Phase Equilibrium Investigation for CaO-SiO<sub>2</sub>-5wt.%MgO-20wt.%Al<sub>2</sub>O<sub>3</sub>-TiO<sub>2</sub> System Relevant to Ti-bearing Slag System

Abstract

In order to resolve the lack of thermodynamic information for the comprehensive unilization of Ti-bearing blast furnace slag, the phase diagram relevant to the Ti-bearing slag composition was widely investigated. In the present work, the phase equilibrium relationships were investigated for the CaO-SiO2-5wt.%MgO-20wt.%Al2O3-TiO2 phase diagram system. The equilibrium phases were experimentally determined at 1300°C and 1400°C using the high temperature equilibrium technique followed by X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM) and Energy Dispersive X-ray spectroscope (EDX) analysis. The liquid phase (L), melilite solid solution ((2CaO·MgO·2SiO2, 2CaO·Al2O3·SiO2)ss) phase, perovskite (CaO·TiO2) phase, Al–Ti diopside phase and pseudobrookite solid solution (MgO·TiO2, Al2O3·TiO2)ss phase were found. Based on the experimental results, the 1300°C to 1500°C liquidus lines and phase diagram were constructed for the specified region of the CaO-SiO2-5wt.%MgO-20wt.%Al2O3-TiO2 system.