method for separating the loeslichen action of any element of the rare earth compound from a mixture of such compounds

摘要

1,261,200. Solvent extraction of rare earths. THORIUM Ltd. 11 Nov., 1969 [12 Nov., 1968], No. 53635/68. Heading C1A. A batchwise method for separating a soluble compound of a rare earth element (or yttrium) from a mixture by countercurrent solvent extraction, in which the R.E. is extracted from an aq. mineral acid solution into DEHPA diluted with an organic diluent, by adding mineral acid to the organic exit end of the system to maintain the pH of the aqueous solution at a level sufficient to hold a chosen R.E. within the system, whilst allowing RE's of higher atomic number to pass out of the system at the organic exit end, whilst transferring all RE's contained in the acid soln. issuing from the aqueous exit end to DEHPA/ diluent solution and readmitting them at the aqueous end, stopping the flow of all materials when the desired purification is achieved; and removing the pure RE solution. Preferred mineral acids are HCl and HNO 3 . Particularly specified RE is Gadolinium.