Abstract: A system includes a well fluid diversion assembly configured to pump a volume of wellbore fluid from a first well to a second well of a single drilling or production platform or of different drilling or production platforms. The diversion assembly includes a first flexible tubing releasably connected to an outlet valve of a wellhead assembly of the first well and a second flexible tubing releasably connected to a wellhead assembly of the second well. The diversion assembly also includes a flowmeter and a sampling valve configured to selectively flow a portion of the volume to a fluid sampling port.

Abstract: The invention relates to a system and a method for the processing of minerals containing the lanthanide series and the production of rare earth oxides, which allow a completely closed and continuous treatment of the different materials and desorbent agents involved in the process, thus improving the efficiency in the extraction and avoiding environmental risks associated.

Abstract: The invention relates to a beneficiation process for uranium ores comprising clay and carbonate minerals, the process comprising: performing a hydrocyclone step to obtain a hydrocyclone underflow fraction substantially comprising the uranium component; treating the hydrocyclone underflow fraction to effect a separation of carbonate and uranium minerals; and recovering the uranium-bearing minerals to produce a uranium concentrate.

Abstract: The present invention relates to single crystalline NaUO3, hydrothermal growth processes of making such single crystals and methods of using such single crystals. In particular, Applicants disclose single crystalline NaUO3 in the R32 space group. Unlike other powdered NaUO3, Applicants' single crystalline NaUO3 has a sufficient crystal size to be characterized and used in the fields of laser light, infrared countermeasures, nuclear fuel material, nuclear forensics and magnetic applications.

Abstract: Novel methods of recovering neodymium and related rare earth elements from permanent magnets of various compositions are described. The methods employ processing steps including converting the magnet material to a higher surface area form such as a powder, treating the mixture with alkaline solutions to form product concentrated in neodymium and rare earth metals. Inexpensive materials such as ammonia, ammonium carbonate, carbon dioxide, water are recycled in a process that uses moderate temperatures, pressures and non-corrosive and environmentally-friendly chemicals.

Abstract: Compositions are provided that include nuclear fuel. Methods for treating nuclear fuel are provided which can include exposing the fuel to a carbonate-peroxide solution. Methods can also include exposing the fuel to an ammonium solution. Methods for acquiring molybdenum from a uranium comprising material are provided.

Abstract: Compositions are provided that include nuclear fuel. Methods for treating nuclear fuel are provided which can include exposing the fuel to a carbonate-peroxide solution. Methods can also include exposing the fuel to an ammonium solution. Methods for acquiring molybdenum from a uranium comprising material are provided.

Abstract: Disclosed is a process for recovery of uranium from a spent nuclear fuel using a carbonate solution, characterized by excellent proliferation resistance of preventing leaching of transuranium element (TRU) nuclides such as Pu, Np, Am, Cm, etc. from the spent nuclear fuel as well as environmental friendliness of minimizing waste generation, wherein a highly alkaline carbonate solution is used to separate uranium alone from the spent nuclear fuel.

Abstract: A method for recovering and recycling catalyst coated fuel cell membranes includes dissolving the used membranes in water and solvent, heating the dissolved membranes under pressure and separating the components. Active membranes are produced from the recycled materials.

Abstract: Soil comprising small soil particles, clay and silt particles, humus, fine vegetation, and contaminated with soluble or insoluble radioactive species is treated by first introducing an aqueous extracting solution comprising a mixture of sodium and potassium carbonate (or bicarbonate), or ammonium carbonate (or bicarbonate) into the soil to solubilize and disperse the radioactive species into solution. The extracting solution has a pH greater than or equal to about 7.5. Contaminated fine vegetation then is separated from the soil and extracting solution. Next, an acid like hydrochloric acid is introduced into the soil. The acid is added in an amount sufficient to lower the pH of the extracting solution at which point desirable organic material will substantially precipitate or coagulate from the extracting solution. The cleansed soil particles, including organic matter, is separated from the contaminated extracting solution.

