Integrated experimental and thermodynamic modeling study of slag-matte-metal equilibrium in the Pb–Fe–O–S–Si-(Al, Ca, Zn) systems at 1100–1200 °C

Integrated experimental and thermodynamic modeling study was undertaken to characterize the effect of Al, Ca and Zn on the partitioning of elements between the slag, matte and metal phases in the Pb–Fe–O–S–Si-(Al), (-Ca), and (-Zn) systems in equilibrium with tridymite at 1100–1200 °C. The experimental methodology involved closed system equilibration in sealed ampoules, quenching and electron probe X-ray microanalysis (EPMA) of compositions of phases. FactSage thermodynamic database obtained by combining earlier assessments of sub-systems was used to plan the targeted experiments, and the results of new experiments were used to improve the thermodynamic database. Important effects were revealed for the conditions of the present study: CaO decreases the concentration of Pb and S in slag; Al2O3 has small effect on Pb in slag, but significantly decreases the concentration of S in slag; ZnO has small effect on Pb in slag, but increases the concentration of S in slag. These experimentally measured effects were reproduced by the model

Equilibrium of Copper Matte and Silica-Saturated Iron Silicate Slags at 1300 °C and PSO2 of 0.5 atm

Experimental study on the phase equilibria between copper matte with silica-saturated iron silicate slags was conducted at 1300 °C and PSO2 = 0.5 atm. The high-temperature isothermal equilibration in silica crucibles under controlled flowing CO-CO2-SO2-Ar was followed by quenching in an ice–water mixture and direct phase composition analyses by an electron probe X-ray microanalyzer. The equilibrium compositions for matte and slag, as well as the distribution coefficients, were displayed as a function of matte grade. The data set obtained at PSO2 = 0.5 atm and the previous study at PSO2 = 0.1 atm by the authors enabled an investigation on the impacts of PSO2 as well as Al2O3 and CaO additions on phase equilibria in the multiphase copper matte smelting system. Thermodynamic calculations using MTDATA software were performed to compare the experimental results with modeling. The present results enrich the fundamental thermodynamic information for the matte/slag/tridymite/gas equilibria in the primary copper smelting process at high PSO2.Peer reviewe