Consider the following statements:
$(i)$ Froth flotation technique is used to concentrate sulphide ore.
$(ii)$ Froth flotation technique is based upon differential wettability of ore and impurity in water.
$(iii)$ Red Bauxite is concentrated by Bayer's process.
$(iv)$ Carbon is used as a reducing agent during the extraction of zinc from zinc blende.
Which of the following statements are correct?

Select the correct option regarding the processes used during metal extraction from their ores.

In the wrought iron of the iron pillar located in Delhi,what other elements are present besides iron?

In the equation: $M + 8CN^{-} + 2H_2O + O_2 \rightarrow 4[M(CN)_2]^- + 4OH^{-}$,metal $M$ is

Which of the following pairs is incorrectly matched?

The correct statement$(s)$ related to the metal extraction processes is(are):
$(A)$ $A$ mixture of $PbS$ and $PbO$ undergoes self-reduction to produce $Pb$ and $SO_2$.
$(B)$ In the extraction process of copper from copper pyrites,silica is added to produce copper silicate.
$(C)$ Partial oxidation of sulphide ore of copper by roasting,followed by self-reduction produces blister copper.
$(D)$ In the cyanide process,zinc powder is utilized to precipitate gold from $Na[Au(CN)_2]$.