Abstract: The invention involves the separation of actinides and lanthanides by membrane transport by means of a calixarene. To this end, a first aqueous solution containing at least one metal from the group of actinides and lanthanides to be separated is placed in the compartment 3 and a second aqueous re-extraction solution such as a 10−2 mol/L solution of HNO3 is placed in the compartment 5. The membrane 6 is a microporous membrane of which the pores are filled with a liquid organic phase (calixarene and diluent) chosen in order to favour membrane transport of the metal(s) to be separated from compartment 3 to compartment 5.

Abstract: A spent fuel reprocessing method includes at least the formation of an aqueous solution and at least one solvent extraction step. Formohydroxarmic acid is used to reduce any Np(VI) to Np(V) and/or to form a complex with Np(IV). As a result, substantially all the neptunium present is retained in the aqueous phase during solvent extraction.

Abstract: The invention pertains to compounds for binding lanthanide ions and actinide ions. The invention further pertains to compounds for binding radionuclides, and to methods of making radionuclide complexes. Also, the invention pertains to methods of extracting radionuclides. Additionally, the invention pertains to methods of delivering radionuclides to target locations. In one aspect, the invention includes a compound comprising: a) a calix[n]arene group, wherein n is an integer greater than 3, the calix[n]arene group comprising an upper rim and a lower rim; b) at least one ionizable group attached to the lower rim; and c) an ion selected from the group consisting of lanthanide and actinide elements bound to the ionizable group.

Abstract: Trivalent actinides can be separated from trivalent lanthanides in aqueous solutions at H.sup.+ concentrations of 2 mol/l to 0.001 mol/liter by extraction with bis(aryl)dithiophosphinic acid and a synergist such as TBP, TOPO and TBPO in an organic solvent. A high separation efficiency results. The method is applicable to high-level liquid waste from reactors and nuclear-material processing plants.

Abstract: The invention relates to crown calix.vertline.4.vertline.arenes, their preparation process and their use for the selective extraction of cesium and actinides. These crown calixl4larenes comply with the formula: ##STR1## in which R.sub.1 represents a group of formula X(C.sub.2 H.sub.4 X).sub.m and X(C.sub.2 H.sub.4 X).sub.n YX(C.sub.2 H.sub.4 X).sub.n with X=O or N(R.sub.4), m=3, 4, 5 or 6, Y=cycloalkylene or arylene and n=1, 2 or 3. These crown.vertline.4.vertline.arenes, whose benzene nuclei are optionally substituted by alkyl groups, can be used as extractants, e.g. in liquid membrane form, for separating cesium from acid solutions containing sodium in a large quantity compared with the cesium quantity, e.g. irradiated fuel reprocessing plant effluents.

Abstract: A composition for extracting a transition metal which comprises as an active ingredient a cyclic phenol sulfide represented by the following formula (1): ##STR1## wherein X represents a hydrogen atom, a hydrocarbon group, an acyl group, a carboxyalkyl group, or a carbamoylalkyl group; Y represents a hydrocarbon group; Z represents a sulfide group, a sulfinyl group, or a sulfonyl group; and n is an integer of 4 to 8; and a method for extracting a transition metal using the composition

Abstract: The invention relates to novel calixarenes of formula: ##STR1## in which m is equal to 0 or 1, n is an integer from 2 to 8, with 4.ltoreq.n(m+1).ltoreq.8,R.sup.1 and R.sup.2, which can be the same or different, are alkyl or O-nitrophenoxyalkyl groups andR.sup.3 and R.sup.4, which can be the same or different, are alkyl or aryl groups.The calixarenes can be used for extracting actinides and lanthanides from aqueous solutions from spent fuel reprocessing.

Abstract: The present invention relates to a process for the selective separation of actinides (III) and lanthanides (III) from a reaction medium containing them. More specifically, the invention permits a selective extraction of actinides (III) by using an aqueous reaction medium containing TcO.sub.4.sup.- pertechnetate ions. The preferred extracting agents are chosen from among picolinamides and their derivatives. A particular use of the process is in the separation of actinides (III) from high activity raffinates produced during the reprocessing of nuclear fuels according to the solvent-based extraction process known as the PUREX process.

