METHOD FOR ESTIMATING PHOSPHORUS CONCENTRATION IN MOLTEN STEEL AND CONVERTER BLOWING CONTROL DEVICE

To estimate the phosphorus concentration in molten steel with high precision when converter blowing is stopped in an operation that uses a multi-refining converter method. A method for estimating thephosphorus concentration in molten steel is used in primary refining using a converter that involves an intermediate slag removal process and comprises: a slag level data-acquiring step for acquiringthe slag level during a dephosphorizing process; an effluent gas data-acquiring step for acquiring effluent gas components and effluent gas flow during a decarbonization process; a molten steel data-acquiring step for acquiring the molten steel temperature and carbon concentration in the molten steel by sublance measurement during the decarbonization process; and a phosphorus concentration-estimating step for calculating a dephosphorization rate constant using data relating to the slag level, effluent gas components, effluent gas flow, molten steel temperature and carbon concentration as wellas operating conditions rel