Liquid-liquid Extracting Patents (Class 423/8)
  • Patent number: 7282187
    Abstract: A process for selectively extracting metal values, including, uranium, thorium, scandium and zirconium, from starting materials which include the metal values. The process is particularly well suited to extracting metal and recovering metal values from tantalum/niobium production process ore residues.
    Type: Grant
    Filed: March 26, 1996
    Date of Patent: October 16, 2007
    Assignee: Caboi Corporation
    Inventors: Patrick M. Brown, Robert A Hard, Donna D. Harbuck, G. Kyle Green
  • Patent number: 7157061
    Abstract: A method of recovering daughter isotopes from a radioisotope mixture. The method comprises providing a radioisotope mixture solution comprising at least one parent isotope. The at least one parent isotope is extracted into an organic phase, which comprises an extractant and a solvent. The organic phase is substantially continuously contacted with an aqueous phase to extract at least one daughter isotope into the aqueous phase. The aqueous phase is separated from the organic phase, such as by using an annular centrifugal contactor. The at least one daughter isotope is purified from the aqueous phase, such as by ion exchange chromatography or extraction chromatography. The at least one daughter isotope may include actinium-225, radium-225, bismuth-213, or mixtures thereof. A liquid-liquid extraction system for recovering at least one daughter isotope from a source material is also disclosed.
    Type: Grant
    Filed: September 24, 2004
    Date of Patent: January 2, 2007
    Assignee: Battelle Energy Alliance, LLC
    Inventors: David H. Meikrantz, Terry A. Todd, Troy J. Tranter, E. Philip Horwitz
  • Patent number: 7157003
    Abstract: The invention concerns a cyclic method for separating at least one chemical element E1 from at least one chemical element E2 from an aqueous solution containing said elements, which employs a mixture of two extractants operating in non-overlapping chemical fields. Each cycle of said method comprises: a) co-extracting elements E1 and E2 by means of an organic phase containing a first extractant suited to causing the migration of said elements into said organic phase; b) adding to the organic phase a second extractant suited to selectively retaining the element(s) E2 in said organic phase during step c): c) selectively stripping the element(s) E1 from the organic phase; d) selectively stripping the element(s) E2 from the organic phase; e) separating the first and second extractants present in said organic phase at the end of step d).
    Type: Grant
    Filed: October 7, 2003
    Date of Patent: January 2, 2007
    Assignee: Commissariat A L'Energie Atomique
    Inventors: Pascal Baron, Michael Lecomte, Xavier Heres, Bernard Mauborgne
  • Patent number: 7063792
    Abstract: A method for separating a metal (a) from a metal (2), preferably zirconium from hafnium, which consists in dissolving said metals in an aqueous solution wherein said metals are in a state preventing them from passing through a nanofiltration membrane; treating the aqueous medium with a ligand, for example EDTA, which is complexed with metal (1) and/or metal (2), then in passing the resulting treated medium on a filtering membrane allowing through the ligand-metal complexes, but retaining the metals not complexed with the ligand.
    Type: Grant
    Filed: September 10, 2001
    Date of Patent: June 20, 2006
    Assignee: Compagnie Europeenne du Zirconium CEZUS
    Inventors: Noël Ozanne, Marc Lionel Lemaire, Alain Jean-Louis Guy, Jacques Henri Foos, Stéphane Pellet-Rostaing, Frédéric Chitry
  • Patent number: 7025899
    Abstract: The preparation of concentrated solutions of oxime metal extractants, such as aldoximes and ketoximes, or mixtures of aldoxime and ketoxime, and the use thereof in formulating or preparing extraction reagent compositions for use in an extractant organic phase in a process of extracting metals from aqueous solutions containing metal values; and in particular, to concentrates which are solutions of individual ketoxime or aldoxime or mixtures of water-insoluble hydroxy aldoximes and ketoximes, in varying ratios by weight of 1:100 aldoxime to ketoxime, or conversely, 100:1 ketoxime to aldoxime, in water-immiscible hydrocarbon solvents or equilibrium modifiers. The invention also provides for maintaining stability of concentrates determined by accelerating rate calorimetry to define the ranges of oxime concentration and volume whereby the concentrate will be a stable, flowable, pourable and pumpable concentrate which can be safely stored long term.
