| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing molten steel with which, when the molten steel is produced from molten pig iron, the blending ratio of cold-iron source of iron scrap, etc., can be increased by adding powdery material, used as a refining agent in dephosphorizing treatment and decarburizing refining under heating or melting condition, to a furnace.SOLUTION: Powdery material 13 of oxidized iron, lime-based flux, etc., is sprayed toward a molten pig iron surface with oxygen gas as the conveying gas while forming flame under the tip of a top-blowing lance 3, and also molten pig iron 14 in a converter is dephosphorized by spraying the oxygen gas toward the molten pig iron surface. Successively, the obtained molten pig iron after dephosphorizing treatment is charged into another converter or the same converter, and while forming the flame under the tip of the top-blowing lance by using a top-blowing lance having the same constitution as the above top-blowing lance, the powdery material of the lime-based flux, manganese ore, etc., is sprayed toward the molten pig iron surface with the oxygen gas as the conveying gas, and also the molten pig iron is carburized and refined by spraying the oxygen gas toward the molten pig iron surface, and thus the molten steel is produced from the molten pig iron. |
