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

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 (E eta) decrease with an increase of MgO/Al2O3 from 0.20 to 0.54. Liquidus temperature (T-L), deformation temperature (T-D), flow temperature (T-F), and breakpoint temperature (T-Br) increase, whereas soft melting interval (T-S) increases and then decreases. With the increase of CaO/SiO2 from 1.05 to 1.35, viscosity and E eta decrease. T-L, T-D, T-F, and T-Br increase, whereas T-S 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 center dot s, and the fluidity and stability of the slags are superior.