    Type: Grant
    Filed: December 21, 2001
    Date of Patent: April 11, 2006
    Assignee: Cognis Corporation
    Inventors: R. Brantley Sudderth, George A. Wolfe, Ralph L. Jensen, Gary A. Kordosky, Michael J. Virnig, Mary Collins, Stephen M. Olafson, Terry L. Crandell, Hans C. Hein
  • Patent number: 6998052
    Abstract: A multicolumn selectivity inversion generator separation method has been developed in which a desired daughter radionuclide is selectively extracted from a solution of the parent and daughter radionuclides by a primary separation column, stripped, and passed through a second guard column that retains any parent or other daughter impurities, while the desired daughter elutes. This separation method minimizes the effects of radiation damage to the separation material and permits the reliable production of radionuclides of high chemical and radionuclidic purity for use in diagnostic or therapeutic nuclear medicine.
    Type: Grant
    Filed: April 9, 2003
    Date of Patent: February 14, 2006
    Assignee: PG Research Foundation
    Inventors: E. Philip Horwitz, Andrew H. Bond
  • Publication number: 20040247504
    Abstract: A two-cycle countercurrent extraction process for recovery of highly pure uranium from fertilizer grade weak phosphoric acid. The proposed process uses selective extraction using di-(2-ethyl hexyl) phosphoric acid (D2EHPA) and tri-n-butyl phosphate (TBP) with refined kerosene as synergistic extractant system on hydrogen peroxide treated phosphoric acid, and stripping the loaded extract with strong phosphoric acid containing metallic iron to lower redox potential. The loaded-stripped acid is diluted with water back to weak phosphoric acid state and its redox potential raised by adding hydrogen peroxide and re-extracted with same extractant system. This extract is first scrubbed with sulfuric acid and then stripped with alkali carbonate separating iron as a precipitate, treated with sodium hydroxide precipitating sodium uranate, which is re-dissolved in sulfuric acid and converted with hydrogen peroxide to highly pure yellow cake of uranium peroxide.
    Type: Application
    Filed: February 11, 2004
    Publication date: December 9, 2004
    Inventors: Harvinderpal Singh, Shyamkant Laxmidutt Mishra, Anitha Mallavarapu, Vijayalakshmi Ravishankar, Ashok Giriyalkar, Manojkumar Kedarnath Kotekar, Tapan Kumar Mukherjee
  • Publication number: 20040202595
    Abstract: A treatment for waste pickling solutions containing iron and method of ferric oxide formation, consisting of spent acid with iron content, the addition therein of sodium hydroxide to adjust the pH value, the execution of a chemical reaction in another tank into which sodium hydroxide and air are added while the admixture is exposed to an ultraviolet beam circuit in a photo-oxidation process, and finally magnetic culling to separate ferric oxide in the solution.
    Type: Application
    Filed: October 2, 2003
    Publication date: October 14, 2004
    Inventors: Ton-Shyun Lin, Po-Jung Tseng, Jong-Kang Huang, Min-Shin Lin
  • Patent number: 6780384
    Abstract: A method of recovering zirconium values from an ore containing zircon, baddeleyite, and uranium is disclosed. The method includes fusing the ore with soda ash and contacting the resulting fused ore with sulfuric acid, which generates an acid leach liquor that contains zirconium and uranium values and solids that comprise baddeleyite and silica. Baddeleyite is recovered by contacting it with sulfuric acid to convert baddeleyite to zirconium sulfate, which can be dissolved in the acid leach liquor. The method also includes separating zirconium from uranium by solvent extraction followed by precipitation.
    Type: Grant
    Filed: March 7, 2002
    Date of Patent: August 24, 2004
    Assignee: Cotter Corporation (NSL)
    Inventors: Allen L. Williams, Robert W. Philips, Jr., David R. Tierney, Daniel R. Dilday
  • Patent number: 6623710
    Abstract: A spent fuel reprocessing method including the steps of partitioning U and Pu(III) in a solvent by solvent extraction and subsequently polishing the solvent in a neptunium rejection operation for removing Np therefrom. The solvent obtained from the neptunium rejection operation (the polished solvent or NpA solvent product) is then recycled to a U/Pu partitioning operation. The method enables a reduction in solvent feed and solvent effluent volumes.
