aluminium from alumina

Question 1

How is aluminium formed

Answer 1

It is formed by using molten alumina then electrolysed using the Hall-Heroult process

Question 2

What happens during the Hall-Heroult process with half equation at the cathode

Answer 2

Cryolite is added to the alumina to dissolve it to save money because its expensive to melt. The lining of the steel tank is made from carbon, which acts as the negative electrode. Aluminium ions receive electrons at the negative electrode and are reduced to aluminium atoms.

Finally the molten aluminium is drained off and cast into ingots
Al3+ + 3e- → Al.