Effect of Al2O3 on the Viscosity and Crystallization Behavior of CaO-SiO2-MgO-Al2O3-TiO2-Cr2O3 Slag

The viscosity and crystallization behavior of CaO-SiO2-MgO-Al2O3-TiO2-Cr2O3 slag with different Al2O3 contents have been investigated by FactSage thermodynamic calculations, melting point and melting rate measurements, viscosity measurements, phase composition, and microscopy analysis. FactSage thermodynamics calculations revealed that with increasing Al2O3 content, the contents of crystallized spinel, perovskite, and anosovite gradually increased, while the contents of sphene and clinopyroxene decreased. The increase in the Al2O3 content increased the softening, hemispherical, and flowing temperatures. The composition and microstructure of the crystallized phase were assessed using x-ray diffraction and scanning electron microscopy. The results indicated that with the increase of Al2O3 content, the peak intensities of the spinel phase with a high melting point increased. Furthermore, a greater amount of the spinel phase crystallized, explaining the observed increase in the viscosity.

Automated summary

The viscosity and crystallization behavior of CaO-SiO2-MgO-Al2O3-TiO2-Cr2O3 slag changed with varying Al2O3 content, resulting in shifts in softening, hemispherical, and flowing temperatures, as well as an increase in viscosity.