DEPHOSPHORIZING TREATMENT METHOD FOR MOLTEN IRON

PROBLEM TO BE SOLVED: To restrain decarburization in molten iron without obstructing dephosphorizing reaction and without lowering the dephosphorizing treatment capacity when the molten iron is dephosphorized by using CaO-base dephosphorizing flux. SOLUTION: This method comprises: blowing the CaO-base dephosphorizing flux 17 from a top-blown lance 3 toward the surface of the molten iron 15 stored in a refining vessel 2 by using oxygen gas as the gas for carrier; and blowing a carbon source 18 from the above top-blown lance via the separated path from the dephosphorizing flux on the surface of the molten iron by using nitrogen gas or rare gas as the gas for carrier to perform the dephosphorizing treatment. At this time, the additional yield can be improved by making the adding speed of the carbon source be ≤2 kg/min×t. COPYRIGHT: (C)2005,JPO&NCIPI