CARRIER MATERIAL AND DESULFURIZATION AGENT FOR DESULFURIZING IRON

摘要

A particulate carrier material for use with particulate passivated magnesium for injection into molten iron to desulfurize the iron, improve characteristics of the slag and increase iron yield. Material flow of a transport gas and the carrier material is established in a lance prior to inserting the lance into a ladle-contained molten iron, then following insertion the passivated magnesium is added to the material flow. A second embodiment of the invention for iron desulfurization, blends the carrier material and passivated magnesium into a single desulfurization agent. In both embodiments the particulate magnesium is 14-20 mesh with the remaining particulate material being about 200 mesh. The composition of the carrier material is 54-74 % calcium oxide, 19-32 % aluminum oxide, no more than 4 % magnesium oxide, no more than 10 % calcium fluoride, no more than 2.5 % silicon dioxide, no more than 1.0 % iron oxide, no more than 0.025 % phosphorus pentoxide, no more than 0.025 % titanium dioxide, no more than 0.5 % manganese oxide, no more than 0.025 % vanadium pentoxide, no more than 0.025 % potassium oxide, no more than 0.05 % sulfur and a combined loss on ignition and moisture content of no more than 1.5 %. A third embodiment uses carrier material of a narrow range of composition with existing desulfurization processes to improve slag characteristics and increase iron yield.