Question

What is fused alumina used in electrolytic reduction?

Answer 1

cryolite is used in the electrolysis of aluminium oxide.
The mixture of cryolite and aluminium oxide has a lower melting point than pure aluminium oxide. This means a lower amount of energy is required to establish effective conditions for electrolysis and thus makes it more cost effective.

Molten cryolite serves as a solvent for the molten aluminium oxide and increases the conductivity of the solution.