| 摘要 |
<p>PURPOSE:To execute smelting reduction of iron ore in a short period of time with good thermal efficiency and to dephosphorize molten iron by charging iron ore together with a carbonaceous material and slag making agent into a smelting furnace and subjecting the molten iron to top blowing of oxygen while stirring the same, then to oxygen blowing by addition of a flux for dephosphorization to the molten iron after discharging of slag. CONSTITUTION:The iron ore treated in a preheating and prereducing furnace 30 is charged together with the carbonaceous material and slag making agent into the smelting furnace 10. The oxygen is blown from a top blowing oxygen lance 21 having nozzles 22, 23 for decarburization and secondary combustion and an inert gas or process gas such as Ar, N2 is blown from tuyeres 25, 26 of the side wall and furnace bottom to stir a slag layer 12 and an iron bath 11. The slag is discharged after the smelting reduction to decrease the amt. of the slag to <=20kg per ton of the molten iron in the above-mentioned method for smelting reduction of the iron ore. The molten iron is then subjected to the oxygen blowing by adding the flux for dephosphorization, by which the molten iron is simultaneously decarburized and dephosphorized. The thermal efficiency for smelting reduction is thereby improved and the content of P in the molten iron is decreased; in addition, thermal losses are decreased and the treatment time for the smelting is shortened.</p> |
