Material & energy requirements
Technical University of Crete Mining
Department of Mineral Resources Engineering
Metalurgical Processes – Prof. Komnitsas
Athanasios Paraschos 2007020037
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Aluminum is a light metal with density of
2.7g/cm3 (three times less than of steel) .
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It is one of those elements which are excessive
on earth. It is an excellent heat and electrical
conductor with very good reflectivity, resistance
to corrosion and ductility.
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Aluminum is used extensively in electronics
infrastructure, packaging and transportation
Worldwide Aluminum production in 2010
Source http://www.alueurope.eu/?page_id=1509
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In 2010, global Al production is 41,4million tons
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Global average energy consumption is 15kWh/kg Aluminum
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Thus,
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Electricity consumption is 621 billion kilowatt hours of electricity
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Global electricity production is 20261 billion kilowatt hours
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Therefore,
 Three percent of the total electrical supply goes to aluminum extraction
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Mostly aluminium is produced in two ways;
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Primarily Production Process
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Bayer process: Bauxite refining
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Hall-Héroult process : Reduction of Alumina to Aluminum
Secondary Production Process
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Recycling of scraps containing Al
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Recyling aluminium hydroxide
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Bayer Process: Refining Bauxite
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The Hall-Héroult Process: Alumina to Aluminum
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2Al2O3 + 3C→ 4Al +3CO2
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Scrap recycling
 The scrap is cleaned and sorted
 If the scrap contains more than 20% Al by wt.
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Aluminum hydroxide
 It is a waste from Al production and can be
assumed as free of impurities
 It is then Calcined directly
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To produce 1kg of aluminum,
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5,900kg earth has to mined
5.1kg Bauxite,
1.93kg alumina and
0.45kg carbon anode
This means that for 2010 annual world
production of 41.1 million tons aluminum,
 210 million tons of bauxite,
 80 million tons of alumina and
 21 million tons of carbon anode
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On the basis of 1kg aluminum
Bayer process
Source: Wang et al.2012
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Al from recycled Al(OH)3,
Requires only 43% total energy
of primary Al prod.
Scrap recycling
If Scrap contains >20% Al (wt.)
Source: Wang et al.2012
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Wang H., Leung D.Y.C, Leung M.K.H, 2012, Energy analysis of hydrogen and
electricity production from aluminum-based processes, Applied energy 90, 100105
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U.S. Department of energy, U.S. Energy requirement for aluminum production:
historical perspective, theoretical limits and current practices, February 2007
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Totten G.E, Mackenzi D.S., 2003, Handbook of Aluminum, Vol 1,Physical
Metallurgy and processes, Marcel Dekker, Inc, USA