Abstract: A process for removal of thorium from titanium chlorinator waste comprising: (a) leaching an anhydrous titanium chlorinator waste in water or dilute hydrochloric acid solution and filtering to separate insoluble minerals and coke fractions from soluble metal chlorides; (b) beneficiating the insoluble fractions from step (a) on shaking tables to recover recyclable or otherwise useful TiO.sub.2 minerals and coke; and (c) treating filtrate from step (a) with reagents to precipitate and remove thorium by filtration along with acid metals of Ti, Zr, Nb, and Ta by the addition of the filtrate (a), a base and a precipitant to a boiling slurry of reaction products (d); treating filtrate from step (c) with reagents to precipitate and recover an iron vanadate product by the addition of the filtrate (c), a base and an oxidizing agent to a boiling slurry of reaction products; and (e) treating filtrate from step (d) to remove any remaining cations except Na by addition of Na.sub.2 CO.sub.3 and boiling.

Abstract: A process for recovering metal and acid values from a source material containing metallic fluorides comprises digesting the source material in sulfuric acid to form a slurry, separating a fluoride containing solid phase and a metal containing first liquid phase. The solid phase is subjected to pyrohydrolysis, sulfuric and hydrofluoric acids are recovered, and the first liquid phase is processed to recover the metal values by solvent extraction or ion exchanges. The tantalum values are extracted from the first liquid aqueous phase by a water immiscible organic extractant such as methylisobutyl ketone to form a first liquid organic phase containing tantalum and a second liquid aqueous phase. The tantalum is stripped from the first organic phase using water. The process includes the additional steps of heating the separated solid phase from about ambient temperature to an elevated temperature in the presence of water vapor to evolve sulfuric acid and render the gangue chemically inert.

Abstract: A process for extracting uranium from uranium-containing waste residues. The process dissolves the residue in hot nitric acid, and precipitates the resulting solution with sodium carbonate/sodium bicarbonate.

Abstract: A process for decontaminating radioactive material comprises the step of contacting the material with a dissolving composition to dissolve the contaminants in the material, said composition comprising a dilute solution of about 0.05 molar ethylene diamine tetraacetic acid, about 0.1 molar carbonate, about 10 grams per liter hydrogen peroxide and an effective amount of sodium hydroxide to adjust the pH of the composition to a pH from about 9 to about 11. Also included are the steps of separating the dissolving composition containing the dissolved contaminants from the contacted material and recovering dissolved contaminants from the dissolving composition that has been separated from the material. A composition for dissolving radioactive contaminants in a material, comprising a dilute solution having a basic pH and effective amounts of a chelating agent and a carbonate sufficient to dissolve radioactive contaminants is also provided.

Abstract: Magnesium is separated from magnesium slag containing radioactive thorium and its daughters by solubilizing magnesium from magnesium slurry using carbon dioxide and separating magnesium from magnesium slurry containing thorium and its daughters by filtering. The process concentrates the radioactive thorium and its radioactive daughters from the magnesium slag and reduces the volume of the radioactive waste that requires disposal.

Abstract: The present invention adds carbonates or chlorides of alkaline earth metals to the radioactive wastes containing sodium sulfate and subjects sulfate group in the radioactive wastes to reduction treatment, thereby converts the sulfate group into sulfides of alkaline earth metals which are chemically stable substances while suppressing SOx generation, and solidifies the radioactive wastes stably for an extended period of time by applying to the converted radioactive wastes solidifying treatment.

Abstract: An organic extraction phase, containing fission materials uranium and plutonium, as well as a minor amount of fission- and corrosion-products, from an extraction step or from a purification step of a nuclear fuel reprocessing process is treated with an aqueous, basic, carbonate ion containing solution, whereby the fission materials and at least a part of the fission- and corrosion-products are stripped into the aqueous phase and the uranium is present in the form of uranium-carbonato-complex. The organic phase is then separated from the aqueous phase. Plutonium is then removed from the separated aqueous phase. The remaining aqueous solution containing the uranium-carbonato-complex and a small residual amount (C) of fission products is adjusted to a ratio of uranyl ion concentration to carbonate ion- or CO.sub.3.sup.-- /HCO.sub.3.sup.-- concentration of 1(UO.sub.2.sup.++) to 4.5(CO.sub.3.sup.-- or CO.sub.3.sup.-- /HNO.sub.3.sup.-), respectively, or more, at a maximum U-concentration of not more than 6- g/l.

