be regulated by GB 16297-1996. Limits set in Table 3 should not be exceeded by unorganized particulate emission in operational field of existing production line from Jul.1st 2006, and by newly-established production line from Jan.1st 2005. 5. Other Administration Regulations Kåre Helge Karstensen [email protected] Page 153 of 189 5.1 Control Requirement of Unorganized Particulate Emission 5.1.1 Effective measures should be adopted to control unorganized particulate emission from cement mine, cement manufacture and cement products production process. 5.1.2 Newly-established production lines should be close in the process of material disposal, transport, loading and unloading, and storage, and effective dust suppression measures should also be adopted for block stone, humid material, paste, and loading and unloading process of vehicle and cargo. 5.1.3 Existing production line should be close in material disposal, transport, loading and unloading, and storage of dry mix, and effective measures against dust and rain erosion should be adopted in open storage; and effective dust suppression measures should be taken during loading and unloading process of vehicle and cargo. 5.2 Control Requirements of Abnormal Emission and Accident Emission. 5.2.1 The dust collector should run synchronically with corresponding manufacturing equipments. The annual running time of manufacturing equipments and dust collector should be calculated respectively. The synchronic running rate should be assessed by the ratio of annual running time of dust collector to that of manufacturing equipments. 5.2.2 Newly-established cement kiln should guarantee that dust collector run normally even under the fluctuation of production process, and prevent abnormal emission. The synchronic Kåre Helge Karstensen [email protected] Page 154 of 189 running rate of the dust collector used in existing cement kiln, relative to the cement kiln ventilator, should not be less than 99%. 5.2.3 When failure of the dust collector results in accident emission, urgent measures should be taken to stop the running of the main unit, which should not be restarted until the examination and reparation of the dust collector finishes. 5.3 Requirement for Exhaust Funnel Height 5.3.1 Except for the dust collector of elevating and conveying equipment and that of the silo below the storage, the exhaust funnel height of production equipments (including exhaust funnel of workshop) should not be less than 15m. 5.3.2 Exhaust funnel height of following production equipments should comply with regulation in Table 4. 5.3.3 If the exhaust funnel height of equipments in an existing cement production line cannot come up to the height regulated in Table 4, its air pollutants emission should be strictly controlled. The emission limit is calculated according to the following formulation: C = C0· h2/h02 Where: C—Actual acceptable emission concentration, mg/Nm3 Kåre Helge Karstensen [email protected] Page 155 of 189 C0— Acceptable emission concentration prescribed in Table1 or 2; mg/Nm3 h —Actual exhaust funnel height; m. h0—Exhaust funnel height prescribed in Table 4; m. 5.4 Other Regulations 5.4.1 Such outdated techniques and equipments polluting ambient environment seriously, as defined in Article 19 of Law of the People’s Republic of China on Prevention and Control of Atmospheric Pollution, are forbidden to be adopted and used. 5.4.2 Mine exploitation, cement and its products production are forbidden in Class ambient air quality region. 5.4.3 The cement kiln should not be used for incinerating hazardous wastes containing heavy metal. Incineration of medical wastes in cement kilns should comply with Technical Codes for Centralized Disposal of Medical Wastes Gas disposal of the cement kiln or in-line kiln/raw mill incinerating hazardous wastes should adopt high-efficient cloth-bag deduster. Kåre Helge Karstensen [email protected] Page 156 of 189 6. Monitoring 6.1 Monitoring of Air Pollutants in Exhaust Funnel 6.1.1 The exhaust funnel of production equipment should be equipped with permanent sampling aperture, and come up to the sampling conditions prescribed in GB/T16157. 6.1.2 Monitoring sampling of particulates or gaseous pollutants in the exhaust funnel should be carried out in accordance with GB/T 16157. 6.1.3 For daily supervisory monitoring, the working condition during sampling should be the same as normal working condition of that time. Workers of the units discharging pollutants and workers carrying out monitoring should not alter the running condition of that time. The average value should be obtained from continuous sampling in any 1 hour, or from more than 3 samples got at equal interval within any 1 hour. The working condition requirement and sampling time and frequency for the examination and monitoring of final completion of environmental protection facilities of constructed project should comply with Rules on the Examination, Acceptatance and Monitoring of Final Completion of Environmental Protection Facilities of Constructed Projects. 6.1.4 Method of Air Pollutant Analysis of Cement Industry refers to Table 5. 6.1.5 The exhaust funnel (kiln outlet) of newly-constructed, expanded and rebuilt cement mine, cement and its products production line should be equipped with continuous monitor of gaseous particulates, sulfur dioxide and nitrogen oxide; the exhaust funnel of cooler (kiln Kåre Helge Karstensen [email protected] Page 157 of 189 head) should be equipped with continuous monitor of gaseous particulates; and existing cement production lines should be equipped with continuous monitors according to the requirement of local executive administration of environmental protection. The continuous monitor should come up to the requirement of Technical Requirement and Test Method of Continuous Emissions Monitoring System of Exhausted Gas of Stationary Sources HJ/T 76. Data of gas emission obtained from the continuous monitor, which has been examined and approved by executive administration of environmental protection of People’s Government above county level, are considered valid, as long as the monitor is used within its period of validity. The hourly average is the basis of assessment up to standard. 6.2 Monitoring of unorganized emission of particulates out of plant boundary. 6.2.1 Samples should be collected from spots 20m away out of plant boundary (if there is not obvious plant boundary, 20m away from the workshop), both up the wind and down the wind. The data obtained up the wind should serve as reference value. 6.2.2 Monitoring should be carried out according to regulations in Technical Guidelines for Unorganized Emission Monitoring of Air Pollutants, HJ/T55. 6.2.3 The analysis of particulates should adopt Ambient Air-Determination of Total Suspended Particulates-Gravimetric Method, GB/T15432 7. Enforcement of Standard Kåre Helge Karstensen [email protected] Page 158 of 189 7.1 This standard should be implemented under supervision of executive administration of environmental protection of People’s Government above county level. 7.2 Considering structural readjustment of cement industry and conditions of enterprises up to standard, the local executive administration of environmental protection should, according to environmental administration requirements, constitute and proclaim the installation plan of continuous monitor of gas for existing cement production lines. 