EP0043765A1 - Process for separating trivalent actinide and lanthanide values from an aqueous acid solution - Google Patents
Process for separating trivalent actinide and lanthanide values from an aqueous acid solution Download PDFInfo
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- EP0043765A1 EP0043765A1 EP19810401060 EP81401060A EP0043765A1 EP 0043765 A1 EP0043765 A1 EP 0043765A1 EP 19810401060 EP19810401060 EP 19810401060 EP 81401060 A EP81401060 A EP 81401060A EP 0043765 A1 EP0043765 A1 EP 0043765A1
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- organophosphorus compound
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- G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
- G21F—PROTECTION AGAINST X-RADIATION, GAMMA RADIATION, CORPUSCULAR RADIATION OR PARTICLE BOMBARDMENT; TREATING RADIOACTIVELY CONTAMINATED MATERIAL; DECONTAMINATION ARRANGEMENTS THEREFOR
- G21F9/00—Treating radioactively contaminated material; Decontamination arrangements therefor
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- G21F9/125—Processing by absorption; by adsorption; by ion-exchange by solvent extraction
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- the subject of the present invention is a process for the separation of actinides and lanthanides present in the trivalent state in an acidic aqueous solution, usable in particular for the treatment of radioactive effluents.
- actinides are of great interest because they can be used in different fields, for example for the production of radioactive sources. Also, it is of great interest to separate the actinides from the lanthanides, on the one hand, to recover the actinides and, on the other hand, to treat, with a view to long-term storage, only fission products with short life, which present less danger.
- this process can find applications in the production of transuranium elements by neutron irradiation of lighter isotope targets, for example the production of americium 241 and curium 244 from irradiated plutonium.
- the lanthanide actinide separation methods which have been used up to now have many disadvantages because they require the use of concentrated saline media, for example 10 M solutions of LiCl, or relatively high pH, which leads to implementation difficulties.
- the present invention specifically relates to a process for the separation of actinides and lanthanides present in the trivalent state in an aqueous solution. This process overcomes these disadvantages. nient and also allows to obtain a quantitative separation of actinides and lanthanides.
- the process for the separation of actinides and lanthanides present in the trivalent state in an acidic aqueous solution is characterized in that the actinides present in said solution are selectively extracted in an organic solvent, by putting in contact with said aqueous solution with an organic solvent comprising a system of extractants constituted by a acid organophosphorus compound comprising at least one electron donor sulfur atom and with a neutral organophosphorus compound comprising at least one electron donor oxygen atom.
- the method of the invention has in particular the advantage of leading to a satisfactory separation. actinides and lanthanides, without requiring the addition of salts or other reagents to the starting aqueous solution, which is generally a nitric solution.
- the acid organophosphorus compound is advantageously a dialkyl dithiophosphoric acid, such as di- (2-ethyl-hexyl) -dithiophosphoric acid, dibutyl-dithiophosphoric acid and di octyl dithiophosphoric acid.
- dialkyl dithiophosphoric acid such as di- (2-ethyl-hexyl) -dithiophosphoric acid, dibutyl-dithiophosphoric acid and di octyl dithiophosphoric acid.
- HDEHDTP di-2-ethyl-hexyl-dithiophosphoric acid
- the neutral organophosphorus compound with an electron donor oxygen atom can consist of a phosphate, a phosphonate, a trialkyl phosphinate, a phosphine oxide in which the alkyl radicals are linear or branched C 4 radicals. to C12, for example, tributyl phosphate (TBP), these oxygenated donors corresponding to the formula: in which the radicals R 1 , R 2 , and R 3 which may be the same or different represent an alkyl, alkoxyalkyl or aryl radical.
- TBP tributyl phosphate
- radicals R 1 , R 2 and R 3 are alkyl or alkoxyalkyl radicals having from 4 to 12 carbon atoms.
- phosphine oxide which can be used, mention may be made of trioctyl phosphine oxide and di-n-hexyl-octoxymethyl phosphine oxide.
- the extractant system is generally diluted in an inert solvent such as dodecane.
- the concentration of each extractant in the organic solvent is such that the molar ratio of the acid organophosphorus compound comprising at least one electron donor sulfur atom to the neutral organophosphorus compound with electron donor oxygen atom is between approximately 2 / 3 and 9/1.
- the method of the invention can be implemented in any conventional extraction device such as batteries of mixer-settlers, pulsed columns, centrifugal extractors, etc.
- dodecane was used as the diluent, and the distribution coefficients of americium and europium by ⁇ spectrometry.
- Americium 241 was present at pocket concentrations of 10 -5 M.1 -1 , europium at concentrations of 2.10 -2 M.1 -1 with 1mCi.1 -1 of the radioactive melagne 152 Eu - 154 Eu.
