Abstract:
L'invention concerne un procédé de séparation du fer à partir d'une phase organique liquide initiale contenant de l'uranium, et du fer, dans lequel on met en contact la phase organique liquide initiale avec une solution aqueuse dite solution aqueuse de déferrisation, moyennant quoi le fer passe dans la solution aqueuse pour former une phase aqueuse liquide finale, et l'uranium reste dans la phase organique liquide initiale pour former une phase organique liquide finale dite phase organique déferrisée; ledit procédé étant caractérisé en ce que la solution aqueuse de déferrisation contient un acide inorganique et de l'uranium, et ne contient pas de fer. L'invention concerne, en outre, un procédé d'extraction de l'uranium à partir d'une solution aqueuse d'un acide inorganique contenant de l'uranium et du fer.
Abstract:
L'invention se rapporte à de nouveaux composés qui sont utiles comme ligands des actinides et qui répondent à la formule générale (I) ci-après : L' invention a également pour objet un procédé de synthèse de ces composés ainsi que leurs utilisations.
Abstract:
The invention relates to a method for separating trivalent actinides from at least trivalent lanthanides, whereby said trivalent actinides are extracted from an aqueous solution containing a H concentration of 0.01 to 2 mol/1 by using an (aryl)dithiophosphonic acid of the general formula (4) = R1R2PS(SH), in which R1 = phenyl or naphthyl, R2 = phenyl or naphthyl, as well as rests of R1 and R2 substituted by methyl, ethyl, propyl, isopropyl, cyano, nitro or halogenyl, with addition of trioctylphosphate, tris-(2-propypentyl)-phosphate or tris-(2-ethylhexyl)-phosphate as synergist. The use of synergists according to the invention allows for a more selective extraction. In a more advantageous formulation, the aromatic solvent used is at least one component from the toluol, xylol, tert.-(butyl)-benzol, bis-(tert.-butyl)-benzol, bis-(tert.-butyl)-benzol, tris-(tert.-butyl)-benzol, bis-isopropylbenzol and tri-isopropylbenzol, resulting in increased selectivity An(III) and distribution coefficient DAn(III).
Abstract:
Methods and agents for extracting cesium and strontium ions from aqueous solutions, including aqueous fission product waste solutions, are disclosed using substituted metal dicarbollide ions containing one or more chemical groups that increase solubility of the substituted metal dicarbollide ion in non-nitraded, non-chlorinated solvents, or using metal dicarbollide ion-substituted silicones.
Abstract:
In the field of metallurgy, specifically processes for recovering uranium from wet process phosphoric acid solution derived from the acidulation of uraniferous phosphate ores, problems of imbalance of iron exchange agents, contamination of recycled phosphoric acid with process organics and oxidizing agents, and loss and contamination of uranium product, are solved by removing organics from the raffinate after iron exchange conversion of uranium to uranous form and recovery thereof by ion exchange, and returning organics to the circuit to balance mono and disubstituted ester ion exchange agents; then oxidatively stripping uranium from the agent using hydrogen peroxide; then after ion exchange recovery of uranyl and scrubbing, stripping with sodium carbonate and acidifying the strip solution and using some of it for said scrubbing; regenerating the sodium loaded agent and recycling it to the uranous recovery step. Economic recovery of uranium as a by-product of phosphate fertilizer production is effected.
Abstract:
L'invention se rapporte à de nouveaux composés qui répondent à la formule générale (I): Formula (I), dans laquelle: m = 0, 1 ou 2; R 1 et R 2 = un groupe hydrocarboné, linéaire ou ramifié, en C 6 à C 12 ; R 3 = H, un groupe hydrocarboné, linéaire ou ramifié, en C 1 à C 12 , comprenant éventuellement un ou plusieurs hétéroatomes; un groupe hydrocarboné monocyclique en C 3 à C 8 , comprenant éventuellement un ou plusieurs hétéroatomes, ou un groupe (hétéro)aryle monocyclique; ou bien R 2 et R 3 forment ensemble un groupe -(CH 2 ) n - avec n = de 1 à 4; R 4 = un groupe hydrocarboné, linéaire ou ramifié, en C 2 à C 8 , ou un groupe aromatique monocyclique; R 5 = H ou un groupe hydrocarboné, linéaire ou ramifié, en C 1 à C 12 . L'invention se rapporte également à des procédés de synthèse de ces composés ainsi qu'à l'utilisation desdits composés comme ligands de l'uranium(VI) et, en particulier pour extraire l'uranium(VI) d'une solution aqueuse d'acide phosphorique.
Abstract:
The invention discloses a metal extraction process and arrangement therefore which includes a microfiltration plant for removing suspended solids from a pregnant leach solution including a metal to form a first retentate including the solids and a first permeate including the metal; a nanofiltration plant for recovering acid from the first permeate to form a second retentate including the metal and a second permeate; a membrane solvent extraction unit for extracting the metal from the second permeate to form a third retentate being an organic phase including the metal and third permeate being an aqueous phase; a membrane acid strip unit for stripping the third retentate to form a fourth retentate and a fourth permeate including the metal; an acid recovering unit for recovering acid from the fourth permeate to form a fifth permeate and a fifth retentate including the metal which is treated in a metal recovering unit.
Abstract:
L' invention se rapporte à un procédé permettant de purifier l'uranium d'un concentré d'uranium naturel. Ce procédé comprend : a) l'extraction de l'uranium présent sous forme de nitrate d' uranyle dans une phase aqueuse A1 résultant de la dissolution du concentré d'uranium naturel dans de l'acide nitrique, au moyen d'une phase organique qui contient un extractant dans un diluant organique; b) le lavage de la phase organique obtenue à l'issue de l'étape a), avec une phase aqueuse A2; et c) la désextraction du nitrate d' uranyle de la phase organique obtenue à l'issue de l'étape b), par circulation de cette phase organique dans un appareil, à contre-courant d'une phase aqueuse A3; et est caractérisé en ce que l' extractant est un N, N -dialkylamide et en ce que le rapport entre les débits auxquels circulent la phase organique obtenue à l'issue de l'étape b) et la phase aqueuse A3 dans l'appareil où se déroule l'étape c) est supérieur à 1. Applications : raffinage des concentrés d'uranium naturel produits par les mines d'uranium.
Abstract:
An apparatus and method to remove uranium from a body of material wherein the method includes the steps of depositing the body of solid material in an ultrasonic extractor and depositing an amount of acid in the ultrasonic extractor. The method also provides for the steps of heating a jacket of the ultrasonic extractor, transporting the body of solid material in the ultrasonic extractor and the amount of acid such that the body of solid material and the acid contact each other inside the heated ultrasonic extractor while the ultrasonic extractor provides ultrasonic energy to both the body of solid material and the amount of acid, wherein the amount of acid strips uranium from the body of solid material. The method further provides for collecting the amount of acid and the body of solid material in the ultrasonic extractor in different positions, transporting the amount of acid with the stripped uranium to an extraction mixer settler, and settling uranium product from the extraction mixer settler.
Abstract:
There is described a method for treating or reprocessing spent nuclear fuel in which an organic phase is contacted with an aqueous nitric acid phase containing zirconium, technetium and at least one extractable actinide metal such that the at least one extractable metal is extracted into the organic phase characterised in that the zirconium and technetium predominantly remain in the aqueous phase. There is also described a Purex reprocessing plant, and the use of such a plant in simultaneously separating both zirconium and technetium along with other fission products from uranium and plutonium.