| 摘要 |
PROBLEM TO BE SOLVED: To adequately secure surplus heat for a post-process, along with effectively dephosphorizing molten pig iron while reducing an additive quantity of CaF<SB>2</SB>as far as possibly. SOLUTION: When manufacturing a low-phosphorus molten pig iron, by adding a smelting agent as an oxygen source and a CaO source into a vessel having retained the molten pig iron to remove phosphorous, this method comprises removing phosphorus, by spraying gaseous oxygen and at least a part of the smelting agent onto the bath surface of the molten pig iron through a top-blowing lance, in such a condition that CaF<SB>2</SB>of 1 kg/molten pig iron ton or substantially no CaF<SB>2</SB>is added to the molten pig iron having an Si concentration of 0.10 mass% or less, and controlling a temperature of the molten pig iron when the phosphorus removal treatment is finished, to 1,360-1,450°C. COPYRIGHT: (C)2004,JPO
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