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: The phenolic chelate resin has a chelate-forming group wherein part or all of the hydrogen atoms in a primary and/or secondary alkylamino group introduced in a phenol nucleus are replaced by a methylenephosphonate group. Also disclosed is a process for producing such a chelate resin, and a method for recovering heavy metal ions with such a resin. The resin has particularly high selectivity for adsorbing uranium ions, as well as high heat, acid and alkali resistance as well as dimensional stability. The resin is very effective for recovering uranium from various uranium-containing solutions such as sea water, crude phosphoric acid fertilizer solutions, low-grade uranium ore, waste water from uranium refining, and uranium mine water.

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 process for treating water containing chemicals comprising ammonium nitrate, fluorides, hydrogen peroxide and uranium compounds, wherein valuable and/or hazardous components of the chemicals-containing water are separated therefrom and concentrated for recovery. The process includes an ion exchange operation in addition to manipulations of chemical components and pH conditions of the water by means of the application of reagents and adsorbents.

Abstract: Uranium is extracted from phosphoric acid with organophosphorus extractants supported or impregnated on polymeric resins, and especially macroreticular resins. Suitable extractants include mono and dialkylphenyl esters of phosphoric acid. Uranium may be stripped from the supported or impregnated resins with hotter or more concentrated phosphoric acid, optionally with oxidation to hexavalent form, or with aqueous fluoride solutions.

Abstract: An organic ion exchange material, which comprises a mixture of grains of a first type bearing groups containing exchangeable hydrogen ions and grains of a second type bearing groups containing exchangeable hydroxyl ions and which has been used in a cleaning circuit in a nuclear reactor, is subjected to a treatment before the ion exchange material is further processed for final storage of the radioactive waste products contained therein. The treatment comprises removing hydrogen ions and/or hydroxyl ions or groups containing hydrogen ions and/or groups containing hydroxyl ions from the grains, whereafter the grains of the first type are separated from the grains of the second type, before the grains of each type are further processed separately for final storage of the radioactive waste products contained therein.

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.

Abstract: A process is described for improving yield and leaching rates of mineral values in uranium-bearing formations associated with high brine aquifers by using high pressure CO.sub.2 /oxidant in the leaching solution. The high pressure CO.sub.2 overcomes the inhibiting effect of NaCl on the rate of leaching. Uranium is recovered at the well head by ion exchange at a pH of about 4.5 to about 5.0 either under pressure to keep the CO.sub.2 in solution or with provision for CO.sub.2 recovery and recycle.

Abstract: The phenolic chelate resin has a chelate-forming group wherein part or all of the hydrogen atoms in a primary and/or secondary alkylamino group introduced in a phenol nucleus are replaced by a methylenephosphonate group. Also disclosed is a process for producing such a chelate resin, and a method for recovering heavy metal ions with such a resin. The resin has particularly high selectivity for adsorbing uranium ions, as well as high heat, acid and alkali resistance as well as dimensional stability. The resin is very effective for recovering uranium from various uranium-containing solutions such as sea water, crude phosphoric acid fertilizer solutions, lowgrade uranium ore, waste water from uranium refining, and uranium mine water.

Abstract: A process is described for recovering uranium from a pregnant lixiviant containing uranium values and a certain portion of molybdenum values comprising passing the pregnant lixiviant through an anion-exchange resin to capture the uranium and molybdenum values on the resin, eluting the uranium and molybdenum values from the resin with a salt solution, passing the eluate through a weak acid cationic resin in its hydrogen form to capture the uranium values on the resin and treating and resulting eluate to precipitate uranium therefrom to produce the familiar "yellow-cake.

Abstract: A process for the enrichment of one isotope in a mixture of uranium isotopes by passing a solution of the mixture in a solvent through an anion exchanger thereby forming on the anion exchanger a boundary (A) between a uranium adsorption zone and an adjacent reducing agent zone and/or a boundary (B) between a uranium adsorption zone and an adjacent oxidizing agent zone, the uranium adsorption zone advancing through the anion exchanger, effecting reduction at the boundary (A) and/or effecting oxidation at the boundary (B), thereby effecting enrichment adjacent said boundary, and separating a fraction enriched in one of said isotopes, which process comprises using as the solvent medium a composition comprising (a) a solvent having a dielectric constant of at least 80 at 20.degree. C., (b) hydrochloric acid and (c) at least one of hydrobromic acid and sulfuric acid, the solvent medium having a hydrogen ion concentration of about 0.1 M/l to about 10 M/l, a total chlorine ion concentration of about 0.

