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:
Mar. 09, 1999
Filed:
Dec. 23, 1996
Applicant:
Inventors:
Ithuo Orihara, Gunma-ken, JP;
Moriyuki Fukushima, Gunma-ken, JP;
Eisaku Mogi, Gunma-ken, JP;
Shiro Yamashita, Gunma-ken, JP;
Assignee:
Kanto Denka Kogyo Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
4232391 ; 4232 / ;
Abstract
A waste gas stream containing toxic NF.sub.3 and optionally other gases, such as acidic fluoride gases, for example, HF, SiF.sub.4, MoF.sub.6 and WF.sub.6 is first treated with particles or ribbons of a Cr-containing Fe alloy at about 300.degree.-600.degree. C. to remove the NF.sub.3 content and, if desired, subsequently with an alkaline neutralizing agent in the form of pellets to remove the acidic fluoride contents, if any; said alloy containing preferably about 16-26% Cr and being used in a form of bed packed with said ribbons.