Phase Equilibria and Minor Element Distributions in Complex Copper/Slag/Matte Systems

Abstract

To address the increasing complexity of feed materials to pyrometallurgical processes, an integrated experimental and thermodynamic modeling research program is in progress to accurately characterize the multi-phase gas-slag-matte-speiss-metal-solids 17-component Cu/Pb-(Cu2O-PbO-ZnO-CaO-FeO-Fe2O3-SiO2)-(Al2O3-MgO)-S-(As-Bi-Sb-Sn-Ag-Au-Ni) system. New experimental data are used to continuously improve the thermodynamic database using FactSage. An example is provided on the slag-matte distributions of Bi, Pb, and Zn in equilibrium with tridymite in the Cu-Fe-O-S-Si system under copper smelting conditions. A closed system equilibration experimental technique with rapid quenching was used. Major element concentrations in phases were measured with electron probe x-ray microanalysis. A laser ablation inductively coupled plasma mass spectrum technique was used for determination of Bi, Pb, and Zn concentrations in slag. New experimental data contributed to the optimization of thermodynamic model parameters. Improved thermodynamic databases can be used to accurately predict the elemental distributions in multi-component systems; an example is given for the minor element distributions between slag and matte for industrial conditions.