Which process is used to convert hydrated alumina into anhydrous alumina?

Heating of ore in the presence of air to remove sulphur impurities is called:

$A$ reverberatory furnace is employed in the metallurgical process mainly for

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.

What is produced when zinc blende is roasted in air?

What is the process of heating pyrites to remove sulfur called?