Oxygen Potential of High-Titania Slag from the Smelting Process of Ilmenite
Oxygen potential of TiO{sub 2}-FeO-Ti{sub 2}O{sub 3} ternary slags was determined by the electromotive force (EMF) method based on the solid electrolyte oxygen sensor at 2003 K (1730 °C). The effect of FeO content and Ti{sup 3+}/Ti{sup 4+} mass ratio on the oxygen potential of the high-titania slag was also studied. At a fixed Ti{sup 3+}/Ti{sup 4+} mass ratio of 3.11, the oxygen potential increased with increasing FeO content. Increase of Ti{sup 3+}/Ti{sup 4+} mass ratio from 2.29 to 3.60 caused a significant decrease in the oxygen potential of the slag. Comparing measured oxygen potential with the calculated values indicated that the oxygen potential of the slag might be determined by FeO/Fe equilibrium reaction rather than TiO{sub 2}/Ti{sub 2}O{sub 3} reaction. In addition, the experimentally measured oxygen potential values were modeled by multiple linear regression analysis, and a semi-empirical mathematical correlation was established between the oxygen potential and slag compositions. The iso-oxygen potential distribution diagram based on the mathematical model was obtained for the high-titania slag.