| 摘要 |
PROBLEM TO BE SOLVED: To efficiently remove phosphorous in hot pig iron when a CaO based flux is blown to the ignition point of the hot pig iron bath face in a converter via a top-blow lance, and the hot pig iron is subjected to dephosphorization refining or decarbonization refining.SOLUTION: Regarding the method for refining hot pig iron, when an oxygen gas is blown to hot pig iron in a converter from a top-blown lance, also, a CaO based flux is blown to the impact face in the bath face of the hot pig iron of the oxygen gas from the top-blown lance, and the hot pig iron in the converter is subjected to dephosphorization refining or decarburization refining, the blowing of the CaO based flux from the top-blown lance is performed over the whole period or a part of period from the start of the blowing of an oxygen gas to the point of time at which the 40 vol% oxygen gas of the estimated acid feed amount is fed, and is further performed over the whole period or a part of period from the point of time at which 70 vol% oxygen gas of the estimated acid feed amount is fed to the completion of refining, and in a period at which an oxygen gas below 70 vol% of the estimated acid feed amount is fed after the point of time at which an oxygen gas of 40 vol% of the estimated acid feed amount is fed, the blowing of the CaO based flux from the top-blown lance is stopped. |
