Influence of Cr2O3 Content on Slag Viscosity Under Different Melting States and Temperature Programs

Viscosities of Cr2O3-bearing slags were examined under different situations. The influence of Cr2O3 content on slag viscosity greatly depends on slag basicity and temperature. In CaO-SiO2-Cr2O3 ternary slags (R = 1.2, 0.8, and 0.5) with a Cr2O3 content lower than 6%, viscosity decreases with an increase in Cr2O3 content; with increasing Cr2O3 content, the slag viscosity tends to decrease, especially in the cases of higher basicity. For CaO-SiO2-10%Al2O3-Cr2O3 (R = 1.2) quaternary slags, when holding at 1953 K for 2 h and measurement was performed during cooling down to 1773 K, viscosities of this slag gradually increased with decreasing temperature to a point and then a sharp increase on viscosity appeared with further decreasing temperature; above 1873 K, the viscosity decreased with increasing Cr2O3 content, while below 1853 K, a raise in Cr2O3 content increased the viscosity. However, in the case of measurement performed from 1813 to 1673 K, the viscosity increased with an increase in Cr2O3 content. It revealed that the slag viscosity showed greater dependency on the precipitation of Cr2O3 and their morphologies.