In the metallurgical process, what is the role of a 'flux'?
Correct: C
Flux is a chemical substance added during smelting to remove non-metallic impurities (gangue) present in the ore. The flux reacts with the gangue to form a fusible product called slag, which is lighter than the molten metal and can be easily separated. For example, limestone (CaCO3) acts as a basic flux to remove acidic impurities like silica (SiO2) in the blast furnace.