- the distribution coefficient is equal to the ratio of the concentration of an element in the organic phase to the concentration of this same element in the aqueous phase.
- This example relates to the separation of americium III and europium III by means of an organic solvent comprising a mixture of tributyl phosphate and di-2-ethyl-hexyl- acid. dithiophosphoric in dodecane, the total concentration of extractants from the organic system being 1 M, and the concentration of nitric acid in the aqueous solution being 0.05 M.
- An americium-europium separation can be carried out by countercurrent extraction in a device comprising 6 extraction stages and 3 washing stages, the ratio of the flow rates of the organic phases to the aqueous phase being 0.25 in the extraction part and 0 , 5 in the washing section. Under these conditions, a recovery of approximately 99.5% of the initial americium is obtained and this recovered americium contains approximately 0.4% of the initial europium.
- FIG. 1 which illustrates the variations of the distribution coefficient D Am (curve I) and of the distribution coefficient D Eu (curve II) as a function of the content of di-2-ethyl-hexyl-dithiophosphoric acid of the solvent expressed in molar percentage of the mixture of extractants shows that this example is not limiting as regards the chemical conditions.
- di- (2-ethyl-hexyl) -dithiophosphoric acid 0.75 M and trioctyl phosphine oxide 0.25 M are used as the solvent.
- the separations can then be carried out at stronger acidities than those suggested in Example 1.
- americium-europium separation can be carried out in 0.3 N nitric acid medium using a battery of mixer-settlers. 6 extraction stages and 3 washing stages are used. The ratio of organic phase flow rates to aqueous phase is 0.25 on extraction and 0.25 on washing. 99.5% of the initial americium is then recovered in the organic phase. This recovered americium contains amounts of europium less than 0.1% of the initial europium.
- This example relates to the separation of americium III, cerium III and europium III present in a nitric acid solution 0.05N using an organic solvent consisting of dodecane containing 0.25 M of tributylphosphate and 0.75 M of di-2-ethyl-hexyl-dithiophosphoric acid.
- the separation is carried out in a mixer-settler battery comprising 6 extraction stages with an organic phase / aqueous phase volume ratio of 0.25 and six washing stages with an organic phase / aqueous phase ratio of 0.5. Under these conditions, an organic phase is obtained containing 99.5% of the americium and 0.4% of the starting lanthanides.
- the distribution coefficients are 4.1 for americium, 0.23 for cerium III and 0.17 for europium III, respectively.
Abstract
Description
La présente invention a pour objet un procédé de séparation des actinides et des lanthanides présents à l'état trivalent dans une solution aqueuse acide, utilisable notamment pour le traitement d'effluents radioactifs.The subject of the present invention is a process for the separation of actinides and lanthanides present in the trivalent state in an acidic aqueous solution, usable in particular for the treatment of radioactive effluents.
Dans l'industrie nucléaire, notamment dans le domaine du traitement des effluents aqueux qui contiennent des lanthanides et des actinides tels que des transuraniens, il est d'un grand intérêt de séparer les actinides des lanthanides avant de conditionner ces déchets radioactifs en vue de leur stockage à long terme, par exemple par vitrification.In the nuclear industry, in particular in the field of the treatment of aqueous effluents which contain lanthanides and actinides such as transuranics, it is of great interest to separate the actinides from the lanthanides before conditioning this radioactive waste for their disposal. long-term storage, for example by vitrification.
En effet, on sait que les lanthanides qui sont des produits de fission émetteurs Q et y ont des périodes beaucoup plus courtes que les actinides qui sont des éléments émetteurs a à vie plus longue. Aussi, il est préférable de conditionner des déchets ne contenant que des émetteurs à vie courte qui deviennent plus rapidement inactifs, ce qui pose moins de problème pour leur stockage à long terme.In fact, it is known that lanthanides which are Q emitting fission products and have much shorter periods there than actinides which are emitting elements have a longer life. Also, it is preferable to condition waste containing only short-lived emitters which become more inactive more quickly, which poses less problem for their long-term storage.
De plus, la récupération des actinides présente un grand intérêt car ils sont utilisables dans différents domaines, par exemple pour la réalisation de sources radioactives. Aussi, il est d'un grand intérêt de séparer les actinides des lanthanides, d'une part, pour récupérer les actinides et, d'autre part, pour ne traiter, en vue du stockage à long terme, que des produits de fission à vie courte, qui présentent un moindre danger.In addition, the recovery of actinides is of great interest because they can be used in different fields, for example for the production of radioactive sources. Also, it is of great interest to separate the actinides from the lanthanides, on the one hand, to recover the actinides and, on the other hand, to treat, with a view to long-term storage, only fission products with short life, which present less danger.
