| 摘要 |
PROBLEM TO BE SOLVED: To provide a method, with which a dephosphorizing treatment can be executed while holding the yield of molten iron high without developing the slopping and the excessive erosion of a refractory in the process of dephos phorizing treatment in the dephosphorizing method of the molten iron by a batch type countercurrent refining method. SOLUTION: This method of dephosphorizing molten iron is composed of a stage in which a decarburizing refining is executed and after discharging molten steel, the molten decarburized slag is left in a converter, a stage in which the decarburized slag is made to semi-molten state by charging slagging accelerator into the molten decarburized slag, and a dephosphorizing stage in which oxygen is supplied into the converter after charging the molten iron into the converter holding the semi-molten slag obtained from the previous stage. In the dephosphorizing stage, the slag composition is controlled so as to become <2 wt.% Al2O3, <7 wt.% T.Fe and >2.0 slag basicity (CaO/SiO2).
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