Abstract: Molybdenum is removed from a uranium bearing alkaline carbonate leach solution, by adding a compound which provides lead ion to react with the molybdenum present to form insoluble lead molybdate (PbMoO.sub.4) which precipitates from the solution.

Abstract: A process is described for extracting phosphoric acid and metal values, such as uranium, from phosphate rock using hydrochloric acid and independently extracting the phosphoric acid and metal values from a slurry of the acidulated rock.

Abstract: A cyclic process for the treatment of a uraniferous liquor containing, in addition to the desired metal, sodium carbonate and/or bicarbonate and sodium sulphate, obtained by the alkaline attack of a sulphur-containing uraniferous ore, the said process comprising the neutralization of the uraniferous liquor then the fixation of the uranium and the SO.sub.4.sup.= ions over a strong anion-exchange resin, the elution thereof with an ammonium carbonate and/or bicarbonate solution in the form of an ammonium uranyl carbonate which is subsequently decomposed and ammonium sulphate, the precipitation and the calcination of the precipitated uranates and/or diuranates with regeneration of the eluent solution of ammonium carbonate and/or bicarbonate, the causticiation of the liquor freed from uranium which leaves the anion-exchange resin to eliminate the SO.sub.4.sup.= ions in calcium form, recycling a carbonated and/or bicarbonated liquor which is free from SO.sub.4.sup.

Abstract: The present invention relates to an improved method for removing uranyl ion complexes from a pregnant alkaline leach solution. More particularly, it relates to an improved method for removing uranyl ion carbonato complexes from a pregnant alkaline leach solution with an ion exchange resin which comprises adding carbon dioxide to the solution prior to removing the uranyl ion complexes.

Abstract: High density ion exchange resins are prepared from cross-linked, haloalkylated monovinylidene aromatic polymers which have been halogenated in the presence of a Friedel-Crafts catalyst. For example, a cross-linked chloromethylated polystyrene brominated in the presence of ferric chloride (FeCl.sub.3) may be subsequently aminated to form a high density anion exchange resin useful in thick process slurries such as those employed in uranium recovery.

Abstract: Alkaline solutions containing sulfate and sodium ions such as uranium leach liquors, are treated with cationic ion exchange resins in the ammonium form to form a solution containing soluble ammonium salts and complexes; the solution is further treated to convert the soluble sulfates into insoluble sulfates and, in the case of uranium, further treating to separate the uranium by heat and/or acidification. The ammonium can be recovered and reused as ammonium carbonate to regenerate the ion exchange resin whereby sodium ions are eluted from the resin in the form of sodium carbonate which is converted to sodium hydroxide and re-cycled for use as leaching solution.

Abstract: A method for controlling calcium, e.g. calcite, build-up in the leach solution of a uranium and/or related values recovery operation wherein the leach solution is flowed through a value bearing ore to dissolve the desired values. A soluble fluoride, e.g. sodium fluoride, is added to the leach solution after it has passed through the ore to thereby precipitate calcium fluoride from the leach solution and lower the calcium content of the leach solution. The soluble fluoride may be added to the leach solution before the leach solution passes through the process equipment which is used to remove the values from the leach solution or the soluble fluoride may be added after the leach solution passes through the process equipment. If added before, it is preferable to also add a carbonate/bicarbonate solution along with the soluble fluoride to prevent coprecipitation of uranyl/desired value fluoride or to redissolve coprecipitated fluoride back into the leach solution.

Abstract: Ion exchange process for the recovery of uranium from a pregnant carbonate lixiviant employed in uranium leaching operations in which the lixiviant is passed over a precipitation inducing anionic ion exchange resin under conditions to load the resin predominantly with non-exchangeable uranium. Non-exchangeable uranium is then recovered from the resin by eluting the resin with an aqueous acid solution having a pH no greater than 2. The process is useful in those applications in which the lixiviant contains chloride ions which inhibit the adsorption of uranyl ions.

Abstract: Organic substances are removed from a highly ionic medium by contacting the medium with a substantially hydrophobic polystyrene type resin. This process is especially useful in the hydrometallurgical processes for the removal of organic substances from highly ionic raffinates prior to the recycle of the raffinate into the hydrometallurgical process.