    Type: Grant
    Filed: September 29, 2000
    Date of Patent: September 23, 2003
    Assignee: British Nuclear Fuels PLC
    Inventors: Emmanuel Gaubert, Gavin Paul Towler, Andrew Lindsay Wallwork
  • Publication number: 20030113247
    Abstract: An improved process of extraction of uranium from phosphoric acid and in particular uranium VI from phosphoric acid especially strong phosphoric acid using a selective synergistic extractant mix of an organo-phosphorous acid and a neutral extraction agent. The process basically involves the steps of extraction comprising contacting said acid with a selective synergistic extractant system of di-nonyl phenyl phosphoric acid (DNPPA) and a neutral agent selected from di-butyl butyl phosphonate (DBBP) and tri-n-octyl phosphine oxide (TOPO); and recovering the uranium values from the loaded organic phase. The above process would provide for an improved process for recovery of uranium both from weak and strong phosphoric acids using a stable and relatively cheap extractant system. The process is directed to improved recovery of U-VI from phosphoric acid by way of a simple, industrially applicable and cost-effective process.
    Type: Application
    Filed: September 7, 2001
    Publication date: June 19, 2003
    Inventors: Harvinderpal Singh, Shyamkant Laxmidutt Mishra, Ravishankar Vijayalakshmi, Ashok Basawanthappa Giriyalkar, Chiranjib Kumar Gupta
  • Patent number: 6533938
    Abstract: A method is describe for removing metal ions of interest from aqueous solutions containing low concentrations of the metal ions of interest. The method involves the use of a microbially produced polymer, &ggr;-glutamic acid. The polymer is used in conjunction with tangential flow filtration and results in substantial removal of metal ions.
    Type: Grant
    Filed: May 26, 2000
    Date of Patent: March 18, 2003
    Assignee: Worcester Polytechnic Institue
    Inventors: Alexander Dilorio, Sonny Mark, Philip A. Tongue
  • Patent number: 6379634
    Abstract: A method of dissolving in an ionic liquid a metal in an initial oxidation state below its maximum oxidation state, characterized in that the ionic liquid reacts with the metal and oxidizes it to a higher oxidation state. The initial metal may be in the form of a compound thereof and may be irradiated nuclear fuel comprising UO2 and/or PuO2 as well as fission products. The ionic liquid typically is nitrate-based, for example a pyridinium or substituted imidazolium nitrate, and contains a Bronstead or Franklin acid to increase the oxidizing power of the nitrate. Suitable acids are HNO3, H2SO4 and [NO+]. Imidazolium nitrates and certain pyridinium nitrates form one aspect of the invention.
    Type: Grant
    Filed: July 2, 1999
    Date of Patent: April 30, 2002
    Assignee: British Nuclear Fuels Plc
    Inventors: Mark Fields, Graham Victor Hutson, Kenneth Richard Seddon, Charles Mackintosh Gordon
  • Patent number: 6328782
    Abstract: The present invention provides a novel process for the removal and recovery of radionuclides from waste waters and process streams. The process of the present invention utilizes a combination of a supported liquid membrane (SLM) and a strip dispersion to improve extraction of the target species while increasing membrane stability and reducing processing costs. Additionally, the invention provides a family of new extractants, alkyl phenylphosphonic acids, for the removal and recovery of radionuclides and/or metals, including the use of the new extractants in the process. The new extractant selectively removes radionuclides and metals from the feed stream to provide a concentrated strip solution of the target species.
    Type: Grant
    Filed: February 4, 2000
    Date of Patent: December 11, 2001
    Assignee: Commodore Separation Technologies, Inc.
    Inventor: W. S. Winston Ho
  • Patent number: 6270737
    Abstract: Cesium and strontium are extracted from aqueous acidic radioactive waste containing rare earth elements, technetium and actinides, by contacting the waste with a composition of a complex organoboron compound and polyethylene glycol in an organofluorine diluent mixture. In a preferred embodiment the complex organoboron compound is chlorinated cobalt dicarbollide, the polyethylene glycol has the formula RC6H4(OCH2CH2)nOH, and the organofluorine diluent is a mixture of bis-tetrafluoropropyl ether of diethylene glycol with at least one of bis-tetrafluoropropyl ether of ethylene glycol and bis-tetrafluoropropyl formal. The rare earths, technetium and the actinides (especially uranium, plutonium and americium), are extracted from the aqueous phase using a phosphine oxide in a hydrocarbon diluent, and reextracted from the resulting organic phase into an aqueous phase by using a suitable strip reagent.
