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. 31, 1999
Filed:
Jan. 02, 1998
Howard J Skidmore, Chubbuck, ID (US);
Klaas J Hutter, Tampa, FL (US);
J. R. Simplot Company, Pocatello, ID (US);
Abstract
In one aspect, the invention includes a method of purifying phosphoric acid comprising filtering a feed solution of phosphoric acid through a membrane, wherein the feed solution is maintained at a temperature of from about 30.degree. F. to about 90.degree. F. during the filtering. In another aspect, the invention includes a method of purifying phosphoric acid comprising: a) providing a feed solution of phosphoric acid, said feed solution comprising greater than 17,000 ppm on a 100% P.sub.2 O.sub.5 basis of each of Al, Fe and Mg; and b) filtering the feed solution through a polyamide filter configured for nanofiltration, the filtering comprising a temperature of from about 30.degree. F. to 90.degree. F., and a pressure of from about 600 psig to about 1000 psig to form a purified phosphoric acid solution, the purified phosphoric acid solution comprising less than 1700 ppm on a 100% P.sub.2 O.sub.5 basis of each of Al, Fe and Mg.