Abstract: A cyclic process for the treatment of a uraniferous liquor containing, in addition to the desired metal, sodium carbonate and/or bicarbonate and sodium sulphate, obtained by the alkaline attack of a sulphur-containing uraniferous ore, the said process comprising fixing the uranium over a first strong anion-exchange resin, eluting it with an ammonium carbonate and/or bicarbonate solution in the form of an ammonium uranyl tricarbonate which is subsequently decomplexed, precipitating and calcinating the precipitated uranates and/or diuranates with regeneration of the eluant solution of ammonium carbonate and/or bicarbonate, passing the liquor which is freed from uranium and leaves the first strong anion-exchange resin into a neutralization zone then over a second anion-exchange resin, eliminating the SO.sub.4.sup..dbd. ions which are subsequently precipitated in calcium form, recycling a carbonate and/or bicarbonated liquor which is free from SO.sub.4.sup..dbd.

Abstract: The invention describes the extraction of values, especially metal values such as copper and uranium, from minerals by passing the mineral in admixture with a leaching agent for the values through a contactor and extracting the values with an extractant stream immiscible with the mixture and of lesser density so that the values are captured by the extractant and can be withdrawn with the extractant and, if desired, isolated by any suitable means.

Abstract: A method for recovering uranium and/or related values which include means for protecting ion-exchange resins in the recovery operation from oxidative degradation due to contact with hydrogen peroxide. A guard chamber is positioned in the elution circuit so that barren eluant, after it is stripped of its uranium and/or related values by treatment with hydrogen peroxide, will flow through the chamber. The guard chamber contains catalytic material, e.g. activated carbon, which decomposes hydrogen peroxide upon contact into water and oxygen. The barren eluant, after it passes through the catalytic material, is used to make up fresh eluant for reuse in the recovery method without the risk of the fresh eluant causing oxidative degradation of the resins.

Abstract: A method for protecting an ion-exchange resin in a uranium and/or related values recovery operation from poisoning by polythionates contained in the leach solution. A guard chamber containing a catalytic material is positioned in the leaching circuit upstream of the resin so the leach solution will pass through the catalytic material before it contacts the resin. The catalytic material, e.g. activated carbon, converts the polythionates to non-poisoning thiosulfates, sulfites, and water which offer no poisoning threat to the resins. An oxidant, e.g. oxygen, is added to the leach solution before it passes through the catalytic material to speed up the catalytic reaction.

Abstract: This information relates to the recovery of uranium from uranium peroxide yellowcake produced by precipitation with hydrogen peroxide. The yellowcake is calcined at an elevated temperature to effect decomposition of the yellowcake to uranium oxide with the attendant evolution of free oxygen. The calcination step is carried out in the presence of a reducing agent which reacts with the free oxygen, thus retarding the evolution of chlorine gas from sodium chloride in the yellowcake. Suitable reducing agents include ammonia producing compounds such as ammonium carbonate and ammonium bicarbonate. Ammonium carbonate and/or ammonium bicarbonate may be provided in the eluant used to desorb the uranium from an ion exchange column.

Abstract: A process for the separation of metals in which a mixture of metal derivatives is converted into anion complexes by means of a complexing anion such as, for example, a halide, thiocyanate, sulphate, nitrate, or the like said anion complexes are bound to a solid, non-soluble polymer, containing oxygen bonded to carbon which is converted into a polyoxonium compound by means of the complexing liquid medium used. The complexes are separated by selective absorption and/or elution over the polymer using suited H.sup.+ ion concentrations and/or complexing anion concentrations.

Abstract: A process as described for extracting at least two desired constituents from a mineral using a liquid reagent which produces the constituents, or compounds thereof, in separable form and independently extracting those constituents, or compounds thereof. The process if especially valuable for the extraction of phosphoric acid and metal values, such as uranium from phosphate rock.

Abstract: An isotope separation apparatus comprises a plurality of independent developing units, each comprising 2 to 20 adsorbent-packed columns forming a continuous developing circuit or passageway, and the developing units are connected to at least one common main pipe for supplying an isotope mixture solution, a regenerating agent solution, or an eluent solution. Also, in a further embodiment the developing units are connected to common liquid-discharge main pipes.The separation or concentration of isotopes such as uranium isotopes, nitrogen isotopes, boron isotopes, etc., is performed by continuously developing the isotope mixture solution passed through the individual adsorbent-packed columns successively in each developing units.

