Optimization of process parameters for selective chlorination and volatilization in FeO-Cu2O-CaCl2 system

Abstract

Selective chlorination and volatilization is an effective approach for element separation in non-ferrous metallurgical processes, and has also been used for the separation of iron oxide and copper oxide within steel industry. In this work, to determine and optimize the conditions for copper and iron separation in FeO-Cu2O-CaCl2 system, a series of orthogonal experiments were carried out to investigate the effects of reaction temperature, holding time, mole ratio of CaCl2 to Cu2O (n(CaCl2)/n(Cu2O)), and gas flow rate on the separation efficiency. Results demonstrated that both reaction temperature and n(CaCl2)/n(Cu2O) take significant effects on the final copper volatilization ratio. In contrast, the gas flow rate and holding time shows a negligible influence on the effect of separation between copper and iron. By increasing the reaction temperature and n(CaCl2)/n(Cu2O), the copper volatilization ratio significantly increases, while the iron volatilization ratio remains at a low level. When the reaction temperature was 1273 K, the holding time was 90 min, n(CaCl2)/n(Cu2O) was 2.0, and the gas flow rate was 100 mL·min−1, the copper volatilization ratio reached 51.08 % and the iron volatilization ratio was only 6.52 %. The chlorination reaction rate of copper was controlled by chemical reaction and the apparent activation energyEa was 57.17 kJ/mol.