Question

The chemical composition of slag formed during the smelting process in the extraction of copper is ______.

Options

• Cu₂O + FeS

• FeSiO₃

• CuFeS₂

• Cu₂S + FeO

Answer 1

The chemical composition of slag formed during the smelting process in the extraction of copper is FeSiO₃.

Explanation:

During the smelting process for extracting copper from copper pyrites (CuFeS₂), the ore contains iron oxide (FeO) as an impurity. To remove this impurity, silica (SiO₂) is added as a flux. It reacts with FeO to form a fusible slag, which is FeSiO₃ (iron silicate). This slag floats on the molten copper and is easily removed.