| 摘要 |
PROBLEM TO BE SOLVED: To reduce splashing of molten metal and occurrence of dust at high oxygen feed rate in the high carbon range at the blowing in a converter and further, to restrain oxidization of the molten metal at low oxygen feed rate in the final stage of the blowing in the converter. SOLUTION: In the method for refining molten metal by using a top-blowing lance 1 provided with a sectorial nozzle 4 at its tip part and blowing the oxygen toward the molten metal, the refining is performed by using the top-blowing lance provided with the sectorial nozzle having a straight barrel part 5 whose length (Ls) is determined to be L<=Ls with regard to the length (L) of the sectorial part 6. Thereby, the occurrence of the dust can be reduced at the high oxygen feed rate. Further, the oxidizing of the molten metal can be restrained at the low oxygen feed rate by regulating the ratio (De/Ds) of an outlet diameter De to the inner diameter Ds in the straight barrel part within the range determined by inequality: De/Ds<=1.20.
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