A rotten egg smell is obtained when an ore is treated with dil. $HCl$. Identify the ore and explain the process of extraction of metal from this ore.

Solution:

The smell of rotten eggs is usually produced by sulphur.
So, it must be sulphide ore.
Let us assume that the one is a zinc blend $\left(ZnS\right)$

The concentration of ore:
First of all, the ore is concentrated by the method of the froth flotation process. Then it is converted into its metal oxide via roasting in the supply of air. The chemical reaction is as follows;

$ZnS+O_2\underset{∆}{\overset{roasting}{\to }}ZnO+S{O}_2$

After that, it is converted into metal form by using a reducing agent like carbon,

$ZnO+C\stackrel{Reduction}{\to } Zn+CO$

It is further refined to get it in a pure form.