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.
Patent No.:
Date of Patent:
Jan. 24, 1978
Filed:
Aug. 23, 1976
Applicant:
Inventor:
Stephen Waslo, Penn Hills Township, Allegheny County, PA (US);
Assignee:
United States Steel Corporation, Pittsburgh, PA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C23F / ; C23F / ;
U.S. Cl.
CPC ...
75 / ; 75 34 ;
Abstract
Passivation of sponge iron by a mild reoxidation thereof is effected by contact, at a temperature of 200.degree. to 600.degree. F, with a gaseous atmosphere consisting essentially of 25 to 80% H.sub.2, 15 to 70% CO and 0.5% to 4.0% O.sub.2 for a time in excess of about 1 hour. The passivation atmosphere may be produced by dilution of a free-oxygen-containing gas with conventional reducing gases. Therefore, the process is particularly amenable to the in-line passivation of hot reduced pellets i.e. wherein passivation may be effected directly within the lower portion of a shaft furnace.