1. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China 2. Steelmaking Department, Shougang Jingtang Iron and Steel Co.,Ltd.,Tangshan 063200,Hebei,China
Abstract:The industrial experiments of 21 heats were conducted at a commercial steel plant to analyze the efficiency of desulfurization during tapping slag infiltration. The results show that the influence of silicon in the steel on the tapping slag infiltration desulfurization was significant for the steel with the aluminum content of 0.025%-0.045% and the sulfur content of 0.002%-0.003%, while the influence of manganese content in the steel on the tapping slag infiltration desulfurization was not apparent. The sulfur content of pipeline steel can be controlled stably below 0.002% in the present process of tapping slag infiltration when the silicon content in steel was controlled above 0.05%. Moreover, the reactions of Al-O, Si-O, CaO-S and Fe-O were coupled based on the coupled reaction kinetics model and it shows the silicon content in steel influences the desulfurization effect during tapping by influencing the oxygen activity at the interface between slag and steel. The oxygen activity at the interface between slag and steel was determined by the oxidability of slag when the oxygen activity of molten steel was certain, and the compositions of slag after tapping slag infiltration desulfurization show that the oxidability of slag with the less than 0.05% silicon content is higher than that with the silicon content beyond 0.05% in steel, which was consistent with the calculated results.