Pyrometallurgy

Pyrometallurgy refers to the set of processes and methods involved in the extraction of metals by the application of heat. The processes in pyrometallurgy can be categorized into three main categories 

Roasting
Here, the ore is converted into an oxide of the metal.

Reduction
The oxygen in the ore is removed by heating with coke or charcoal. The oxygen escapes as carbondioxide or carbonmonoxide.

Refining
The metal thus obtained is further purified by electrolysis.