Question

What is the role of cryolite `(Na_3AIF_6)` in the electrolytic reduction of alumina in Hall’s process?

Answer 1

The role of cryolite in the electrolytic reduction of alumina in Hall's process is :
1. Lowers the fusion temperature from 20500C to 9500C and enhances conductivity.

2. Increases its conductivity since pure alumina is almost a non-conductor of electricity.

3. Cryolite acts as a solvent for the electrolytic mixture.