Abstract: A process for treating composite materials comprising metals and having significant radioactivity for separation into concentrated individual products is provided. The process of the invention recovers valuable metals and semi-metal elements including rare earth, transition metal, radioactive elements, and compounds and composites thereof as commercially viable products while isolating the radioactive components. They key components in the composite material which are desired to be recovered are tantalum, niobium, and scandium due to their high commercial values and significant quantities. The process further includes the capability to recover uranium, thorium, rare earth, and zirconium products. Generally, the process consists of an initial sulfate roast followed by a series of hydrometallurgical unit operations designed to separate and purify the desired components into commercially usable products, such as tantalum and/or niobium in the form of metal oxides, M.sub.2 O.sub.

Abstract: A process of selectively separating a target metal contained in an aqueous solution by contacting the aqueous solution containing a target metal with an aqueous solution including a water-soluble polymer capable of binding with the target metal for sufficient time whereby a water-soluble polymer-target metal complex is formed, and, separating the solution including the water-soluble polymer-target metal complex from the solution is disclosed.

Abstract: A method of reducing the entrainment of aqueous mineral acid solutions in organic extractants used in the solvent extraction of metals from the aqueous fluid is disclosed. The method comprises adding an effective, entrainment prevention amount of a water soluble cationic polymer having a molecular weight of from about 10,000 to about 500,000 to a metal rich aqueous mineral acid solution, immediately prior to, or during mixing with a metal poor organic extractant, and then recovering a metal poor aqueous mineral acid phase, and a metal rich organic extractant phase having a reduced level of entrainment of the aqueous mineral acid solution. In a preferred embodiment the metal is copper, and the polymer is poly(diallyldimethylammonium) chloride.

Abstract: Thermodynamically-unstable complexing agents which are diphosphonic acids and diphosphonic acid derivatives (or sulphur containing analogs), like carboxyhydroxymethanediphosphonic acid and vinylidene-1,1-diphosphonic acid, are capable of complexing with metal ions, and especially metal ions in the II, III, IV, V and VI oxidation states, to form stable, water-soluble metal ion complexes in moderately alkaline to highly-acidic media. However, the complexing agents can be decomposed, under mild conditions, into non-organic compounds which, for many purposes are environmentally-nondamaging compounds thereby degrading the complex and releasing the metal ion for disposal or recovery. Uses for such complexing agents as well as methods for their manufacture are also described.

Abstract: The invention relates to bis-crown calix[4]arenes, their preparation process and their use for the selective extraction of cesium and actinides. Bis-crown calix[4]arenes are in accordance with the formula: ##STR1## in which R.sup.1 and R.sup.2 respectively represent X(C.sub.2 H.sub.4 X).sub.m and X(C.sub.2 H.sub.4 X).sub.n with X.dbd.O, NH and/or N(CH.sub.3), m and n=3, 4, 5 or 6, or X (C.sub.2 H.sub.4 X).sub.p/2 XY(C.sub.2 H.sub.4 X).sub.p/2 with p=2 or 4 and Y=cycloalkylene or arylene. These bis-crown calix[4]arenes, whose benzene nuclei are optionally substituted by alkyl groups, can be used as an extracant, e.g. in the form of a liquid membrane, for separating cesium from acid solutions containing sodium in a large quantity compared with the cesium quantity, e.g. effluents of irradiated fuel reprocessing plants.

Abstract: The improved method of separating transplutonium elements from lanthanides comprises the steps of adding an organic solvent containing an N-heterocyclic compound and a hydrophobic anion to an acidic aqueous solution containing both a lanthanide and a transplutonium element (TPE) and then extracting the transplutonium element into the organic phase. The method is capable of selective extraction of TPE without producing liquid wastes, is adapted to the continuous treatment process and yet can be implemented using inexpensive chemicals.

