Experimental study of phase equilibria in the MnO-SiO 2-"TiO2"-"Ti2O 3" system

Abstract

Phase equilibria and liquidus surface in the system MnO-SiO 2-"TiO2"-"Ti2O 3" under controlled atmosphere have been investigated in the temperature range from 1 200 to 1 500°C and in the range of log pO 2 from -7.6 (pCO/pCO2=1) to -16.6 (C-CO equilibration). High-temperature equilibration, quenching and electron probe microanalysis (EPMA) were employed to obtain equilibrium compositions of liquid and several solid solutions. The following primary phases have been observed; molten oxide, manganosite (MnO), rutile (TiO2-δ), tridymite and cristobalite (SiO2), tephroite (Mn2SiO4), rhodonite (MnSiO3), spinel (Mn2TiO4-MnTi 2O4), pyrophanite (MnTiO3-Ti2O 3) and pseudobrookite ("MnTi2O 6"-Ti3O5) solid solutions. By decreasing oxygen partial pressure, homogeneous liquid oxide area becomes smaller. No ternary compounds or ternary solid solutions were observed. © 2005 ISIJ.