Abstract: Process for the recovery of uranium from a pregnant lixiviant employed in uranium leaching operations in which the uranium is concentrated by ion exchange resin. The ion exchange resin is eluted with an eluant containing 0.05-0.5 molar ammonium carbonate. The eluant also contains a base such as ammonium hydroxide in an amount sufficient to increase the pH to a value within the range of 9.0-11.0, thus increasing the carbonate/bicarbonate ratio. This enables the use of a relatively small quantity of ammonium carbonate to provide the desired carbonate ion concentration during the elution step.

Abstract: Weakly acidic cationic ion exchange resin particles are charged with uranyl ions by contacting the particles step wise with aqueous uranyl nitrate solution at higher uranium concentrations from stage to stage. An alkaline medium is added to the uranyl nitrate solution in each stage to increase the successive pH values of the uranyl nitrate solution contacting the particles in dependence upon the uranium concentration effective for maximum charging of the particles with uranyl ions.

Abstract: A macromolecular adsorbent is suitable for recovering heavy metal ions such as uranium ions from a dilute solution such as sea water and is a polymer having pendant groups having the formula ##STR1## wherein R.sup.1 represent a C.sub.1 -C.sub.8 divalent organic group; R.sup.2 and R.sup.3 respectively represents a C.sub.1 -C.sub.5 divalent organic group; p, q, r and l respectively represent 0 or 1; R.sub.f represents a C.sub.1 -C.sub.10 divalent perfluoro group; X.sup.1 and X.sup.2 respectively represent hydroxyl group or a hydroxyl convertible group or atom.

Abstract: The present invention relates to a method for the renovation of an aquifer subsequent to the solution mining of a mineral from the aquifer. More specifically, the invention relates to the utilization of spent ion exchange resin to remove chloride ions from the aquifer.

Abstract: Uranium is recovered from alkaline leach liquors of uranium ores by treating the leach liquors with an ion exchange resin in the ammonium form to provide a solution of salts and complexes of uranium and ammonium from which the uranium is separated by treating with heat or an acid.

Abstract: An ion exchange process for the recovery of uranium from a pregnant lixiviant employed in uranium leaching operations in which the lixiviant contains chloride ions inhibiting the adsorption of uranyl ions. The ion exchange resin employed to adsorb uranium from the lixiviant has cationic adsorption sites provided by quaternary ammonium groups having a hydroxyalkyl group as a quaternizing substituent. Through the use of a resin of this type, the resin loading in the presence of chloride ions is materially increased.

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 the recovery of uranium from a saline alkaline lixiviant employed in a uranium leaching operation. An ion exchange resin is employed to adsorb uranium from the lixiviant. Prior to contacting the resin with the lixiviant, the pH of the lixiviant is reduced to a value of less than 7. By this technique, the resin loading in the presence of chloride ion is materially increased. The pH values for optimum resin loading capacity decrease as the salinity of the lixiviant increases. Resin loading is also enhanced by the presence of bicarbonate ion in the lixiviant.

Abstract: A process for selectively removing tetravalent and/or hexavalent uranium ions from a solution by using a chelate-forming cation exchanger. The solution may be prepared by contacting uranium bearing ore with either an acid or a dilute carbonate or bicarbonate solution. To facilitate removal of the uranium ions, the solution may have a pH value greater than 1.0 and a redox potential of from -50 to +250 mV.

Abstract: A process for continuously separating uranium isotopes by oxidation-reduction reaction using an anion exchanger comprising the steps of subjecting an eluant containing a deactivated oxidizing agent and a deactivated reducing agent as a mixture to oxidation to regenerate the deactivated oxidizing agent, separating the regenerated oxidizing agent from the eluant with an anion exchanger and reusing the regenerated oxidizing agent for continuing the separation of uranium isotopes.

Abstract: The oxidation of uranium is catalyzed with water-soluble copper or zinc chelates. An aqueous solution is prepared containing carbonate or bicarbonate ion, an oxidizer such as hydrogen peroxide or oxygen, and a water-soluble copper or zinc chelate which has at least two amino, carboxylic acid, or thiocarboxylic acid donor groups. The solution is pumped into an underground deposit of uranium. The water-soluble +4 state uranium is oxidized to the water-soluble +6 state which forms a complex with the carbonate ion. The solution is pumped to the surface and is recycled after precipitation of the uranium.

Abstract: Uranium is recovered from its solution through contact with a uranium-recovering material of higher resistance to water and higher mechanical strength comprising a weakly basic anion exchange resin having pyridine nuclei at its main chain or side chain, and a crossed-linked polymer structure with a high uranium selectivity at a high uranium-adsorbing speed.

