Aluminium is produced from bauxite, which is a reddish rock containing aluminium oxide as well as oxides of silicon, iron and other metals. It was discovered by Pierre Bertier in 1822, near a village in southern France called Les Baux.

It is mined, using an opencast strip method, mainly in Australia, West Africa and the West Indies. Before mining begins, the topsoil is removed and special nurseries established to grow indigenous plants from collected seed. Once the mining phase is completed, the topsoil and plants are used in the rehabilitation programme, which focuses on biodiversity, reforestation and water quality.

Producing the metal

Aluminium is extracted from the ore using an electrolytic process which involves
two main stages:

First alumina, or aluminium oxide, is refined from bauxite in a caustic soda/high temperature process

Thn the alumina is mixed with a molten cryolite (sodium-aluminium fluoride) in an electrolytic smelting process which breaks down the alumina into molten aluminium
and oxygen

Other elements are then added to produce particular alloys for different end-markets, and the metal is cast into ingots.

It takes four tonnes of bauxite to make two tonnes of alumina, which makes one tonne of aluminium, consuming around 15,000 kwh electricity and emitting 9.6 tonnes of carbon equivalent gases.

Recycling the metal uses only 5% of the energy, with equivalent reductions in carbon emissions.