Abstract: A process for separating large amounts of uranium from small amounts of radioactive fission products, which are present in basic, aqueous carbonate containing solutions, by means of a basic, organic anion exchanger. Uranium values present as uranykl-carbonato complex in a basic, aqueous, carbonate containing solution can be separated from fission products of the group ruthenium, zirconium, niobium and lanthanide, and with a relatively high degree of decontamination as well. The aqueous solution is adjusted to a ratio of uranyl ion concentration to carbonate ion- or CO.sub.3.sup.-- /HCO.sub.3.sup.- concentration of 1(UO.sub.2.sup.++) to 4.5(CO.sub.3.sup.--, or CO.sub.3.sup.-- /HCO.sub.3.sup.-), or more, at a maximum U concentration of not more than 60 g/l. The adjusted solution is led over a basic anion exchanger made from a polyalkene matrix provided with a preponderant part tertiary and a minor part quaternary amino groups to adsorb fission products ions or fission products containing ions.

Abstract: A method of improving the recovery of U.sub.3 O.sub.8 from circulating aqueous leach fluids used to extract uranium from its ores in underground uranium fields, which fields are made up of a series of injection and producing wells, which aqueous fluids are contaminated by suspended and dissolved inorganic iron compounds caused by the presence of anerobic and aerobic bacteria, which comprises treating such aqueous leach fluids with at least 0.1 ppm of a mixture of 75% of 5-chloro-2-methyl-4-isothiazolin-3-one and 25% 2-methyl-4-isothiazolin-3-one.

Abstract: A process is described for the recovery or uranium from wet-process phosphoric acid utilizing an alkyl pyrophosphoric extractant. The extractant also contains a modifier for retaining the alkyl pyrophosphoric acid ester in solution in an essentially water-immiscible organic diluent during stripping. After extracting the uranium from wet-process acid, the APPA extractant is treated with an oxidizing agent such as hydrogen peroxide and the uranium stripped into an alkaline stripping solution. The alkaline stripping solution is an aqueous solution of an alkali metal or ammonium carbonate unsaturated in uranium. The barren extractant is recycled for contacting with fresh wet-process acid. Any ferric iron present is precipitated in the stripping solution and then separated from the solution. The uranium is precipitated, separated, dried and calcined to a U.sub.3 O.sub.8 product.

Abstract: A process is described for the recovery of uranium from wet-process phosphoric acid utilizing an alkyl pyrophosphoric extractant. The extractant also contains a modifier for retaining the alkyl pyrophosphoric acid in solution in an essentially water-immiscible organic diluent during stripping. After extracting the uranium from wet-process acid, the APPA extractant is treated with an oxidizing agent such as hydrogen peroxide and the uranium stripped into an alkaline stripping solution. The alkaline stripping solution is an aqueous solution of an alkali metal or ammonium carbonate or hydroxide. The barren extractant is recycled for contacting with fresh wet-process acid. The uranium and any ferric iron present is precipitated in the stripping solution. The uranium is dissolved in an aqueous solution such as an aqueous solution of ammonium uranyl tricarbonate (AUT), any precipitated ferric solids are separated from the solution, and the uranium is reprecipitated, separated, dried and calcined to a U.sub.3 O.sub.

Abstract: A process for separating radium-226 from an aqueous liquid by adding a precipitant to the liquid. The liquid, including the precipitant, is passed upwardly through a particulate bed to assist co-precipitation and removal of the radium-226. The effect is to produce a fluidized bed of the particulate bed. The process is efficient, rapid and undemanding of space, all advantages not found in the prior art.

