Question

Heating an ore in a limited supply of air or in the absence of air at a temperature just below its melting, point is known as:

• A. smelting
• B. ore dressing
• C. calcination
• D. bessemerisation

Answer 1

The correct option is C

calcination

Explanation for correct option (c) Calcination

• For the extraction of an ore, it is converted to oxide.
• In calcination method, the ore is heated in the limited amount of air, the air is almost absent in the heating of ore.
• The ore is heated at a temperature lower than melting point.
• This method is used for the carbonate ores.
• It removes impurities from ore, and makes it porous

Explanation for incorrect options:

(a) Smelting

In smelting the ore is heated and converted to reduced form using reducing agent.

(b) Ore dressing

Ore dressing is the removal of gangue from the ore to extract metals.

(d) Bessermerisation

It includes the blowing of air into the molten copper.

Therefore, option (c) calcination is correct.