Commissariat a L'energie Atomique

Claude Ginisty

Andre Bathellier

Bernard Mauborgne

Michel Marteau

Process for the recovery of uranium (VI) present in a phosphoric acid solution by contacting the latter with an organic solvent able to extract uranium, the organic solvent comprising a system of extractants constituted by a neutral phosphine oxide and an acid organophosphorus compound. The process comprises a re-extraction stage for the uranium extracted in the organic solvent, said re-extraction stage being performed in a re-extraction apparatus comprising at least two stages in which the uranium-containing organic solvent is circulated in the said stages by introducing it into the first stage, an aqueous ammonium carbonate solution is circulated in countercurrent with respect to the organic solvent in the said stages by introducing it into the final stage in a quantity such that it represents 50 to 80% of the stoichiometric quantity necessary for neutralizing the acid organophosphorus compound and for transforming the uranium present in the organic solvent into uranyl ammonium tricarbonate, ammonia being added in the form of a gas or an aqueous solution to the ammonium carbonate solution circulating in the first stage in order to keep the pH of the final stage as a value between 8 and 9.5 and preferably between 8 and 8.5.

Uranium (VI) recovery process using acid organophosphorus extractant

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 organic solvent comprises a system of extractants constituted by an acid organophosphorus compound and by a neutral phosphine oxide of formula: ##STR1## in which the radicals R.sub.1, R.sub.2 and R.sub.3 are identical or different alkyl, aryl or alkoxyalkyl radicals, at least one of the radicals R.sub.1, R.sub.2 and R.sub.3 being an alkoxyalkyl radical.

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Villeneuve le Roi, France

Claude Ginisty