| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for efficiently desulfurizing molten pig iron with mechanical stirring, in order to deal with an increasing tendency for smelting a steel having lower sulfur concentration. <P>SOLUTION: This desulfurization method comprises, when desulfurizing molten pig iron with mechanical stirring, using a refining agent containing FeO of 0.02-0.07 pts.wt. added to CaO of 1 pts.wt., and controlling the value of (CaO /SiO<SB>2</SB>) at the end of desulfurization treatment to 3.5 or higher. The above refining agent includes one or two out of Na<SB>2</SB>O and Al<SB>2</SB>O<SB>3</SB>, wherein 0.02-0.10 pts.wt. in terms of Na<SB>2</SB>O and 0.02-0.20 pts.wt. in terms of Al<SB>2</SB>O<SB>3</SB>, in order to realize the higher desulfurization efficiency. In the above method, preferably, converter slag is used for the FeO source, secondary refining slag for the Al<SB>2</SB>O<SB>3</SB>source, and soda glass scrap, glass cullet, or sodium metasilicate for the Na<SB>2</SB>O source; and the Al source is charged into the molten pig iron to adjust Al concentration after desulfurization treatment to 0.01% (mass%) or higher, in order to more stably obtain the high desulfurization efficiency. <P>COPYRIGHT: (C)2003,JPO</p> |
