| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of efficiently and effectively decarburizing dephosphorized molten iron while suppressing generation of spitting and dust using a converter. <P>SOLUTION: Using a top-bottom blowing converter, the dephosphorized molten iron is decarburized by blowing top-blown oxygen at a rate of 4.0-5.5 Nm<SP POS="POST">3</SP>/min per ton of the molten iron. At this time, a ladle slag is loaded into the converter by the time when the blowing time of the top-blown oxygen passes 1/5 of the total blowing time, and a ratio of Al<SB POS="POST">2</SB>O<SB POS="POST">3</SB>mass% to CaO mass% contained in the slag in the converter is controlled to be in a range of 0.05-0.09 at the point of completing blowing of the top-blown oxygen. Furthermore, L/L<SB POS="POST">0</SB>by the blowing of the top-blown oxygen is controlled to be in the range of 0.03-0.10 by the time 1/4 of the total blowing time of the top-blown oxygen has passed, and subsequently to be in the range of 0.20-0.35 until the end of the blowing of the top-blown oxygen. <P>COPYRIGHT: (C)2013,JPO&INPIT |