    Type: Grant
    Filed: March 3, 2000
    Date of Patent: August 7, 2001
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Boris N. Zaitsev, Vyacheslav M. Esimantovskiy, Leonard N. Lazarev, Evgeniy G. Dzekun, Valeriy N. Romanovskiy, Terry A. Todd, Ken N. Brewer, Ronald S. Herbst, Jack D. Law
  • Patent number: 6258333
    Abstract: The present invention relates to solvents, and methods, for selectively extracting and recovering radionuclides, especially cesium and strontium, rare earths and actinides from liquid radioactive wastes. More specifically, the invention relates to extracting agent solvent compositions comprising complex organoboron compounds, substituted polyethylene glycols, and neutral organophosphorus compounds in a diluent. The preferred solvent comprises a chlorinated cobalt dicarbollide, diphenyl-dibutylmethylenecarbamoylphosphine oxide, PEG-400, and a diluent of phenylpolyfluoroalkyl sulfone. The invention also provides a method of using the invention extracting agents to recover cesium, strontium, rare earths and actinides from liquid radioactive waste.
    Type: Grant
    Filed: October 7, 1999
    Date of Patent: July 10, 2001
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Valeriy Nicholiavich Romanovskiy, Igor V. Smirnov, Vasiliy A. Babain, Terry A. Todd, Ken N. Brewer
  • Patent number: 6238566
    Abstract: Proposed is an improvement in a multi-stage solvent extraction process of a metal value such as rare earth elements from an acidic feed solution containing the metal value in the form of a water-soluble salt by bringing the aqueous solution into contact with a water-immiscible organic extractant solution containing an extractant compound which releases an acid when combined with the metal ions.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: May 29, 2001
    Assignee: Shin-Etsu Chemical Co., Ltd.
    Inventors: Norifumi Yoshida, Jun-ichi Nakayama
  • Patent number: 6093375
    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.
    Type: Grant
    Filed: August 7, 1998
    Date of Patent: July 25, 2000
    Assignee: British Nuclear Fuels PLC
    Inventors: Robin John Taylor, Iain Stewart Denniss, Andrew Lindsay Wallwork
  • Patent number: 5966584
    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.
    Type: Grant
    Filed: September 17, 1997
    Date of Patent: October 12, 1999
    Assignee: Forschungszentrum Julich GmbH
    Inventors: Giuseppe Modolo, Reinhard Odoj
  • Patent number: 5965025
    Abstract: A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated .beta.-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated .beta.-diketone and a trialkyl phosphate, or a fluorinated .beta.-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated .beta.-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides.
    Type: Grant
    Filed: January 21, 1998
    Date of Patent: October 12, 1999
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Kenneth E. Laintz
  • Patent number: 5928616
    Abstract: In a solvent extraction method a contactor comprises a forward extraction section comprising sub-sections thereof and a back extraction section comprising sub-sections thereof. To enable higher concentrations of solute to be obtained in the backwash liquor, the contactor is operated with recycle of partially-loaded solvent, via a line from a back extraction sub-section to a forward extraction sub-section.
    Type: Grant
    Filed: May 22, 1995
    Date of Patent: July 27, 1999
    Assignee: British Nuclear Fuels PLC
    Inventor: Geoffrey Horrocks Bailey
  • Patent number: 5926687
    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.
