Effect of MgO/Al2O3 and CaO/SiO2 on the Metallurgical Properties of CaO–SiO2–Al2O3–MgO–TiO2 Slag

Abstract

Melting performance and viscosities of CaO–SiO2–17.5wt.%Al2O3–MgO–2wt.%TiO2 slags were studied. Results show that viscosity and the activation energy for viscous flow (Eη) decrease with an increase of MgO/Al2O3 from 0.20 to 0.54. Liquidus temperature (TL), deformation temperature (TD), flow temperature (TF), and breakpoint temperature (TBr) increase, whereas soft melting interval (TS) increases and then decreases. With the increase of CaO/SiO2 from 1.05 to 1.35, viscosity and Eη decrease. TL, TD, TF, and TBr increase, whereas TS decreases and then remains unchanged. CaO/SiO2 has little effect on the thermal stability of the slags. When CaO/SiO2 is 1.24, MgO/Al2O3 should be 0.31–0.43; when MgO/Al2O3 is 0.37, CaO/SiO2 should be 1.15–1.25. Viscosity in the range of slag discharge temperature is 0.3–0.5 Pa•s, and the fluidity and stability of the slags are superior.