Effect of substituting CaO with BaO and CaO/Al2O3 ratio on the viscosity of CaO–BaO–Al2O3–CaF2–Li2O mold flux system

Abstract

The effect of substituting CaO with BaO and CaO/Al2 O3 ratio on the viscosity of CaO–BaO–Al2 O3 –CaF2 –Li2 O mold flux system was studied by rotational viscosity method. The results showed that the viscosity increased with increasing BaO as a substitute for CaO, while the viscosity decreased with the increase in CaO/Al2 O3 ratio. The viscous activation energy of the slags is from 92.1 kJ·mol−1 to 133.4 kJ·mol−1. Either the Arhenius or the Weymann–Frenkel equation can be applied to establish the viscosity prediction model. In this paper, the Weymann–Frenkel equation and a new optical basicity with regard to Al2 O3 as an acidic oxide were applied to the modified NPL model for predicting the viscosity of CaO–BaO–Al2 O3 –CaF2 –Li2 O mold flux system. The estimated viscosity is in good agreement with the measured viscosity.