Experimental study and thermodynamic modeling of distribution of elements among slag, matte and metal in the Cu-Fe-O-S-Si-(Zn)-(Al, Ca, Mg) system for copper slag cleaning applications

The distributions of zinc and other elements in the Cu-Fe-S-Si-O-(Zn) system among slag, matte and metal phases were determined experimentally at 1200 degrees C (1473 K). The experimental procedure involved high-temperature equilibration, quenching of the sam-ples and measurement of the phase compositions using the electron probe X-ray micro-analysis. Conditions of experiments were planned using thermodynamic calculations and the experimental results were used to further develop thermodynamic models. Matte grades from 0 to 80 wt. pct Cu were investigated, concentrations of 3, 6 and 8 wt. pct Zn in slag were targeted. Additional set of experiments was undertaken to study the effects of Al2O3, CaO and MgO on the distribution of zinc and other elements. All samples were in equilibrium with tridymite (SiO2). Metal phase was either liquid copper or solid metallic iron. Conditions of equilibrium with metal phase are of practical importance for the development of smelting reduction technologies for the copper slag cleaning and recycling. Crown Copyright (c) 2023 Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).