Commissariat a L'energie Atomique

Rhone-poulenc Chimie

Rhone-poulenc S.a.

Richard Fitoussi

Claude Musikas

Jean-Louis Sabot

Alain Leveque

Sylvie Lours

Hubert Ranarivelo

Rare earth and cobalt values are separated and recovered from residue materials containing them, e.g., the waste residues from the production of samarium/cobalt magnets, by (a) dissolving such residues with nitric acid, (b) liquid/liquid extracting the resulting aqueous nitric phase with an organic phase including at least one water-insoluble organic extractant having at least one primary, secondary, tertiary or quaternary amine function, whereby the rare earth values are transferred into the organic phase, and (c) recovering the rare earth values from the organic phase.

Liquid/liquid extraction of rare earth/cobalt values

Rare earth and cobalt values are separated and recovered from residue materials containing them, e.g., the waste residue from the production of samarium/cobalt magnets, by (a) dissolving such residues with nitric acid, (b) liquid/liquid extracting the resulting aqueous nitric phase with an organic phase including at least one water-insoluble neutral organophosphoric extractant, whereby the rare earth values are transferred into the organic phase, and (c) recovering the rare earth values from the organic phase.

Gallium values are separated and recovered from strongly basic aqueous solutions thereof, e.g., Bayer process aluminate liquors, by (i) contacting such basic solution with an organic phase comprising an organic extractant and an organic solvent and liquid/liquid extracting gallium values therefrom, and permitting phase separation into an aqueous phase and an organic phase containing said extracted gallium values; (ii) contacting said organic phase with a solution of an acid halide in part comprising acidic phase recycled from the below stage (iv), after the selective extraction thereof, and liquid/liquid extracting gallium values therefrom, and permitting phase separation into a second organic phase and an acid phase containing said extracted gallium values; (iii) adjusting the halide ion concentration of the acidic gallium phase; (iv) selectively extracting gallium values from said acidic gallium phase; and (v) recovering such selectively extracted gallium values.

Liquid/liquid extraction of gallium values

Acidic aqueous phases comprising sulfate ion and particularly sulfuric acid values, titanium ion and particularly titanium (IV) values, and iron ion, particularly iron (II) values, and advantageously waste streams emanating from a sulfate process for the production of TiO.sub.2, are extracted with an initial organic phase which comprises at least one neutral organic extractant having the general formula: ##STR1## in which A and B, which may be the same or different, are the groups R.sub.1 or OR.sub.2, wherein R.sub.1 and R.sub.2 are straight or branched chain alkyl, alkenyl, alkynyl, alkoxyalkyl, aryl or alkylaryl radicals, or halogen substituted such radicals; and R is either R.sub.1 or R.sub.2 as above-defined, with R, R.sub.1 and R.sub.2 either being the same or different, or R is a group having the general formula: ##STR2## in which Y is a straight or branched chain alkylene radical, and A and B are as defined above, to provide a final aqueous phase comprising substantially all of said iron (II) values present in said initial aqueous phase and a final organic phase comprising substantially all of said sulfuric acid values and substantially all of said titanium values present in said initial aqueous phase; the respective iron/sulfate/titanium values may then be facilely recovered from their respective final phases.

Liquid/liquid extraction of acidic aqueous streams comprising

A method for the separation of actinides from lanthanides present in a trivalent state in an acidic aqueous solution. Said method consists in selectively extracting in an organic solvent the actinides present in said solution, by bringing said aqueous solution into contact with an organic solvent comprising a system of extractants constituted by an acidic organo-phosphorated compound containing at least one electron doner sulfur atom such as di-2-ethylhexyl-dithio-phosphoric acid, and by a neutral organophosphorated compound containing at least one electron-doner oxygen atom such as tributyl phosphate.

Method for separating actinides from lanthanides in an acidic aqueous

Process for the plutonium decontamination of an organic solvent comprising adding to the said organic solvent a reducing agent which is a dialkyl dithiophosphoric acid and which is soluble in the organic solvent, bringing the organic solvent containing the reducing agent into contact with an acid aqueous solution and separating the aqueous solution containing the plutonium from the decontaminated organic solvent, useful in reprocessing of irradiated nuclear fuels.

Process for the plutonium decontamination of an organic solvent

The invention relates to a process for the determination of uranium (VI) or dialkyl dithiophosphoric acid present in an organic solvent. In this process, a dialkyl dithiophosphoric acid or a uranium (VI) salt is added to the organic solvent so as to convert all the uranium or dialkyl dithiophosphoric acid present in said solvent into a mixed uranium (VI) - dialkyl dithiophosphoric acid-organophosphorus compound complex. The optical density of the solvent containing the complex in solution is measured so as to determine the concentration of this solvent in the complex, together with its uranium dialkyl dithiophosphoric acid content. Application to the determination of traces of uranium in tributylphosphate obtained from the reprocessing of irradiated fuels.

Process for the determination of uranium (VI) or dialkyl

Process for the recovery of the uranium present in a phosphoric acid solution by bringing the said solution into contact with an organic solvent suitable for extracting the uranium, wherein the said organic solvent comprises a system of extractants constituted by an acid organophosphorus compound having at least one sulphur atom and by a neutral phosphine oxide of formula: ##STR1## in which R.sub.1, R.sub.2 and R.sub.3 are identical or different alkyl, alkoxyalkyl or aryl radicals.

Uranium recovery process

Process for the recovery of the ruthenium present in an aqueous nitric solution, wherein the ruthenium is extracted in an organic solvent by contacting the nitric solution with an organic phase comprising an organophosphorous compound having at least one electron donor sulphur atom in the presence of a compound able to displace NO.sup.+ ions of the ruthenium complexes present in the nitric solution. Application to the recovery of ruthenium contained in a nitric solution obtained by dissolving irradiated fuel elements.

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Paris, France

Richard Fitoussi