Abstract: An ion-exchange hollow fiber is prepared by introducing into the wall of the fiber polymerizable liquid monomers, and polymerizing the monomers therein to form solid, insoluble, cross-linked, ion-exchange resin particles which embed in the wall of the fiber. Excess particles blocking the central passage or bore of the fiber are removed by forcing liquid through the fiber. The fibers have high ion-exchange capacity, a practical wall permeability and good mechanical strength even with very thin wall dimensions. Experimental investigation of bundles of ion-exchange hollow fibers attached to a header assembly have shown the fiber to be very efficient in removing counterions from solution.

Abstract: Anion exchange resin derived from insoluble crosslinked polymers of vinyl benzyl chloride which are prepared by polymerizing vinyl benzyl chloride and a crosslinking monomer are particularly suitable in the treatment of uranium bearing leach liquors.

Abstract: Uranium ore deposits which contain certain proportions of other metals and elemental components, such as are present in redox roll front ore deposits, are selectively leached in situ by passing therethrough relatively dilute aqueous leach solutions comprising essentially from about 0.5 to 5 grams per liter of ammonium bicarbonate and from about 0.1 to 3 grams per liter of peroxide, preferably introduced as aqueous H.sub.2 O.sub.2, and sufficient ammonia to bring the solution to a pH of from about 7.4 to 9, and preferably from 7.5 to 8.5, thereafter withdrawing from the ore deposit the aqueous leach solution enriched in uranium which it preferentially extracts along with a generally lower proportion of other metals and elements as compared to their respective ratios in the ore deposit, and contacting the enriched leach solution with a strong base anion exchange material to strip the uranium from the leach solution.

Abstract: Heavy metal ions are recovered from a dilute aqueous solution by flowing the solution through either a single bed of ion-absorbing material in successive forward and reverse directions, or through a first bed of ion-absorbing material and thereafter through a second bed of ion-absorbing material in the reverse direction of flow. The reversal of flow is to periodically mechanically agitate a bed of ion-absorbing material to dislodge contaminants, such as gelatin.The method is accomplished by using one enclosed vessel, or a pair of enclosed vessels, that have valves to control the direction of flow. A timing device preferably automatically reverses the direction of flow about each hour.After a relatively large number of reversals of flow the heavy metal ions are recovered from the ion-absorbing material and the same is regenerated in the process to again absorb ions from the dilute aqueous solution.

Abstract: PuO.sub.2 -containing solids, particularly residues from incomplete HNO.sub.3 dissolution of irradiated nuclear fuels, are dissolved in aqueous HI. The resulting solution is evaporated to dryness and the solids are dissolved in HNO.sub.3 for further chemical reprocessing. Alternatively, the HI solution containing dissolved Pu values, can be contacted with a cation exchange resin causing the Pu values to load the resin. The Pu values are selectively eluted from the resin with more concentrated HI.

Abstract: A process for removing pollutants or minerals from lake, river or ocean sediments or from mine tailings is disclosed. Magnetically attractable collection units containing an ion exchange or sorbent media with an affinity for a chosen target substance are distributed in the sediments or tailings. After a period of time has passed sufficient for the particles to bind up the target substances, a magnet drawn through the sediments or across the tailings retrieves the units along with the target substance.

Abstract: An anion exchange resin particle provided with specific structure as well as specific functional groups is found to be suitable for uranium technology, especially for separation of uranium isotopes.

Abstract: Uranium-235 is efficiently concentrated using a solution containing uranium-238 and uranium-235 by passing a solution containing uranium (VI) complex anions through a body of an anion exchange material to adsorb uranium (VI) complex anions on a portion of the anion exchange material and then passing a solution of a reducing agent through the anion exchange material thus retaining uranium in the form of the uranium (VI) complex anions to elute the uranium ions while reducing the uranium (VI) complex anions to uranium (IV) complex ions.

Abstract: A process for separation of uranium isotopes by chromatography through an anion exchange material is found to be improved in efficiency of separation as well as in productivity by addition of a catalyst for accelerating electron exchange reactions occurring in the system under conditions to retain uranyl ions on the anion exchange material preferentially over uranous ions.

Abstract: A process for removing polonium from hydrocarbons which process comprises contacting fluid polonium containing hydrocarbons with an ion exchange resin, having a dry surface area of at least 1 m.sup.2 /g and containing exchange groups selected from the group consisting of acidic and strongly basic exchange groups.The ion exchange resins are preferably macroreticular resins. Suitable hydrocarbons for treatment are natural gas condensates.