To provide a method for dephosphorizing molten iron highly efficiently in a high productivity without using any halide such as fluorite.
In a converter type molten iron pretreating furnace, a targeted basicity after dephosphorizing is defined as 1.8-2.2, and the supplying speed of fine powdery CaO is controlled so that the targeted basicity becomes 1.0-1.4 after 2 min of the treatment and becomes 1.4-1.8 after 5 min of the treatment. Thus, the solidification of the slag at the early stage is prevented and the slopping at the rear-half stage is prevented. When the silicon concentration before treatment is high, the upper part addition of the converter slag having granular diameter of ≥5 μm may be performed.
COPYRIGHT: (C)2010,JPO&INPIT
MATSUMOTO SHU
| JPH1150123A | 1999-02-23 | |||
| JP2005126784A | 2005-05-19 | |||
| JP2006249568A | 2006-09-21 | |||
| JP2003113409A | 2003-04-18 | |||
| JP2004307941A | 2004-11-04 | |||
| JPH09143529A | 1997-06-03 | |||
| JP2000073112A | 2000-03-07 | |||
| JPH1150123A | 1999-02-23 | |||
| JP2005126784A | 2005-05-19 | |||
| JP2006249568A | 2006-09-21 |
Fumio Yamamoto
Yukine Sekine