An empirical formula for accurate calculation of liquidus temperature of blast furnace slags in SiO 2 –Al 2 O 3 –CaO–MgO system

Abstract

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°C, which is much more accurate than CalPhad method. Present work also suggests that the liquidus region of BF slag at 1500°C should be slightly extended based on the classic phase equilibrium diagram.