What is calcination?

Calcination is the conversion of carbonate ores into their oxides by heating strongly in limited air in the presence of suitable reducing agents such as carbon.

Definition: The process of converting carbonate ores into their oxides by heating strongly in the absence or limited supply of air.

Purpose: It is used to remove volatile substances (e.g., carbon dioxide, moisture, or impurities) from the ore and obtain a more reactive or pure form of the metal oxide.

Examples of Calcination:

1. Calcium Carbonate (CaCO₃):

   CaCO₃ (s) → CaO (s) + CO₂ (g)
   Here, calcium carbonate is decomposed into calcium oxide (quicklime) and carbon dioxide.

2. Zinc Carbonate (ZnCO₃):

   ZnCO₃ (s) → ZnO (s) + CO₂ (g)

Key Features of Calcination:

• It is conducted in limited or no air supply to prevent oxidation.
• Mainly used for carbonate and hydrated ores.
• Removes volatile impurities like CO₂ or H₂O.

This process is an essential step in the metallurgy of many metals.