Abstract: Zirconium- and uranium-containing hydrocarbon-amine solutions are treated for separation of zirconium and uranium by means of a process comprising: (1) selective stripping of zirconium with an aqueous chloride solution, and (2) scrubbing the resulting aqueous solution with chloride-loaded hydrocarbon-amine solution to selectively remove uranium, thereby yielding an aqueous zirconium solution of low uranium content.

Abstract: Uranium ores, concentrates, calcines or tailings are processed to remove radium and thorium as well as uranium. Selected ores, concentrates or tailings, or if more appropriate, chlorination calcines thereof, are leached by selected aqueous chlorine-containing media (preferably in two stages) until uranium, radium and thorium are substantially all dissolved, with the insoluble residual solids being suitable for disposal. The leach solution is treated to recover sequentially uranium, usually thorium, and radium by selected techniques. The radium recovered can be disposed of in any environmentally-acceptable manner. The amount of iron in the residual leach liquor should be controlled to avoid iron build-up, with the barren leach solution being suitable for recycle.

Abstract: The invention concerns a process for the recovery of the uranium contained in an impure phosphoric acid. The impure acid is treated with an organic phase capable of extracting U (VI), and the resultant organic phase is then re-extracted with an aqueous solution containing complexing acid and an oxidizing-reducing agent in the reduced state, said oxidizing-reducing agent being capable of reducing U.sup.+6 to U.sup.+4 in said aqueous solution. The resultant aqueous phase is then subjected to electrochemical oxidation, followed by extraction with a second organic phase from which the uranium is recovered, the depleted aqueous solution being recycled to the re-extraction after electrochemical reduction, with the process comprising two organic phase cycles and a cycle of a complexing aqueous solution.The process is of particular interest when applied to the recovery and concentration of uranium contained in a wet process phosphoric acid.

Abstract: A process for separating by means of an organic agent the uranium and the molybdenum contained in an aqueous liquor originating from a sulphuric attack of an urano-molybdeniferous ore which involves placing the said attacking liquor in contact with an organic extraction solution containing at least one tertiary or secondary amine in an (amine)/(Mo) molar ratio of up to 0.8, separating the molybdenum-charged organic phase from the uranium-rich aqueous phase, treating the organic phase with an aqueous liquor containing at least one mineral agent in the form of alkaline and ammonium hydroxide and/or carbonates to form an aqueous solution which is concentrated in molybdate.

Abstract: The invention relates to a process for the recovery and the concentration of uranium (VI) contained in an organic phase. The organic phase is treated continuously in a contact zone with an aqueous solution containing an oxidizing-reducing agent in the reduced state, said oxidizing-reducing agent being capable of reducing U.sup.+6 to U.sup.+4 in said aqueous solution. The aqueous solution employed in the process issues in part or in its entirety from the cathodic compartment of an electrolytic separation cell, which is under a direct current potential, and the aqueous phase issuing from the contact zone feeds in part or in its entirety the anodic compartment of the electrolytic cell. The process is of particular interest when applied to the recovery and concentration of uranium contained in a wet process phosphoric acid.

Abstract: A process to restore solvent after the stripping step in recovering uranium from phosphoric acid, comprises passing stripped, water-immiscible organic extraction solvent, containing contaminants and having a lowered uranium extraction coefficient value, through a water scrub, to scrub contaminants from the organic solvent and raise its uranium extraction coefficient. The scrubbed solvent is then passed back to the extractor and the contaminated water is passed into at least one purification means and then back to the scrubber.

Abstract: A method of stabilizing wet process phosphoric acid containing acid soluble impurities preparatory to solvent extraction for the recovery of valuable minerals. The acid is introduced into a vessel containing crystal seed bed of the impurities. A portion of the acid then is withdrawn and concentrated to effect supersaturation of the impurities contained therein. The supersaturated acid is returned to the vessel to mix with the remaining solution and cause additional impurities to precipitate. Thereafter, a portion of the solution, containing precipitated impurities, is withdrawn and introduced into a separator. In the separator, the solution is separated into an essentially solids-free stream containing unprecipitated soluble impurities and a solids-containing stream.

