Experimental Study and Thermodynamic Calculations in the CaO–Cu2O–FeO–Fe2O3–SiO2 System for Applications in Novel Copper-Based Processes

Abstract

A combination of high-temperature experiments and thermodynamic modeling in the CaO–Cu2O–FeO–Fe2O3–SiO2 system provides the fundamental information necessary to design and improve processes such as WEEE recycling through black copper route, continuous converting of copper matte, copper dross smelting, slag cleaning, and valorization of copper slag. In the experiments, samples were equilibrated on a primary phase substrate or Fe metal foil, then rapidly quenched and studied using the Electron Probe X-ray Microanalysis. The FactSage software was used for calculations, combined with custom developed thermodynamic database. A systematic analysis is provided to select the fluxing strategy and increase the copper recovery in industrial processes. Slag liquidus and concentration of copper in slag were assessed as functions of oxygen partial pressure, temperature, Fe/SiO2 in slag, and wt% CaO in slag.