Anode Electrolysis of Copper Matte to Produce Copper and Iron

Abstract

Electrochemically splitting sulfides to metals and sulfur gas is a promising clean method to reduce energy consumption and environmental burden. Anode electrolysis has been proven to break metal-sulfur bonds at the anode in molten salts, but the electrolysis of complex sulfides has not been investigated. Herein, the selective extraction of Fe, Cu and S in copper matte (the mixture of FeS and Cu2S) by anode electrolysis was thoroughly studied by both thermodynamics and electrochemical tests. The FeS component was preferentially oxidized from copper matte on the anode while releasing sulfur gas, and the Fe powder as the main product was first collected from the cathode and then Cu was obtained. During potentiostatic electrolysis of copper matte on the anode, the content of Fe element was reduced from 49.1% to 18.6%, and the content of Cu element was enriched from 1.8% to 41.2%, showing the potential for not only achieving the clean sulfide electrochemical metallurgy but also effective separation. Thus, anode electrolysis could be applied to extract various complex sulfide ores.