The progress of reactions in roasting of chalcopyrite by thermoanalytical studies

The sulphation roasting is an important technique to recover copper from chalcopyrite. In order to study the progress of reaction during the sulphation step, chalcopyrite as well as binary sulphides of copper and iron have been subjected to thermal treatment. The role of catalytic addition of ferric oxide, sodium sulphate and ferrous sulphate with the chalcopyrite was investigated. TG/DTA plots were used to find the coarse of reactions and nature of products formed at varying temperature. A weight gain of 8% (TG) for chalcopyrite corresponding to copper sulphate formation was observed in the temperature range 628-738K. The TG plots showed respective weight gain of 14%, 17% and 12% in presence of 10% Fe2O3, 10% Na2SO4 and 20% FeSO4 with chalcopyrite in the wider temperature range 698-923K. The reaction products were confirmed by XRD analysis.