    Type: Grant
    Filed: October 4, 1995
    Date of Patent: July 20, 1999
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Jean-Fran.cedilla.ois Dozol, Helene Rouquette, Rocco Ungaro, Alessandro Casnati
  • Patent number: 5888397
    Abstract: A solid/liquid process for the separation and recovery of chaotropic anions from an aqueous solution is disclosed. The solid support comprises separation particles having surface-bonded poly(ethylene glycol) groups, whereas the aqueous solution from which the chaotropic anions are separated contains a poly(ethylene glycol) liquid/liquid biphase-forming amount of a dissolved salt (lyotrope). A solid/liquid phase admixture of separation particles containing bound chaotropic anions in such an aqueous solution is also contemplated, as is a chromatography apparatus containing that solid/liquid phase admixture.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: March 30, 1999
    Assignees: ARCH Develop. Corp., The Board of Regents for Northern Illinois University
    Inventors: Robin Rogers, E. Philip Horwitz, Andrew H. Bond
  • Patent number: 5881358
    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
    Type: Grant
    Filed: December 24, 1997
    Date of Patent: March 9, 1999
    Assignees: Cosmo Research Institute, Cosmo Oil Co., Ltd.
    Inventors: Sotaro Miyano, Nobuhiko Iki, Fumitaka Narumi, Naoya Morohashi, Hitoshi Kumagai
  • Patent number: 5863439
    Abstract: A process for preconcentrating and separating radium from a contaminated solution containing at least water and radium includes the steps of adding a quantity of a water-soluble macrocyclic polyether to the contaminated solution to form a combined solution. An acid is added to the combined solution to form an acidic combined solution having an ?H.sup.+ ! concentration of about 0.5M. The acidic combined solution is contacted with a sulfonic acid-based strong acid cation exchange medium or a organophilic sulfonic acid medium having a plurality of binding sites thereon to bind the radium thereto and to form a radium-depleted solution. The radium-depleted solution is separated from the strong acid cation exchange medium or organophilic sulfonic acid medium. The radium remaining bound to the exchange medium or organophilic reagent is then stripped from the exchange medium or organophilic medium and the activity of the radium is measured.
    Type: Grant
    Filed: June 6, 1997
    Date of Patent: January 26, 1999
    Assignee: Arch Development Corporation
    Inventors: Mark Dietz, E. Philip Horwitz, Renato Chiarizia, Richard A. Bartsch
  • Patent number: 5826161
    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.
    Type: Grant
    Filed: May 15, 1997
    Date of Patent: October 20, 1998
    Assignees: Commissariat a l'Energie Atomique, Compagnie Generale des Matieres Nucleaires
    Inventors: Charles Madic, Pierre-Yves Cordier
  • Patent number: 5792357
    Abstract: A method of extracting metal and metalloid species from a solid or liquid substrate using a supercritical fluid solvent containing one or more chelating agents followed by back-extracting the metal and metalloid species from the metal and metalloid chelates formed thereby. The back-extraction acidic solution is performed utilizing an acidic solution. Upon sufficient exposure of the metal and metalloid chelates to the acidic solution, the metal and metalloid species are released from the chelates into the acid solution, while the chelating agent remains in the supercritical fluid solvent. The chelating agent is thereby regenerated and the metal and metalloid species recovered.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: August 11, 1998
    Assignee: Idaho Research Foundation, Inc.
    Inventors: Chien M. Wai, Neil G. Smart, Yuehe Lin
  • Patent number: 5766478
    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.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: June 16, 1998
    Assignee: The Regents of the University of California, Office of Technology Transfer
    Inventors: Barbara F. Smith, Thomas W. Robison
  • Patent number: 5758255
    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.
    Type: Grant
    Filed: August 19, 1996
    Date of Patent: May 26, 1998
    Assignee: Nalco Chemical Company
    Inventors: E. Michael Kerr, Kenneth M. Smith, II
  • Patent number: 5750081
    Abstract: A method of extracting metal species from a metal species containing medium which comprises contacting the medium with an extractant solvent which comprises a supercritical fluid and a complexant for solubilizing metal species in the said medium and also a conditioning agent for changing the oxidation state of the metal species.
    Type: Grant
    Filed: January 31, 1996
    Date of Patent: May 12, 1998
    Assignee: British Nuclear Fuels plc
    Inventor: Neil Graham Smart
  • Patent number: 5708958
    Abstract: A method is provided for separating trivalent actinides and rare earth elements in the TRUEX method using a CMPO-TBP mixed solvent. The method of separating trivalent actinides and rare earth elements comprises a trivalent actinide/rare earth extraction step wherein trivalent actinides and rare earth elements are extracted by a solvent from highly acid waste generated by reprocessing of spent nuclear fuel, a nitric acid removal step wherein the nitric acid concentration of the solvent used to extract the trivalent actinides and rare earth elements is reduced, and a separation step wherein the trivalent actinides and rare earth elements contained in the solvent of low nitric acid concentration, are separated from each other.
