METHOD FOR PRETREATING MOLTEN IRON HAVING LITTLE AMOUNT OF SLAG BY USING CONVERTER TYPE VESSEL

摘要

PROBLEM TO BE SOLVED: To provide a method for pretreating molten iron having little amount of slag by using a converter type vessel with which consumption of flux used for pretreatment of desiliconization and dephosphorization and the produced slag are reduced by using the converter type vessel and the obtained Si and P concentrations can be reduced by improving the reactional efficiency of desiliconizing and dephosphorizing reactions. SOLUTION: In the method for pretreating the molten iron having little amount of slag, performing the desiliconizing treatment and the dephosphorizing treatment by using the converter type vessel 10, 40-60 weight % the slag produced in the pretreatment of the molten iron at the previous heat, is left in the converter type vessel 10 and new molten iron 16 is charged into the converter type vessel 10. Then, the desiliconizing treatment and the dephosphorizing treatment to the molten iron 16, are performed by blowing oxygen, and on the of the desiliconizing treatment and the dephosphorizing treatment, flux 15 is added into the molten iron 16, and further, desiliconizing treatment and the dephosphorizing treatment are successively performed.