Effect of MgO and SiO2 on surface tension of fluoride containing slag

Surface tensions of slag addition MgO and SiO2 based on conventional 70%CaF2-30%Al2O3 and 60%CaF2-20%CaO-20%Al2O3 (mass fraction) at 1300 A degrees C, 1400 A degrees C and 1500 A degrees C were investigated. Influence mechanism of MgO and SiO2 on slag surface tension was also analyzed. Results indicate that surface tension decreases with the increase of MgO content in the case of the MgO content (mass fraction) less than 8%, however, when MgO content (mass fraction) is from 8% to 30%, surface tension increases with the increase of MgO content. When SiO2 content (mass fraction) is from 2% to 8%, surface tension decreases with the increase of SiO2 content. Additionally, the relationship between surface tension and optical basicity is a monotonically increasing linear function. Research findings can provide important reference for slag design and the study of slag-metal interfacial tension.