De même, ce procédé peut trouver des applications dans la production des transuraniens par irradiation neutronique de cibles d'isotopes plus légers, par exemple la production d'américium 241 et de curium 244 provenant du plutonium irradié.Likewise, this process can find applications in the production of transuranium elements by neutron irradiation of lighter isotope targets, for example the production of americium 241 and curium 244 from irradiated plutonium.
Cependant, le problème de la séparation des actinides et des lanthanides est difficile à résoudre car les ions lanthanides (III) et actinides (III) présentent des propriétés chimiques très peu différentes, leurs rayons ioniques sont voisins et la plupart des complexes formés à partir de lanthanides ou d'actinides ont un caractère ionique marqué.However, the problem of the separation of actinides and lanthanides is difficult to solve because the lanthanide (III) and actinide (III) ions have very little different chemical properties, their ionic rays are close and most of the complexes formed from lanthanides or actinides have a marked ionic character.
Les procédés de séparation actinides lanthanides qui ont été utilisés jusqu'à présent, présentent de nombreux inconvénients car ils nécessitent l'utilisation de milieux salins concentrés, par exemple de solutions 10 M en LiCl, ou des pH relativement élevés, ce qui conduit à des difficultés de mise en oeuvre.The lanthanide actinide separation methods which have been used up to now have many disadvantages because they require the use of concentrated saline media, for example 10 M solutions of LiCl, or relatively high pH, which leads to implementation difficulties.
La présente invention a précisément pour objet un procédé de séparation des actinides et des lanthanides présents à l'état trivalent dans une solution aqueuse. Ce procédé pallie ces inconvé-. nients et permet de plus d'obtenir une séparation quantitative des actinides et des lanthanides.The present invention specifically relates to a process for the separation of actinides and lanthanides present in the trivalent state in an aqueous solution. This process overcomes these disadvantages. nient and also allows to obtain a quantitative separation of actinides and lanthanides.
Selon l'invention, le procédé de séparation des actinides et des lanthanides présents à l'état trivalent dans une solution aqueuse acide, se caractérise en ce que l'on extrait sélectivement dans un solvant organique, les actinides présents dans ladite solution, en mettant en contact ladite solution aqueuse avec un solvant organique comprenant un système d'extractants constitués par un composé organophosphoré acide comportant au moins un atome de soufre donneur d'électrons et par un composé organophosphoré neutre comportant au moins un atome d'oxygène donneur d'électrons.According to the invention, the process for the separation of actinides and lanthanides present in the trivalent state in an acidic aqueous solution, is characterized in that the actinides present in said solution are selectively extracted in an organic solvent, by putting in contact with said aqueous solution with an organic solvent comprising a system of extractants constituted by a acid organophosphorus compound comprising at least one electron donor sulfur atom and with a neutral organophosphorus compound comprising at least one electron donor oxygen atom.
Grâce à l'utilisation du système d'ex- tractants précité, le procédé de l'invention présente notamment l'avantage de conduire à une séparation satisfaisante entre. les actinides et les lanthanides, sans nécessiter pour autant l'adjonction de sels ou d'autres réactifs à la solution aqueuse de départ, qui est généralement une solution nitrique.Through the use of such system - tracting supra, the method of the invention has in particular the advantage of leading to a satisfactory separation. actinides and lanthanides, without requiring the addition of salts or other reagents to the starting aqueous solution, which is generally a nitric solution.
Selon l'invention, le composé organophosphoré acide est avantageusement un acide dialkyl dithiophosphorique, tel que l'acide di-(2- éthyl-hexyl)-dithiophosphorique, l'acide dibutyl- dithiophosphorique et l'acide di octyl dithiophosphorique.According to the invention, the acid organophosphorus compound is advantageously a dialkyl dithiophosphoric acid, such as di- (2-ethyl-hexyl) -dithiophosphoric acid, dibutyl-dithiophosphoric acid and di octyl dithiophosphoric acid.
De préférence, on utilise l'acide di-2- éthyl-hexyl-dithiophosphorique (HDEHDTP).Preferably, di-2-ethyl-hexyl-dithiophosphoric acid (HDEHDTP) is used.
Selon l'invention, le composé organophosphoré neutre à atome d'oxygène donneur d'électrons peut être constitué par un phosphate, un phosphonate un phosphinate de trialkyle, un oxide de phosphine dans lesquels les radicaux alkyl sont des radicaux linéaires ou ramifiés en C4 à C12, par exemple, le tributyl phosphate (TBP), ces donneurs oxygénés répondant à la formule :
De préférence, les radicaux R1, R2 et R 3 sont des radicaux alkyle ou alcoxyalkyle ayant de 4 à 12 atomes de carbone.Preferably, the radicals R 1 , R 2 and R 3 are alkyl or alkoxyalkyl radicals having from 4 to 12 carbon atoms.
