| 摘要 |
<p>PURPOSE:To reduce load on the steel making and refining by converter by the procedure in which molten pig iron taken out of blast furnace is separated from molten slag and then iron oxide, e.g., mill scale, etc., is added to the molten pig iron with stirring for making a preliminary silicon removal. CONSTITUTION:The molten pig iron 3 taken out of the blast furnace 1 is introduced into the molten pig iron through 6 and then the blast furnace molten slag is discharged from the molten slag exhaust ports 4 and 4' to separate it from the molten pig iron 3. Then, the molten pig iron 3 separated from the molten slag is sent to the round silicon-removing tank 5 into which is added the silicon removing agent 10 composed mainly of iron oxides, e.g., mill scale, iron ore, return sintered ore, etc., at the same time, where the mixture is stirred by the stirring blade 8 rotating at 50 to 100 r.p.m. in order to bring the silicon removing agent 10 into contact with the molten pig iron strongly. Thus, Si present in the molten pig iron is oxidized by the silicon removing agent into slag and low-silicon pig iron is obtained. The slag, containing much SiO2 and little harmful impurities, e.g., P, etc., is used as a raw material for sintered ore and recycled to blast furnace. The low silicon molten pig iron can reduce load on oxidative refining operation in converter using oxygen.</p> |
