# Define calcination and roasting give one example of each

The definition and examples of calcination and roasting is:

Calcination:

The process in which the ore is heated to a high temperature below its melting point in the absence of air. The ore becomes porous when the organic matter, moisture, and volatile impurities get expelled from the ore.

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The following is an example of calcination:

Zinc carbonate is decomposed to give zinc oxide and carbon dioxide.

$ZnCO_{3}overset{Delta }{rightarrow}ZnO+CO_{2}$

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Roasting:

The process in which the ores are heated to a high temperature below their melting point in the presence of excess air. The impurities are oxidized to their volatile oxides while the moisture escapes from the ore.

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The following is an example of roasting:

Sulphide ore is converted into metal oxide:

2ZnS+3O<sub>2</sub>→2ZnO+2SO<sub>2</sub>↑