Thermodynamics of Iron Oxide in Fe(*)O-Dilute CaO + Al2O3 + Mg0 + Fe(*)O Slags at 1873 K

in order lo determine the ferrous and lerric ion capacities: (pct Fe^2+) /afe*p02^1/2 and C(Fe^3) = pct Fe^3+)/aFe *Po2^-3/4 for an MgO-saturated MgO + CaO + Al2O3 slag, two experiments were carried out at 1873 K: (1) the distribution of iron between Fe.,0 dilute slags of the system and Pt + Fe alloys under controlled atmosphere, and (2) the equilibrium among molten iron or iron alloys, magnesiowustite, and molten slags. Although the activity of iron and the partial pressure of oxygen in each experiment are remarkably different, the values of the ferrous and ferric ion capacities agree well with each other. The influence of the MgO:CaO.-Al2O3 ratio on the values of C(Fe^2+) and C(Fe^3+) was found to be limited within the experimental composition range. Using C(Fe^2+ and C(Fe^3+, the relationship between total iron content, (pct Fe^T), and partial pressure of oxygen, pO2 under iron saturation was calculated. The change in log PO2 with respect to the bulk slag composition is less than 0.2 within the range of (pct Fe^T) < 5.