A titre d'exemple, d'oxyde de phosphine susceptible d'être utilisé, on peut citer l'oxyde de trioctyl phosphine et l'oxyde de di-n-hexyl- octoxyméthyl-phosphine.By way of example, phosphine oxide which can be used, mention may be made of trioctyl phosphine oxide and di-n-hexyl-octoxymethyl phosphine oxide.
Pour la mise en oeuvre du procédé de l'invention, on dilue généralement le système d'extractants dans un solvant inerte tel que du dodécane.For the implementation of the process of the invention, the extractant system is generally diluted in an inert solvent such as dodecane.
Avantageusement, la concentration de chaque extractant dans le solvant organique est telle que le rapport molaire du composé organophosphoré acide comportant au moins un atome de soufre donneur d'électrons au composé organophosphoré neutre à atome d'oxygène donneur d'électrons soit comprise entre environ 2/3 et 9/1.Advantageously, the concentration of each extractant in the organic solvent is such that the molar ratio of the acid organophosphorus compound comprising at least one electron donor sulfur atom to the neutral organophosphorus compound with electron donor oxygen atom is between approximately 2 / 3 and 9/1.
On précise que le procédé de l'invention peut être mis en oeuvre dans tout appareil classique d'extraction tel que des batteries de mélangeurs-décanteurs, des colonnes pulsées, des extracteurs centrifuges, etc...It is specified that the method of the invention can be implemented in any conventional extraction device such as batteries of mixer-settlers, pulsed columns, centrifugal extractors, etc.
D'autres caractéristiques et avantages de l'invention apparaîtront mieux à la lecture des exemples suivants donnés bien entendu à titre illustratif et non limitatif, se référant au dessin annexé sur lequel :
- - la figure 1 est un diagramme représentant les variations des coefficients de distribution DAm de l'américium (courbe I) et DEU de l'europium (courbe II) en fonction de la concentration en tributyl phosphate et en acide di-(2-éthyl- thiophosphorique du solvant organique ; la concentration totale en extractant était constante et égale à 1, la solution aqueuse était constituée par de l'acide nitrique 0,05 M.
- - la figure 2 est un diagramme représentant les variations des coefficients de distribution DAm de l'américium (III) (courbe I) et DEu de l'europium (III) (courbe II) en fonction du pH de la solution aqueuse de départ ; le solvant était constitué d'acide di-2-éthyl-hexyl-dithiophosphô- rique 0,75 M et de phosphate de tributyle 0,25 M en solution dans le dodécane ; la concentration des ions N03 en phase aqueuse était maintenue constante . et égale à 1 M,
- - la figure 3 est un diagramme représentant les variations des coefficients de distribution DAm de l'américium (III) (courbe I) et DEU de l'europium (III) (courbe II), en fonction de la concentration en acide di-2-éthyl-hexyl-dithiophosphorique du solvant organique ; la concentration en tributyl-phosphate a été maintenue constante et égale à 0,1 M, la phase aqueuse était de l'acide nitrique 0,05 N,
- - la figure 4 est un diagramme représentant les variations des coefficients de distribution DAm de l'américium (III) (courbe I) et DEu de l'europium (III) (courbe II) en fonction de la concentration en acide nitrique de la solution aqueuse. La phase organique était constituée par un mélange d'acide di-2-éthyl-hexyl-dithiophosphorique 0,75 M et d'oxyde de trioctylphosphine 0,25 M en solution dans le dodécane. La phase aqueuse contenait des ions NO- 3 en concentration constante provenant soit de l'acide nitrique, soit du nitrate de potassium.