7.3 According to demand of local environmental administration, the environmental protection department of People’s Government of each province, autonomous region, and municipality under direct administration of the central government can advance the inforcement of the limits prescribed in Table1 or Table 2 after the proposal has been approved by province-level government, and reported to state executive administration of environmental protection for record. Kåre Helge Karstensen [email protected] Page 159 of 189 Table 1 Production Production Process Equipment Particulates Sulfur Dioxide Nitrogen Oxide (Based on Nitrogen Fluoride (Based on Total Fluorin) Dioxide) Emission Unit Emission Unit Emission Unit Emission Unit Concentr Product Concentr Product Concentr Product Concentra Product -ation Emission -ation Emission -ation Emission -tion Emission 3 mg/m Quantity 3 mg/m kg/t Mine Crusher Exploitation other and Quantity 3 mg/m kg/t Quantity 3 mg/m kg/t Quantity kg/t 50 -- -- -- -- -- -- -- 100 0.30 400 1.20 800 2.40 10 0.03 100 0.30 -- -- -- -- -- -- 50 0.04 -- -- -- -- -- -- 50 -- -- -- -- -- -- -- ventilated production equipments Cement and kiln in-line kiln/raw mill* Cement Dryer, drying Manufacture mill, coal mill and cooler Crusher, mill, packing machine and other ventilated production equipments Cement Cement silo Products and Production ventilated other production equipments Note: * indicates the emission concentration and unit product emission quantity when content of O2 in gas is 10%. Kåre Helge Karstensen [email protected] Page 160 of 189 Table 2 Production Production Process Equipment Particulates Sulfur Dioxide Unit Emission Unit Emission Unit Emission Unit Concentr Product Concentr Product Concentr- Product Concentr- Product -ation Emission -ation Emission ation Emission ation Emission mg/m Quantity 3 mg/m kg/t Crusher Exploitation other and Fluoride Emission 3 Mine Nitrogen Oxide Quantity 3 mg/m kg/t Quantity 3 mg/m kg/t Quantity kg/t 30 -- -- -- -- -- -- -- 50 0.15 200 0.60 800 2.40 5 0.015 50 0.15 -- -- -- -- -- -- 30 0.024 -- -- -- -- -- -- 30 - -- -- -- -- -- -- ventilated production equipments Cement and kiln in-line kiln/raw mill* Cement Dryer, drying Manufacture mill, coal mill and cooler Crusher, mill, packing machine and other ventilated production equipments Cement Cement silo Products and Production ventilated other production equipments Note: * indicates the emission concentration and unit product emission quantity when content of O2 in gas is 10%. Kåre Helge Karstensen [email protected] Page 161 of 189 Table 3 Operational field Monitoring spot of Concentration limit*1mg/m3 unorganized particulate emission Cement plant (including pulverizing 1.0 (reference value*2deducted) 20m away out of plant boundary mill), Cement products plant Notes: *1 indicates 1-hour concentration of total suspended particulates (TSP) at monitoring *2 See 6.2.1 for definition of reference value. spot. Table 4 Name of Cement kiln and in-line kiln/raw mill Equipment Dryer, drying mill, coal mill and Crusher, mill, packing cooler machine and other ventilated production equipments Single Line ≤240 (Machine) >240 >700~ ~700 1200 45* 60 >1200 ≤500 >500~ >1000 At least 3m higher than the building 1000 Production Capability Minimum 30 80 20 25 30 Acceptable Height Note: * The exhaust funnel of existing shaft kiln should still be 35m or higher. Table 5 No. Item Manual Analysis Automatic Analysis 1 Particulates Gravimetric Method, GB/T16157 Technical 2 Sulfur Dioxide Iodine Titration Method, HJ/T56 Method of Continuous Emissions Potential Electrolysis Method, HJ/T 57 Monitoring System of Exhausted Gas Ultraviolet Spectrophotometric Method, HJ/T 42 of Stationary Source, HJ/T 76 3 Nitrogen Oxide Ethylenediamine Requirement Dihydrochloride Spectrophotometric Method HJ/T 43 4 Fluoride 5 Dioxin Ion-Selective Electrode Analysis, HJ/T 67 Joint Usage of Chromatography and Mass Spetrometry, HJ/T77 Kåre Helge Karstensen [email protected] --- and Test Page 162 of 189 Annex 3 Chinese companies providing equipment to the cement industry The Institute of Technical Information for Building Materials Industry (ITIBMI) provided in their Cement Sub Sector Survey (2004) a list of Chinese companies providing equipment and technical services to the cement industry. A copy of this information is provided below. *************************************************************************** 3-2. The leading cement equipment manufacturers in China and their techniques 3-2.1 CITIC Heavy Machinery Company Ltd (CITIC HMC,Original, Luoyang Mining Machinery Plant) CITIC Heavy Machinery Company Ltd (CITIC HMC) is a group company and founded on the basis of the former Luoyang Mining Machinery Plant after it enters into China International Trust and Investment Corporation (CITIC).The company is located in Luoyang ,Henan, a city always called"Ancient Capitals of Nine Dynasties". And it is one of 156 important engineering of the “First Five-ear Plan” in China. It has become the largest heavy machinery manufacturing enterprise in China after expanding and reforming during these 40 years. The company possesses the property of 25 bil. yuan with the coverage of 2.16 mil. m2 .It yields about 30,000t product a year and the output values at 0.8 bil. yuan. Currently 20,000-odd staff and workers are working for CITIC HMC, among whom some 2,500 are technologists and 400-odd senior engineers, 12 experts under authority of Henan provincial government and 9 experts under authority of central government. Luoyang Mining Machinery Engineering Academy, which is subordinate to CITIC HMC, is the state-class enterprise technical center and the designing academy A level. Both subordinate companies, CITIC Heavy Machinery Imp. & Exp. Company and CITIC Project Contracting Company are formed by skillful technical people of great strength. The company is one of the eight large heavy-duty machinery manufacturers in the trade. And it is also the casting, forging and heattreating center in central southern area and a large processing base of heavy-load gear. CITIC HMC is the enterprise with the right for independent foreign trade appointed by the state. Kåre Helge Karstensen [email protected] Page 163 of 189 CITIC HMC has exported machines and casting and forging parts to dozens of countries and regions in the world, e.g. America, Australia, southeast Asia, western Europe etc. and imported technology and manufacturing equipment from USA, Japan, Germany, Sweden, Demark, France etc. CITIC HMC operates a tourist company with hotel, restaurant, limousines which are able to provide best services to the guests from home and abroad. CITIC Heavy Machinery Company LTD. has a long-standing record in making the complete equipment for the cement and activated lime plant and the aluminum refineries. The whole set of equipment for 700-2000t/d cement plant can be provided. The company co-operates with the foreign partners to make the complete set of equipment for the cement plant of 4000t clinker. Main Product: CITIC Heavy Machinery Company LTD. can supply large complete mechanical equipment for the basic industries, e.g mine, coal mining, metallurgical, chemical, cement, transportation, environment protection, water conservancy and power generation. Meanwhile the project engineering and equipment integration are also undertaken.The products and equipment are distributed worldwide to 17 countries and regions, in Asia, Africa,Europe, America, Australia etc. It covers many of the markets at home and abroad. Add：No. 206 Jianshe Rd., Luoyang City, 471039, Henan, China Tel：0379-4086586 Fax：0379 4222192 http://www.citichmc.com E-mail:[email protected] 3-2.2 Tangshan Cement Machine Works Tangshan Cement Machinery Works, TCMW, is the leading manufacturer of cement machinery in People’s Republic of China. Its main products are rotary kilns, mechanized shaft kilns, various tube mills, gear boxes, roller presses, roller mills, coolers, dryer, separators, dish type nodulizers, mixers, washer mills, crushers. Various wear-resistance materials, such as high-Cr cast steel balls, medium alloy liners, super high- Mn hammers are also supplied by TCMW. Kåre Helge Karstensen [email protected] Page 164 of 189 These products produced by TCMW, enjoying a high reputation both at home and abroad, have been exported to the USA, Japan, Germany, Indonesia, Philippine, Pakistan, Thailand, Vietnam, Singapore, S. Korea, Iraq, Namibia and many other countries and regions in the world. E-mail: [email protected] 3-2.3 Shanghai Jianshe Luqiao Machinery Co., Limited. The enterprise was founded in 1946. The joint state-private ownership began in 1956. In 1989, the assets was combined with the Road & Bridge Limited Company (Hong Kong) and Shanghai mechanical equipment limited company of road & bridge construction was founded. In 1998, the company annexed the property of Shanghai Hujiang machinery plant in the lease form. Shanghai mechanical equipment limited company of road & bridge construction: Registered capital: 10 million US dollars Classification of the enterprise: joint venture (capital from Hong Kong) Shanghai Hujiang machinery plant: Registered capital: 1124.6 thousand yuan Classification of the enterprise: state enterprise The developed , manufactured and sold products: The main machine and the complete sets of equipment can be put to use in such aspects as mine, metallurgy, building materials, traffic, energy, city public utilities, environmental protection engineering and light textile industry etc. Kåre Helge Karstensen [email protected] Page 165 of 189 Quality system recognition: Passed the recognition of examine and verification center of Shanghai quality system in Feb. 1999. Shanbao brand crusher Evaluated as the state quality silver medal, top quality prize, the high quality product of the Ministry of