Froth floatation is based upon

The substance added to the ore to remove impurities is known as........

$A$ substance which reacts with gangue to form fusible material is called:

Reagent used in Bayer's process of concentration of bauxite ore is:

Wolframite ore is separated from tinstone ore by the process of

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 :-