Abstract: Process for the separation of americium from curium contained in an aqueous nitric solution, wherein the initial solution undergoes oxidation at ambient temperature in the presence of phosphoric acid or phosphate ions at a concentration at the most equal to 0.1 mol per liter in such a way as to pass the americium at valency VI, the thus treated solution is brought into contact with a slightly reducing organic solvent having a high affinity for americium at valency VI in such a way as to extract the americium in the organic phase, the organic phase containing the americium at valency VI is then washed, followed by the re-extraction of the americium in the organic phase by means of an aqueous solution.

Abstract: Certain metals, and especially uranium, are recovered from an organic solvent by stripping with an aqueous solution containing polymeric phosphates under conditions in which the polymeric phosphate does not quickly hydrolize and metal preferentially dissolves in the aqueous solution. The metal may then be recovered from the aqueous solution by hydrolizing the polymeric phosphates and either precipitating the metal or reextracting the metal at higher concentrations with an organic solvent containing extractants.

Abstract: The invention described herein relates to a method for improving the acid leachability of aluminum and other metal values found in fly ash which comprises sintering the fly ash, prior to acid leaching, with a calcium sulfate-containing composition at a temperature at which the calcium sulfate is retained in said composition during sintering and for a time sufficient to quantitatively convert the aluminum in said fly ash into an acid-leachable form.

Abstract: A process and apparatus are described for stripping uranium values from a uranium-loaded organic extractant phase containing, usually, a tertiary amine capable of forming organic-soluble uranium complexes. The sulphate-containing aqueous strip liquor is fed in co-current with the extractant phase to be stripped through a number of mixing stages in series connected one to another without intermediate settling stages and finally to a final settling stage. A "primary" dispersion is maintained in each mixing stage and controlled stepwise pH adjustment of the mixing stages is effected by metered addition of a base, such as ammonia.

Abstract: A process for partitioning and recovering actinide values from acidic waste solutions resulting from reprocessing of irradiated nuclear fuels by adding hydroxylammonium nitrate and hydrazine to the waste solution to adjust the valence of the neptunium and plutonium values in the solution to the +4 oxidation state, thus forming a feed solution and contacting the feed solution with an extractant of dihexoxyethyl phosphoric acid in an organic diluent whereby the actinide values, most of the rare earth values and some fission product values are taken up by the extractant. Separation is achieved by contacting the loaded extractant with two aqueous strip solutions, a nitric acid solution to selectively strip the americium, curium and rare earth values and an oxalate solution of tetramethylammonium hydrogen oxalate and oxalic acid or trimethylammonium hydrogen oxalate to selectively strip the neptunium, plutonium and fission product values.

Abstract: A method of resolving water-in-oil emulsions resulting from the organic solvent extraction of uranium from aqueous leach liquors which comprises treating said emulsions with at least 20 parts per million of a water-soluble acrylamide copolymer which contains from 5 - 50% by weight of a lower alkyl substituted tertiary aminoethyl methacrylate and quaternary ammonium salts thereof.

Abstract: A process for chemical enrichment of uranium with respect to a lighter one of its isotopes. The process consists in contacting uranium of valence state III and uranium of valence state IV, or a compound of uranium of valence state III and a different compound of uranium of valence state III. One of the phases which are contacted or the only phase is liquid. The system should be substantially free of elements which would cause uranium III to oxidize to valence IV.

Abstract: A liquid-liquid extraction process for the recovery and partitioning of actinide values from acidic nuclear waste aqueous solutions, the actinide values including trivalent, tetravalent and hexavalent oxidation states is provided and includes the steps of contacting the aqueous solution with a bidentate organophosphorous extractant to extract essentially all of the actinide values into the organic phase. Thereafter the respective actinide fractions are selectively partitioned into separate aqueous solutions by contact with dilute nitric or nitric-hydrofluoric acid solutions. The hexavalent uranium is finally removed from the organic phase by contact with a dilute sodium carbonate solution.

