Commercial production of aluminium for over 100 years largely commenced with the mining of bauxite, an impure form of aluminium oxide which constitutes approximately 16% of the earth's crust. Bauxite contains significant quantities of iron oxide, silicon and other impurities generally has a reddish-brown appearance and is found in large quantities in most tropical regions of the world. It typically occurs as blanket deposits, at or near the earth's surface and is formed by the cyclical (wet-dry-wet, etc.) weathering of aluminium oxide bearing ores.
Major deposits are found today in Brazil, West Africa, Australia and Malaysia and for the most part, the crude bauxite is mined and shipped to other locations where it is refined using the Bayer Process to the purer aluminium oxide, called alumina.
Transforming alumina to aluminium metal requires significant quantities of electrical energy, and this conversion is carried out in large carbon lined vessels or electrolytic cells. Using the same principles as developed by Hall and Heroult in 1876, this process reduces the metal oxide to a molten metal. By dissolving the alumina in a bath or melt of cryolite (Sodium aluminium flouride) at 960 hC and using a consumable carbon anode, the oxygen component combines to form carbon dioxide and the aluminium left behind forms in a molten pool in the bottom of the electrolytic cell or vpot', as it is sometimes called. The metal is periodically siphoned off and cast into one of the many ingot or product forms as required by the customer or downstream process.
Nigeria also has a well-developed downstream aluminium industry making finished goods from the rolled products and extruded profiles made by the intermediate industry.
Nigeria's aluminium industry would, therefore, be more integrated once the aluminium smelter being constructed at lkot Abasi is operational and is able to feed the intermediate industry.
![]() | ![]() | ![]() | ![]() |
---|---|---|---|
![]() |
![]() |
![]() |
![]() |