- Flux is a chemical substance that is added to the concentrated ore, to remove impurities present. The impurities combine with the flux and form a fusible mass slag.
- Acidic impurities are removed by using a basic flux and basic impurities are removed by adding acidic fluxes.
- Silicon dioxide is an acidic flux and limestone (CaO) is a basic flux.
- CaO(s), the basic flux removes the gange silicon dioxide (SiO2), as calcium silicate (slag) in the extraction of iron.
Slag: Slag is a compound formed when flux and gangue can combine with each other. The slag is a feasible mass, which removes, the impurities in the ore. In the extraction of iron, FeO is added as a flux to remove the gangue (SiO2) as ferrous silicate (slag).
