| 摘要 |
<p>PURPOSE:To easily and efficiently remove impurity elements in molten iron at a low cost by supplying sulfide or sulfate of alkali metal or alkaline earth metal through a top blowing lance at the oxygen gas blowing point on molten iron in a reaction vessel. CONSTITUTION:Steel scrap is charged to the reaction vessel 4 of a converter, etc., possible to top-blow, and fine powdered coal is blown from a bottom blowing tuyere 1 and also oxygen gas is supplied from the top blowing lance 2. By this method, carbonized melting for the scrap is executed with combustion heat of the fine powdered coal to form a molten iron 6 having high carbon concn. Then, Si, Zn, etc., in the impurities in the molten iron 6 are removed by oxidizing and vaporizing. Further, as the above lance 2, by using the top blowing lance 2 possible to oxygen-blow and at the same time, to powder-blow, one or two kinds of the sulfide or the sulfate of alkali metal or alkaline earth metal are supplied to fire point 3 of the oxygen blowing point. Tramp elements of Sn, Cu, As, Bi, Pb, etc., as the impurity elements in the molten iron 6 generate the sulfide at the fire point 3 of high temp. and are vaporized and removed.</p> |
