A process for recovering uranium from components contaminated with uranium oxide includes providing a cleaning apparatus with a cleaning solution for dissolving the uranium oxide of the components, carrying out a cleaning process by introducing a batch of components into the cleaning apparatus, and carrying out a measurement for determining the uranium content of the components. The cleaning and the measuring are repeated if a limit value for the uranium content is exceeded. The components are discharged from the process if the uranium content falls below a limit value. The cleaning is carried out on a plurality of successive batches of components until a control measurement indicates an unsatisfactory cleaning action of the cleaning solution. The uranium oxide dissolved in the cleaning solution is recovered after indication of the unsatisfactory cleaning action.

Processing schemes for the extraction and/or separation of rare earth elements (REEs) from rare earth containing products such as rare earth mineral ore bodies and intermediate products derived from rare earth mineral ore bodies. The processing schemes may be applied independently or in various combinations to produce end-products that have a very high purity with respect to REEs, including high value critical REEs. The processes may include acid digestion, formation of rare earth oxalate compounds, metathesizing of rare earth oxalate compounds, selective precipitation and/or solvent extraction to form the high purity REE end products.

The invention relates to a hydrometallurgical process which makes it possible to selectively recover at least one “heavy” rare earth metal, i.e. a rare earth metal with an atomic number at least equal to 62, that is in an acidic aqueous phase resulting from the treatment of spent or scrapped permanent magnets. It also relates to a hydrometallurgical process which makes it possible to selectively recover, on the one hand, at least one heavy rare earth metal present in an acidic aqueous phase resulting from the treatment of spent or scrapped permanent magnets and, on the other hand, at least one “light” rare earth metal, i.e. a rare earth metal with an atomic number at most equal to 61, that is also in this acidic aqueous phase. The invention has in particular an application in the recycling of rare earth metals present in spent or scrapped permanent magnets of the type Neodymium-Iron-Boron (or NdFeB) and, in particular, dysprosium, praseodymium and neodymium, and also in the recycling of samarium present in spent or scrapped permanent magnets of the type samarium-cobalt (or SmCo).

Processing schemes for the extraction and/or separation of rare earth elements (REEs) from rare earth containing products such as rare earth mineral ore bodies and intermediate products derived from rare earth mineral ore bodies. The processing schemes may be applied independently or in various combinations to produce end-products that have a very high purity with respect to REEs, including high value critical REEs. The processes may include acid digestion, formation of rare earth oxalate compounds, metathesizing of rare earth oxalate compounds, selective precipitation and/or solvent extraction to form the high purity REE end products.

Processing schemes for the extraction and/or separation of rare earth elements (REEs) from rare earth containing products such as rare earth mineral ore bodies and intermediate products derived from rare earth mineral ore bodies. The processing schemes may be applied independently or in various combinations to produce end-products that have a very high purity with respect to REEs, including high value critical REEs. The processes may include acid digestion, formation of rare earth oxalate compounds, metathesizing of rare earth oxalate compounds, selective precipitation and/or solvent extraction to form the high purity REE end products.

A process for recovering uranium from components contaminated with uranium oxide includes providing a cleaning apparatus with a cleaning solution for dissolving the uranium oxide of the components, carrying out a cleaning process by introducing a batch of components into the cleaning apparatus, and carrying out a measurement for determining the uranium content of the components. The cleaning and the measuring are repeated if a limit value for the uranium content is exceeded. The components are discharged from the process if the uranium content falls below a limit value. The cleaning is carried out on a plurality of successive batches of components until a control measurement indicates an unsatisfactory cleaning action of the cleaning solution. The uranium oxide dissolved in the cleaning solution is recovered after indication of the unsatisfactory cleaning action.

The invention relates to a hydrometallurgical process which makes it possible to selectively recover at least one heavy rare earth metal, i.e. a rare earth metal with an atomic number at least equal to 62, that is in an acidic aqueous phase resulting from the treatment of spent or scrapped permanent magnets. It also relates to a hydrometallurgical process which makes it possible to selectively recover, on the one hand, at least one heavy rare earth metal present in an acidic aqueous phase resulting from the treatment of spent or scrapped permanent magnets and, on the other hand, at least one light rare earth metal, i.e. a rare earth metal with an atomic number at most equal to 61, that is also in this acidic aqueous phase. The invention has in particular an application in the recycling of rare earth metals present in spent or scrapped permanent magnets of the type Neodymium-Iron-Boron (or NdFeB) and, in particular, dysprosium, praseodymium and neodymium, and also in the recycling of samarium present in spent or scrapped permanent magnets of the type samarium-cobalt (or SmCo).

The invention relates to the ROANEX method, which extracts actinides from used nuclear fuel in a single purification cycle. The used nuclear fuel contains actinides, U, Am, Pu, Np. and Cm, and fission products, Cs, Sr and Tc. The fission products are separated first from the used nuclear fuel. The actinides are reduced to their lowest oxidation states and then oxidized to their highest oxidations states. Uranium, Pu and Np move to an organic phase solution and Am and Cm move to a nitrate solution. Uranium, Pu, and Np are stripped from the organic phase solution, and then treated with an oxalic acid to form a precipitate. Americium and Cm are treated with a potassium carbonate solution and Am precipitates. Actinides Am, U, Pu, and Np precipitates are heated in an oven and then blended together to form a mixed oxide fuel of UO.sub.2, PuO.sub.2, NpO.sub.2 and AmO.sub.2.

Novel dissymmetric N,N-dialkylamides which meet the following formula (I): ##STR00001##
where R represents a linear or branched alkyl group at C.sub.8 to C.sub.15. A method for synthesizing these N,N-dialkylamides, and to the uses of same as extractants, alone or in admixture, in order to extract uranium and/or plutonium from an aqueous acid solution, or to totally or separate uranium from plutonium from an aqueous acid solution and, in particular, an aqueous solution resulting from dissolving spent nuclear fuel in nitric acid. Further, a method for processing an aqueous solution resulting from the dissolution of a spent nuclear fuel in nitric acid, allowing the uranium and plutonium contained in the solution to be extracted, separated and decontaminated in a single cycle, without requiring any plutonium reduction operation, and in which one of the aforementioned N,N-dialkylamides or a mixture of same is used as extractant. Applications for the method include the processing of spent nuclear fuels, in particular comprising uranium (e.g. UOX) or uranium and plutonium (e.g. MOX).

Novel dissymmetric N,N-dialkylamides which meet the following formula (I):

##STR00001##

where R represents a linear or branched alkyl group at C.sub.8 to C.sub.15. A method for synthesizing these N,N-dialkylamides, and to the uses of same as extractants, alone or in admixture, in order to extract uranium and/or plutonium from an aqueous acid solution, or to totally or separate uranium from plutonium from an aqueous acid solution and, in particular, an aqueous solution resulting from dissolving spent nuclear fuel in nitric acid. Further, a method for processing an aqueous solution resulting from the dissolution of a spent nuclear fuel in nitric acid, allowing the uranium and plutonium contained in the solution to be extracted, separated and decontaminated in a single cycle, without requiring any plutonium reduction operation, and in which one of the aforementioned N,N-dialkylamides or a mixture of same is used as extractant. Applications for the method include the processing of spent nuclear fuels, in particular comprising uranium (e.g. UOX) or uranium and plutonium (e.g. MOX).