| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an effective method for reusing a converter slag which contains 5.0 mass% or more by mass concentration of free CaO and is not suitable for being converted to a roadbed material. <P>SOLUTION: When producing molten steel by blowing molten pig iron which has not been subjected to preliminary dephosphorizing treatment in a top and bottom combined blown converter, this method for reusing the converter slag which has 5.0% or more by mass concentration of free CaO and is not suitable for being converted to the roadbed material includes: classifying the converter slag which has been produced when decarburization-blowing preliminarily dephosphorized pig iron and contains 5.0% or more by mass concentration of free CaO, from the others; spraying water to the classified converter slag for 30 minutes or longer; adjusting the converter slag to a grain size of 10-100 mm; charging the converter slag into the top and bottom combined blown converter; and blowing the molten pig iron so that a mass concentration ratio (%CaO)/(%SiO<SB>2</SB>) of the slag after blowing becomes 3.0 to 5.0 and (%Al<SB>2</SB>O<SB>3</SB>) becomes 4.0 mass% or less. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
