Question

Calcination is the process used to produce metal oxides from its ore.Answer the following questions based on calcination-1. What type of ore is it used for?(1)2. How is it different from Roasting?

Answer 1

1) Calcination is used for Carbonate ores such as Siderite (FeCO3) , Calamine (ZnCO3), Calcite(CaCO3).

2) =>Roasting is the strong heating of an ore in supply of excess air or oxygen, it involves the oxidation of the ore to give its oxide along with a gas. It is generally used for Sulphide ores such as Galena (PbS) and Zinc Blende (ZnS). Example:  2 ZnS + 3O2 ---------> 2 ZnO + 2SO2 .

=> Calcination of an ore is the strong heating of a carbonate ore in the absence of air or oxygen. It involves formation of metal oxide and carbon dioxide gas. Example:  ZnCO3 (heat)-------------> ZnO + CO2