Extraction of Aluminium

1
Extraction of Aluminium

• Aluminium is extracted using electrolysis because
  it is too reactive to be extracted using carbon.

2
Raw materials

• Ore bauxite aluminium oxide
• The ore is dissolved in cryolite to lower the
  melting point.

3
The electrolysis cell
Carbon anode
Molten aluminium oxide
Oxygen bubbles
cathode
Molten aluminium
Steel case
Temperature 900 C
4
Reactions in the cell

• At the cathode
• Al3 3e- ? Al
• At the anode
• 2O2- ? O2 4e-
• The oxygen formed reacts with the carbon anodes
  to form carbon dioxide.
• They have to be replaced periodically.

5
Cost
Extracting aluminium is expensive because of the
high cost of electricity. Extraction takes place
where there is a cheap source of electricity e.g.
hydroelectric power