Question

Heating of pyrites to remove sulphur is called as _______________.

• A. roasting
• B. calcination
• C. smelting
• D. froth-floatation

Answer 1

Answer: (A)

roasting

In roasting (Metal sulphides $\to$ Metal oxide + $S{O}_2$ ) the removal of excess sulphur contained in sulphide ores by heating in an excess of air is called roasting. The concentrated sulphide ore is heated in a reverberatory furnace, below its melting point or fusion temperature, in the presence of an excess of air with or without the addition of an external substance.

$2C{u}_{2}S+3O_2\to 2C{u}_{2}O+S{O}_2$