| 摘要 |
PURPOSE:To make usable converter slag and dephosphorization slag of a molten iron as a raw material for sintered ore by blowing the powder of said slag together with carbon powder and oxygen into the molten iron in a reaction vessel and forming low-phosphorus slag and to make usable the phosphorus concd. in the molten iron as high phosphorus-content slag for a phosphatic fertilizer, etc. CONSTITUTION:P2O5 is contained at a high ratio in the converter slag or the dephosphorization slag of the molten iron and is not usable as it is as the raw material for the sintered ore and therefore such slag is pulverized and is mixed with coke powder 12. The mixture is blown with gaseous N2 14, 15 as a carrier gas from a lance 4 into the reaction vessel 5. Gaseous O2 11 is at the same time ejected from the lance 4 to burn the coke powder and the pulverized converter slag, etc., 13 are melted by the generated high temp. and is blown into the molten iron 6 in the vessel 5. The P2O5 in the slag 13 is reduced and absorbed into the molten iron 6 to form the converted slag 7 contg. P2O5 at the lower ratio. Such slag is cooled, solidified and ground and is thus made usable as raw material for the sintered ore. Oxygen is blown to the molten iron 6 to decarburize and dephosphorize the molten iron to steel when the content of P therein attains the upper limit. The formed slag contains P2O5 at a high ratio and is therefore utilized as phosphatic fertilizer. |
