| 摘要 |
PROBLEM TO BE SOLVED: To provide a method, with which the concentration of P in molten iron is stably lowered to <=0.025% without using fluorspar, etc. at the dephosphorizing time in the molten iron, even in the case the concentration of Si in the molten iron is at the low lever of <=0.15%. SOLUTION: When mixed powder containing CaO powder, Al2O3 powder and Fe2O3 powder, is injected into the molten iron from a top-blown oxygen lance, the mixed ratio of the Al2O3 powder in the mixed powder is 3-20% of the CaO powder added quantity, and the mixed ratio of the Fe2O3 is 5-50% of the CaO powder added quantity, and the oxygen of 0.5-2.8 Nm3/min/ton of molten iron is blown as carrier gas from the top-blown lance and also, the stirring gas of 0.05-0.60 Nm3/min/ton of molten iron is blown from the furnace bottom.
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