What is the role of flux in metallurgical processes?

Explanation

Flux is a substance which combines with gangue which may still be present in the calcined or roasted ore to Turn all asily fusille material called the slay.
Flux + Gangue `to` Slag (Fusible)
In the metallurgy of copper, most of the ferrous sulphide present as impurity gets oxidised to ferrous oxide which combines with silica (flux) to form fusible slag.
`FeO + SiO_2 to FeSi O_3`
The slag being lighter Coats and forms the upper layer which is removed from the slag hole from time to time. In the blast furnace for metallurgy of iron, lime acts as a flux and combines with silica present as impurity to form slag.
`CaO + SiO_2 to underset("Slag")(CaSiO_3)`