- FIG. 1 is a diagram representing the variations of the distribution coefficients D Am of americium (curve I) and DEU of europium (curve II) as a function of the concentration of tributyl phosphate and of di- (2- ethylthiophosphoric organic solvent; the concen total extraction was constant and equal to 1, the aqueous solution consisted of 0.05 M nitric acid
- FIG. 2 is a diagram representing the variations in the distribution coefficients D Am of americium (III) (curve I) and D Eu of europium (III) (curve II) as a function of the pH of the aqueous solution of departure ; the solvent consisted of 0.75 M di-2-ethyl-hexyl-dithiophosphoric acid and 0.25 M tributyl phosphate dissolved in dodecane; the concentration of NO3 ions in the aqueous phase was kept constant. and equal to 1 M,
- - Figure 3 is a diagram representing the variations of the distribution coefficients D Am of americium (III) (curve I) and D EU of europium (III) (curve II), as a function of the acid concentration di -2-ethyl-hexyl-dithiophosphoric organic solvent; the tributyl phosphate concentration was kept constant and equal to 0.1 M, the aqueous phase was 0.05 N nitric acid,
- FIG. 4 is a diagram representing the variations of the distribution coefficients D Am of americium (III) (curve I) and D Eu of europium (III) (curve II) as a function of the nitric acid concentration of the aqueous solution. The organic phase consisted of a mixture of di-2-ethyl-hexyl-dithiophosphoric acid 0.75 M and trioctylphosphine oxide 0.25 M in solution in dodecane. The aqueous phase contained constantly concentrated NO - 3 ions from either nitric acid or potassium nitrate.
Dans toutes ces expériences on a utilisé le dodécane comme diluant, et on a déterminé les coefficients de distribution de l'américium et de l'europium par spectrométrie γ. L'américium 241 était présent à des concentrations poches de 10-5M.1-1, l'europium à des concentrations de 2.10-2M.1-1 avec 1mCi.1-1 du mélagne radioactif 152Eu - 154Eu.In all of these experiments, dodecane was used as the diluent, and the distribution coefficients of americium and europium by γ spectrometry. Americium 241 was present at pocket concentrations of 10 -5 M.1 -1 , europium at concentrations of 2.10 -2 M.1 -1 with 1mCi.1 -1 of the radioactive melagne 152 Eu - 154 Eu.
On précise que le coefficient de distribution est égal au rapport de la concentration d'un élément dans la phase organique sur la concentration de ce même élément dans la phase aqueuse.It is specified that the distribution coefficient is equal to the ratio of the concentration of an element in the organic phase to the concentration of this same element in the aqueous phase.
Ces résultats indiquent que les mécanismes d'extraction des ions Am (III) et Eu (III) sont différents. Les courbes des figures 1 à 4 suggèrent que ces mécanismes correspondent aux réactions sui-
En effet, au vu des résultats obtenus sur les figures 2 et 3 où les pentes des courbes (I) et (II) sont respectivement de 3 et de l, il apparaît que 3 ions H et 3 ions (DEHDTP) sont échangés au cours de l'extraction de l'américium, alors qu'un seul ion H+ et un seul ion (DEHDTP)- sont échangés au cours de l'extraction de l'europium.Indeed, in view of the results obtained in Figures 2 and 3 where the slopes of the curves (I) and (II) are respectively 3 and l, it appears that 3 H ions and 3 ions (DEHDTP) are exchanged during of the extraction of americium, while a single H + ion and a single ion (DEHDTP) - are exchanged during the extraction of europium.
Cet exemple se rapporte à la séparation de l'américium III et de l'europium III au moyen d'un solvant organique comprenant un mélange de tributyl phosphate et d'acide di-2-éthyl-hexyl- dithiophosphorique dans du dodécane, la concentration totale en extractants du système organique étant égale à 1 M, et la concentration en acide nitrique de la solution aqueuse étant de 0,05 M.This example relates to the separation of americium III and europium III by means of an organic solvent comprising a mixture of tributyl phosphate and di-2-ethyl-hexyl- acid. dithiophosphoric in dodecane, the total concentration of extractants from the organic system being 1 M, and the concentration of nitric acid in the aqueous solution being 0.05 M.
On peut effectuer une séparation américium-europium par extraction à contre-courant dans un appareil comportant 6 étages d'extraction et 3 étages de lavage, le rapport des débits des phases organiques sur phase aqueuse étant de 0,25 dans la partie extraction et 0,5 dans la partie lavage. Dans ces conditions, on obtient une récupération d'environ 99,5 % de l'américium initial et cet américium récupéré contient environ 0,4 % de l'europium initial.An americium-europium separation can be carried out by countercurrent extraction in a device comprising 6 extraction stages and 3 washing stages, the ratio of the flow rates of the organic phases to the aqueous phase being 0.25 in the extraction part and 0 , 5 in the washing section. Under these conditions, a recovery of approximately 99.5% of the initial americium is obtained and this recovered americium contains approximately 0.4% of the initial europium.
La figure 1 qui illustre les variations du coefficient de distribution DAm (courbe I) et du coefficient de distribution DEu (courbe II) en fonction de la teneur en acide di-2-éthyl-hexyl- dithiophosphorique du solvant exprimée en pourcentage molaire du mélange d'extractants montre que cet exemple n'est pas limitatif en ce qui concerne les conditions chimiques.FIG. 1 which illustrates the variations of the distribution coefficient D Am (curve I) and of the distribution coefficient D Eu (curve II) as a function of the content of di-2-ethyl-hexyl-dithiophosphoric acid of the solvent expressed in molar percentage of the mixture of extractants shows that this example is not limiting as regards the chemical conditions.
