The influence of temperature and matte grade on gas-slag-matte-tridymite equilibria in the Cu-Fe-O-S-Si system at p (SO2) = 0.25 atm

ABSTRACT Experimental measurements have been made of the compositions of slag, matte and tridymite phases in chemical equilibrium in the Cu-Fe-O-S-Si system at 1300°C, p(SO2) = 0.25 atm and selected oxygen partial pressures. The high temperature equilibration experiments were conducted using silica substrates under controlled CO-CO2-SO2-Ar gas atmospheres. The resulting phases obtained from the equilibrations were retained at room temperature through rapid quenching of the samples. The condensed phase compositions from the equilibrium experiments were measured by Electron Probe X-ray Microanalysis (EPMA). The data obtained in the present study, combined with those from previous studies, have enabled the liquidus slag temperature to be accurately described as a function of Fe/SiO2 ratio at p(SO2) = 0.25 atm for temperatures between 1200 and 1300oC and mattes containing from ∼44 to ∼ 78 wt pct Cu.