Question

Copper pyrites is an ore of copper.

Describe all the steps, with equations, to convert the concentrated ore to blister copper.

Answer 1

Concentration: Crush and concentrate by froth flotation to get the sulphide concentrate.

Roasting: Partially oxidise sulphides to oxides and SO₂.
\[\ce{2Cu2S + 3O2 -> 2Cu2O + 2SO2. 2FeS + 3O2 -> 2FeO + 2SO2}\].

Smelting (matte/slag): \[\ce{Cu2O + FeS -> Cu2S + FeO; FeO + SiO2 -> FeSiO3_{(slag)}}\].

Converting (blowing air): \[\ce{2Cu2O + Cu2S -> 6Cu + SO2}\] It yields blister copper (~98%).

Final reduction/poling: reduce residual oxide (e.g., \[\ce{Cu2O + H2 -> 2Cu + H2O}\]) by poling to remove oxygen.