Question

During smelting silica is added to roasted copper ore to remove:
(a) Cuprous Supphide
(b) Cuprous Oxide
(c) Ferrous oxide
(d) Ferrous sulphide

Answer 1

......ferrous sulphide

Answer 2

(d) Ferrous sulphide.

Roasting of the pyrite ore which is a mixture of FeO and Cu2O are obtained.

Main role of the silica are metallurgy of copper and helps to easily remove iron oxide obtained the process of roasting as 'slag'.

When sulphide ore of copper contains iron is added, then silica (SiO2) is added as flux before the roasting.