Au vu de cette figure, on constate que l'on obtient le meilleur résultat lorsque le mélange d'extractants comprend 75% de HDEHDTP et 25% de TBP. Par ailleurs, on note que de bons résultats sont obtenus lorsque le rapport molaire de l'acide di-(2-éthyl-hexyl)-dithiophosphorique sur le tributyl phosphate est compris entre environ 2/3 et 9/1.In view of this figure, it can be seen that the best result is obtained when the mixture of extractants comprises 75% of HDEHDTP and 25% of TBP. Furthermore, it is noted that good results are obtained when the molar ratio of di- (2-ethyl-hexyl) -dithiophosphoric acid to tributyl phosphate is between approximately 2/3 and 9/1.
Le choix de l'appareil d'extraction et de ses conditions de fonctionnement devra être adapté aux coefficients de distribution de l'américium et de l'europium selon les règles habituelles du génie chimique.The choice of the extraction device and its operating conditions must be adapted to the distribution coefficients of americium and europium according to the usual engineering rules chemical.
Dans cet exemple, on utilise comme solvant l'acide di-(2-éthyl-hexyl)-dithiophosphorique 0,75 M et l'oxyde de trioctyl phosphine 0,25 M. On peut alors se permettre d'effectuer les séparations à des acidités plus fortes que celles suggérées dans l'exemple 1. Par exemple, on peut effectuer une séparation américium-europium en milieu acide nitrique 0,3 N à l'aide d'une batterie de mélangeurs-décanteurs. On utilise 6 étages d'extraction et 3 étages de lavage. Le rapport des débits de phase organique sur phase acqueuse est de 0,25 à l'extraction et de 0,25 au lavage. On récupère alors 99,5 % de l'américium initial dans la phase organique. Cet américium récupéré contient des quantités d'europium inférieures à 0,1 % de l'europium initial.In this example, di- (2-ethyl-hexyl) -dithiophosphoric acid 0.75 M and trioctyl phosphine oxide 0.25 M are used as the solvent. The separations can then be carried out at stronger acidities than those suggested in Example 1. For example, americium-europium separation can be carried out in 0.3 N nitric acid medium using a battery of mixer-settlers. 6 extraction stages and 3 washing stages are used. The ratio of organic phase flow rates to aqueous phase is 0.25 on extraction and 0.25 on washing. 99.5% of the initial americium is then recovered in the organic phase. This recovered americium contains amounts of europium less than 0.1% of the initial europium.
Comme pour l'exemple 1, ces conditions ne sont pas limitatives, comme le montrent les coefficients de distribution de l'américium et de l'europium de la figure 4. Il faut remarquer que les facteurs de séparation américium-europium peuvent être plus importants que ceux de la figure 4 à acidité identique si on supprime le nitrate de potassium. En effet, les équations (1) et (2) des équilibres d'extraction, montrent que la présence d'ions N03 favorise seulement l'extraction des ions Eu (III). D'autres conditions de fonctionnement de la séparation en contre-courant peuvent être utilisées.As for example 1, these conditions are not limiting, as shown by the distribution coefficients of americium and europium in figure 4. It should be noted that the americium-europium separation factors may be more important than those of Figure 4 with identical acidity if we remove the potassium nitrate. In fact, equations (1) and (2) of the extraction equilibria show that the presence of N03 ions only favors the extraction of the Eu (III) ions. Other operating conditions of the counter-current separation can be used.
Cet exemple se rapporte à la séparation de l'américium III, du cérium III et de l'europium III présents dans une solution d'acide nitrique 0,05N au moyen d'un solvant organique constitué par du dodécane contenant 0,25 M de tributylphosphate et 0,75 M d'acide di-2-éthyl-hexyl-dithiophosphorique. On effectue la séparation dans une batterie de mélangeur-décanteur comprenant 6 étages d'extraction avec un rapport en volume phase organique/phase aqueuse de 0,25 et six étages de lavage avec un rapport phase organique/phase aqueuse de 0,5. Dans ces conditions, on obtient une phase organique contenant 99,5 % de l'américium et 0,4 % des lanthanides de départ.This example relates to the separation of americium III, cerium III and europium III present in a nitric acid solution 0.05N using an organic solvent consisting of dodecane containing 0.25 M of tributylphosphate and 0.75 M of di-2-ethyl-hexyl-dithiophosphoric acid. The separation is carried out in a mixer-settler battery comprising 6 extraction stages with an organic phase / aqueous phase volume ratio of 0.25 and six washing stages with an organic phase / aqueous phase ratio of 0.5. Under these conditions, an organic phase is obtained containing 99.5% of the americium and 0.4% of the starting lanthanides.