Abstract: The invention relates to a process for the selective extraction of (III) actinides by means of amides having a nitrogenous heterocyclic substituent of formula: ##STR1## in which R.sup.1 is an alkyl or alkoxy group or a hydrogen atom, R.sup.2 and R.sup.3, which can be the same or different, represent a hydrogen atom, an alkyl or an alkoxy group and R.sup.4 is a hydrogen atom or a group of formula: ##STR2## in which R.sup.5 and R.sup.6, which can be the same or different, represent a hydrogen atom or an alkyl or alkoxy group. This process makes it possible to separate (III) actinides from (III) lanthanides.

Abstract: A process for selectively removing metal values which may include catalytic values from a mixture containing same, wherein a magnetic particle is contacted with a liquid solvent which selectively dissolves the metal values to absorb the liquid solvent onto the magnetic particle. Thereafter the solvent-containing magnetic particles are contacted with a mixture containing the heavy metal values to transfer metal values into the solvent carried by the magnetic particles, and then magnetically separating the magnetic particles. Ion exchange resins may be used for selective solvents.

Abstract: A controlled multi-stage process for the stripping of uranium includes the introduction at one end of a solvent extraction device a uranium loaded organic solution. A concentrated stripping acidic aqueous solution is introduced at the other end of the solvent extraction device so that the aqueous solution and the organic solution are contacted counter-currently in the solvent extraction device at a temperature not substantially exceeding 35.degree. C.

Abstract: An organic extracting solution comprised of a bis(acylpyrazolone or a substituted bis(acylpyrazolone) and an extraction method useful for separating certain elements of the actinide series of the periodic table having a valence of four from one other, and also from one or more of the substances in a group consisting of hexavalent actinides, trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals and also from one or more of the substances in a group consisting of hexavalent actinides, trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals and also useful for separating hexavalent actinides from one or more of the substances in a group consisting of trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals.

Abstract: Thermodynamically-unstable complexing agents which are diphosphonic acids and diphosphonic acid derivatives (or sulphur containing analogs), like carboxyhydroxymethanediphosphonic acid and vinylidene-1,1-diphosphonic acid, are capable of complexing with metal ions, and especially metal ions in the II, III, IV, V and VI oxidation states, to form stable, water-soluble metal ion complexes in moderately alkaline to highly-acidic media. However, the complexing agents can be decomposed, under mild conditions, into non-organic compounds which, for many purposes are environmentally-nondamaging compounds thereby degrading the complex and releasing the metal ion for disposal or recovery. Uses for such complexing agents as well as methods for their manufacture are also described.

Abstract: The invention relates to a process for the separation of actinides from lanthanides by the selective extraction of the actinides in an organic solvent incorporating a propane diamide.This process consists of adding to the aqueous nitric solution containing the actinides and lanthanides a thiocyanate, e.g. ammonium thiocyanate, followed by the contacting of said solution with an organic solvent incorporating at least one propane diamide, e.g. 2-tetradecyl-N,N'-dimethyl-N,N'-dibutyl-propane diamide and optionally a quaternary ammonium salt such as trilauryl methyl ammonium (TMA) thiocyanate or a mixture of quaternary ammonium thiocyanates.This leads to distribution coefficients D.sub.M for the actinides (Am) and the lanthanides (Eu, Ce) making it possible to achieve high actinide/lanthanide separation factors.

Abstract: The invention relates to a process for separating iron and/or zirconium from the actinides and/or lanthanides present in an aqueous acid solution by means of a propane diamide.According to the invention, use is made of a pentasubstituted propane diamide of formula: ##STR1## in which R.sup.1, R.sup.2 and R.sup.3, which can be the same or different, are alkyl radicals, which can have 1 or 2 oxygen atoms in their chain.To maintain the iron in aqueous solution, a choice is made of an appropriate propane diamide of formula (I) with R.sup.3 representing a C.sub.12 to C.sub.25 alkyl in order to have different extraction kinetics between Fe and the actinides or lanthanides, or an additive is added to the aqueous solution, e.g. oxalic acid or sodium nitrate.

Abstract: Metal values (especially uranium values) are extracted from aqueous solutions of metal oxyions in the absence of halogen ion using an imidazole of defined formula. Especially preferred extractants are 1-alkyl imidazoles and benzimidazoles having from 7 to 25 carbon atoms in the alkyl group.

