Describe the process of obtaining blister copper.

(N/A) The $\Delta_{r} G^{\circ}$ vs $T$ plot for the formation of oxides shows that the $Cu_{2}O$ line is at the top.
Therefore,the reduction of copper oxide ore to metal by heating with coke is very easy.
Both $(C, CO)$ and $(C, CO_{2})$ lines are at much lower positions in the graph,especially above $500-600 \ K$.
However,most ores are sulfides and often contain iron.
Smelting of sulfide ore yields oxide:
$2Cu_{2}S + 3O_{2} \rightarrow 2Cu_{2}O + 2SO_{2}$
Then,the oxide can be easily reduced to metallic copper using coke:
$Cu_{2}O + C \rightarrow 2Cu + CO$
In the actual process,the ore is mixed with silica and heated in a reverberatory furnace.
Iron oxide is removed as iron silicate slag,and copper is produced in the form of copper matte,which contains $Cu_{2}S$ and $FeS$:
$FeO + SiO_{2} \rightarrow FeSiO_{3} \text{ (slag)}$
Copper matte is then charged into a silica-lined converter. Some silica is added,and a hot air blast is blown.
This converts the remaining $FeS$ to $FeO$ and $Cu_{2}S/Cu_{2}O$ to metallic copper:
$2FeS + 3O_{2} \rightarrow 2FeO + 2SO_{2}$
$FeO + SiO_{2} \rightarrow FeSiO_{3}$
$2Cu_{2}S + 3O_{2} \rightarrow 2Cu_{2}O + 2SO_{2}$
$2Cu_{2}O + Cu_{2}S \rightarrow 6Cu + SO_{2}$
The solidified copper has blisters due to the evolution of $SO_{2}$ gas,hence it is called blister copper.