Which of the following statements is/are correct based on the provided Ellingham diagram?

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

In the extraction process of copper,the product obtained after carrying out the reactions
$(i) 2 Cu_2S + 3 O_2 \rightarrow 2 Cu_2O + 2 SO_2$
$(ii) 2 Cu_2O + Cu_2S \rightarrow 6 Cu + SO_2$ is called

$Al_{2}O_{3}$ was leached with alkali to get $X$. The solution of $X$ on passing of gas $Y$,forms $Z$. $X$,$Y$ and $Z$ respectively are

The chemical that is added to reduce the melting point of the reaction mixture during the extraction of aluminium is

Choose the correct option with reference to the following statements:
$(1)$ Pig iron is produced at a temperature of $1270 \ K$.
$(2)$ Pig iron contains $4 \%$ carbon.
$(3)$ Pig iron cannot be cast into a variety of shapes.
$(4)$ Pig iron contains small amounts of impurities like $P, S, Si, Mn$.