| 摘要 |
PROBLEM TO BE SOLVED: To provide a molten iron pretreating method by which rephosphorization at the time of desiliconizing molten iron, is prevented and the lime quantity used for the desiliconizing treatment and the dephosphorizing treatment is saved and the produced slag quantity is reduced. SOLUTION: The dephosphorized molten iron 3 is left in a vessel and the produced slag 7 is removed and dephosphorizing flux is added into the molten iron 3 in the vessel 4 to execute the dephosphorizing treatment. After tapping only the dephosphorized molten iron 3, the new molten iron 3 is received into the vessel 4, in which the dephosphorized slag 10 produced with the dephosphorizing treatment is left, to again execute the desiliconizing treatment. The desiliconizing treatment using the dephosphorizing slag 10 is executed so that FeO concn. in the slag at the time of completing the desiliconizing treatment, becomes 1-20 wt.%.
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