Coke and Flux are used in smelting. Why?

• Smelting is a form of extractive metallurgy to give a metal from its ore.
• Flux reacts with impurities and forms slag which floats over the matter and metal is removed.

Example: Flux used in copper smelting is Silica (${\mathrm{SiO}}_2$), Silica powder ($\mathrm{Si}$), Lime-water($\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$)

$\mathrm{FeO}\left(\mathrm{s}\right)+{\mathrm{SiO}}_2\left(\mathrm{s}\right)\to {\mathrm{FeSiO}}_3\left(\mathrm{s}\right)$