Difference between calcination and roasting?

1.	Difference between calcination and roasting?
Answer» Roasting : 1. Ore is heated in the presence of air. 2. Used generally for sulphide ores. SO₂ gas is given off. 2ZnS+ 3O₂ → 2ZnO + 2SO₂ 3. Volatile impurities are removed as oxides. Calcination : 1. Ore is heated in the absence of air. 2. Hence Used generally for carbonate ores. Hence, CO₂ gas is given off. ZnCO₃ → ZnO + CO₂ . 3. Moisture, organic impurities and volatile impurities are removed.

Answer»

Roasting :

1. Ore is heated in the presence of air.

2. Used generally for sulphide ores. SO₂ gas is given off. 2ZnS+ 3O₂ → 2ZnO + 2SO₂

3. Volatile impurities are removed as oxides.

Calcination :

1. Ore is heated in the absence of air.

2. Hence Used generally for carbonate ores. Hence, CO₂ gas is given off. ZnCO₃ → ZnO + CO₂ .

3. Moisture, organic impurities and volatile impurities are removed.

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