Roasting is done in

Zinc is obtained from zinc blende by:

When limestone is heated,$CO_{2}$ is given off. The metallurgical operation is

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

Consider the following statements:
Roasting is carried out to:
$(i)$ convert sulphide to oxide and sulphate
$(ii)$ remove water of hydration
$(iii)$ melt the ore
$(iv)$ remove arsenic and sulphur impurities
Of these statements:

What are the methods to convert concentrated ore into oxide? Explain them in detail.