Question

When copper pyrites is roasted in excess of air, a mixture of `CuO + FeO` is formed. `FeO` is present as impurity. This can be removed as slag during reduction of `CuO`. The flux added to form slag is
A. `SiO_(2)` which is an acidic flux
B. Lime stone, which is a basic flux
C. `SiO_(2)` which is basic flux
D. CaO, which is basic flux

Answer 1

Correct Answer - A
The compound which combines with impurities present in ore (at high temperature) and removes them as a fusible substance (slag), are know as flux. When bsic impurities are present, an aicidn flux is used and vice -versa.
`underset("Basic impurity")(FeO)+underset("Acidic flux")(SiO_(2)) to underset("Slag")(FeSiO_(3))`