Mechanical Industry and the high quality product of Shanghai before 1994, it has also been appraised the famous product of Shanghai and mechanical industry of China and the satisfactory product for the nationwide customers since 1994. Hammer Crusher The Single –Stage Hammer Crusher are suitable used to crushing ordinary fragile ores of the compressive strength no more than 200Mpa, such as limestone, gypsum, coal, marl, sandshale etc. This series product features of high crushing ratio, even product graininess, simple construction, reliable operation, easily maintenance, economical running cost etc., so are widely used in cement industry. PE-1 Series Impact Crusher This crusher have features of greater reducing ratio, Created product with cubical shape, be suitable for crushing material with edge length up to 100~500mm, compression strength up to 350 Mpa. Production and management: Actively studying and importing the domestic and foreign advanced standard and technology, the company has made strenuous efforts to develop new products . The company is also Kåre Helge Karstensen [email protected] Page 166 of 189 determined as the “ double intensive enterprise” of technology and knowledge by the foreign trade committee and foreign capital committee of Shanghai. The amount of sale is up to 750 million yuan in 2000. Thus, the company has been occupied in the rank of 500 biggest foreign enterprises in China and 500 biggest sals of industry enterprises in Shanghai. Consequently, the company has been the production and export base of kibbler in China and has been appraised the “double excellent” trinity joint venture for its foreign exchange and profit earnings by China and Shanghai foreign tradesman investment enterprise association in successive 8 years. Address: No.480 Banshongyuan Road, Shanghai P.C.：200011 Tel：021－63139054 Fax：021－63133936 http://jslq.chinasec.com E-mail：[email protected] 3-2.4 Shengyang Cement Machinery Co., Ltd. Shenyang Cement Machinery Co., Ltd is a large-sized limited company in China’s building materials industry, based on Shenyang Cement Machinery Factory as a main body and specializing mainly in the design and manufacture of cement machinery, and is a comprehensive economic entity integrating the design and development of cement equipment, import and export of electro-mechanical equipment, equipment set complement, installation and commissioning of equipment and handling and transportation as a whole. It can supply cement enterprises at home and abroad advanced, excellent, high-efficient technological equipment set for 200t/d, 1000t/d, 2000t/d and 4000t/d cement clinker production lines. Shenyang Cement Machinery Factory has more than half a century development history and has a capacity of manufacturing the main equipment for new dry process cement production lines with a capacity of and under 4000t/d. It is a state-level A class enterprise. Kåre Helge Karstensen [email protected] Page 167 of 189 Shenyang Cement Machinery Co., Ltd is a large-sized backbone enterprise in China’s building materials industry, the products of which represent the most advanced technique in China’s building materials industry, enjoying a good reputation at home and abroad. The enterprise was awarded one of the “key enterprises of Machine-building Industry for Building Materials” approved by the State Machinery Commission of China in 1987. It is approved as a “State-owned large-sized A Class Enterprise” by State Commission of Economy and Trade of China in 1993 and one of “The Ten Most Powerful Enterprises of Building Materials Machinery Industry in China” in 2000. The company is the leading enterprise of China’s Cement machinery industry, having a most powerful cement machinery complement capacity. The company is located in the High-and New-Tec Development Zone of Shenyang City, occupying an area of 0.23 mil. sq.m and having 200 pieces (sets) advanced heavy-duty, CNC processing equipment and is capable to provide equipment set complement, installation and commissioning for the 4000t/d cement clinker production lines. The major products of the company are the complete set of cement machinery, and it has a capacity and qualification of designing, manufacturing, erecting and commissioning of the first and the second category of compressed containers. The company stands at a international leading position in new generation aerated beam-type grate cooler and the products of the type have already installed in hundreds of new dry process cement production lines at home and abroad replacing imported ones. The large-sized main machines, such as cement kilns, ball mills, crushers, etc, produced by the company have also high technical content and quality advantages. The products of the company not only equips the Chinese cement enterprises but also exported to Australia, Japan, USA, Brazil and the countries and regions in Southeast Asia, enjoying trust of broad circle of customers at home and abroad. The company has passed in the first group ISO9001 Quality System Attestation in building materials industry of China in 1997. In the past years the company has trained a contingent of technical personnel with rich experience and has advanced cement machinery manufacturing technique and processing technology and has formed an independently creative design and development institution using modern information technology. Kåre Helge Karstensen [email protected] Page 168 of 189 In the sixty years’ development process, the company has achieved dozens of “the first” in the domestic building materials industry. It produced the first grate cooler in the country in 1965; It introduced firstly the grate cooler technology of 1980’s international advanced standard from Fuller Co. of USA; It independently and initially designed, developed and manufactured the first in the country 3000t/d grade cooler in 1993 and exported it to Philippine; It successfully manufactured the first in the country 4000t/d grate cooler in 1995; It successfully produced the first in the country 2200t/d aerated beam-type grate cooler in 1998. 3-2.5 Chaoyang Heavy Machinery Co., Ltd. (CHM) Chaoyang Heavy Machinery Co., Ltd. (former Chaoyang Heavy Machinery Factory) is one of 500 largest enterprises of machinery industry in China and a large-sized backbone enterprise of Chinese building materials machinery industry. It accupies the first place in equipment strength, product sales volume, foreign currency earning capability and economic benefits in the Chinese building materials industry. It is a certificated enterprise passed ISO9001 Quality System attestation and enjoys independent import and export right. It has been successively awarded the honored titles and prizes, such as National First-class Measurement Qualified Unit”, “National Quality Control Prize”, “National Energy-saving silver Prize”, “The first Place among the 100 Best Industrial Enterprises for Environmental Protection in China”, “AAA Grade Unit of the Best Prestigious Chinese Enterprises and the Best Image Chinese Enterprises”, etc. The enterprise is situated in the ancient city of Chaoyang in the west Liaoning Province, China and was founded in 1959. It develops and produces “Chaozhong” Brand machinery for building materials production with an annual production capacity of more than 40,000 t, with Kåre Helge Karstensen [email protected] Page 169 of 189 being about 1 eighth of market demand for the building materials machinery at home in China. The enterprise occupies an area of 80617 m2. The fixed assets are 0.113 bil. yuan. It employs 1100 people, of which 165 engineers and technicians and 61 of them have highdegree technical titles. It has more than 1500 pieces (sets) of equipment, of which more than 200 are large-sized, precise and rare ones. The production technology is advanced and the testing means are sophisticated. The ISO 9001 Quality Standard is fully implemented in the production. The CHM is fully capable in providing large- and medium-sized complete set of equipment with a daily capacity of 300 t to 4000 t from engineering development, production, testing, quality guarantee system, hoisting and delivering to after-sales service. Since the mid 1980’s, CHM has successively introduced from Japan, Germany, USA and other developed countries and developed the engineering and manufacturing technique for the key equipment for the 2000t/d, 1000t/d and 800t/d cement clinker production lines of precalcing kilns, double-spout stationary and six-spout rotary cement packing machines, highefficient bucket elevator, bag dust collector series, vertical mills, plate-chain bucket elevator and