How Aluminium Produced

Aluminium usually found in nature as bauxite ore. Bauxite is usually in form of oolitic, solid and like clay. Bauxite contains alumina and also mixture of elements such as iron, manganese hydroxides and hydrargyrite. [1] Bauxite is generally mined a few meters below the earth surface. After mining, bauxite is grinded so the clay in it is released.

Bauxite Ore
Bauxite Ore. [2]

 Alumina, or Aluminium Oxide
Alumina, or Aluminium Oxide.


After grinding the ore, outcome of the process is refined and alumina, or aluminium oxide is acquired. During refining process, hot sodium hydroxide and calcium oxide solution is used.

Obtained mixture heated and filtered so aluminium oxide, in a white powder form, is obtained. But since it is in powder form, it is far from being usable.

Obtained aluminium oxide is then electrolysed. During electrolyse, negative and positive anode and cathodes are used, both made of carbon material. During electrolyse, because of the high current between anode and cathode, aluminium oxide reacts with oxygen. For this process, approximately 17.000 kW/H energy is required.

This reaction creates Co2 and liquid aluminium. Liquid aluminium then transferred to extrusion moulds, panel moulds, or foundry, depending on where it is going to used. This type aluminium which is obtained ore is called primary aluminium.



[1], [2] Wikipedia,