| 摘要 |
PROBLEM TO BE SOLVED: To prevent return of sulfur caused by fine desulfurization slag generated during a molten iron desulfurization treatment and suspended in the molten iron or desulfurization slag deposited on a side wall of a treatment vessel, in a process of manufacturing molten steel from molten iron by applying decarburization treatment, etc. as a succeeding process to molten iron subjected to desulfurization treatment.SOLUTION: A method for preventing return of sulfur to molten iron after subjected to a desulfurization treatment includes: stirring a CaO-based desulfurizer and molten iron in a treatment vessel to react the CaO-based desulfurizer and sulfur in the molten iron, applying to the molten iron a desulfurization treatment for reducing an amount of sulfur in the molten iron by taking the sulfur in the molten iron into desulfurization slag including the CaO-based desulfurizer, and then blowing inactive gas of 0.010 Nm/(min/molten iron-ton) or more to the molten iron to stir the molten iron thereby allowing the desulfurization slag suspended in the molten iron or the desulfurization slag adhered on the inner wall of the treatment vessel to float up on the surface of a molten iron bath, discharging the floated desulfurization slag out of the treatment vessel, and then transporting the molten iron in the treatment vessel to a succeeding process. |
