Which one of the following statements is true about the froth flotation method?

In the following reactions, identify $P, Q$ and $R$, respectively

I. $3 \mathrm{Fe}_2 \mathrm{O}_3+\mathrm{CO} \longrightarrow 2 P+\mathrm{CO}_2 \uparrow$

II. $\mathrm{Fe}_3 \mathrm{O}_4+4 \mathrm{CO} \longrightarrow 3 Q+4 \mathrm{CO}_2 \uparrow$

III. $\mathrm{Fe}_2 \mathrm{O}_3+\mathrm{CO} \longrightarrow 2 R+\mathrm{CO}_2 \uparrow$

The method, which is based on the principle that "different components of a mixture are differently adsorbed on an adsorbent" is called

The solubilities of the impurities in the melt and solid states is not same. This principle is applied during the extraction of boron. This method is known as