so on, which are up to international advanced level of 1990’s. The main products of the enterprise are 789 specifications in 181 assortments, 29 series and 9 categories of complete sets of cement plants with an annual capacities between 0.88 and 1.20 mil.t. The production capacity of those products is 40000 t. In the recent years CHM has developed 215 specifications new products at its own selection, obtaining 12 national patents, winning 10 technical achievement prizes at ministerial or provincial level, among which 7 are the firstly developed in China. Address: 22 Third section, Huanghe Road, Chaoyang City, Liaoning Province P.C.:122000 Tel: (86-421) 2814979 Fax: ((86-421) 2813151 3-2.6 Wuxi Jianyi Instrument & Machinery Co., Ltd. Situated at the lakeside of scenic spot of Taihu lake, Wuxi Jianyi Instrument & Machinery Co.,Ltd., founded in 1958, is one of the key and large scale enterprises under former the State Kåre Helge Karstensen [email protected] Page 170 of 189 Administration of Building Material Industry specialized in manufacturing apparatus for physical test of building materials, machinery for building materials and new decoration materials. With its long history, complete set of products, high technology content and workmanship, the company enjoys the high reputation and has been authorized the right of operating I/E business. Its products sell well both at home and abroad. The company, covering an area of 102,000 sq. m, is equipped with fine working facilities and equipment, complete measuring and inspection means and powerful backing of technical personnel. It has 1000 staff members and workers including 200 engineers and technicians. Under the company there are foundry, metal working, cold work and welding, heat treatment and assembly plants, a product developing and research center and a Sino-Holland joint venture enterprise WuxiProfil Metal Ceiling Co., Ltd. The company has established a quality system for the whole process of raw material and auxiliary parts procurement, production, assembling, inspection, packing and servicing and has been granted the Quality System Certificate in conformity with ISO9001:2000 standard. The company’s products meet the requirements of national GB standards and JC standards for building materials industry. Part of its products conforms to relevant stipulations of ASTM of the USA. Adhering to the principles of quality first and clients first, we are ready to design and manufacture the products with the requirements of our clients and supply the best after –sale service. Address: No.8 Fangqianchunyangdong Road, Wuxi City, Jiangshu Province Tel: 0510-8275668 Fax： 0510-8275118 E-mail：[email protected] 3-2.7 Zhuzhou Cement Machinery Factory Kåre Helge Karstensen [email protected] Page 171 of 189 Zhuzhou Cement Machinery Factory is a key enterprise under the State Administration for Building Materials Industry of China. It has more than 40 years’ production history, possessing a strong technical power and good product development capability and complete testing means. It is capable to supply the complete set of equipment and all-round technical service for the 0.3 mil. t/a rotary kiln and shaft kiln cement production lines. It is also able to provide part of equipment for 0.6 mil. t/a rotary kiln cement production lines. The company can provide complete set of cement manufacturing equipment and accessories for the 1000t/d rotary kiln cement plant and shaft kiln cement plant. The major products of the company are ball mills, rotary kilns, mechanical shaft kilns, the equipment for drying, pelleatizing and cooling and the main equipment complementary machines for elevating, handling, feeding and dust-collecting. It supplies constantly the accessories. The most of main equipment produced by the company are the superior quality products of Hunan Province. 3-2.8 Pingdingshan Electrostatic Precipitator Factory (PEPF) Established in 1972, Construction Corporation for Pingdingshan Electrostatic Precipitator Factory (CBMCC PEPF) under China National Building Material Industry is one of the leading enterprises subordinated to the China Noumetallic Minerals Industry Group Corporation. Now the factory is one of the largest and earliest enterprises in China engaged in research, development, manufacturing and installation of environmental protection equipment. During more than 20 years, the factory has produced and supplied more than 2000 Eps, bag filters and cement industry conditioning towers of different sizes and specifications to such industrial sectors both at home and abroad, as building material industry, metallurgical industry, electric power industry and chemical industry, and has got unanimous praise from all clients and successively won many honorable titles, such as National Second-class Enterprise, one of China’s 100 Top Enterprises for Environment Protection, China’s Advanced Enterprise for Science and Technology of Environmental Protection, Enterprise of Henan Province of Advanced and New Technology, Civilized Unit of Henan Province and so on. PEPF is entitled to operate import and export business by itself. In 1996, PEPF got the ISO9002 Quality System Certification of China, France, USA, Germany, Netherlands, Australia and New Zealand. Kåre Helge Karstensen [email protected] Page 172 of 189 EP lies in Pingdingshan, the “Famous City in the Central Plain of China”. The occupied area of PEPF is 155 thousand square meters. PEPF has fixed assets of 35 million yuan, 6 main workshop (Riverting & Welding shop, Metal Processing shop, Casting shop, Forging shop, Rolling shop) and 7 specialized parts production lines. PEPF has more than 200 sets of advanced different equipment, such as rolling machines for electrode plates, CO2 automatic housing welder, numerical control plasma cutter and so on. It has an ability to manufacture dedusting equipment in amount of 20 thousand tons per annum. In 1984, 1987, and 1996, PEPF successively imported the designing, manufacturing, installation and commissioning technology of the BS780 EP of Lurgi GmbH, Germany, the Baf Filter of Fuller Inc, of USA and BS930 E of Lurgi GmbH, Germany. The factory has done a lot of digesting, assimilation and improvement works of the imported technology, so as to upgrade all the technical and economic targets of the factory’s leading products – “aflyng” EP and Bag FILTER –up to the advanced world level, and to make the products sell well both at home and abroad such as in USA, Germany, Australia, Philippines, Pakistan, Malaysia, Iran, Brunei, Vietnam, Rwanda and others. Add：35 West Nanhuan Rd., Pingdingshan, 467001 Henan, China Tel：0375-4944054 Fax：0375-4945874 3-2.9 China National Building Material Equipment Corporation (CBMEC) Established in 1981, China National Building Material Equipment Corporation (CBMEC) is now subordinated to China National Non-metallic Minerals Industry Corporation (Group) (www.cnmc.com). Through the development and innovation in more than 20 years, CBMEC has become into a leading company in the field of building material equipment of China as a supplier of complete set of equipment and machinery, contractor of turn-key project at home and abroad, chartered tender agency for national technical renovation project and construction project, agency of foreign partners, trader of materials and products and importer of advanced foreign technique and equipment, etc. With “major business with multiple operation as her development strategy, and with excellent service for the building material industry of China and other developing countries in Asia, Kåre Helge Karstensen [email protected] Page 173 of 189 Africa and Latin America as her mission, CBMEC provides domestic and foreign customers with fine quality, low energy consumption and high efficiency complete specialized equipment and machinery and auxiliary facilities, repairing and spare parts, and other building materials and products. Periodical, “China Cement", published and distributed by CBMEC, is a state-level professional technical monthly in the Cement Industry of China. China Building Material Machinery Association (CBMMA) and the Technical Standardization Committee of China Building Material Machinery (SCCBMM), standing in CBMEC, execute the managerial functions including reasonable adjustment and control on the building material industrial structure, working-out technical and quality standard in the field of building material equipment and machinery. CBMEC owns her own research and design institute of cement industry, research and design institute of automatic control and manufacturing factories. Since 1984, CBMEC