The oxidation of llmenite and its relationship to the FeO-Fe₂O₃-TiO₂ phase diagram at 1073 and 1140 K

Abstract

The oxidation of synthetic ilmenite was investigated in the temperature range of 1048 to 1273 K using a continuous flow electrobalance, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS). The phases observed and their relative distribution in partially oxidized samples were related to the FeO-Fe₂O₃-TiO₂ phase diagrams at 1073 and 1140 K. Initial stages of oxidation were characterized by the formation of rutile and ilmenite-hematite solutions containing up to 10 mole pct hematite at 1073 K and 7 mole pct at 1140 K. Final stages of oxidation included the formation of ferropseudobrookite-pseudobrookite solutions containing up to 56 mole pct ferropseudobrookite at 1073 K and up to 66 mole pct ferropseudobrookite at 1140 K. Although not all of the predicted phase fields were observed during oxidation, generally the expected oxidation sequences were followed.