| 摘要 |
PROBLEM TO BE SOLVED: To provide a desiliconizing and dephosphorizing method for molten iron, which prevents the deterioration of a yield of molten steel and the flowing-out of slag by improving the fluidity of the slag at the intermediate slag-off time without using a fluorite and attains the decrease of CaO-source due to the intermediate slag-off. SOLUTION: This invention relates to the desiliconizing and dephosphorizing method for molten iron, in which the intermediate slag-off is performed after applying the desiliconizing treatment in the molten iron in a converter-type furnace and further, the dephosphorizing treatment is applied in the same furnace, wherein a converter slag or an ingot-making slag generated in the following process from the dephosphorizing treatment, is charged in the furnace for performing desiliconizing treatment and the desiliconizing treatment is applied while the slag basicity (CaO/SiO<SB>2</SB>) is adjusted in the range of 0.5-1.8. Further, it is desirable that the intermediate slag-off is performed under condition that Si concentration in the molten iron is≥0.2%. COPYRIGHT: (C)2011,JPO&INPIT
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