Abstract

The rate of reduction of Cu2S with carbon in the presence of lime was investigated in the temperature range of 900 to 1050 °C by means of thermogravimetric analysis. The composition of the gas phase evolving during the reduction of Cu2S was determined. The effects of temperature, the amount of carbon and the amount of CaO on the reduction rate were also determined. The results indicate that reduction of Cu2S to Cu proceeded through the gaseous intermediates of CO and CO2. The controlling step of the overall kinetics was the oxidation of carbon by CO2. Temperature had the largest influence on the reduction rate. An energy of activation of 363 kJ/mol was calculated for the reduction of Cu2S with carbon in the presence of CaO within the temperature range of 900 to 1050 °C.