Thermodynamic Properties of Sulfur in the CaO–AlO1.5–CeO1.5 Slag System at 1873 K

Elements with a high affinity for O and S in molten steel are desirable as deoxidizing and desulfurizing agents in the steel refining process, and Ce has attracted attention. In this study, the thermodynamic properties of sulfur in a CaO–AlO 1.5 –CeO 1.5 slag system at 1873 K are investigated. A chemical equilibrium method using Cu is employed for these measurements. Sulfide capacities are determined in the CaO–AlO 1.5 –CeO 1.5 system to show desulfurization ability; the precipitated phases are identified when large amounts of sulfur are added to the CaO–AlO 1.5 –CeO 1.5 system; the solubility of CaS in the CaO–AlO 1.5 –CeO 1.5 system is determined. It is suggested that the slag of this system can improve sulfur distribution while reducing the Al concentration in the steel.