Aluminium production begins with bauxite, the “aluminium ore”. Most bauxite is mined in tropical areas, with around 50km2 of new land mined each year. At the same time, a matching area of land is restored to nature.
© Casting - Vigeland Metal Refinary by Norsk Hydro ASA (Flikr)
Bauxite mining
Alumina production
Pure aluminium oxide, called alumina, is extracted from bauxite via a process called refining, composed of two steps: a digestion process, using caustic soda, which allows the separation of aluminium hydroxide from the so-called “bauxite residue”, followed by a calcination step which removes the water content in the hydroxide.
Both the aluminium hydroxide and the aluminium oxide have further applications outside of the metal industry.
Making metal: Primary aluminium production
Molten aluminium is extracted from the alumina through an electrolytic process called smelting, which breaks the strong chemical bond of the aluminium and oxygen atoms using a powerful electric current. Once the liquid metal is collected it is transferred in the casthouse, where it is purified, alloyed to specification and then cast into ingots.
Using Aluminium
The primary aluminium is cast into ingots and used in the production of aluminium alloys. Aluminium can be rolled into sheets from which aluminium foil and beverage cans are made, as well as parts of car bodies and a vast array or other products. Using the forming process of extrusion, the aluminium is shaped in its required form and delivers almost unlimited possibilities in product design.
See also
© Aluminium billets - Høyanger Metal Plant by Norsk Hydro ASA (Flikr)
Recycling
Aluminium can be recycled endlessly without loss of its properties, and this makes it a key contributor to a more resource-efficient European economy.
The current end-of-life recycling rates of more than 90% in transport and construction and more than 60% in packaging show a clear commitment from European aluminium industry towards a real circular economy, and we are working with policymakers to make sure that as much aluminium as possible is recovered and recycled in Europe.