has organized local manufacturers importing from abroad and developing more than 40 advanced technique and equipment with the world advanced level of late 1980’s and early 1990’s, And all these help the production technologies and equipment of cement and flat glass reach the world advanced level. Up to now, CBMEC has successfully provided more than 40 domestic cement plants with over 50 complete sets of cement production lines, 20 of which have a capacity of from 2000t to 4000t clinker per day, and provided about 10 glass plants with complete sets of float glass production lines. Based on the advanced technique, fine quality equipment and rich experiences on engineering construction, CBMEC exported many cement production lines with a capacity of from 400t to 2000t clinker per day to about 10 countries including Malaysia, Pakistan, Myanmar and Bangladesh, etc.. At present, CBMEC has powerful abilities of providing complete set of cement equipment and machinery with a capacity of 350t, 700t, 1000t, 2000t, 4000t clinker per day, complete set of float glass equipment and machinery with a melting capacity of 300t, 400t and 500t per day. complete set of equipment and machinery for producing refractory, ceramic and mining or processing machinery producing marble, granite, terrazzo slabs. In order to further adopt the developing requirements of market economy, CBMEC pays a close attention to multiple operations, and has expanded its businesses to all the fields related to equipment manufacturing or building material products, including providing of repairing and spare parts, development and production of special cement and wall materials, distribution of building material, platinum-rhodium alloy, nonferrous metals, timber, pig iron and copper. In addition, Kåre Helge Karstensen [email protected] Page 174 of 189 CBMEC becomes the sole agencies of some famous world companies including Johnson Window Films Inc. and PEWAG, etc.. With providing domestic and foreign customers with satisfactory services as her tenet, CBMEC strengthens and expands foreign economic and technical co-operation based on the faith of “Quality First, Service First and Reputation first" for the mutual benefit and common development, CBMEC warmly welcomes all clients and partners to cooperate in building material industry and other related fields. CBMEC has the following certificates of qualification: The First Class Certificate ff General Contractor For Supplying Complete Plant Of Mechanical & Electrical Equipment authorized by the State Administration of Building Materials Industry and Ministry of Machinery and Electric Industry of P.R.C. The First Class Certificate of Tender Agency For Equipment In Construction Project authorized by the National Planning Council and the State Administration of Technical Supervision; Certificate of First Class Chartered Tender Agency For National Technical Renovation Project authorized by State Economic and Trade Commission of People’s Republic of China (SETC); Certificate of Approval for Export Credit for undertaking turnkey projects and export of complete set of equipment authorized by Ministry of Foreign Trade and Economic Cooperation P.R.C. and People’s Bank of China; Certificate of Approval for Enterprises with Foreign Trade Rights in the People’s Republic of China issued by Ministry of Foreign Trade and Economic Cooperation, P.R.C. Add：No.12 Floor, Canjiakou Plaza, No.21 Sanlihe Rd., 100037,Beijing, China Tel：（010）88372171 Fax：（010）68311354 http://www.cbmec.com E-mail:cbmec@public3,bta.net.cn Kåre Helge Karstensen [email protected] Page 175 of 189 3-2.10 Shannxi Yanhe Cement Machinery Factory Shannxi Yanhe Cement Machinery Factory is an appointed specialized factory for producing cement machinery and equipment and wear-resistant castings in national building materials industry. It is also considerably large and well equipped cement machinery and equipment manufacturing enterprise in Northwest China, responsible for supplying cement machinery and equipment and wear-resistant castings to large- and medium-sized cement producing enterprises. It is listed as a state level large enterprise, having an authorized independent import and export right. The factory was initially founded in 1966, having a over 30 years experience in producing cement machinery and equipment. Its products are in 200 specifications, 16 categories, main ones of which are rotary kilns, mechanical shaft kilns, ball mills, dryers, coolers, crushers, electric fans, dust collectors, high-quality wear-resistant castings and other industrial and mining accessories. It is capable to provide complete sets of 0.6 mil. t/a cement production lines and can also supply key and non-standard equipment for chemical, metallurgical and building materials industries. The factory has a strong technical contingent, excellent technological equipment and advanced testing means with over 800 pieces (sets) of main production equipment including automatic high-pressure caseless vertical separately modeling lines from DISA Co. of Denmark, VRH-CO2 technological modeling lines from Japan and other large-sized specialized equipment from Sweden and other countries. The casting and processing capacity is strong. Registered fund: 38.25 mil. yuan Address: Fangnan Road, Textile city, Xian City, Shannxi Province P.C.: 710038 Tel: (86-29)3523423 Fax: (86-29)3524911 Kåre Helge Karstensen [email protected] Page 176 of 189 3-2.11 Ningguo City Wear-resistant Materials General Factory of Anhui Province Ningguo City Wear-resistant Materials General Factory of Anhui Province has a more than thirty years’ history of professional production and sale of “Fengxing” brand wear-resistant materials. Its products include various kinds of balls, wear-resistant and heat-resistant cast steel segments, as well as abrasive aides for cement and mining industries. It passed ISO 9002 Quality System Attestation and International Standardization Attestation in July 1998 and ISO 9001 (2000 version) conversion Attestation in March 2001. The “Fengxing” brand trade mark was approved as “Chinese Famous Trade Mark by State Bureau of Industry and Commerce” in 1999. The “Fengxing” brand wear-resistant materials are widely applied in powder preparation and superfine grinding for the cement and building materials industry, metallic or mining industry, power generation with coal slurry, chemical engineering, ceramic coating, light industry and paper-making, magnetic materials manufacturing and so on. There are at present more than 100 varieties and specifications of products in 7 series. The products are well sold to more than 2000 enterprises in 31 provinces, municipalities and autonomous regions in the country and exported to Japan, Korea, USA, Australia and different countries in Southeast Asia and Africa. Ningguo City Wear-resistant Materials General Factory of Anhui Province is a State-level Large-scale Enterprise, State Second-class Enterprise, one of the 50 Most Powerful Industrial Enterprises of Anhui Province. It has formed a production capacity of producing 0.1 mil.t/a of cast ball and cast sticks and 20,000 t/a of cast steel segments. The scale of the factory stands in the lead of the same trade in Asia. 3-2.12 Luoyang Refractory (Group) Co., LTD, Luoyang Refractory (Group) Co., LTD., established in 1958 during the state "First Five-year Plan" period, is the largest refractory commercial enterprise at present, and only one of 520 state key enterprises dealing with refractory in China. It has 8 production branches, 3 auxiliary shops, one technology center, one limited company and one joint-venture company. Kåre Helge Karstensen [email protected] Page 177 of 189 There are 5758 employees including 507 managerial personnel, 1018 technicians. The corporation occupies an area of 1,114,900 square meters. The corporation is equipped with 3,910 production devices, including 9 tunnel kilns, such as 98.4m, 59.4m ultra-high temperature tunnel kilns, 202.5m tunnel kilns which is the longest in China, two 30m3 one 20m3 full-auto shuttle kilns imported from Germany, 750t compoundfriction press imported from Japan, 1,250t automatic hydraulic press imported from Germany, 2,500t full-auto hydraulic press imported from Italy,1,000t hydraulic automatic press made in China, computer-assistance design systems for moulds, computer-control batching systems and advanced testing systems for both physical and chemical properties, and necessary installations for packing and special railway line. Various refractories (acid, basic and neutral )are now produced in a large scale according to the requirements of