Effect of Fluorine on Copper Slag Properties and Structure During Reduction by Spent Cathode Carbon

Industrial production processes generate a large amount of secondary resources (copper slag and spent cathode carbon (SCC)) every year. Reducing copper slag by fixed carbon from SCC would fully utilize the substance and the fluxing effect of fluoride. In addition to effectively utilizing hazardous waste resources, the reduction of copper slag using SCC could also effectively separate copper particles from the slag. In the present study, the effect of fluorine on copper slag properties and structure was investigated. With up to 5 wt pct addition of CaF₂ and NaF, the decreased viscosity increased the particle size of the copper metal from 60 to 500 μm and 150 μm, respectively. CaF₂ and NaF reduced the polymerization of the silicate structure by introducing F⁻, thus reducing the viscosity of the copper slag and facilitating the separation of copper from the slag. Furthermore, aluminum-containing spinel, which was generated by the reaction of Al₂O₃ with the slag, may prevent the copper from settling.