All about aluminium

Aluminium production

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How aluminium is produced

The pure form of aluminium does not naturally occur in nature, so remained largely unknown until as recently as 200 years ago. Creating aluminium using electricity was first developed in 1886 and is still used to this day.

BAUXITE MINING

The aluminium production process starts with the mining of bauxites, an aluminium rich mineral in in the form of aluminium hydroxide. About 90% of global bauxite supply is found in tropical areas.

ALUMINA PRODUCTION

Bauxite is crushed, dried and ground in special mills where it is mixed with a small amount of water. This process produces a thick paste that is collected in special containers and heated with steam to remove most of the silicon present in bauxites.

REDUCTION PROCESS

At an aluminium smelter, alumina is poured into special reduction cells with molten cryolite at 950℃. Electric currents are then induced in the mixture at 400 kA or above; this current breaks the bond between the aluminium and oxygen atoms resulting in liquid aluminium settling at the bottom of the reduction cell.

PRIMARY ALUMINIUM

Primary aluminium is cast into ingots and shipped to customers or used in the production of aluminium
alloys for various purposes.

ALUMINIUM ALLOYS

The process where the aluminium is shaped to its required form. This process is used for making the vast majority of aluminium products from spectacle frames, telephone bodies, aeroplane fuselages or spaceship bodies.

 

RECYCLING

Unlike iron, aluminium is corrosion resistant so it can be remelted and reused an infinite number of times. The added benefit is that recycling aluminium requires only 5% of the energy needed to make the same amount of primary aluminium.

How aluminium
is produced

The pure form of aluminium does not naturally occur in nature, so remained largely unknown until as recently as 200 years ago. Creating aluminium using electricity was first developed in 1886 and is still used to this day.
Bauxite mining

BAUXITE MINING

The aluminium production process starts with the mining of bauxites, an aluminium rich mineral in in the form of aluminium hydroxide. About 90% of global bauxite supply is found in tropical areas.
Crushing

ALUMINA PRODUCTION

Bauxite is crushed, dried and ground in special mills where it is mixed with a small amount of water. This process produces a thick paste that is collected in special containers and heated with steam to remove most of the silicon present in bauxites.
Digestion
The ore is loaded into autoclaves and treated with lime–caustic soda. Aluminium oxide appears in the resulting slurry while all the admixtures settle to the bottom as red mud.
Precipitation
The sodium aluminate solution is stirred in precipitators for several days, eventually pure alumina or Al2O3 settles at the bottom.
Electrolytic reduction

REDUCTION PROCESS

At an aluminium smelter, alumina is poured into special reduction cells with molten cryolite at 950⁰С. Electric currents are then induced in the mixture at 400 kA or above; this current breaks the bond between the aluminium and oxygen atoms resulting in liquid aluminium settling at the bottom of the reduction cell.
Casting

PRIMARY ALUMINIUM

Primary aluminium is cast into ingots and shipped to customers or used in the production of aluminium alloys for various purposes.
Foundry alloys

ALUMINIUM ALLOYS

Foundry aluminium alloys are used to make finished goods by casting the alloys into special moulds. The required properties are given to the metal by adding various admixtures such as silicon, copper or magnesium. These alloys are used in the manufacture of automobile and aviation engines and aluminium alloy wheels.
Rolling
The malleability of aluminium means it can be easily rolled into thin sheets. To that end, aluminium alloys are cast into rectangular beams up to 9 metres in length, these are then rolled into sheets from which aluminium foil and beverage cans are made, as well as parts of automobile bodies and a vast array of other products.
Extrusion
The process where the aluminium is shaped to its required form. This process is used for making the vast majority of aluminium products from spectacle frames, telephone bodies, aeroplane fuselages or spaceship bodies.
Recycling

RECYCLING

Unlike iron, aluminium is corrosion resistant so it can be remelted and reused an infinite number of times. The added benefit is that recycling aluminium requires only 5% of the energy needed to make the same amount of primary aluminium.
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