Geomicrobiology of Aluminum: MICROBES AND BAUXITE
Although a metal, aluminum does not occur in a metallic state in nature. This is best explained by the fact that the reduction of aluminum salts or oxides to Al0 is an extremely endothermic process (for the Reaction Al2O3 → 2Al0 + 1.5O2,
ΔG0 is ~+377 kcal mol-1 or ~+1578 kJ mol-1). Commercial production of aluminum metal involves electrolysis at high temperature of molten Al2O3 in cryolite (sodium aluminum uoride).