Kinetic Analysis for Steel Desulfurization during Ruhrstahl–Heraeus Process

Abstract

A kinetic model for the Ruhrstahl–Heraeus (RH) desulfurization process is established based on the FactSage Macro Processing. The desulfurizer addition, the desulfurization reaction, the steel mixing, the flow circulation, and the desulfurizer floating during the RH refining process are considered in the model. Simulated results agree well measured results, indicating that the current model can be used to predict the desulfurization reactions during the RH refining process. The CaO activity increases with a higher CaO/Al2O3 ratio and a lower SiO2 content, which exhibits a similar tendency with the desulfurization ratio. It is indicated that it is necessary to increase the CaO activity in the desulfurizer to improve the desulfurization ratio. The S content in the molten steel decreases with time and a higher ratio of the powder blowing. The cost increases with time due to the refractory erosion and the steam consumption. The cost of the desulfurizer added by the powder blowing is lower than that of the gravity sinking.