Title:
Desiliconization , Depressed , the decarbonization method of reusing Desiliconization slag
Document Type and Number:
Japanese Patent JP6223249
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To reduce phosphorus of a molten steel while promoting slag formation during decarbonization by using desiliconized slag having low melting point (SiOsource) and preventing erosion of refractory and reduce slag quantity discharging from whole steel making process.SOLUTION: When manufacturing a molten steel having phosphorus concentration of 0.015 mass% or less from a molten iron, the invention includes a first process of desiliconization at basic degree of 0.6 to 1.2 by supplying an oxygen source, a second process for conducting dephosphorization by supplying a CaO source so that the basic degree becomes 1.2 or more, a third process of separating dephosphorized slag and molten steel after dephosphorization treatment and a fourth process for adding desiliconized slag generated the first process before charging and conducting decarbonization with desiliconized slag satisfying "5/X≤SiOin the desiliconized slag/SiOin whole auxiliary material≤10/X" and basicity after the treatment of 3.0 to 4.5. X=(%AlO+%TiO)/(%CaO+%SiO+%AlO+%TiO).
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Inventors:
Atsushi Tatsuki
Takashi Fujita
Takashi Fujita
Application Number:
JP2014056646A
Publication Date:
November 01, 2017
Filing Date:
March 19, 2014
Export Citation:
Assignee:
KABUSHIKI KAISHA KOBE SEIKO SHO
International Classes:
C21C5/28; C21C1/02; C21C1/04; C21C5/36
Domestic Patent References:
| JP10306305A | ||||
| JP56133413A | ||||
| JP2000256720A | ||||
| JP2004190067A | ||||
| JP54137420A | ||||
| JP2015078419A |
Foreign References:
| US4388112 |
Attorney, Agent or Firm:
Toshio Yasuda
Mikio Yasuda
Mikio Yasuda