Abstract: Uranium is recovered from refractory carbonaceous-sulfidic ores or concentrates by leaching with nitric acid, followed by sorption on an ion exchange resin. In addition, the nitric acid leach solution is regenerated and recycled.

Abstract: The present invention relates to the recovery of uranium from carbonate leach solutions. More particularly, it relates to the recovery of uranium from ammonium carbonate leach solutions having molybdenum as an impurity.

Abstract: An anion exchange column, containing anion exchange resin particles with uniform degree of sphericity, restricted average diameter and uniform particle size distribution and having devices for flowing a liquid uniformly, is suitably used for uranium technology, especially for separation of uranium isotopes.

Abstract: An improved method of preparing nuclear reactor fuel by carbonizing a uranium loaded cation exchange resin provided by contacting a H.sup.+ loaded resin with a uranyl nitrate solution deficient in nitrate, comprises providing the nitrate deficient solution by a method comprising the steps of reacting in a reaction zone maintained between about 145.degree.-200.degree. C, a first aqueous component comprising a uranyl nitrate solution having a boiling point of at least 145.degree. C with a second aqueous component to provide a gaseous phase containing HNO.sub.3 and a reaction product comprising an aqueous uranyl nitrate solution deficient in nitrate.

Abstract: Boron or uranium isotopes can be chemically separated and enriched with high speed and with high separating efficiency by using weakly basic anion exchange fibers having a diameter of not more than 100 .mu., an aspect ratio of at least 5 and an exchange capacity of at least 2 meq/g-dry fiber, which are packed in a column at a specific volume of 2.0 - 20.0 ml/g-dry fiber.

Abstract: A novel catalyst for isotope exchange reaction between uranium(IV) and uranium(VI) compounds enables acceleration of the reaction rate as much as 3000 times to make industrial separation of uranium isotopes economically possible.

Abstract: An improved process for continuous counter-current contact between a fluid to be treated and solid particles wherein the fluid flows through a column containing a plurality of contacting chambers each of which contains solid particles and in which intermittent transfer of the particles in a direction opposite to that of the fluid from each chamber to the chamber immediately adjacent is effected while maintaining a continuous flow of the fluid through the column.

Abstract: Contaminated wash water in nuclear plants are processed by mixing the wash waters with ion exchange resins to form a suspension and then feeding the resulting suspension to a filter.

Abstract: A process for recovering uranium as an anionic sulfate complex from sulfuric acid leach liquors is disclosed and claimed. A novel weak base anion exchange resin is used in this process.

Abstract: A method of separating actinide values from nitric acid waste solutions resulting from reprocessing of irradiated nuclear fuels comprises oxalate precipitation of the major portion of actinide and lanthanide values to provide a trivalent fraction suitable for subsequent actinide/lanthanide partition, exchange of actinide and lanthanide values in the supernate onto a suitable cation exchange resin to provide an intermediate-lived raffinate waste stream substantially free of actinides, and elution of the actinide values from the exchange resin. The eluate is then used to dissolve the trivalent oxalate fraction prior to actinide/lanthanide partition or may be combined with the reprocessing waste stream and recycled.

Abstract: Uranium yields, derived from alkaline leaching of a uranium ore, are increased and at the same time the need for fresh water to dissolve a flocculant is eliminated by using sodium polyacrylate as the flocculant, diluted with and dissolved by system water.

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 process for separately recovering uranium, plutonium and neptunium substantially free of fission products from irradiated nuclear fuel is presented in which the fuel is dissolved in a strong mineral acid forming an aqueous dissolved nuclear fuel solution and treated to separate the uranium, plutonium and neptunium therefrom substantially free of said fission products by the sequential steps of solvent extraction, ion exchange and fluorination. The process has an improvement comprising the addition of a sufficient quantity of an additive of a stable metallic complex to the aqueous dissolved nuclear fuel solution prior to solvent extraction. This achieves improved purity of the separated uranium, plutonium and neptunium.

