| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for pre-treating molten iron by which the slopping and the consumption of carbon in the molten iron are restrained, desulfurization and dephosphorization of the molten iron are continuously performed, the consumption of flux used in the pre-treatment is saved and the desulfurizing efficiency and the dephosphorizing efficiency can be improved. SOLUTION: In the method for pre-treating the molten iron, the desulfurization and dephosphorization are performed by blowing gaseous oxygen onto the surface of the molten iron 11 from a top-blown lance 26 while injecting a flux containing CaO and solid oxygen from a lance 24 dipped into the molten iron 11 after performing desiliconizing treatment. The ratio of the weight of CaO contained in the flux injected in the first half of the pre-treatment to the weight of the oxygen blown in the first half is regulated to 2.0-3.5, and the ratio of the weight of CaO contained in the flux to the weight of oxygen composed of the solid oxygen and the gaseous oxygen in the latter half of the pre-treatment is regulated to 0.8-1.2.
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