PRODUCTION OF LOW SI, LOW S AND LOW P MOLTEN IRON

摘要

PURPOSE:To execute preliminary refining of deisliconizing, dephosphorizing and desulfurizing for a molten iron by blowing pulverized iron ore, quick lime as a slag forming agent and pulverized carbon, as required, into the molten iron. CONSTITUTION:Pulverized oxide iron ore and pulverized quick lime as a slag forming agent are blow into the molten iron produced from blast furnace. The oxidizing power of Fe2O3 in the iron ore desiliconizes Si in the molten iron into SiO2, and together with the added quick lime forms a high basic slag with =1.5 basicity (CaO/SiO). Also, P in the molten iron is oxidized into P2O5 by the Fe2O3 in the iron ore to be stably fixed in CaO in the high basic slag. The residue of Fe2O3 in the iron ore is reduced into Fe by the saturated carbon in the molten iron to increase molten iron quantity. By promoting the reduction of iron ore with simultaneously adding pulverized carbon as required and facilitating the removal of S in the molten iron to make the basicity at reduction below 3.0 by reducing the content of Fe2O3 in the molten slag, the molten iron of a lower content of Si P and S can be produced.