| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a converter type pretreating method with which the pretreating cost in refining process can drastically be reduced without increasing the non-melted scrap so that the steelmaking cost is reduced drastically, and further desirably, metal-containing slag generated in the refining process can be recovered and the blowing can be performed at the low temperature and improvement of a dephosphorizing performance can be expected. SOLUTION: Before the converter type pretreatment is performed, crude concentrate is charged into the first converter and successively, molten iron is charged and further, burnt lime, ingot-making slag and auxiliary raw material containing silica rock, are charged, and after adjusting the basicity to 1-4, the blowing is started. The iron ore is charged and the temperature is adjusted to 1250-1400 deg.C, and the dephosphorized molten iron is tapped off from the first converter and this dephosphorized molten iron is again charged into the second converter, and main blowing is performed to attain the above purpose.</p> |
