Question

Why is so much graphite required for this electrolytic process?

Answer 1

A large amount of graphite is required because the carbon anodes are gradually consumed during electrolytic aluminium extraction. The oxygen liberated at the anode reacts with the carbon to form carbon dioxide and carbon monoxide.

\[\ce{C + O2 -> CO2}\]

\[\ce{2C + O2 -> 2CO}\]

Therefore, graphite anodes must be replaced frequently.