The process of heating an ore in the presence of excess air to a temperature below its melting point is called:

Choose the correct code regarding the Roasting process.
$I$. It is the process of heating ore in air to obtain the oxide.
$II$. It is an exothermic process.
$III$. It is used for hydrated oxide and oxysalt ore.
$IV$. It is used after the concentration of ore.

In metallurgy,calcination is used for ...... .

In order to bring initial chemical change in the ore,the process of heating of ore below its melting point is known as

Select the process in which $SO_2$ is $NOT$ evolved:

When limestone is heated strongly,it gives off $CO_2$. In metallurgy,this process is known as: