Experimental study on the viscosity of CaF₂-SiO ₂-Al₂O₃-CaO-MgO slag

To study the effects of CaF₂-SiO₂-Al ₂O₃-CaO-MgO slag composition on viscosity, the slag samples was prepared by the method of quadratic orthogonal rotary regression. On the conditions of dropping in the temperature between 1600 and 1300 °C, the slag viscosity was measured by the rotary cylinder method with RTW-10 melt physical properties measuring apparatus. The regression calculation equation on viscosity was established according to the viscosity analysis using regression analysis method at 1600 °C, then the influence of oxide on CaF ₂-based refining slag viscosity was studied. The results show that the viscosity of slag declined dramatically with the increase of CaF ₂, and the viscosity of slag increased rapidly with the increase of SiP₂, MgO and Al₂O₃ when the content range of CaF₂ is from 10% to 70%. However, with the increase of CaO, the changeable viscosity is attributed to the interaction of other components. When SiO₂ content is 10%, MgO content is 10%, and CaF₂ content is 50%, with the increase of CaO, the viscosity first increased, then decreased, and the viscosity is maxima when the CaO content is 10%. When A1 ₂O₃ content is 20%, MgO content is 10%, and CaF ₂ content is 50%, with the increase of CaO, the viscosity first increased, then decreased at SiO₂ content of less 20%. On the contrary, the viscosity of slag containing more than 20% SiO₂ decreased due to addition of CaO.