Abstract: The invention relates to a process for the extraction of uranium (VI) and/or plutonium (IV) present in an acid aqueous solution by means of a mixture of N,N-dialkyl amides usable for the reprocessing of irradiated nuclear fuels.In (50 or 52) contacting takes place between an aqueous solution containing U(VI) and Pu(IV) and an organic solvent incorporating a mixture of two N,N-dialkyl amides, e.g. of formulas: ##STR1## and then by separating (in 50 or 52) the organic solvent containing either U(VI) and Pu(IV), or U(VI).

Abstract: A process for removing metal salts from an H.sub.4 EDTA precipitate by esterification with an esterification reagent to produce an esterification mixture comprising a solid metal salt an EDTA ester and thereafter separating the solid metal salt from the esterification mixture.

Abstract: A metallurgical processing system for economically recovering metal values, such as columbium, tantalum, thorium, and uranium from dilute source solids, such as digestion sludges, by a series of steps including:1) slurrying the source solids with dilute hydrofluoric acid to produce a solid phase and a liquid phase containing dissolved tantalum and columbium, then extracting tantalum and/or columbium from the liquid phase by means of a liquid ion-exchange process and then, additionally;2) roasting the solid phase with sulfuric acid to recover and recycle hydrofluoric acid, leaching the roasted solids with dilute sulfuric acid to produce a disposable solid phase and a liquid phase containing thorium and uranium, and extracting thorium and uranium from the liquid phase by means of a liquid-liquid amine extraction process.

Abstract: The invention relates to a process for the reextraction in aqueous solution of the plutonium present in an organic solvent, more particularly usable for uranium-plutonium separation.According to this process the organic solvent is contacted with an acid aqueous solution of uranous salt, e.g. uranous nitrate, and hydroxylamine salt, e.g. hydroxylamine nitrate. Under these conditions, the uranous nitrate acts as a reducing agent for plutonium at valency (III and the hydroxylamine nitrate, which is also a plutonium reducing, agent, stabilizes Pu(III) and U(IV) in aqueous phase.Performances comparable to those of the U(IV)-hydrazone nitrate system are obtained without forming prejudicial hydrazine nitrate decomposition products. (FIG. 2).

Abstract: The invention is directed to a method of washing a solvent in the reprocessing of irradiated nuclear fuel. The solvent is washed with an aqueous solution in a mixer-settler having at least one stage which includes a mixing chamber and a settling chamber. The pH of the dispersion in the mixing chamber is measured and an amount of washing solution is added which influences the pH toward the desired operational value. An apparatus for carrying out the method is also disclosed.

Abstract: Novel organic tertiary phosphine oxides for example, bidentate organophosphorus actinide extractants, such as the carbamoylmethylphosphine oxides (CMPO's) are disclosed, such compounds can be prepared (e.g., in 85% or better yield and purity) by a process involving phase transfer catalysis, under conditions where degradive hydrolysis of the products or reactants is substantially avoided. For example, tertiary carbamoylmethylphosphine oxides which are useful as extractants for transplutonium elements are disclosed and can be prepared by reaction of the corresponding secondary phosphine oxides with 2-substituted acetamides (wherever the substituent is a good leaving group, e.g., chlorine) in a two-phase system containing a high concentration of an aqueous base (preferably sodium hydroxide) and a suitable phase transfer catalyst, e.g., tetralkylammonium chlorides.

Abstract: This is an improvement to a process for making zirconium metal from uranium-containing zircon ore. The process being improved is of the type which utilizes a fluidized bed carbochlorination process of the zircon ore in which uranium chloride is volatilized at the ore chlorinator temperature and follows as an impurity in the zirconium-hafnium tetrachloride stream, and in which removal of iron impurities is performed by liquid-liquid iron extraction with methyl isobutyl ketone, and the zirconium-hafnium stream is further processed by a separations step to reduce the hafnium content to low levels by liquid-liquid hafnium extraction. The improvement comprises adding 1-9 weight percent quaternary ammonium halide (e.g. tricaprylmethylammonium chloride) to the methyl isobutyl ketone in the liquid-liquid iron extraction.

