Study of the effect of the MgO/Al₂O₃ ratio on viscosity of blast furnace slag

The effect of the MgO/Al₂O₃ ratio on the viscosity of blast furnace slag was studied systematically at temperatures of 1773 K and below under the conditions of the same Al₂O₃ content and binary basicity. The results showed that the viscosity and the melting temperature of the slag first decreased, then increased, while the MgO/Al₂O₃ ratio decreased from 0.90 to 0.75. The appropriate MgO/Al₂O₃ ratio, which is not too high or too low, could optimize the properties of blast furnace slag significantly, such as stability and fluidity. In addition, according to the effect of depolymerization of MgO and the strengthening of Al₂O₃, the influence of the structure on the viscosity coincides with the results of these experiments under the combined action of MgO and Al₂O₃. Understanding the effect of the mechanism of MgO/Al₂O₃ on the viscosity of blast furnace slag could provide a promising method for optimizing its viscosity value and improving the blast furnace operation.