Abstract: A process for the selective removal of arsenical material in the course of a process for the hot oxidizing attack on a uraniferous and/or molybdeniferous ore containing arsenical materials, comprising attacking said ore with an aqueous liquor of sodium or potassium carbonate and/or bicarbonate, said attack operation being carried out under conditions with respect to levels of concentration, temperatures and pressures which cause solubilization of the uranium and/or molybdenum and the arsenic present in the ore, then collecting a suspension of a solid phase in a liquid phase, and finally, separating said phases, wherein the arsenic which is solubilized in the attack operation is extracted in the form of magnesium arsenate by treating the material containing the arsenic with a magnesium compound.

Abstract: A process and apparatus for recovering uranium from a carbonate solution containing uranium ions whereby the carbonate solution containing uranium ions is brought in contact with a cation exchanger so that a uranium cation is removed from solution and adsorbed by the cation exchanger, and the uranium cation is then removed from the cation exchanger. The treated carbonate solution from which uranium ions hve been removed by cation exchange is then further processed by removing carbon dioxide from the treated carbonate solution to produce a decarbonated solution, and passing the decarbonated solution through a membrane process to remove some remaining impurities.

Abstract: The invention relates to a process for recovering and purifying the molybdenum from a solution containing more molybdenum than vanadium.The process of the invention comprises the step of contacting the solution which contains molybdenum and vanadium, originally at a pH at least equal to 11 with an excess of an ammonium salt sufficient to precipitate the greatest part of vanadium in the form of solid ammonium vanadate, this excess being yet hot higher than a value such that after precipitation of vanadium, the quantity of ammonium having not reacted with the vanadate would be over a concentration which would account for risks of precipitating also molybdenum which is contained in the liquid phase of the supernatant.The molybdenum which is obtained is of industrial grade.

Abstract: A method for treating process waste consisting of uranium hexafluoride, UF.sub.6, molybdenum hexafluoride, MoF.sub.6 and molybdenum oxytetrafluoride, MoOF.sub.4 is provided wherein the foregoing mixture is hydrolyzed in an aqueous solution of ammonium carbonate and ammonium hydroxide. The resulting mother liquor is digested at 60.degree.-80.degree. C. to drive off carbon dioxide and convert the ammonium uranyl carbonate, (NH.sub.4).sub.4 UO.sub.2 (CO.sub.3).sub.3 to ammonium diuranate, (NH.sub.4).sub.2 U.sub.2 O.sub.7. The pH is maintained above 9 to prevent premature precipitation of the molybdenum values as molybdic acid or uranyl molybdate.The ammonium diuranate which forms as a yellow solid is filtered, slurried in aqueous ammonium hydroxide, filtered and dried. The yield is quantitative. Pyrolysis results in conversion of the diuranate salt to uranium oxide, U.sub.3 O.sub.8, of suitable purity to be recycled in the uranium hexafluoride production process.

Abstract: The present invention relates to a process for the recovery of mineral values from ores containing such wherein at least part of the mineral values is present as a refractory mineral complex. A fluid bed reactor is utilized to simultaneously solubilize the mineral values not present as the refractory complex and to separate the refractory complex from the ore.

Abstract: Mineral values, particularly uranium, are recovered from subsurface earth formations containing the same, as well as cations which form precipitates with sulfuric acid leach solutions, by injecting into at least one injection well a preliminary acidic solution capable of forming soluble materials with at least one of the precipitate-forming cations, such as calcium and iron cations, passing the preliminary acidic solution through the subsurface formation for a time sufficient to form such soluble materials, withdrawing the preliminary acidic solution containing the solubilized materials from at least one producing well, thereafter, injecting a sulfuric acid leach solution into said injection well, contacting the subsurface formation with the leach solution for a time sufficient to extract significant amounts of mineral values from the formation and produce a pregnant leach solution containing the thus solubilized mineral values and withdrawing the pregnant leach solution from the production well.

