In the concentrated ore, small quantity of silica is added and heated in the presence of excess of air in reverberatory furnace. During this, moisture and other volatile impurities are repelled in the form of oxide.
Following chemical changes occur in the furnace :
2CuFeS2 + 2O2 Cu2S + 2FeS + 2SO2 ↓
2FeS + 3O2 → 2FeO + 2SO2 ↓
2Cu2S + 3O2 → 2Cu2O + 2SO2 ↓
Cu2O + FeS → Cu2S + FeO
This mixture Cu,Sand Cu, thus obtained is know copper matte.
