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:
Apr. 01, 1980
Filed:
Feb. 27, 1978
Bernhard Wojtech, Bad Soden, DE;
Klaus P Ehlers, Hurth-Knapsack, DE;
Wolfgang Scheibitz, Leverkusen, DE;
Hoechst Aktiengesellschaft, Hurth Knapsack, DE;
Abstract
Contaminated phosphoric acid, particularly wet-processed phosphoric acid, is purified by extracting it from its aqueous solution by means of an organic solvent, which is immiscible or partially miscible with water and in which phosphoric acid is soluble, separating the phosphoric acid being dissolved in the organic solvent from extraction residue, and recovering the phosphoric acid from the organic solution. The aqueous phosphoric acid is more particularly mixed in a reaction zone, in a ratio by volume within the range 1:0.3 to 1:30, with a solvent having a boiling point higher than that of water or higher than that of the resulting water solvent-azeotrope, the phosphoric acid/solvent-mixture is heated to temperatures between the boiling point of water or of the said azeotrope and that of the solvent until distillation of substantially all uncombined water originally present in the mixture, and residue and resulting anhydrous phosphoric acid solution in the organic solvent are separated.