    Type: Grant
    Filed: August 12, 1996
    Date of Patent: January 13, 1998
    Assignee: Doryokuro Kakunenryo Kaihatsu Jigyodan
    Inventors: Yoshikazu Koma, Masayuki Watanabe, Shinichi Nemoto
  • Patent number: 5666642
    Abstract: Methods and agents for extracting cesium and strontium ions from aqueous solutions, including aqueous fission product waste solutions, are disclosed using substituted metal dicarbollide ions containing one or more chemical groups that increase solubility of the substituted metal dicarbollide ion in non-nitrated, non-chlorinated solvents, or using metal dicarbollide ion-substituted silicones.
    Type: Grant
    Filed: April 21, 1995
    Date of Patent: September 9, 1997
    Assignee: Coremetals Research, Inc.
    Inventors: M. Frederick Hawthorne, Gary B. Dunks
  • Patent number: 5463177
    Abstract: The extraction process includes supplying solvent under gas pressure for introduction of the solvent adjacent the bottom of a vessel containing the sample. The vessel lies in a water bath and ultrasonic energy is applied to the bath and hence to the sample to facilitate interaction between the solvent and the sample. Because the solvent is immiscible in the sample and of lesser density, the solvent and solubilized material rise to the top of the vessel. An extraction tube under vacuum pressure continuously removes the solvent with the solubilized material.
    Type: Grant
    Filed: August 23, 1994
    Date of Patent: October 31, 1995
    Assignee: General Electric Company
    Inventor: John K. Youngs
  • Patent number: 5422084
    Abstract: The invention relates to a process for dissolving plutonium dioxide by means of OH.sup.- radicals produced by radiolysis of water and usable for the treatment of dissolving fines and plutoniferous waste.To this end, contacting takes place in a reactor (1) of solid products containing PuO.sub.2 coming from the hopper (5) with an aqueous nitric solution (3) irradiated by radiation or charged particles for producing OH.sup.- radicals by radiolysis of said solution, in the presence of a reagent such as N.sub.2 O, able to trap the solvated electrons and the H.sup.- radicals produced in simultaneous manner and optionally a redox mediator such as silver.Irradiation can take place by an alpha or beta emitter present in the solution or by an external source such as an irradiator or an electron accelerator.
    Type: Grant
    Filed: March 5, 1993
    Date of Patent: June 6, 1995
    Inventor: Charles Madic
  • Patent number: 5419887
    Abstract: The isotopes of boron, .sup.10 B and .sup.11 B, are separated by means of a gas-liquid chemical exchange reaction involving the isotopic equilibrium between gaseous BF.sub.3 and a liquid BF.sub.3 . donor molecular addition complex formed between BF.sub.3 gas and a donor chosen from the group consisting of: nitromethane, acetone, methyl isobutyl ketone, or diisobutyl ketone.
    Type: Grant
    Filed: January 25, 1994
    Date of Patent: May 30, 1995
    Assignee: Research & Development Institute, Inc.
    Inventors: Frank P. McCandless, Ronald S. Herbst
  • Patent number: 5344624
    Abstract: The invention concerns the recovery of Pu (IV) by using crown compounds.According to the invention, the aqueous solution containing the plutonium (IV) is placed in contact with at least one crown compound, for example DCH 18C6, dissolved in an organic diluting agent, such as benzonitrile. In the case where the solution only contains traces of Pu, it is possible to use a crown compound secured to a solid phase, such as silica.The aqueous solution is a concentrated solution of fission products, an effluent originating from an irradiated nuclear fuel reprocessing installation or a concentrated solution of plutonium with americium.
