How is copper extracted from its sulphide ore (copper glance), Cu2S? Explain with equations of the reactions involved.
The concentrated Copper Glance (ore used to extract copper metal) is first roasted in air when a part of copper(I) sulphide is oxidized to copper(I) oxide.

2Cu2S(s) + 3O2(g) -> 2Cu2O(s) + 2SO2(g)


When a good amount of copper(I) oxide is formed, then the supply of air for roasting stopped. In the absence of air, copper(I) oxide reacts with remaining copper(I) sulphide to form copper metal and sulphur di oxide.


2Cu2O(s) + Cu2S(s) -> 6Cu(s) + SO2(g)


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