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:
May. 15, 1979
Filed:
Oct. 14, 1977
Yoichi Hiraga, Shin-nanyo, JP;
Mitsuo Kikuchi, Shin-nanyo, JP;
Toyo Soda Manufacturing Co., Ltd., Yamaguchi, JP;
Abstract
Wet process phosphoric acid prepared by treating phosphate rock with sulfuric acid and separating calcium sulfate, is purified to obtain a purified phosphoric acid by (a) an acid extracting section contacting the wet process phosphoric acid and a phosphoric acid solution containing impurities obtained in the scrubbing section with an organic solvent in the presence of the hydrochloric acid required for extracting a substantial amount of the phosphoric acid component; (b) a scrubbing section contacting the extract obtained in the acid extracting section with aqueous phosphoric acid or water while maintaining the chloride ion concentration in the aqueous phase in the range of 20 to 40 g/liter as Cl; (c) an acid stripping section contacting the purified extract obtained in the scrubbing section with water and (d) an adsorbing section contacting the extracted phosphoric acid obtained in the acid stripping section with an anion-exchange resin.