PROCESS FOR THE VALORIZATION OF URANIUM AND RARE EARTHS CONTAINED IN IMPURED UF4 FROM EXTRACTION OF URANIUM FROM PHOSPHORIC ACID

摘要

A process for making into useful products the uranium and rare earths contained in impure uranium tetrafluoride resulting from the recovery of uranium from phosphoric acid, comprising dissolving it in a hot condition in a nitric medium in the presence of an aluminum compound, treating the resulting solution with a solvent for extracting uranyl nitrate, which contains a phosphoric ester, and separating from the aqueous phase from which the uranium is removed, the solvent which is charged with uranyl nitrate to be made into a useful product, which provides that, in order to achieve easy separation of the aqueous phase from which the uranium has been removed, from the uranyl nitrate extraction solvent: (a) The operation of dissolution of UF4 is carried out in two steps at a suitable temperature, the first step comprising introducing insufficient amounts of nitric acid and the aluminum compound for complete dissolution of the impure uranium tetrafluoride and keeping the resulting suspension in an agitated condition for a period of time of at least 0.5 hour, and the second step comprising introducing amounts of nitric acid and the aluminum compound, which are at least sufficient to put into solution the uranium which was not dissolved in the first step, and while maintaining the suspension in an agitated condition; and (b) the uranyl nitrate is extracted by bringing into contact the aqueous medium resulting from the dissolution of UF4 and the uranyl nitrate extraction solvent containing the phosphoric ester.