Abstract: An organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

Abstract: A method and apparatus for the quantitative recover of actinide values from biological and environmental sample by passing appropriately prepared samples in a mineral acid solution through a separation column of a dialkyl(phenyl)-N,N-dialylcarbamoylmethylphosphine oxide dissolved in tri-n-butyl phosphate on an inert substrate which selectively extracts the actinide values. The actinide values can be eluted either as a group or individually and their presence quantitatively detected by alpha counting.

Abstract: The invention relates to a process for the extraction of uranium (VI) and/or plutonium (IV) present in an aqueous solution by means of N,N-dialkylamides.These N,N-dialkylamides are in accordance with formula: ##STR1## in which R.sup.1 is a straight or branched alkyl radical with 2 to 12 carbon atoms, R.sup.2 and R.sup.4, which can be the same or different, are straight or branched alkyl radicals with 2 to 6 carbon atoms, R.sup.3 and R.sup.5, which can be the same or different, are straight or branched alkyl radicals with 1 to 6 carbon atoms and a and b, which can be the same or different, are integers between 1 and 6.For example, it is possible to use N,N-di-(2-ethyl hexyl)-2,2-dimethyl butyramide, N,N-di-(2-ethyl hexyl)-hexanamide or N,N-di-(2-ethyl hexyl)-dodecanamide for simultaneously extracting uranium and plutonium, or for separating the uranium from the plutonium without reducing the latter.

Abstract: The invention relates to novel extracting agents and novel propane diamides, their use for the recovery of actinides and/or lanthanides and their preparation process. These extracting agents are constituted by propane diamides of formula: ##STR1## For example, the extracting agent can be 2-hexyl-N,N'-dimethyl-N,N'-dibutyl-propane diamide or 2-ethoxyethyl-N,N'-dimethyl-N,N'-dibutyl-propane diamide. They are more particularly used for the recovery of actinides and/or lanthanides present in the trivalent state in an acid aqueous solution, particularly in a nitric solution.

Abstract: The invention relates to a process for the recovery of molybdenum-99 from an irradiated uranium alloy target.This process comprises the following stages:(a) dissolving the irradiated uranium alloy target in sulphuric acid,(b) separating the iodine and tellurium present in the thus obtained solution,(c) oxidizing the molybdenum-99 present in the Mo (VI) solution, and(d) extracting the thus oxidized molybdenum-99 with a hydroxamic acid of formula: ##STR1## in which R is a radical chosen from the group including straight or branched-chain alkyl radicals, the phenyl radical, phenyl radicals substituted by at least one alkyl radical, arylalkyl radicals and the cyclohexyl radical and R' is a hydrogen atom or an alkyl radical.The hydroxamic acid can be tri-n-butylacetohydroxamic acid and the molybdenum recovered can be used in a technetium generator for medical purposes.

Abstract: Process for the removal of plutonium polymer and ionic actinides from aqueous solutions by absorption onto a solid extractant loaded on a solid inert support such as polystyrenedivinylbenzene. The absorbed actinides can then be recovered by incineration, by stripping with organic solvents, or by acid digestion. Preferred solid extractants are trioctylphosphine oxide and octylphenyl-N,N-diisobutylcarbamoylmethylphosphine oxide and the like.

Abstract: The invention concerns the recovery of heavy metals from concentrated solutions.The process comprises complexing the metals with an organophosphorous complexing agent and recovering the metallic complex by sedimentation, filtration, flotation and the like.The process can be used to recover uranium and rare earths from phosphoric acid solutions.

Abstract: A process for the purification by selective separation of uranium and/or molybdenum from zirconium and/or hafnium among other impurities contained in an amino organic phase by bringing them together with an aqueous sulphuric re-extraction solution, characterized in that, with a view to increasing the separation factor of the zirconium and/or hafnium on the one hand and the uranium and/or molbydenum on the other hand, the aqueous sulphuric re-extraction solution contains at least one alkali or equivalent sulphate.

