An empirical formula for accurate calculation of liquidus temperature of blast furnace slags in SiO2-Al2O3-CaO-MgO system

Precise numerical simulations of blast furnace (BF) rely on accurate and convenient thermophysical property models of BF slags. Liquidus temperature (T-liq) is one of the most fundamental properties of BF slag, however, the conventional phase equilibrium diagram method for T-liq calculation can be hardly used in numerical simulations. In this work, an accurate and simple empirical formulation suitable for T-liq calculation of BF slags in numerical simulations is established. The model was calibrated by 707 measurement representing 11 primary phase fields in SiO2-Al2O3-CaO-MgO system. The calculated T-liq in present work agrees very well with the measured values, with an average error of only 17.1 degrees C, which is much more accurate than CalPhad method. Present work also suggests that the liquidus region of BF slag at 1500 degrees C should be slightly extended based on the classic phase equilibrium diagram.