Reduction of Magnetite from Copper Smelting Slag in the Presence of a Graphite Rod

Abstract

Through the reduction reaction of Fe3O4 and graphite rod, the viscosity of slag was reduced and the settlement of matte in slag was promoted. The reduction of Fe3O4 in copper slag by a graphite rod was studied and the kinetics of the reduction process analyzed. The results show that the content of Fe3O4 decreased with increase in reduction temperature and reduction time. The slag samples after reduction were examined and found to consist of three layers: a slag foam layer, a fayalite layer, and a matte layer. A substantial number of large-sized matte particles were found in the slag foam layer. Also, a layer of Fe3O4 was attached to the upper surface of the matte layer. The reduction of Fe3O4 was concluded to be a second-order reaction, the apparent activation energy was 610 kJ/mol, and the limiting step was the Boudouard reaction.