the strict quality guarantee system of ISO-9002. The main products are silica, magnesia, high-alumina, magnesia-chrome, middle-and high-grade sintered product and alumina-carbon, alumina-magnesia-carbon, alumina-zirconia-carbon products for continuous casting, sinalon composites, electrofused magnesia-chrome, alumina-silicazirconia products, insulating products, unburned products, ceramic kiln furnitures and necessary monolithic refractories. The corporation has a production capacity of 160,000t and 600,000 ceramic rollers. The products have been sold all over China, 20% of the products have been exported to more than 20 countries and regions, such as Japan, USA, Brazil, Italy, South Africa countries and Southeast Asia. Add：Xiyuan Rd., Luoyiang City, 471039, Henan, China Tel：（0379）4226148 4208809 4209546 Fax：（0379）4210864 http://www.lyrg.com E-mail: [email protected] Kåre Helge Karstensen [email protected] Page 178 of 189 Annex 4 Chinese research institutes providing service to the cement industry The Institute of Technical Information for Building Materials Industry (ITIBMI) provided in their Cement Sub Sector Survey (2004) a list of Chinese research institutes and professional organisations providing research and technical services to the cement industry. A copy of this information is provided below. *************************************************************************** 4－1 Brief introduction of main research institutes in cement industry in China 4－1.1 Tianjin Cement Industry Design and Research Institute (TCDRI) Tianjin Cement Industry Design and Research Institute (TCDRI) is one of the prospecting and designing institutes under the management of Central Enterprises Operating Committee (former under SABMI). As one of the earliest founded design institutes in China, TCDRI now became a first-class design institute with the strongest design capability in building materials industry in China since it was set up in 1953. Through years of development and expanding, TCDRI now has turned into a large comprehensive designing enterprise incorporated scientific research, engineering design, construction supervision, turnkey contract construction, consultative engineering technical service and machinery & electrical equipment manufacture. In 1992, TCDRI was granted "the Direct Business Right with Foreigners" by the Ministry of Economy and Trade, and in 2000 TCDRI was granted "Self-run Import Enterprise" by Tianjin Foreign Economic Relations and Trade Committee. In 1995, TCDRI was entitled by the Development and Research Center of the State Council as "the first institute for design and research on new dry process cement production line in China", and was enlisted in the book "Honor Records of the Most in China" (1949~1995). In 1993 TCDRI was honored as one of "the Hundred Strongest Institutes" (the sole design institute gained this title in building materials industry) and afterwards, was successively chosen as one of "the Hundred Strongest Prospecting and Designing Institutes in Overall Strength in China ". In Kåre Helge Karstensen [email protected] Page 179 of 189 1996, TCDRI was the first one passing the conformity of quality system certification ISO9000. China Cement Development Center (CCDC) under the TCDRI created by Chinese government and UNIDO is a sole international institution in Asian and Pacific region. From the founding of CCDC in 1983, entrusted by UNIDO, TCDRI successfully organized and sponsored three international mini-cement meetings and trained more than 100 cement professional staffs for Asian and pacific region. TCDRI played an important role in training professionals, providing technical assistance and international technical exchange in Asian and Pacific region. At the present, TCDRI has obtained several qualifications on engineering and consultation including non-metallic minerals, construction engineering, environmental pollution protection and control. The certificates which TCDRI commanded involve "Export Licence of Engineering Design", "Grade A Certificate on Cement and Waste-heat Generation Engineering Design", "Grade A Certificate on Turnkey Contract Construction", "Grade A Certificate on Engineering Consultation" and "Special Qualification on Intelligent System of Construction Engineering" as well as the "Conformity of Quality System Certification ISO 9000". The major business and services include: Cement engineering design, cement raw materials quarry engineering design, new process / technology and new materials development and application, raw materials testing and evaluation, pressure vessels design, environmental impact assessment and prevention, turnkey contract construction, construction supervision and operation management, construction costs and consultation service, equipment manufacture and complete installation supply, cement technical information and consultation service etc. There are about 800 staffs and 300 other employees in TCDRI. Among 800 staffs, 700 are professionals in different sectors including 2 design masters, 2 experts at national level and 4 experts at provincial and ministerial level, 220 professors and senior engineers, 300 engineers and 160 assistant engineers. Kåre Helge Karstensen [email protected] Page 180 of 189 In order to respond to meet market competition, TCDRI has established several sections of multiple economic structure comprising 24 divisions, 2 wholly-owned subsidiaries, 11 holding subsidiaries and 1 collectively-owned company. There are varieties of advanced facilities for scientific research in TCDRI. 16 labs including laboratory test center, cold and hot model pilot plants, machinery and electric plants, cement technical training center and computer center etc. In TCDRI it is possible to carry out simulating test, research experiments, semi-industrial scale tests and auto-control development for cement manufacturing, industrial wastes utilization, raw materials grindability and burnability testing, as well as training programs for technicians. The results of these activities provide reliable technical guarantee for first-rate engineering design and scientific research in China’s cement industry. The completion of the state "Torch Plan" project - new energy conservation cement installation manufacture base is a beneficial practice for industrial development of TCDRI technical achievements, this plant has a stronger ability on equipment manufacturing and sales and has become a new economic growth point of TCDRI. As one of the demonstration units of CAD, various intelligent computer soft-wares are widely-applied in scientific research and engineering design in TCDRI, now, the level for applying computer-integrated circuit makes progressing, computer network and shared engineering database, as well as office automation realized. This makes TCDRI being in a leading position among design institutes in China. Over 50 years, TCDRI has accomplished more than 400 cement plants and other engineering designs, over 200 projects of turnkey contract construction, construction supervision and engineering consultation, has developed and designed more than 6000 sets cement equipment and fulfilled scientific research on 140 subjects. With these achievements, TCDRI has made great contributions to the products adjustment and technical progress in China building materials industry and created notable social and economic returns both for state and clients. Add: Beichen District, 300400, Tianjin, China Tel: 022-26391311 Fax: 022-26390071 Kåre Helge Karstensen [email protected] Page 181 of 189 http://www.tcdri.com.cn E-mail: [email protected] 4-1.2 China Building Materials Academy (CBMA) CBMA, founded in the early 1950s, is the largest comprehensive research and development organization in China in the fields of building materials and advanced inorganic non-metallic materials. Since 1999, CBMA has become one of the high-tech enterprises under the central government. CBMA’s R&D covers cement and concrete, ceramics, refractory, glass fiber, housing materials, engineering design, test technology, quality supervision, environment engineering and technology information etc. Over the past 50 years, CBMA has completed about 2300 research projects. The contributions made by CBMA to the Chinese building materials and advanced material industries are well demonstrated by more than 430 government awards, including 100 national prizes. CBMA has close academic and trade relations with organizations of more than 50 countries and regions all over the world. Its technologies and products are widely acknowledged both at home and abroad, and have been exported to