The flux added in the extraction of iron is

The cyanide process of gold extraction involves leaching out gold from its ore with $CN^{-}$ in the presence of $Q$ in water to form $R$. Subsequently,$R$ is treated with $T$ to obtain $Au$ and $Z$. Choose the correct option$(s)$.
$1$. $T$ is $Zn$
$2$. $R$ is $[Au(CN)_2]^-$
$3$. $Z$ is $[Zn(CN)_4]^{2-}$
$4$. $Q$ is $O_2$

Iron obtained from blast furnace is:

From the Ellingham graphs on carbon,which of the following statements is false?

Which of the following elements is present as the impurity to the maximum extent in the pig iron?

Although thermodynamically feasible,in practice,magnesium metal is not used for the reduction of alumina in the metallurgy of aluminium. Why?