BLOWING METHOD FOR SIDE-BLOWN CONVERTER AND SIDE-BLOWN CONVERTER

摘要

PURPOSE:To achieve high dephosphorization and the good yield of iron simultaneously by supplying a blowing gas in a larger amt. to upper tuyeres than lower tuyeres the start of blowing in a side-blown converter, and changing this in a way as to supply a larger amt. to the lower tuyeres than to the upper tuyeres during blowing. CONSTITUTION:Molten iron and CaO which is an auxiliary raw material are charged into a side-blown converter 1. At the start of blowing, the flow rate of the blowing gas to be supplied to the upper tuyeres 5 near the surface of a steel bath is made large and the flow rate of the blowing gas to supplied to the lower tuyeres 6 near the bottom of the furnace 1 is made small. In this state the blowing is continued to about a middle period, and when the concn. of C in the molten steel attains about 0.3%, the flow rate of the gas to be supplied to the lower tuyeres 6 is increased and the flow rate of the gas to be supplied to the upper tuyeres 5 is changed to a small flow rate, and in this state, the blowing is continued up to the end.