Reduction Kinetics of Copper Slag by H2

Abstract

In order to maximize the utilization value of copper slag, a process of smelting copper–iron alloy with copper slag is proposed here. The reduction kinetics of copper slag by H2 are studied in this paper. The main phases of the copper slag were Fe2SiO4 and Fe3O4. The suitable conditions of reduction were a temperature of 1373.15 K, a H2 partial pressure of 40%, and a calcium oxide addition amount of 30%. In these conditions, the metal reduction ratio was 85.12%. The copper slag, after reduction, was heated to 1773.15 K for 4 h. The content of iron in the metal was 85.11%, and the copper content was 10.40%. According to the unreacted nuclear model, the reduction process of copper slag is controlled by internal diffusion and chemical reaction. With the increase of the reduction ratio, internal diffusion is the main influencing factor. The activation energy of H2 reduction copper slag is 29.107~36.082 kJ/mol, which decreases gradually with the H2 partial pressure’s increase. The metal obtained by copper slag reduction contains a certain amount of sulfur, and a desulfurization process is required before it is used.