Evaluate the purpose of adding cryolite in the extraction of Al:

The correct answer is: Fusion temperature decreases and conductivity increases

• The Hall–Héroult process is the major industrial process for smelting aluminium. It involves dissolving aluminium oxide (alumina) (obtained most often from bauxite, aluminium's chief ore, through the Bayer process) in molten cryolite, and electrolyzing the molten salt bath, typically in a purpose-built cell.
• Cryolite plays an important role in the refining of aluminium. The melting point of aluminium oxide is very high (more than 2000∘C) and so melting it would be a very expensive process.
•  Cryolite lowers the melting point and increases the conductivity of alumina and thus helps in the process of extraction of aluminium.