With an example, explain roasting.

Explanation

Roasting is a method in which sulphide ore is heated in a regular supply of air at a temperature below the melting point of the metal . It converts sulhide ores into oxide ores . A part of sulphide may also act as reducing agent. In this method , impurities such as S, As, P,etc. is removed as volatile gases and ore becomes porous e.g ,
`2ZnS +3O_(2) overset (Delta) to 2ZnO +2SO_(2)`