| 摘要 |
<p>PURPOSE:To decrease the amt. of a flux such as quicklime to be used and to permit application of this method to a molten steel of low P as well by using residual slag generated at the time of ladle refining as part of the flux at a specific ratio. CONSTITUTION:The molten steel 7 is received from a converter into a ladle 1 and the molten steel 7 is covered by basic slag 8 formed by throwing of the flux such as quicklime and slightly burned dolomite into the ladle. A pouring pipe 2 is inserted at the same instant into the molten steel 7 and the powder of an alkaline earth metal or the compd. Thereof is ejected together with gase ous Ar into the molten steel 7 from the pipe 2 to execute ladle refining. The molten steel 7 in the ladle 1 is continuously cast from a nozzle 11 upon ending of said refining and the residual slag 81 remaining in the bottom of the ladle 1 is poured into a cooling pan 4 where the the slag is cooled to solidify and is then disintegrated to a pellet shape. Residual slag lumps 82 are thus obtd. Such slag lumps are thrown as part of the flux into the converter 6 at a propor tion of <=30kg per ton of the molten iron at the time of refining the molten iron in the converter 6.</p> |
