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. 29, 1980
Filed:
Dec. 12, 1977
Klaus-Peter Ehlers, Erftstadt, DE;
Wolfgang Scheibitz, Hurth-Knapsack, DE;
Klaus Schrodter, Cologne, DE;
Gero Heymer, Erftstadt, DE;
Hoechst Aktiengesellschaft, , DE;
Abstract
Wet-processed phosphoric acid is decontaminated. To this end, the phosphoric acid and an organic solvent, which is partially miscible with water and capable of absorbing phosphoric acid, are contacted countercurrently with respect to one another. The resulting organic phosphoric acid solution is separated from contaminants unabsorbed by the solvent, termed primary raffinate, decontaminated phosphoric acid is recovered either in the form of free acid by re-extracting the organic phosphoric acid solution with water, or in the form of an alkali metal phosphate by reacting the organic phosphoric acid solution with an alkali, and the primary raffinate is treated countercurrently with a solvent containing a mineral acid. More specifically, the organic phosphoric acid extract, which orginates from the primary raffinate treatment and contains more than 0 up to at most 10 weight% of water, is mixed with an anhydrous solvent in a ratio by weight necessary to ensure the formation of a mixture containing more than 0 and less than 50% of water than would correspond to the saturation concentration of water in the solvent; and the mixture is contacted countercurrently with the phosphoric acid which is to be decontaminated.