MOLTEN IRON DEPHOSPHORIZING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a molten iron dephosphorizing method capable of reducing the phosphor concentration to a low or super-low phosphor zone without using any environmental regulating substance such as fluorite as a flux in the preliminary treatment of the molten metal. SOLUTION: In the preliminary treatment of dephosphorizing the molten iron in which the phosphor concentration in the molten iron is set to be <=0.040 mass % by feeding oxygen source and CaO source to the molten metal held in the converter as a reaction vessel, the CaO source of the quantity required for the treatment is charged in a divided manner so that the melting ratio of the slag to be formed during the treatment is >=70% without charging any flux for promoting the melting of the slag.