Question

The substance, which is added to ore in order to remove impurities during smelting, is known as:

• A. catalyst
• B. gangue
• C. flux
• D. slag

Answer 1

Answer: (C)

Flux is added to roasted ore in order to remove impurities in form of slag, which floats above the molten reduced metal in smelting process, e.g., $\underset{\begin{array}{c}\text{Impurity}\text{in}\\ \text{iron-extraction}\end{array}}{\mathrm{MnO}}+\underset{\text{flux}}{Si{O}_2}\to \underset{\text{Slag}}{MnSi{O}_3}$