Question

(a) Write the steps involved in the extraction of pure metals in middle of the activity series from carbonate ores.

(b) How is copper extracted from its sulphide ore ? Explain the various steps supported by chemical equations. Draw labelled diagram for electrolytic refining of copper.

Answer 1

(a) First of all the carbonate ore of a metal is heated in absence of air. This process is called calcination.

$\underset{\text{Zinc carbonate}}{ZnC{O}_3}\underset{\text{absence of air}}{\overset{\text{Heat}}{\to }}\underset{\text{Zinc oxide}}{ZnO}+\underset{\text{Carbon dioxide}}{C{O}_2}$

Then, ZnO is heated with coke.

$ZnO+\underset{\text{Coke}}{C}\to \underset{\text{Pure metal}}{Zn}+\underset{\text{Carbon monoxide}}{CO}$

(b) Copper is extracted from sulphide ore by the process of roasting. It is done is presence of air :

$2C{u}_{2}S+3O_2\underset{}{\overset{\text{Heat}}{\to }}C{u}_{2}O+2S{O}_2$

$2C{u}_{2}O+C{u}_{2}S\underset{}{\overset{\text{Heat}}{\to }}6Cu+2S{O}_2$

Electrolytic Refining of Copper :