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

Abstract

The viscosity and crystallization behavior of CaO-SiO 2 -MgO-Al 2 O 3 -TiO 2 -Cr 2 O 3 slag with different Al 2 O 3 contents have been investigated by FactSage thermodynamic calculations, melting point and melting rate measurements, viscosity measurements, phase composition, and microscopy analysis. Fact-Sage thermodynamics calculations revealed that with increasing Al 2 O 3 content, the contents of crystallized spinel, perovskite, and anosovite gradually increased, while the contents of sphene and clinopyroxene decreased. The increase in the Al 2 O 3 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 Al 2 O 3 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.

Effects of Basicity and Al2O3 Content on Viscosity and Crystallization Behavior of Super-High-Alumina Slag

“…As shown in Figure5h, both the liquidus temperature and complete solidification temperature of the slags increase with the basicity of slag increases from 0.8 to 1.1. In addition, the liquidus temperatures and complete solidification temperatures of the slags also increase with the increasing Al 2 O 3 content, and this result is similar to the calculations of Ma et al[31].…”

“…The hemispherical temperature (HT) implies the melting temperature of the slag at which the solid phase begins to precipitate out of the molten slag. Correspondingly, the flowing temperature can also be called the liquefaction temperature [31].…”