The steps involved in the extraction of metals of low and medium reactivity from their respective sulphide ores are heating the ores in the presence of oxygen to produce the oxides of the metal. This method of extraction of metals is very effective.
For Example:
1. Mercuric oxide is produced by mercuric sulphide via the heating process of cinnabar.
The reaction involved in this process is 2HgS+3O2 →2HgO+2SO2
2. Mercury is obtained by heating the obtained mercuric oxide.
The reaction involved in this process is 2HgO→ 2Hg+O2
3. Zinc oxide is obtained by the roasting process of Zinc blend.
The reaction involved in this process is (a) 2ZnS+3O2 →2ZnO+2SO2 (b)ZNCO3 →ZnO+ CO2
4. Zinc is finally extracted when the zinc oxide is heated with CO2
The reaction involved in this process is ZnO + C→ Zn + CO