1986 Volume 27 Issue 5 Pages 361-371
The oxidation of Cu2S pellet in a mixed O2–Ar gas stream was studied at 1023 to 1123 K. The oxygen partial pressure in the mixed gas stream was 5.05×103 to 2.02×104 Pa. In the initial 100 s of oxidation, the pellet temperature was raised due to the heat of oxidation, and the formation of CuO was hindered, which resulted in a rapid mass decrease due to the oxidation of Cu2S to form Cu2O. At 1123 K, the pellet was partly melted, and the oxidation was accelerated at the initial stage, where the rate was controlled by the gas film mass transfer especially when the oxygen partial pressure was lower. It was found at 1023 K that the basic sulfate was formed during the oxidation in addition to Cu2O and CuO. It was decomposed to form CuO at the later stage of oxidation. The oxidation rate at 1073 K was analysed by a two-interface model in which the formation of the Cu2S/Cu2O and Cu2O/CuO interfaces was taken into consideration.