Abstract: Uranium is stably stripped from an organic solvent containing a uranium-laden, amine-based extracting agent into an aqueous ammonium sulfate solution with a very high stripping efficiency in an emulsion-formable high pH range by mixing the organic solvent, the aqueous ammonium sulfate solution and an alkali as a pH-controlling agent, thereby forming a mixture having a pH of 4.5 to 6.0 and a temperature of 15.degree. to 50.degree. C., preferably 25.degree. to 40.degree. C., and subjecting the resulting mixture to an action of centrifugal force of 850 G or higher, thereby separating it into an organic solvent freed from the uranium and an aqueous ammonium sulfate solution containing the uranium.

Abstract: An apparatus is provided that is useful for effecting liquid-liquid extraction by contacting a first liquid medium with a substantially immiscible heavier second liquid medium. Each mixer-settler unit includes a vertically extending settling tank having a top and a bottom with an outlet for the first liquid medium near the top and an outlet for the second liquid medium near the bottom. An elongated extraction column extends generally vertically upwardly through the settling tank bottom. The extraction column is open at its top with the top of the extraction column below the top of the settling tank. A diverter surrounds and extends downwardly along a top portion of the extraction column. The diverter has a closed top and an open bottom with an annulus being between the diverter and the portion the extraction column surrounded by the diverter. The dispersion flows from the pumping and mixing means upwardly through the extraction column and out its top.

Abstract: A process for the recovery of actinide and lanthanide values from aqueous solutions with an extraction solution containing an organic extractant having the formula: ##STR1## where .phi. is phenyl, R.sup.1 is a straight or branched alkyl or alkoxyalkyl containing from 6 to 12 carbon atoms and R.sup.2 is an alkyl containing from 3 to 6 carbon atoms and phase modifiers in a water-immiscible hydrocarbon diluent. The addition of the extractant to the Purex process extractant, tri-n-butylphosphate in normal paraffin hydrocarbon diluent, will permit the extraction of multivalent lanthanide and actinide values from 0.1 to 12.0 molar acid solutions.

Abstract: This invention relates to a process of recovering trivalent actinides, trivalent lanthanides or mixtures thereof from an aqueous acid solution by contacting the aqueous solution with an organic solution containing the diamides of the formula: ##STR1## where R is C.sub.2 -C.sub.10 alkyl. This process affords a good extraction efficiency level for the recovery of lanthanides and actinides, both of which are present in the trivalent state, or mixtures thereof, from installations for the reprocessing of irradiated nuclear fuels.

Abstract: A process for the recovery of actinide and lanthanide values from aqueous acidic solutions with an organic extractant having the formula: ##STR1## where .phi. is phenyl, R.sup.1 is a straight or branched alkyl or alkoxyalkyl containing from 6 to 12 carbon atoms and R.sup.2 is an alkyl containing from 3 to 6 carbon atoms. The process is suitable for the separation of actinide and lanthanide values from fission product values found together in high level nuclear reprocessing waste solutions.

Abstract: A process for the separation of the actinides and lanthanides present in the trivalent state in an acid aqueous solution, wherein the actinides present in such aqueous solution are extracted selectively in an organic solvent by bringing the solution into contact with an organic solvent comprising a first extracting agent formed by an organic bonding agent having an electron-donor nitrogen atom and a second extracting agent formed by an acid organosoluble organic compound able to exchange its H.sup.+ ions for metal ions or by metallic salt of such compound.Application to the nuclear industry, inter alia in the field of the treatment of aqueous effluents containing lanthanides and actinides, such an transuranic elements.

Abstract: A method for separating an ionic substance from a liquid medium, which comprises including a metal ion, a metal oxide ion, a metal complex ion, ammonium compounds, etc. dissolved or dispersed in the liquid medium by using a fluorine containing compound of the following formula[{Rf-(A).sub.a -Y}(X).sub.b ].sub.n (Z).sub.ccontaining a fluoroalkyl group (Rf) having 3 to 20 carbon atoms and a group (Y) having affinity for the ionic substances. A composition for trapping ionic substances, comprising the aforesaid fluorine-containing compound as a main ingredient. The invention can be advantageously applied to the recovery of useful metals from ocean waters.

