| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method of pre-treating molten iron by which fluorine content in the whole slag produced in iron works is reduced and also, can be made to harmless by diluting. SOLUTION: In the molten iron pre-treatment for pre-removing silicon, phosphorus and sulfur contained in the molten iron before charging the molten iron into a steelmaking furnace, after desiliconizing and dephosphorizing by blowing refining agent containing no fluorite into the molten iron held in a torpedo car through a lance with carrier gas, the desiliconized and dephosphorized molten iron is shifted into a ladle. Desulfurization is performed by adding desulfurizing agent containing the fluorite and mechanically stirring and also, the fluorine-containing slag produced in the desulfurization is used for a part of the raw material charged in a blast furnace thereby diluting the fluorine in the fluorine-containing slag, and discharged from the blast furnace as the blast furnace slag having <=1,000 ppm fluorine content.</p> |
