Aluminium recycling is the process in which secondary commercial aluminium is created from scrap or other forms of end-of-life or otherwise unusable aluminium. It involves re-melting the metal, which is cheaper and more energy-efficient than the production of virgin aluminium by electrolysis of alumina (Al2O3) refined from raw bauxite by use of the Bayer and Hall–Héroult processes.
Model promoting aluminium recycling at Douglas Aircraft Company in 1942
Image: Press for aluminium cans
Image: Compressed aluminium cans
Bauxite is a sedimentary rock with a relatively high aluminium content. It is the world's main source of aluminium and gallium. Bauxite consists mostly of the aluminium minerals gibbsite, boehmite and diaspore, mixed with the two iron oxides goethite and haematite, the aluminium clay mineral kaolinite and small amounts of anatase and ilmenite .
Bauxite appears dull in luster and is reddish-brown, white, or tan.
Reddish-brown bauxite
Bauxite with US penny for comparison
Bauxite with core of unweathered rock
One of the world's largest bauxite mines in Weipa, in northern Queensland, Australia