The System Iron–Titanium–Oxygen at 1200°C. and Oxygen Partial Pressures Between 1 Atm. and 2 × 10−14 Atm.

Abstract

The 1200°C. isotherm in the system Fe‐Ti‐O has been studied by equilibrating mixtures of iron oxide (Fe2O3) and titanium oxide (TiO2) with atmospheres of controlled oxygen partial pressure. These atmospheresmnsisted of CO2, air, oxygen, mixtures of CO2 and H2, and mixtures of CO2 and CO. The resulting oxide mixtures were examined at room temperature by chemical analysis and by X‐ray diffraction. The stability regions of the α‐oxides (FemTi2‐mO3), of the spinels, (FenTi3‐nO4), and of the orthorhombic oxides (FepTi3‐p O5)were determined. Some nonstoichiometry occurs in the spinels and in the α‐oxides. The oxygen partial pressures at which spinel is reduced to (iron +α‐oxides) and at which α‐oxide (ilmenite) is reduced to (iron + orthorhombic oxide) were determined as 2.1 × 10−13 and 9.3 × 10−14atm., respectively. The orthorhombic solid solution series extends over the whole range of oxygen partial pressures studied.