Abstract: A method of regenerating fuel and/or breeder elements with thorium as brer material for nuclear reactors. The fuel and/or breeder material is dissolved in an acid such as nitric acid, sulfuric acid or the like and the thus obtained solution is subjected to a liquid-liquid reaction with an extraction substance such as tributyl phosphate dissolved in an organic solvent. The fuel material and breeder material are enriched in the organic phase and the fission products remain in the aqueous phase, whereafter the fuel material and/or breeder material are converted into oxides, carbides etc. Prior to the above mentioned liquid-liquid extraction, the acid solution containing the fuel material and/or breeder material is passed over a sorption column in such a way that the number of mols of adsorbed .sup.233 Pa per time unit equals the number of mols of .sup.233 Pa disintegrating per time unit in the sorption column to form .sup.233 U.

Abstract: The method of selective stripping from plutonium-loaded organic solvents which may also contain uranium consists in passing the organic solvent in countercurrent contact with an aqueous solution of a salt of hydroxylamine and formic acid, the concentration of formic acid in the reaction medium being within the range of 1M to 5M.The method finds an application in the stripping of plutonium from trilaurylamine diluted in an aromatic hydrocarbon such as tert-butyl benzene or in the separation of uranium and plutonium contained in tributylphosphate diluted in an aliphatic hydrocarbon such as dodecane.

Abstract: The method of selective stripping from plutonium-loaded organic solvents which may also contain uranium consists in bringing the initial organic solvent into countercurrent contact with a solution containing a reducing agent consisting of an aromatic organic compound selected from the group comprising the substituted hydrazines, the polyamines, the aminophenols, and an agent for the removal of the nitrites which are formed.One field in which the method finds an application is the extraction of uranium and plutonium from nitric acid solutions derived from the reprocessing of irradiated nuclear fuels.

Abstract: In solvent-in-pulp extractions where aqueous leach slurries containing dissolved metal values and gangue particles of the silica, sericite or sulphide types are contacted with organic amine extractants, the loss of amine extractant to the solids is decreased sharply by pretreating the slurries with organic non-ionic hydrophilic material which is adsorbed by the gangue solids and decreases the affinity of the gangue solids for the amine. A combination of inexpensive materials has been found to be most effective. Crud formation is substantially avoided and the separation of phases is facilitated.

Abstract: Uranium is separated from contaminating metal ions in an aqueous feed liquor containing the uranyl ion. The liquor is extracted with a first, non-interfering, waterimmiscible, organic solvent containing a reagent which reacts with the uranyl ion to form a complex soluble in the organic solvent. The organic solvent is scrubbed with water if necessary, then stripped with a stripping liquor of an aqueous sulfuric acid liquor having a pH of about 0.5 to about 6 containing a reducing ion or an aqueous carbonate solution having a pH of about 8 to about 9. If the sulfuric acid liquor is used the stripped uranous ion is oxidized and the sulfuric acid liquor is diluted to prevent the precipitation of a uranium complex. The stripping liquor is extracted with an amine liquor comprising a second, noninterfering, water-immiscible, organic solvent and a tertiary or quaternary amine. The amine liquor is stripped with an ammonium carbonate solution to precipitate a uranium complex.

Abstract: 17. A process for separating fission product values from uranium and plutonium values contained in an aqueous solution, comprising adding an oxidizing agent to said solution to secure uranium and plutonium in their hexavalent state; contacting said aqueous solution with a substantially water-immiscible organic solvent while agitating and maintaining the temperature at from -1.degree. to -2.degree. C. until the major part of the water present is frozen; continuously separating a solid ice phase as it is formed; separating a remaining aqueous liquid phase containing fission product values and a solvent phase containing plutonium and uranium values from each other; melting at least the last obtained part of said ice phase and adding it to said separated liquid phase; and treating the resulting liquid with a new supply of solvent whereby it is practically depleted of uranium and plutonium.

Abstract: A process for the recovery of metal values, principally molybdenum, by contacting an acidic aqueous solution containing iron, copper and sulfate ions in addition to the metal values to be recovered with an alkyl amine dissolved in a water-insoluble liquid hydrocarbon and subsequently contacting the resultant organic phase in multiple stages at controlled pH.