Question $3$

a$)$ What do you understand by calcination? $[2$ Marks$]$

b$)$ Give three factors which affect the rate of calcination. $[3$ Marks$]$

c$)$ The copper ore contains $7\%Cu$ and $36\%S.$ The copper mineral is chalcopyrite $(CuFe{S}_2)$ and $S$ is also present as iron pyrite $(Fe{S}_2).$ The rest of the ore is gangue containing no $Cu,S,$ or Fe$.$ The ore is roasted until all the sulphur is removed; the following reactions are taking place:

$4Fe{S}_2+11O_2=2F{e}_2{O}_3+8S{O}_2$

$4CuFe{S}_2+13O_1=4$CuO$+2F{e}_2{O}_3+8S{O}_2$

Calculate per $1000kg$ of ore treated:

i$.$ The weight of each mineral and the gangue; $[9$ Marks$]$

ii$.$ Oxygen required in cubic metre $(m^3)$; $[2$ Marks$]$

iii. The weight of $F{e}_2{O}_3$ and the volume of $S{O}_2$ produced. $[4$ Marks$]$