CONVERTER REFINING METHOD USING MOLTEN IRON SUBJECTED TO MOLTEN IRON PRETREATMENT

摘要

PROBLEM TO BE SOLVED: To provide a converter refining method which suppress the formation of (T.Fe) and is low in cost of bottom blowing gas. SOLUTION: In top and bottom blown converter blowing of molten iron previously lowered in [P] to <=0.05% and [Si] to <=0.25, the flow rate of the bottom blowing is changed at least >=1 times in the refining in such a manner that the flow rate of the bottom blowing gas in the period of part or the whole of a period when [C] is >=0.5% attains 3 to 8 Nm3/h/t and the flow rate of the bottom blowing gas in the period of part or the whole of a period when [C] is lower than 0.5% attains 8 to 15 Nm3/h/t.