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:
Dec. 27, 1983
Filed:
Mar. 23, 1981
Pierre Maurel, Aix-en-Provence, FR;
Francois Nicolas, Aix-en-Provence, FR;
Aluminium Pechiney, Lyons, FR;
Abstract
Process for the purification of an aqueous solution containing alkali metal carbonate, sulphate, and hydroxide or hydrogen carbonate and primarily one at least of the metals belonging to the group formed by vanadium, uranium and molybdenum, in the form of alkali metal salts, and mineral and/or organic impurities, said solutions resulting from an ore attack cycle and being taken off after extraction of the metal being sought, which comprises treating said solutions by means of lime at a temperature which is at most equal to the boiling temperature, to convert the carbonate and hydrogen carbonate present into alkali metal hydroxide, then effecting separation and washing of a first precipitate of calcium carbonate and a liquor which is enriched in respect of alkali metal hydroxide, concentrating it by evaporation to cause production of a second precipitate which essentially comprises alkali metal sulphate, separating it from the hydroxide-rich liquid phase, re-dissolving it in an aqueous medium and treating the resulting alkali metal sulphate solution by means of barium aluminate and then carbon dioxide, and separating the resulting precipitate which is subjected to a heat treatment to regenerate the barium aluminate which is recycled.