Abstract: Method for precipitating and removing soluble metal compounds from solutions of phosphoric acid. The method is useful in the disposal of metal-containing phosphoric acid waste from electrolytic operations, including such acid solutions contaminated with uranium compounds.

Abstract: The present invention relates to the in situ recovery of mineral values, particularly uranium, from subterranean formations that contain sulfur in organic or inorganic forms where the sulfur causes premature deletion of an oxidant and reduction in permeability of the formation. The adverse effects due to the presence of the sulfur in the formation are substantially reduced in accordance with the present invention by treating the formations with an aqueous solution of iron-complexing agent and then oxident to preferentially oxidize and solubilize at least a portion of the sulfur in the formation. The present process may be applied either as a pre-treatment process to be followed by a leaching process or simultaneously with the leaching process.

Abstract: Uranium and other base metals are leached from their ores with aqueous solutions containing bicarbonate ions that have been generated or reconstituted by converting other non-bicarbonate anions into bicarbonate ions. The conversion is most conveniently effected by contacting solutions containing SO.sub.4.sup.= and Cl.sup.- ions with a basic anion exchange resin so that the SO.sub.4.sup.= and Cl.sup.- ions are converted into or exchanged for HCO.sub.3.sup.- ions. CO.sub.2 may be dissolved in the solution so it is present during the exchange. The resin is preferably in bicarbonate form prior to contact and CO.sub.2 partial pressure is adjusted so that the resin is not fouled by depositing metal precipitates. In-situ uranium mining is conducted by circulating such solutions through the ore deposit. Oxidizing agents are included in the injected lixiviant.

Abstract: Uranium is recovered from a carbonate leach solution containing a dissolved uranium salt and a monovalent ion. The pH of the leach solution is adjusted to about 5 to about 7.5, and preferably to about 6 to about 7. Phosphate ion is then added to typical in-situ leach solutions in an amount from about 10 to about 30 mole % in excess of the amount needed to stoichiometrically react with the uranium in said solution. This results in the precipitation of a compound made up of the monovalent ion, uranium, and the phosphate ion, which is insoluble in the solution. The precipitate is then separated from the solution preferably by means of a centrifuge or a vortex clarifier. It can then be dissolved in acid, and the uranium extracted into an organic solvent such as DEHPA-TOPA in kerosene.

Abstract: In the subsurface solution mining of mineral values, especially uranium, in situ, magnesium bicarbonate leaching solution is used instead of sodium, potassium and ammonium carbonate and bicarbonates. The magnesium bicarbonate solution is formed by combining carbon dioxide with magnesium oxide and water. The magnesium bicarbonate lixivant has four major advantages over prior art sodium, potassium and ammonium bicarbonates.

Abstract: The present invention relates to a process for recovery of uranium from a carbonate lixiviant additionally containing other contaminants such as molybdenum and silica, by adjusting the pH of the lixiviant to a value of at least 4 and treating the lixiviant to obtain a carbonate concentration of at least 50 ppm by weight. Subsequently the lixiviant is treated with an aqueous solution containing a sufficient amount of ferric iron to precipitate the contaminants without substantial precipitation with the uranium values. The precipitate is separated from the lixiviant. The treated lixiviant is passed through an ion exchange to retain uranium values.

Abstract: A process for the separation of actinide ions from aqueous, basic, carbonate containing solutions with the use of basic ion exchangers. The actinide ions are sorbed at a weakly basic anion exchanger comprised of a polyalkene matrix provided in the majority with tertiary and in the minority with quaternary amino groups. The charged ion exchanger is separated from the solution and then the actinide ions are eluted from the exchanger with nitric acid.

Abstract: A process is described for improving yields and leaching rates of mineral values in highly reducing uranium-bearing formations, while minimizing deleterious environmental impact, by injecting an oxidant such as gaseous air or O.sub.2 into the formation prior to leaching. The preoxidation may be enhanced by the presence of CO.sub.2 gas in the pre-leaching oxidant. The process is particularly suitable for systems employing a CO.sub.2 /O.sub.2 lixiviant. The presence of sulfate ion further improves the leaching rate of such a system.

