Explain the isolation of metals from concentrated ore.

(N/A) The process of isolation of metals from concentrated ore involves two main steps:
$(i)$ Conversion to oxide
$(ii)$ Reduction of the oxide to metal
Step $1$: Conversion to oxide:
$(i)$ Calcination: Calcination involves heating the ore in the absence or limited supply of air. It removes volatile matter and moisture,leaving behind the metal oxide:
$Fe_{2}O_{3} \cdot xH_{2}O_{(s)} \stackrel{\Delta}{\longrightarrow} Fe_{2}O_{3_{(s)}} + xH_{2}O_{(g)}$
$ZnCO_{3_{(s)}} \stackrel{\Delta}{\longrightarrow} ZnO_{(s)} + CO_{2_{(g)}}$
$CaCO_{3} \cdot MgCO_{3_{(s)}} \stackrel{\Delta}{\longrightarrow} CaO_{(s)} + MgO_{(s)} + 2CO_{2_{(g)}}$
$(ii)$ Roasting: In roasting,the ore is heated in a regular supply of air in a furnace at a temperature below the melting point of the metal. This is commonly used for sulphide ores:
$2ZnS_{(s)} + 3O_{2_{(g)}} \rightarrow 2ZnO_{(s)} + 2SO_{2_{(g)}}$
$2PbS_{(s)} + 3O_{2_{(g)}} \rightarrow 2PbO_{(s)} + 2SO_{2_{(g)}}$
$2Cu_{2}S_{(s)} + 3O_{2_{(g)}} \rightarrow 2Cu_{2}O_{(s)} + 2SO_{2_{(g)}}$
The sulphide ores of copper are heated in a reverberatory furnace. If the ore contains iron,it is mixed with silica before heating. Iron oxide is removed as iron silicate slag $(FeSiO_{3})$,and copper is produced in the form of copper matte,which contains $Cu_{2}S$ and $FeS$.