more than 30 countries and regions. Add：No. 1 Guanzhuang Dongli, Chaoyiang District, 100024, Beijing,China Tel：010-65761787 Fax：010-65762976 http://www.cbma.com.cn E-mail:[email protected] 4-1.3 Nanjing Cement Design and Research Institute Nanjing Cement Design and Research Institute (NCDRI) was founded in 1953 and is one of the earliest design and research institutes of its kind in China. In the past 50 years or so, NCDRI has been developed into a distinguished and strong class A design and research institute in China’s building materials industry. Kåre Helge Karstensen [email protected] Page 182 of 189 NCDRI has incorporated the process, mechanical and control technologies in the development of a large variety of cement production lines, process control systems and special cement manufacturing equipment of national or world advanced level. It is capable to undertake the engineering project of technical services and technical transformation of 1000-8000tpd plus NSP/SP kiln, pre-heater kiln, cogeneration kiln, wet process kiln, anthracite burning kiln and cement production with wastes and low-grade raw materials for cement plants. Since its establishment, NCDRI has accomplished design of more than 200 cement production lines of various scales for clients both at home and abroad and has been awarded over 60 prizes of national and provincial levels. It was awarded with certificate of ISO-9001 in 1997. NCDRI’s major business scope is: engineering design for cement plant and quarry; Turn-key project contract for building material engineering, power engineering and environmental engineering; development, manufacture and sales of specialized equipment for cement plants and transfer of related technology, technical services and supply of complete set of equipment; construction supervision for ordinary civil and industrial construction and installation projects of Grade , and of building materials industry, engineering survey, consultation, design and supervision for overseas funded projects at home and abroad; export of equipment, materials and spare parts; export of labor and technical services in the building materials industry etc. Add：No. 209 Hanzhong Rd, Nanjing, 210029, Jiangsu, China Tel：025-6611333 Fax：025-6611234 http://www.NCDRI.COM E-mail:[email protected] 4-1.4 Chengdu Design & Research Institute of Building Materials Industry (CDI) Initially founded in 1953, Chengdu Design & Research Institute of Building Materials Industry (hereafter referred to as CDI) is one of the prestigious design and research institutes among China’s building materials industry and also the first one being granted the premier Kåre Helge Karstensen [email protected] Page 183 of 189 design certificate regarding cement plant and non-metallic quarry. Entitled to deal with direct foreign trade, domestic and international engineering design, engineering general contracting, and premier design qualification of civil engineering, and taking research, design, engineering consulting, technical service, general contracting and engineering supervision of building materials and non-metallic quarry works and promotion of new technology as the major businesses, CDI through 50-year hard working has developed into one of the top design and research institutes in China. In June 1998, CDI passed the ISO 9001 qualify system qualification. Since its foundation 50 years ago, CDI has undertaken design, consulting, supervision, and general contracting of hundreds of cement plants at home and abroad, non-metallic quarries and civil buildings, and fulfilled dozens of new technology development and raw materials researches as well, among which about 50 designs and new technologies have been respectively awarded national, ministerial, provincial excellent design or technology improvement awards. Scores of new dry process cement production lines with capacity ranged from 600t/d to 4000t/d designed by the CDI have finished construction and reached their expected output, gaining substantial economic and social benefits. Moreover, in recent years CDI has finished successively 5 large projects by general contracting both at home and overseas: 1.5 million limestone quarry of Lafarge-Dujiangyan Cement Co., Ltd., quarry and plant of 3000t/d clinker production line of Shandong Yantai Dongyuan Cement Co., technology upgrading of 2000t/d clinker production line of Gansu Wushan Cement Plant, 3000t/d clinker production line of Iran Fars Nov Group, and 2000t/d clinker production line in Xinjiang, that makes CDI among domestic design institutes of building materials industry the first one in undertaking independently the large-scale general contracting projects. Concerning deploitation of international operation, besides technical communication and contact with companies in Iraq, Laos, Sri Lanka, Bangladesh, Thailand and Burma, CDI has offered engineering design and technical service to cement plants and non-metallic quarries in various countries such as Pakistan, Vietnam, Iran and Albania, and established technical cooperation with many renowned companies from Germany, United States of America, Canada, Denmark, Japan and etc., which lays a solid foundation for a broader reach of CDI’s operation all over the world. Kåre Helge Karstensen [email protected] Page 184 of 189 Add：No. 331 Xinhong Rd, Chengdu City, 610051, Sichuan, China Tel：028-4333584 Fax：028-4333545 http://www.cdi-china.com.cn E-mail:[email protected] 4-1.5 Hefei Design & Research Institute of Building Materials Industry Hefei Cement Research and Design Institute (HCRDI)used to be a key research institution and a state Class-A qualification holder under the State Administration of Building Materials Industry. Its predecessor is The Research Institute of Ministry of Building Materials Industry and Beijing Cement Design Institute. After the system reform in 1997, it has been integrated into China New Building Materials (Group) Company. The institute takes up 25 hectares of land. It owns 895000 square meters of covered area. It has more than 680 employees, with about 500 technical staff, of whom there are more than 200 senior technical professionals and more than 200 are middle level technical professionals. HCRDI has 12 departments (centers and companies): Design Department, Powder Engineering Company, Jinshan Industrial Company of Science and Technology. Environment Protection Engineering Company, Equipment and Metal Materials Engineering Company, New Building Materials Company, Machinery and Motor Engineering Company and Information Center and etc. It is mainly engaged in the design, technical service, construction supervision, complete set of equipment supply, construction project contracting and environment evaluation related to cement production lines of all types of kilns. Supply of new process, new equipment, new materials, new technology and new products is supported by running enterprises that produce high-tech products. Since its establishment, the institute has undertaken 300 research projects including 16 scientific projects of the state government, 50 such projects of the state ministry. The total investment of these projects amounts to 16,000,000 yuan. 180 research projects have been evaluated and accepted. 78 of them have reached up to world’s or national advanced level, and found wide application both at home and abroad. There are quite a few technological Kåre Helge Karstensen [email protected] Page 185 of 189 achievements that have been listed in the state scientific achievements promotion plan. It has made great contributions to the technological progress of cement industry. Today, HCRDI has formed a competitive advantage in such technical fields as thermal process, powder engineering, production automation, environment protection, metal materials, optimized exploitation of cement materials and comprehensive utilization of resources. It has brought up large numbers of experts in various specialized areas. In the field of design, during the eighth five-year plan period, the institute further developed pre-calciner kiln with capacities ranging from 1000 – 6000 tons clinker per day. It has been applied in the design of cement plants of various scales achieving good results. Up till now, the institute has designed more than 100 cement production lines of various types with capacities ranging from 1000 to 6000 tons. In addition, many projects of various production capacities have been awarded the titles of excellent design. In the field of scientific and technological industries, the manufacturing entities of the institute are growing steadily. The institute’s manufactured products