Research Progress of Desulfurization Refining Slag: A Review

The development of refining slag is the core of the ladle furnace (LF) refining processes and is essential for fast and effective desulfurization refining. Desulfurization reactions are mainly determined by slag–steel interactions, which are closely related to the physicochemical properties of slags. This study reviews the research progress of desulfurization refining slag for the LF process. First, the chemical composition of the refining slag is described, and then three theories of desulfurization and the concepts of sulfide capacity and sulfur partition ratio are introduced. Second, the effects of operating parameters and slag components on desulfurization are examined. Furthermore, the microscopic analysis of the desulfurization process is performed. The prediction models of slag properties related to desulfurization are summarized. Finally, a research direction for LF desulfurization refining is proposed. The question of how to ensure the uniformity of desulfurization remains open. The industrialization of the new refining slag developed by replacing CaO with BaO or Li2O and replacing CaF2 with B2O3 should be accelerated to solve the CaF2 slag volatilization problem. One of the most pressing issues that must be addressed is improving the accuracy of the existing slag performance forecast model.