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:
Aug. 29, 2000
Filed:
Apr. 01, 1997
Jean-Michel Lamerant, Beouc Bel Air, FR;
Aluminum Pechiney, Courbevoie, FR;
Abstract
The invention concerns a process that uses an ion exchanger resin to recover the sodium contained in industrial alkaline waste and, in particular, in the 'red mud' and sodium effluents coming from the manufacture of aluminum hydrate according to the Bayer process. It includes putting the alkaline resins (1), usually 'red mud' in the form of an aqueous suspension in contact with an RH.sup.+ type cationic resin, preferably, a carboxylic resin to attach the sodium selectively and quantitatively to the resin (5) and then to extract it quantitatively in the form of NaOH (8) by displacement using a lime suspension (6), preferably, lime milk. The resin (9), after attaching the calcium, is then regenerated for reuse at the beginning of the process (2) by elution of the calcium as CaCl.sub.2 (12) with a diluted hydrochloric acid solution (10).