are based on either imported or self-developed technology. Product quality is increasingly improving, gaining good reputation both at home and abroad. The manufacturing facilities of the institute are able to supply equipment for the cement production lines with capacities ranging from 1000 to 5000 tons per day. The institute has established an industrial park where Zhongya Cement Machinery Works, Feixi Energy Saving Equipment Works, Environment Protection Equipment Works, Wear and Heat Resistant Materials Works, Building Materials Machinery Works, Zhongya Steel Structure Factory are located. The total output value of these entities has amounted to 600, 000, 0000 yuan. Add：No. 60 Wangjiang Rd, Hefei City, 230051, Anhui, China Tel：0551-3439196 Fax：0551-3424995 4-1.6 Institute of Technical Information for Building Materials Industry (ITIBMI) Kåre Helge Karstensen [email protected] Page 186 of 189 ITIBMIC was established in 1958. Through more than 40 years construction and development, the institute has become the scientific, technological, economic and trade information research, consultation services and documentation center for building materials industry on China. ITIBMIC has accomplished about 1000 reports on special subjects and more than 100 research projects of soft science. Meanwhile, having a function of building materials documentation resources center of China, ITIBMI has a collection of more than 180.000 special books in Chinese and foreign languages, about 500 domestic and foreign special periodicals subscribed and the databases on building materials literatures in Chinese language, Chinese building materials patents and scientific & technological achievements of Chinese building materials industry established. ITIBMIC undertakes fundamental research projects assigned by the Ministry of Science &Technology and edits and publishs more than 10 periodicals, including “Cement” which has the largest circulation in Chinese building materials industry, “Building Materials Industry Information” and so on. A line within the Institute and a web site of China Building Materials Industry Information Network on Internet have been set up. ITIBMC is capable to offer all kinds of web services for the domestic and foreign clients on web site. Add：No.2 Guanzhuang Dongli, Chaoyang District, 100024,Beijing, China Tel：010-51164601 Fax：010-6575-61207 http://chinabmi.com E-mail:[email protected] 4-2 Industrial associations and other administrative institutions in China 4-2.1 China Building Material Industry Association (CBMIA) China Building Material Industry Association (CBMIA) is a nation wide, non-profitable and self disciplined social organization that is voluntarily formed by the building material industrial enterprises, social organizations and individual members and serves as a bridge Kåre Helge Karstensen [email protected] Page 187 of 189 between the government and enterprises, offering them services in the meantime. Its major tasks are as follows: (1) Conduct studies on key and important topics related to the building material industry as a whole and its development, submit economic and legal suggestions to the central government. (2) Voice out the interests of its members and enterprises, coordinate relations among its members, organize and formulate the industrial regulations, coordinate disputes on products’ prices, normalize the enterprises behaviors, establish the industrial discipline mechanism and protect the legal rights and interests of enterprises. (3) Provide timely and accurate information and various services on technology, management consultant and talent development, promote contacts with foreign colleagues, develop international economic and technical cooperation, participate in coordination of economic disputes, and assist its member enterprises to develop international market. (4) Authorized or entrusted by the central government or departments concerned to participate in working out the industrial planning, making of revising national standards and industrial standards and other industrial management. (5) Exercise supervision over the trade associations, i.e. to guide them in activities according to their constitutions, oversee their disciplines, observe legal regulations and the state policies; provide the final approval of reformation, adjustment and development suggestions and their structural alterations etc. of its subordinated associations; be responsible for the personnel management, party construction and ideological and political work. Assist the government to check in –discipline behaviors. Add: No. 11 Sanlihe Rd., Haidian District, 100831, Beijing, China Tel: 010-68311144-2215 68314360 Fax: 01068332658 http://www.bm.cei.gov.cn E-mail: [email protected], [email protected] Kåre Helge Karstensen [email protected] Page 188 of 189 4-2.2 China Cement Association China Cement Association (CCA), established in February 5, 1987 is a mass social organization of cement enterprises and other institutions related to cement industry under the principle of voluntary participation. Ever since its establishment, the CCA possesses a great attraction to the entire industry. The organization and various businesses have been rapidly developed and strengthened. Up to date, there are 3200 members among which 900 are direct members and 50 collective members of provincial and municipal sub-associations and trade committees etc. that forms the nation wide network of cement industry, which possesses highly extensiveness, representation and authority. Add: No. 11 Sanlihe Rd., Haidian District, 100831, Beijing, China Tel: 010-68332654 Fax: 010-68332654 http://www.cncement.com.cn E-mail:[email protected], [email protected] 4-2-3 Chinese Ceramic Society The Chinese Ceramic Society is voluntarily formed by the silicate non-organic non-metallic materials Science and technology after registration according to law. It is a social organization of learned and public characters having independent legal representative and is a component part of the Chinese Society of Science and Technology. The aim of the society is to unite the broad mass of workers of ceramic science and technology for the promotion of prosperity and development of science and technology, the facilitation of popularization and spreading of Science and technology, the promotion of growth and upgrade of scientific and technical talents and the promotion of the integration of science and technology with economy. The former body of Chinese Ceramic Society is the Chinese Ceramics Society. It was initially established in 1945 and its name was changed to Chinese Kiln Engineering Society in January 1951 and ceased action for some reasons in October the same year. In December 1956, the Kåre Helge Karstensen [email protected] Page 189 of 189 Preparation Commission of Chinese Ceramic Society was formed. In November 1959 the First National Congress was held in Shanghai, and it is decided on the congress that the name of the society was Chinese Ceramic Society. The members of the society include personal members, senior members, organization members and foreign members. The member of personal members is 33.000 at present and that of organization members is 40. There are 18 professional branch societies and 3 working commissions. There are 124 local societies at present. The administrative body of the society consists of 5 departments (sections). The main tasks of the society are to carry out academic and science and technological exchanges between domestic and foreign learners and implement international science and technological co-operation among peoples, to edit and publish scientific and technical books and magazines, to undertake continuous education and popularization work of science and technology; to undertake consultation for decision-making, technical consultation and technical service; to carry out citation and reward for outstanding persons and works, to organize scientific and technical exhibitions and demonstrations at home or abroad. 4-2.4 Beijing Building Materials Association (BBMA) Beijing Building Materials Association (BBMA) is a mass organization consisting of building materials trade associations in Beijing area, units of production, management, scientific research and design and information etc. BBMA is the building materials industrial organization administered by Beijing Municipality, sponsored by Beijing Jinyu Group, a nonprofit legal organization approved and registered by Beijing Social Organization Register Administration Office. Kåre Helge Karstensen [email protected]
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