Abstract
Measurements of the Fe3+/Fe2+ ratio in Al2O3-CaO-FeOx-SiO2 and Al2O3-CaO-FeOx-MgO-SiO2 slags in equilibrium with Ar-CO-CO2 gas mixtures have been made in the temperature range of 1400 to 1500°C and oxygen potentials between 3×10-9 and 10-5 atm. The results from these experiments indicate that in Al2O3-CaO-FeOx-SiO2 slags with 0-10 wt% MgO, the ratio of activity coefficients of ferrous oxide to that of ferric oxide decreases sharply as the total iron oxide content increases from about 0.8 to 3 wt%. However, at total iron contents of greater than 6 wt% the ratio of the activity coefficients of iron oxides becomes virtually independent of the iron content of the slag.
