The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Date of Patent:
Feb. 26, 1991

Filed:

Dec. 12, 1988
Applicant:
Inventors:

Katsuhiro Iwasaki, Tokyo, JP;

Kenji Takahashi, Tokyo, JP;

Shigeru Inoue, Tokyo, JP;

Haruyoshi Tanabe, Tokyo, JP;

Masahiro Kawakami, Tokyo, JP;

Osamu Terada, Tokyo, JP;

Assignee:

NKK Corporation, Tokyo, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21B / ;
U.S. Cl.
CPC ...
75502 ; 75443 ; 75446 ; 266172 ; 266182 ; 266186 ;
Abstract

A method for smelting reduction of iron ore, comprises the steps of: introducing iron ore into a preheat and prereduction furnace and preheating and prereducing the iron ore, a prereduction degree being less than 30%; charging the iron ore, carbonaceous material and flux into a smelting reduction furnace; blowing oxygen gas, through decarburization nozzles and post-combustion nozzles placed in a top end of an oxygen lance, into the smelting reduction furnace, the top end of the oxygen lance being located so as to be between a top level and a bottom level of a slag layer; blowing a stirring gas through side tuyeres placed in a side wall and bottom tuyeres placed in a bottom wall of the smelting reduction furnace; and controlling a flow amount of the oxygen gas and the stirring gas so that an oxidation degree of an exhaust gas generated in the smelting reduction furnace ranges 0.4 to 0.9 and still a temperature of the exhaust gas ranges 300.degree. to 1300.degree. C. when the exhaust gas is introduced into the preheat and prereduction furnace. Furthermore, an apparatus for smelting reduction of iron ore comprises: a preheat and prereduction furnace; a smelting reduction furnace; a top blow oxygen lance with decarburization nozzles and post-combustion nozzles; side tuyeres and bottom tuyeres.


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