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:
Jan. 24, 1978
Filed:
Jun. 22, 1976
Mitsuo Kikuchi, Shin-nanyo, JA;
Yoichi Hiraga, Shin-nanyo, JA;
Abstract
A process for removing sulfate ions from extracted phosphoric acid which is substantially free of metallic ion impurities and which has been prepared by extracting wet process phosphoric acid with an organic solvent which comprises: A. adjusting the extracted phosphoric acid concentration to a concentration greater than 70%; B. adding an amount of a barium compound which is less than the stoichiometric equivalent amount of barium relative to the amount of dissolved sulfate ion to form barium sulfate crystals; and C. separating said barium sulfate from the resulting slurry at a temperature less than 80.degree. C and recovering purified, extracted phosphoric acid; Wherein the amount of barium compound added is such that said purified extracted phosphoric acid contains at least 5 ppm of sulfate ions.