Question

Describe the role of flux in smelting process.

Answer 1

1. Flux is a substance added during smelting to remove impurities (gangue) from the ore.
2. It combines with the gangue to form a fusible slag.
3. The slag floats over molten metal and can be easily removed.
4. The choice of flux depends on the nature of gangue:
   • Acidic gangue (SiO₂, P₂O₅) → Basic flux (CaO).
   • Basic gangue (FeO, CaO) → Acidic flux (SiO₂).