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

The flux used to remove the $FeO$ impurity present in the mixture obtained from the roasting of copper pyrites,and its nature,is .....

Consider the following reactions of metallurgy:
Ore '$X$' $\xrightarrow{\text{Roasting}}$ '$Y$' + $SO_2$ $\uparrow$
Ore '$Z$' $\xrightarrow{\text{Calcination}}$ '$Y$' + $CO_2$ $\uparrow$
'$Y$' + $C$ $\xrightarrow{1673 \ K}$ '$A$' (vapour) + '$B$' $(g)$
where '$A$' and '$B$' are respectively:

Blister copper is.......

What is blister copper?

The addition of silica during the extraction of copper from its sulphide ore: