| 摘要 |
PURPOSE:To prevent the lowering of the molten iron temp. in the phosphorizing stage by gradually increasing the ratio of the amt. of a solid oxide to the amt. of gaseous oxygen when the powder of the solid oxide is blown into molten iron with the gaseous O2 as a carrier gas to oxidize the P in the molten iron and to dephosphorize the molten iron. CONSTITUTION:An oxidizing agent flux as the dephosphorizing agent consisting essentially of mill scales as Fe2O3 and contg. quick lime (CaO) and fluorite (CaF2) is blown into molten iron along with gaseous O2 to oxidize the P in the molten iron to P2O5 which forms a stable compd. with CaO and CaF2, the compd. transfers into molten slag, and the molten iron is dephosphorized. In this case, the amt. of the flux consisting of Fe2O3, CaO, and CaF2 is gradually increased with the lapse of time in the desiliconization reaction zone 1 before the dephosphorization reaction, the succeeding dephosphorization reaction zone 2, and the low-phosphorus zone 3 after dephosphorization. Conversely, the amt. of gaseous O2 as the carrier gas is gradually decreased. Furthermore, the total feed rate of the O2 is the flux (expressed in terms of gas) and the O2 in the carrier gas is kept at 6.0Nm<3>/hr per ton of molten iron, and the lowering of the temp. of the molten iron in the dephosphorizing stage is prevented.
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