Question

Write a note on the extraction of moderately reactive metals.

Answer 1

Moderately reactive metals such as zinc, iron, lead and copper are generally found in nature as oxides, sulphides or carbonates. Their extraction usually involves the following steps:

1. Concentration of ore: The ore is concentrated by suitable methods such as hydraulic washing, magnetic separation or froth flotation.
2. Conversion into oxide: Sulphide ores are converted into oxides by roasting, while carbonate ores are converted into oxides by calcination.
3. Reduction of oxide: The metal oxide is reduced using a suitable reducing agent such as carbon, carbon monoxide or aluminium.
   Example:
   \[\ce{ZnO + C -> Zn + CO}\]
4. Refining: The crude metal obtained is purified by suitable methods such as electrolytic refining, liquation or distillation.