Question

In the extraction of aluminium which is mixed with ore

Answer 1

The extraction is done by electrolyais. But first the aluminium oxide must be made molten so that electricity can pass through it. Aluminium oxide has a very high melting point (over 2,000°C), so it would be expensive to melt it. Instead, it is dissolved in molten cryolite, an aluminium compound with a lower melting point than aluminium oxide. The use of cryolite reduces some of the energy costs involved in extracting aluminium.