Les coefficients de distribution sont respectivement de 4,1 pour l'américium, de 0,23 pour le cérium III et de 0,17 pour l'europium III.The distribution coefficients are 4.1 for americium, 0.23 for cerium III and 0.17 for europium III, respectively.
Bien que dans ces exemples, on ait décrit la mise en oeuvre du procédé de l'invention pour la séparation américium/europium ou Am/Ce-En qui constituent des couples d'éléments du groupe des actinides et des lanthanides les plus difficiles à séparer, le procédé de l'invention s'applique également à la séparation des autres éléments du groupe des actinides et des lanthanides.Although in these examples, the implementation of the process of the invention has been described for the separation americium / europium or Am / Ce-En which constitute pairs of elements from the group of actinides and lanthanides most difficult to separate , the process of the invention also applies to the separation of the other elements from the group of actinides and lanthanides.
Claims (8)
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8014840 | 1980-07-03 | ||
| FR8014840A FR2486299A1 (en) | 1980-07-03 | 1980-07-03 | PROCESS FOR SEPARATING ACTINIDS AND LANTHANIDES PRESENT AT THE TRIVALENT STATE IN AQUEOUS ACID SOLUTION |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0043765A1 true EP0043765A1 (en) | 1982-01-13 |
| EP0043765B1 EP0043765B1 (en) | 1985-01-16 |
Family
ID=9243809
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP19810401060 Expired EP0043765B1 (en) | 1980-07-03 | 1981-07-01 | Process for separating trivalent actinide and lanthanide values from an aqueous acid solution |
Country Status (4)
| Country | Link |
|---|---|
| EP (1) | EP0043765B1 (en) |
| JP (1) | JPS5747729A (en) |
| DE (1) | DE3168298D1 (en) |
| FR (1) | FR2486299A1 (en) |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3718338A1 (en) * | 1987-06-01 | 1989-01-05 | Karlsruhe Wiederaufarbeit | METHOD AND DEVICE FOR SOLVENT WASHING IN THE REPROCESSING OF IRRADIATED NUCLEAR FUELS |
| GB2228611A (en) * | 1989-02-27 | 1990-08-29 | British Nuclear Fuels Plc | Removal of thorium from raffinate. |
| US5510090A (en) * | 1991-12-05 | 1996-04-23 | Commissariat A L'energie Atomique | Process for the selective extraction (III) actinides by means of amides having a nitrogenous heterocyclic substituent |
| GB2305291A (en) * | 1995-09-12 | 1997-04-02 | Doryokuro Kakunenryo | A method of separating trivalent actinides and rare earth elements |
| RU2517651C1 (en) * | 2013-05-07 | 2014-05-27 | Александра Валерьевна Ануфриева | Method for solvent refining of nitrate solutions containing rare-earth metals |
| RU2535332C2 (en) * | 2013-02-25 | 2014-12-10 | Открытое акционерное общество "Радиевый институт имени В.Г. Хлопина" | App irradiated fuel processing method |
| RU2576763C1 (en) * | 2014-08-22 | 2016-03-10 | Открытое акционерное общество "Научно-исследовательский институт двигателей" (ОАО "НИИД") | Method for extraction separation of rare-earth metals from nitrate solutions |
| RU2611001C1 (en) * | 2016-03-04 | 2017-02-17 | Акционерное общество "Ведущий проектно-изыскательский и научно-исследовательский институт промышленной технологии" (АО "ВНИПИпромтехнологии") | Extraction separation of scandium and thorium |
| RU2623943C1 (en) * | 2016-02-03 | 2017-06-29 | Акционерное общество "Радиевый институт им. В.Г. Хлопина" | Extraction mixture for the recovery of tpe and ree from high-active rafinat of npp snf processing and the method of its use (versions) |
| RU2626206C1 (en) * | 2016-09-22 | 2017-07-24 | Федеральное государственное бюджетное учреждение науки Институт физической химии и электрохимии им. А.Н. Фрумкина Российской академии наук (ИФХЭ РАН) | Method of extracting scandium from concentrates of rare-earth elements |
| RU2647047C1 (en) * | 2017-05-02 | 2018-03-13 | Акционерное общество "Далур" | Method for scandium oxide production from scandium concentrate |
