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:
Sep. 04, 1990
Filed:
Nov. 30, 1989
Applicant:
Inventor:
William C Ziegenhain, Ponca City, OK (US);
Assignee:
E. I. DuPont de Nemours and Company, Wilmington, DE (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
C01B / ; C01G / ; B01D / ;
U.S. Cl.
CPC ...
423484 ; 203 31 ; 210911 ; 210758 ;
Abstract
A process for preparing hydrogen fluoride involving treating anhydrous hydrogen fluoride containing primarily trivalent arsenic impurities with an effective amount of chromium (VI) oxide (i.e., CrO.sub.3) and oxygen such as to oxidize substantially all of the trivalent arsenic to pentavalent arsenic (i.e., As.sup.+3 .fwdarw.As.sup.+5) followed by separation and recovery (e.g., by distillation) of purified anhydrous hydrogen fluoride.