    Type: Grant
    Filed: August 25, 1992
    Date of Patent: September 6, 1994
    Assignee: Cogema-Compagnie Generale des Matieres Nucleaires
    Inventors: Jacques Foos, Marc Lemaire, Alain Guy, Vincent Guyon, Rodolphe Chomel, Andre Delo Ge, Pierre Doutreluigne, Henri Le Roy
  • Patent number: 5183645
    Abstract: The invention concerns the recovery of Pu (IV) by using crown compounds.According to the invention, the aqueous solution containing the plutonium (IV) is placed in contact with at least one crown compound, for example DCH 18C6, dissolved in an organic diluting agent, such as benzonitrile. In the case where the solution only contains traces of Pu, it is possible to use a crown compound secured to a solid phase, such as silica.The aqueous solution is a concentrated solution of fission products, an effluent originating from an irradiated nuclear fuel reprocessing installation or a concentrated solution of plutonium with americium.
    Type: Grant
    Filed: December 11, 1990
    Date of Patent: February 2, 1993
    Assignee: Cogema-Compagnie Generale des Matieres Nuclearies
    Inventors: Jacques Foos, Marc Lemaire, Alain Guy, Vincent Guyon, Rodolphe Chomel, Andre Deloge, Pierre Doutreluigne, Henri Le Roy
  • Patent number: 5171546
    Abstract: The invention relates to the use of thioether ligands in accordance with the formula: ##STR1## in which R.sup.1 and R.sup.2, which can be the same or different, represent alkyl radicals, R.sup.3 is an alkyl radical and A represents a divalent radical chosen from among the radicals of formula:--(CH.sub.2).sub.m ----(CH.sub.2).sub.n --X--(CH.sub.2).sub.p -- ##STR2## in which m is equal to 0 or is an integer from 1 to 6, n and p are integers between 1 and 6 and X represents O or S, for recovering the palladium present in a nitric aqueous solution (A.sub.0) for dissolving irradiated nuclear fuel elements.For example, it is possible to use the ligand of formula (I) with A representing CH.sub.2 --S--CH.sub.2 and R.sup.1 and R.sup.2 representing C.sub.10 H.sub.21.
    Type: Grant
    Filed: May 14, 1991
    Date of Patent: December 15, 1992
    Assignee: Cogema-Compagnie Generale des Matieres Nucleaires
    Inventors: Alain Guy, Marc Lemaire, Jacques Foos, Gerard Le Buzit, Vincent Guyon, Thierry Moutarde, Rodolph Chomel, Micheline Draye
  • Patent number: 5085834
    Abstract: A method for separating plutonium from uranium and from fission products with the aid of crown ether compounds comprising contacting an aqueous solution A0 containing Pu, U and fission products with an organic solvent O0 containing at least one crown ether compound to obtain an organic solution O1 containing Pu and U; extracting U from the organic solution O1 with an aqueous solution A4 such as water or nitric acid to obtain an aqueous solution A5 containing U and an organic solution O3 containing mainly of Pu and recovering Pu from the organic solution using an aqueous solution A6 such as sulfuric acid.
    Type: Grant
    Filed: December 11, 1990
    Date of Patent: February 4, 1992
    Assignee: Cogema-Compaignie Generale des Matieres Nucleaires
    Inventors: Marc Lemaire, Alain Guy, Jacques Foos, Rodolphe Chomel, Pierre Doutreluigne, Thierry Moutarde, Vincent Guyon, Henri Le Roy
  • Patent number: 5057289
    Abstract: A process for the separation of uranium and plutonium as well as fission ducts including technetium from a nitric acid feed solution (fuel solution) in which said solution is treated with an extraction agent in an organic solvent to charge said agent with U, Pu and fission products including technetium by the counterflow process. The charged extraction agent containing U, Pu and fission products including technetrium is treated with a washing solution and subsequently with a reducing agent for the separation of the uranium from the plutonium and from fission products including technetium not previously washed out. To improve the separation of uranium and obtain a cleaner uranium end product, the treatment of the organic solvent containing said charged agent with reducing agent is effected in one or more stages by the crossflow process instead of by the counterflow process.
    Type: Grant
    Filed: March 9, 1989
    Date of Patent: October 15, 1991
    Assignee: Deutsche Gesellschaft fur Wideraufarbeitung von Kernbrennstoffen mbH
    Inventors: Wolfgang Issel, Werner Knoch, Hartmut Ramm
  • Patent number: 5035840
    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.
    Type: Grant
    Filed: October 1, 1990
    Date of Patent: July 30, 1991
    Assignee: Chemical Waste Management, Inc.
