| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for dephosphorizing molten iron by which low-phosphorus steel is produced without using fluorite. <P>SOLUTION: The method includes removing phosphorus from molten iron by using a top and bottom-blown converter and feeding an oxygen source and a CaO source without using fluorite which is a slag formation accelerator. Under the condition that the ratio by mass% of CaO to SiO<SB>2</SB>obtained by analyzing the slag collected from the converter after the completion of dephosphorization blowing is 1.8 or more and 2.4 or less, the ratio of the firing point area formed on a molten iron bath surface by the oxygen blown from a top-blown lance to the molten iron bath surface area in the converter is set to 0.15 or more. It is preferable to use a powder CaO source having a particle size adjusted to 3 mm or less as the CaO source and blow it to the molten iron in the furnace from the top-blown lance. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