Abstract: A process for the purification of solutions containing sodium or potassium carbonate, sulphate, hydroxide or hydrogen carbonate, and mainly at least one of the metals belonging to the group formed by vanadium, uranium or molybdenum, in the form of sodium or potassium salts, and inorganic and/or organic impurities, wherein the above-mentioned solutions are completely or partially caustified by the addition of an adequate amount of lime, whereby a first precipitate essentially containing calcium carbonate is separated, and the separated liquor is concentrated by evaporation until the hydroxide content is at most equal to 50%, to cause the production of a second precipitate which essentially comprises sodium or potassium sulphate, then, after separation thereof, a hydroxide-rich liquor is collected.This process is more particularly adapted for treatments of liquors resulting from the alkaline attach of vanadiferous and uraniferous ores.

Abstract: A process for recovering one or more non-radioactive transition metal compounds from an ore containing one or more compounds of said transition metal or metals and further containing at least one complex of a member selected from the group consisting of uranium, thorium, radium, titanium, and rare earth metals, which comprises decomposing said ore in crushed condition by means of an acid so that a portion of the ore is brought into solution in a liquid phase and another portion of the ore remains in a solid phase, said compound or compounds of the transition metal or metals to be recovered passing into only the liquid or into only the solid phase, the uranium in the crushed ore being treated so as to cause substantially all of said uranium to be present in an oxidation state in which it cannot, during the decomposition step, pass into the phase containing the transition metal compound or compounds.

Abstract: A process for recovering metallic values by putting the values into solution and separating undesired mineral matter from the solution using countercurrent flotation is provided. The process involves leaching metallic values from host rock, conditioning the resultant ore pulp with the required reagents to achieve selective flotation of mineral matter in the metallic values solution, introducing the conditioned ore pulp into flotation cells, along with counterflow of solution from an immediately subsequent flotation step, wherein simultaneous washing and flotation is achieved, and the mineral matter is removed leaving a solution of the metallic values. The resultant mineral matter froth product is subjected to subsequent stages of flotation and simultaneous washing with counterflow of solution removed from each subsequent stage of flotation, water and/or barren solution being used for washing in the final flotation stage.

Abstract: The present invention relates to a process for the recovery of uranium and other minerals from uranium ore where at least part of the uranium is present as refractory uranium-mineral complexes, comprising subjecting the uranium ore to mild oxidative carbonate leach fluid to dissolve and remove readily soluble uranium minerals, subsequently subjecting the uranium ore to an oxidative chemically severe leaching system to dissolve and remove the refractory uranium-mineral complexes, and separating and recovering the uranium and other mineral species in the leachate fluids. The process may be applied to in-situ uranium leaching operations or to surface leaching operations.

Abstract: A method of recovering uranium dioxide from a sodium uranyl carbonate solution obtained by the alkaline carbonate leaching of uranium ore in which a solution is reacted at a temperature above 130.degree. C. and at superatmospheric pressure with particular metallic iron. The precipitated UO.sub.2 is recovered from the solution.

Abstract: Process for the purification of an aqueous solution containing alkali metal carbonate, sulphate, and hydroxide or hydrogen carbonate and primarily one at least of the metals belonging to the group formed by vanadium, uranium and molybdenum, in the form of alkali metal salts, and mineral and/or organic impurities, said solutions resulting from an ore attack cycle and being taken off after extraction of the metal being sought, which comprises treating said solutions by means of lime at a temperature which is at most equal to the boiling temperature, to convert the carbonate and hydrogen carbonate present into alkali metal hydroxide, then effecting separation and washing of a first precipitate of calcium carbonate and a liquor which is enriched in respect of alkali metal hydroxide, concentrating it by evaporation to cause production of a second precipitate which essentially comprises alkali metal sulphate, separating it from the hydroxide-rich liquid phase, re-dissolving it in an aqueous medium and treating the

