| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method for dephosphorizing molten pig iron that can obtain high dephosphorization efficiency while keeping slag at a low degree of basicity, and also prevent spitting and dust from being produced to suppress a decrease in an iron yield. <P>SOLUTION: The dephosphorizing method for adding a refining agent containing a CaO source as a main component to the molten pig iron in a converter type container, and spraying gaseous oxygen onto the surface of the molten pig iron bath from the top-blowing lance, includes: spraying a powdery and granular solid oxygen source onto the surface of the molten pig iron bath from the top-blowing lance; setting the feed rate of the gaseous oxygen blown from the top-blowing lance at 1.5 to 5.0 Nm3/min/molten pig iron ton; and treating the molten pig iron so that the slag basicity (%CaO/%SiO2) can be kept at 1.0 or more but less than 2.5 after the treatment. <P>COPYRIGHT: (C)2013,JPO&INPIT |
