Purifying and defluorinating impure phosphoric acid
CA 1109635 A · Owner: Societe Rhone Poulenc Industries · Inventors: Mamourian, Armand; Bousquet, Francois; Helgorsky, Jacques
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
It is known to prepare phosphoric acid from the acidic leaching of phosphate bearing minerals. Such acids generally contain a high fluorine content and thus are unsuitable for use in the food industry. The present invention seeks to overcome this drawback by providing a process for purifying and defluorinating an impure phosphoric acid produced by a sulphuric acid treatment of a phosphate-bearing rock which comprises the counter-current extraction of the impure aqueous phosphoric acid solution with an organic solvent having a low miscibility with water in the presence of concentrated, sulfuric acid washing of the resulting phosphoric acid organic phase with water or purified phosphoric acid …
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Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Granted September 29, 1981. A Canadian patent filed before October 1, 1989 lasted 17 years from grant, so its term ended September 29, 1998.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.