Abstract: A process for the selective removal of arsenical materials, in the course of a continuous hot oxidizing attack process, comprising attacking a uraniferous ore containing arsenical materials as impurities in the presence of an oxidizing agent in the reaction medium by means of an aqueous liquor formed by a recycling solution containing alkali metal carbonate and bicarbonate, and uranium close to the limit of solubility thereof, under concentration, temperature and pressure conditions which causes solubilization of the uranium present in the ore, and re-precipitation thereof in the attack medium, then collecting a suspension of a solid phase in a liquid phase which, after cooling, is subjected to a separation operation, recycling the liquid phase to the attack operation, and treating the separated solid phase by means of an aqueous liquor to re-dissolve the precipitated uranium which is characterized in that the arsenic which is solubilized in the attack operation is extracted by means of a magnesium compound w

Abstract: The present invention relates to a process for effectively recovering uranium from dilute solutions, particularly alkaline carbonate leachates from an in-situ leaching process. The uranium complexes are made unstable by adjusting the pH of the leachate to about 6.5 using mineral acids or carbon dioxide. The solution is then passed over ion exchanger resin which induces percipitation of uranium. This non-exchangeable uranium on the resin is then eluted or leached with acid or carbonate solution to obtain eluate of high uranium concentration.

Abstract: A process is described for minimizing accumulation of undesirable polythionates on an ion exchange resin used to recover uranium values from a leachate from an in situ mining operation by adding sulfite, either as a sulfite salt or as SO.sub.2, directly to the leachate or to the eluant.

Abstract: A direct precipitation method based on the insolubility of uranyl phosphate in carbonate containing solutions at pH 6-6.5 and its insolubility at pH 8 is described. The method eliminates the use of ion exchange columns for removing uranium values from uranium leachates and can be readily applied to an integrated field operation.

Abstract: In accordance with the present invention, uranium values are extracted from solid materials containing uranium in lower valence states than its hexavalent state comprising contacting the solid materials containing uranium with an alkaline leach solution containing the ionic species NH.sub.4.sup.+ and NO.sub.3.sup.- in an amount sufficient to convert at least a portion of the uranium in valence states lower than its hexavalent state to its hexavalent state. In another embodiment of the present invention, the aqueous alkaline leach solution is an aqueous solution of a carbonate selected from the group consisting of ammonium carbonate, ammonium bicarbonate and mixtures thereof. In a further embodiment, ionic species NO.sub.3.sup.31 is supplied by an alkaline nitrate.

Abstract: In accordance with the present invention, uranium values are extracted from materials containing uranium in valence states lower than its hexavalent state by contacting the materials containing uranium with an aqueous alkaline leach solution containing an alkaline chlorate in an amount sufficient to oxidize at least a portion of the uranium in valence states lower than its hexavalent state to its hexavalent state. In a further embodiment of the present invention, the alkaline leach solution is an aqueous solution of a carbonate selected from the group consisting of ammonium carbonate, ammonium bicarbonate and mixtures thereof. In yet another embodiment of the present invention, at least one catalytic compound of a metal selected from the group consisting of copper, cobalt, iron, nickel, chromium and mixtures thereof adapted to assure the presence of the ionic species Cu.sup.++, Co.sup.++, Fe.sup.+++, Ni.sup.++, Cr.sup.

Abstract: The present invention concerns a continuous process for the oxidizing attack of a uraniferous ore by means of an aqueous recycling liquor which contains in a dissolved state alkaline carbonate and bicarbonate and uranium at a concentration close to the limit of solubility thereof at the temperature of the attack operation. The uranium which is precipitated in the course of the attack operation is collected within the solid phase which remains after attack. By redissolution in a suitable aqueous liquor and separation from the sterile materials, a uraniferous liquor is obtained.

Abstract: A process is described for restoring and maintaining the total ion exchange capacity of the resin used for uranium recovery in in situ uranium leaching. The used resin of lowered exchange capacity is treated with a solution containing Na.sub.2 CO.sub.3 or NaHCO.sub.3, or admixtures thereof. The process preferably is used in conjunction with acid elution of the uranium from the resin.