| 摘要 |
PURPOSE:To contact CaC2 with molten pig iron sufficiently and to heighten the utilization efficiency of desulfurizing agent, by blowing the desulfurizing agent mainly composed of powdered CaC2 after adding an annex mainly composed of quicklime or/and calcined dolomite on the surface of the molten pig iron preliminary. CONSTITUTION:Annex mainly composed of quicklime and/or calcined dolomite having 30-200mm of each grain diameter, is added on the surface of molten pig iron in the vessel and a greater part of the surface is covered by the above annex. Or moreover, 5-20wt.% of powdered or granular carbon, such so coke etc., having 10mm or less of grain diameter against the quicklime and/or calcined dolomite, is added. Next, desulfurization is carried out by blowing desulfurizing agent mainly composed of CaC2, using N2 gas as carrier gas, in the molten pig iron added the annex. On this occasion, 10-100wt.% of calcium cyanamide against CaC2 is added to the desulfurizing agent moreover in order to prevent oxidation of CaC2. As a result of it, the surface of the molten pig iron is able to make non-oxidative state by stirring the molten pig iron surrounding the desulfurizing agent by the gas generated by the decomposition of calcium cyanamide and oxidation of CaC2 is prevented favorably. |
