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:
Aug. 17, 1976
Filed:
May. 28, 1974
John F McCullough, Florence, AL (US);
Leland L Frederick, Florence, AL (US);
Tennessee Valley Authority, Muscle Shoals, AL (US);
Abstract
Our invention relates to an improved process for the partial purification of wet-process phosphoric acid with co-production of impure phosphoric acid or solid fertilizer materials containing most of the impurities originally present in the crude acid. The crude acid is treated with methanol and ammonia to precipitate most of the metallic and fluorine impurities as solid ammonium metallic phosphates and fluorine compounds that filter and settle rapidly. The solids are separated from the reaction mixture and methanol is distilled from the resulting clarified solution to form concentrated partially purified acid. The solid ammonium metallic phosphates are fertilizer materials. Alternately, the reaction slurry is separated into a clarified liquid fraction and a settled slurry fraction. Methanol is distilled from the settled fraction which causes most of the impurities to redissolve yielding an impure phosphoric acid.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile