Q.A process of heating ore of a metal in excess of air below its melting point is called -

Before reduction, a concentrated ore is usually converted to its oxide, since metal oxides are generally easier to reduce than sulphides or carbonates.

• Calcination: strongly heating an ore (typically a carbonate or hydrated oxide) in limited or no air, below its melting point, to drive off volatile matter such as CO2 or H2O — e.g., $\text{ZnCO}_3 \xrightarrow{\Delta} \text{ZnO} + \text{CO}_2$. …