Thermophysical properties, crystallization behavior and structure of CaO–SiO2–MgO–Al2O3–TiO2–FeO slag with varying TiO2 contents

Abstract

This study investigated the effect of TiO2 content on the viscosity, free running temperature, electrical conductivity, crystallization behavior, and structure of high-titanium CaO–SiO2-10 wt% MgO-13 wt%Al2O3–TiO2-4 wt.% FeO slag by experiments and molecular dynamics simulations. The results revealed that increasing TiO2 weakened the overall bonding energy and simplified the slag structure, leading to a decrease in viscosity and an increase in electrical conductivity. Thermodynamic calculations revealed a continuous enrichment of the slag towards the pseudobrookite region with increasing TiO2 content. The precipitation of pseudobrookite phase during cooling resulted in short-slag characteristics and a rising free running temperature. Additionally, the peak intensity of pseudobrookite phase gradually enhanced and its morphology changed from elongated strips to plates with higher TiO2 concentration. Structural analysis demonstrated that the poorly stabilized [TiO6] octahedron was the major form of Ti atoms in the slag, and its proportion progressively increased with increasing TiO2 content.