Abstract: A recovery process of uranium comprising:(1) extracting uranium ions with an organic solvent containing one or more compounds selected from the group consisting of alkyl phosphoric acid, alkyl-aryl phosphoric acid, alkyl dithio phosphoric acid, aryl dithio phosphoric acid, neutral phosphoric acid ester and alkyl amine together with a petroleum hydrocarbon as a diluent; and(2) stripping the uranium ions in the resultant organic solvent from the step (1) to an aqueous phase with contact of an aqueous solution containing one or more compounds selected from the groups of NH.sub.4 F, NH.sub.4 HF.sub.2, KF or KHF.sub.2.

Abstract: A nuclear fuel material green body of density from about 30 to 70% of theoretical density having tensile strenght and plasticity adequate to maintain the integrity of the body during processing leading to ultimate sintered condition is produced by adding an amine carbonate or carbamate or mixture thereof to a particulate mass of the nuclear fuel material under conditions resulting in reaction with the amine compound to form a water-soluble compound effective as a binder for the particulate material.

Abstract: A process for the recovery of uranium values from uranium-containing material which also contains iron, arsenic and siliceous matter, includes leaching the uranium-containing material in aqueous sulphuric acid solution under conditions to provide dissolved iron present in the resultant leach solution as predominantly ferrous iron rather than ferric iron and/or to provide a sulphuric acid concentration in the leach solution sufficiently high to substantially prevent the precipitation of arsenates. Uranium values are recovered from the leach solution by solvent extraction agent which has little affinity for arsenic.

Abstract: The invention concerns a method for the liquid/liquid extraction of uranium from phosphoric acid with the aid of alkylamine polyphosphate and/or alkylamine metaphosphate compounds, dissolved in organic solvents insoluble in water. The uraniferous phosphoric acid is brought into contact with an organic phase compound of a long-chain alkylamine polyphosphate and/or alkylamine metaphosphate compound and an organic solvent, the alkylamine in the alkyl residue containing 8 to 30, preferably 8 to 18 C-atoms corresponding to the formula ##STR1## wherein R.sub.1 and R.sub.2 denote hydrogen or alkyl radicals and R.sub.3 denotes an alkyl radical, the polyphosphate and/or metaphosphate residue having 2 to 10,000 P-atoms per molecule and being of the straight-chain and/or linked-chain or cyclic chain type. The uranium is transferred from the aqueous into the organic phase from which the uranium is re-extracted in the known way.

Abstract: The invention concerns a method for the liquid/liquid extraction of uranium from phosphoric acid with the aid of alkylamine polyphosphate and/or alkylamine metaphosphate compounds, dissolved in organic solvents insoluble in water, in the presence of Fe.sup.II ions.The uraniferous phosphoric acid is brought into contact with an organic phase. The organic phase is composed of a long-chain alkylamine polyphosphate and/or alkylamine metaphosphate compound and an organic solvent, the alkylamine in the alkyl residue containing 8 to 30, preferably 8 to 18 C-atoms corresponding to the formula ##STR1## R.sub.1 and R.sub.2 denoting hydrogen or alkyl radicals and R.sub.3 alkyl radicals, the polyphosphate and/or metaphosphate residue having 2 to 10,000 P-Atoms per molecule and being of the straight-chain and/or link-chain or cyclic type. The uranium is transferred from the aqueous into the organic phase from which the uranium is reextracted in the know way.

Abstract: The present invention relates to a process for the selective separation of uranium and molybdenum which are contained in an extract resulting from an amino solvent liquid-liquid extraction of a solution resulting from an attack on a molybdo-uraniferous ore by means of sulphuric acid, and which comprises re-extraction of the uranium in the presence of an oxidizing agent by means of an acid solution of an alkali metal chloride, followed by re-extraction of the molybdenum by means of an alkali metal carbonate solution. This process is characterized by using an oxidizing agent such as hydrogen peroxide, a small amount of which is added to the acid alkali metal chloride solution before the latter is brought into contact with the extract. This makes it possible to achieve selective separation of the uranium and molybdenum.