The fluid flow, species transport, and chemical reaction between the mold flux and high-Al steel in the slab continuous casting mold are simulated by a multiphase model. The slag layer thickness and slag viscosity on the species concentration evolution are investigated. The results show that the SiO 2 concentration decreases from the slab’s narrow face to the submerged entry nozzle, and the Al 2 O 3 distribution presents the opposite trend. The slag composition mainly changes at the beginning of the reaction stage. As the reaction time extends beyond 10 min, the SiO 2 and Al 2 O 3 concentrations do not vary much. Since slag viscosity is higher than that of molten steel, the liquid velocity and mass transfer coefficient near the interface decrease with a increasing slag layer thickness. With lower slag viscosity, the mass transfer coefficient and the chemical reaction rate are enhanced. As the slag viscosity decreases from 0.5 Pa·s to 0.1 Pa·s, the residual SiO 2 concentration decreases from 23.5 wt.% to 21.1 wt.%, and the Al 2 O 3 concentration increases from 20.0 wt.% to 22.5 wt.%. Therefore, the mold flux property affects the evolution of slag concentration during the continuous casting process.
Jiang et al. (Mon,) studied this question.