Abstract: The recovery of non-ferrous transition metals such as copper and nickel from acidic hydrometallurgical leach liquors with a 2-picolylamine chelate exchange resin is improved by the in situ reduction of Fe.sup.+.sup.3 present in the leach liquor with a water soluble reducing agent during the resin loading cycle. The chelate resin functions not only as a selective sorbent for the desired metal values, but also as a catalyst for the in situ reduction of Fe.sup.+.sup.3 to Fe.sup.+.sup.2. A suitable reducing agent such as SO.sub.2 or HCHO is fed into the chelate resin column with the leach liquor. When the loading cycle is completed, regeneration with sulfuric acid gives an enriched eluent with a high non-ferrous metal:Fe ratio. For example, using SO.sub.2 with a copper leach liquor feed, subsequent regeneration at about 70.degree. C gives better than 90 percent recovery of the copper as a highly enriched copper sulfate solution with a Cu:Fe ratio of about 10,000.

Abstract: A method for loading ion exchange resins is described. The process comprises contacting a weak acid cation exchange resin in the ammonium form with a uranyl fluoride salt solution.

Abstract: In a plant for uranium enrichment using a cascade of ion exchange beds, each bed operates more efficiently because an annular chamber is rotated about a stationary annular ion exchange bed at a speed corresponding to the speed of migration of a region so that, with respect to such rotating chamber, each of the regions of a system remains substantially stationary. An aqueous solution of ferric chloride is pumped to the ferric region and flows forwardly to the forwardly moving rear boundary of the uranium region.

Abstract: Waste water containing large amounts of fluorides and ammonia and trace amounts of uranium, as is produced during the hydrolysis and ammonium hydroxide treatment of uranium hexafluoride (UF.sub.6) to produce ammonium diuranate (ADU) therefrom, is rendered suitable for cyclic reuse by initially treating the waste water with sufficient lime to precipitate substantially all of the fluorides present in the waste water to a relatively insoluble CaF.sub.2 precipitate, the treated solution is subjected to distillation to drive off ammonia for reuse in the ADU precipitation, the CaF.sub.2 precipitate is separated from the aqueous distilland leaving water with dissolved calcium, the distilland is treated by a cationic ion-exchange material to remove substantially all of the calcium and other cationic metal impurities and the resulting water containing small amounts of uranium, fluoride and ammonia is recycled to react with UF.sub.

Abstract: A system utilizing membrane extraction is provided to recover metal values. The system may be used to separate metal ions from an aqueous solution through the membrane by an organic liquid containing a chelating agent. This invention also contemplates the recovery of metal values from an organic phase, containing the metal complexed with a chelating agent, by an aqueous phase using membrane extraction. In the former case, the metal ion is passed through the membrane from the aqueous phase to the organic phase where it forms a complex with a chelating agent present in the organic phase. In the latter case the metal is extracted from the organic phase into the aqueous phase through the membrane. In both cases a chelating exchange reaction is involved at the interface between the membrane and one of the two phases. This hydro-metallurgical process employs membranes with metal ion diffusivity in the range of about 10.sup..sup.-5 to about 10.sup..sup.-8 cm.sup.2 /sec.

Abstract: A method of simultaneously obtaining separate enriched fractions of .sup.235 U and .sup.238 U from isotopic mixtures thereof with the use of an ion exchange column by passing a liquid body containing the isotopic mixture through the column. The uranium as it is passed through the column is present as a U(IV) coordination compound with a ligand at different valent states and is followed by an eluant and forms a band which travels through the column, the front and rear portions of which are respectively enriched in one of the isotopes and depleted in the other.

Abstract: A method of simultaneously obtaining separate enriched fractions of heavier and lighter isotopes from mixtures thereof with the use of an ion exchange resin column by passing a ligand body containing this isotope mixture through the column. The isotopes, as they are passed through the column, are present in the forms of ligand-containing coordination compounds having different valence states and are followed by an eluant and form a band which travels through the column, the front and rear portions of which are respectively enriched in one of the isotopes and depleted in the other.