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. 22, 1983
Filed:
Jul. 13, 1981
Fernando Ore', Whittier, CA (US);
Occidental Research Corporation, Irvine, CA (US);
Abstract
A process for producing low aluminum content phosphoric acid from high aluminum matrix comprises digesting the matrix in phosphoric acid; adding a flocculant to consolidate gelatinous or fine undigested solids; separating the flocculated solids from the mother liquid comprising monocalcium phosphate; acidifying the monocalcium phosphate with sulfuric acid to precipitate solid calcium sulfate and simultaneously adding at least one sodium or potassium compound or both to co-precipitate some of the soluble fluoride with the gypsum; separating the product phosphoric acid from the precipitated solids; recycling part of the lower fluoride content phosphoric acid back to the digestion step; and, aging the remainder of the product phosphoric acid until a precipitate of aluminum fluorophosphate forms and separating the precipitate to produce a low aluminum content phosphoric acid. Additional fluorine (e.g., a fluoride compound) can be added to accellerate formation of the aluminum fluorophosphate.