In the extraction of $Al$,the chemical used in the $Serpek$ process during leaching is:

How do we separate two sulphide ores by the Froth Flotation Method? Explain with an example.

Why is the concentration of ore performed?

Given below are two statements :-
Statement $I$: In froth floatation method,a rotating paddle agitates the mixture to draw air into it.
Statement $II$: Iron pyrites are generally avoided for the extraction of iron due to environmental reasons.
In the light of the above statements,choose the correct answer from the options given below :-

When $ZnS$ and $PbS$ minerals are present together,then $NaCN$ is added to separate them in the froth floatation process as a depressant,because

Leaching is commercially carried out for the concentration of which of the following ores?