| RU2669737C1 (en) * | 2018-01-18 | 2018-10-15 | Общество с ограниченной ответственностью "Объединенная Компания РУСАЛ Инженерно-технологический центр" | Method for preparation of scandium oxide from scandium-containing concentrates |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2348728A1 (en) * | 1976-04-21 | 1977-11-18 | Berol Kemi Ab | PROCESS FOR EXTRACTING METAL IONS FROM AN AQUEOUS SOLUTION |
| FR2442797A1 (en) * | 1978-11-28 | 1980-06-27 | Commissariat Energie Atomique | PROCESS FOR THE RECOVERY OF URANIUM PRESENT IN PHOSPHORIC ACID SOLUTIONS |
-
1980
- 1980-07-03 FR FR8014840A patent/FR2486299A1/en not_active Withdrawn
-
1981
- 1981-07-01 EP EP19810401060 patent/EP0043765B1/en not_active Expired
- 1981-07-01 DE DE8181401060T patent/DE3168298D1/en not_active Expired
- 1981-07-02 JP JP56102327A patent/JPS5747729A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2348728A1 (en) * | 1976-04-21 | 1977-11-18 | Berol Kemi Ab | PROCESS FOR EXTRACTING METAL IONS FROM AN AQUEOUS SOLUTION |
| FR2442797A1 (en) * | 1978-11-28 | 1980-06-27 | Commissariat Energie Atomique | PROCESS FOR THE RECOVERY OF URANIUM PRESENT IN PHOSPHORIC ACID SOLUTIONS |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3718338A1 (en) * | 1987-06-01 | 1989-01-05 | Karlsruhe Wiederaufarbeit | METHOD AND DEVICE FOR SOLVENT WASHING IN THE REPROCESSING OF IRRADIATED NUCLEAR FUELS |
| GB2228611A (en) * | 1989-02-27 | 1990-08-29 | British Nuclear Fuels Plc | Removal of thorium from raffinate. |
| GB2228611B (en) * | 1989-02-27 | 1992-08-19 | British Nuclear Fuels Plc | Removal of thorium from raffinate |
| US5510090A (en) * | 1991-12-05 | 1996-04-23 | Commissariat A L'energie Atomique | Process for the selective extraction (III) actinides by means of amides having a nitrogenous heterocyclic substituent |
| GB2305291A (en) * | 1995-09-12 | 1997-04-02 | Doryokuro Kakunenryo | A method of separating trivalent actinides and rare earth elements |
| GB2305291B (en) * | 1995-09-12 | 1999-04-07 | Doryokuro Kakunenryo | A method of seperating trivalent actinides and rare earth elements |
| RU2535332C2 (en) * | 2013-02-25 | 2014-12-10 | Открытое акционерное общество "Радиевый институт имени В.Г. Хлопина" | App irradiated fuel processing method |
| RU2517651C1 (en) * | 2013-05-07 | 2014-05-27 | Александра Валерьевна Ануфриева | Method for solvent refining of nitrate solutions containing rare-earth metals |
| RU2576763C1 (en) * | 2014-08-22 | 2016-03-10 | Открытое акционерное общество "Научно-исследовательский институт двигателей" (ОАО "НИИД") | Method for extraction separation of rare-earth metals from nitrate solutions |
| RU2623943C1 (en) * | 2016-02-03 | 2017-06-29 | Акционерное общество "Радиевый институт им. В.Г. Хлопина" | Extraction mixture for the recovery of tpe and ree from high-active rafinat of npp snf processing and the method of its use (versions) |
| RU2611001C1 (en) * | 2016-03-04 | 2017-02-17 | Акционерное общество "Ведущий проектно-изыскательский и научно-исследовательский институт промышленной технологии" (АО "ВНИПИпромтехнологии") | Extraction separation of scandium and thorium |
| RU2626206C1 (en) * | 2016-09-22 | 2017-07-24 | Федеральное государственное бюджетное учреждение науки Институт физической химии и электрохимии им. А.Н. Фрумкина Российской академии наук (ИФХЭ РАН) | Method of extracting scandium from concentrates of rare-earth elements |
| RU2647047C1 (en) * | 2017-05-02 | 2018-03-13 | Акционерное общество "Далур" | Method for scandium oxide production from scandium concentrate |
| RU2669737C1 (en) * | 2018-01-18 | 2018-10-15 | Общество с ограниченной ответственностью "Объединенная Компания РУСАЛ Инженерно-технологический центр" | Method for preparation of scandium oxide from scandium-containing concentrates |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5747729A (en) | 1982-03-18 |
| EP0043765B1 (en) | 1985-01-16 |
| DE3168298D1 (en) | 1985-02-28 |
| FR2486299A1 (en) | 1982-01-08 |
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