Experimental Determination and Model Prediction of the Surface Tension of CaO-SiO2-MgO-Al2O3-CaF2 Slag

In this study, the surface tension of molten slag was measured using the hanging ring method. Based on the ion and molecular coexistence theory (IMCT), an activity prediction model for the CaO-SiO2-MgO-Al2O3-CaF2 slag system was established, and a corresponding surface tension model was subsequently derived. The investigation explores the effects of basicity R = (w(CaO)/w(SiO2)), the mass ratio w(MgO)/w(Al2O3), and the Al2O3 mass fraction (w, mass fraction of the corresponding oxide). Results show that the surface tension increases with higher values of R, w(MgO)/w(Al2O3), and w(Al2O3) content. The proposed model exhibits high predictive accuracy and provides a reliable tool for evaluating the surface tension of multicomponent blast furnace slags.