    Inventor: Yuval Halpern
  • Patent number: 5028402
    Abstract: Process for separating plutonium from uranium contained in a nitric acid aqueous solution from the reprocessing of irradiated fuels comprising plutonium, uranium and fission products by means of crown ethers. Nitric acid aqueous solution (5) containing plutonium, uranium and fission products is contacted at (2) with an organic liquid membrane (3) containing a crown ether. The uranium and plutonium are extracted in the liquid membrane (3) and then transferred by said membrane into a receiving solution (7), which becomes enriched with uranium, because the latter is transferred more rapidly than the plutonium. The crown ether can be DCH 18 C6 or DB 18 C6.
    Type: Grant
    Filed: June 16, 1989
    Date of Patent: July 2, 1991
    Assignee: Cogema Compagnie General des Matieres Nucleaires
    Inventors: Jacques Foos, Pierre Epherre, Alain Guy, Marc Lemaire, Rodolph Chomel, Gerard Cauquil, Pierre Patigny, Alain Vian
  • Patent number: 4968504
    Abstract: The separation of uranium, iron and scandium is achieved by the following process wherein a material containing these values is dissolved in mineral acid to form an aqueous solution, thereafter, an iminodiacetic acid cationic ion exchange resin is used to retain a major portion of the scandium and uranium. A raffinate containing the iron is formed. The ion exchange resin having said scandium and uranium retained thereon is rinsed with a dilute acid to remove residual metals other than scandium and uranium. The resin is eluted with an aqueous solution of an organic chelating acid to remove a major portion of the scandium from said resin and to form an aqueous solution containing scandium. The resin is then eluted with an aqueous solution of a mineral acid to remove a major portion of the uranium from the resin to form an aqueous solution containing the uranium. The scandium and uranium are recovered as solids.
    Type: Grant
    Filed: October 19, 1989
    Date of Patent: November 6, 1990
    Assignee: GTE Laboratories Incorporated
    Inventor: William J. Rourke
  • Patent number: 4954293
    Abstract: Thorium and rare earth values are separated from a fluoride concentrate thereof, by decomposing such concentrate with aqueous sodium hydroxide under conditions such that the amount of sodium hydroxide is at least 1.4 times the stoichiometric amount and the initial sodium hydroxide/water ratio in the medium of decomposition ranges from 1 to 40% by weight, whereby a precipitate of thorium hydroxide and rare earth hydroxides is produced, together with a solution of sodium fluoride, and then separating the NaF solution therefrom.
    Type: Grant
    Filed: November 28, 1988
    Date of Patent: September 4, 1990
    Assignee: Rhone-Poulenc Chimie
    Inventors: Francinet Cailly, Frederic Fabre
  • Patent number: 4941998
    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.
    Type: Grant
    Filed: May 18, 1988
    Date of Patent: July 17, 1990
    Assignee: Deutsche Gesellschaft fur Wiederaufarbeitung von Kernbrennstoffen mbH
    Inventors: Klaus Eiben, Heinz Evers
  • Patent number: 4913884
    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.
    Type: Grant
    Filed: November 9, 1988
    Date of Patent: April 3, 1990
    Assignee: Westinghouse Electric Corp.
    Inventor: Robert J. Feuling
  • Patent number: 4871478
    Abstract: A process for the extraction of uranium and plutonium from spent nuclear fuels or breeder reactor materials. The spent nuclear fuels or breeder reactor materials are dissolved in nitric acid to provide an aqueous acid solution containing uranium, plutonium, neptunium, other transuranium elements, fission products, corrosion products, activation products and other contamination products. This aqueous acid solution is fed, as an aqueous phase, at a controllable flow rate into a liquid-liquid extraction apparatus also having an organic solvant phase flowing at a controllable rate. The organic phase contains an extraction agent. The temperature of solutions in the extraction apparatus and/or the concentration of the aqueous acid solution before the said aqueous acid solution is fed into the extraction apparatus, is adjusted to satisfy the following inequality: ##EQU1## where T.sub.E =the temperature of the solutions in the extractor (.degree.C.);U.sub.f =the uranium concentration of the feed solution (g/l);Pu.
    Type: Grant
    Filed: November 9, 1987
    Date of Patent: October 3, 1989
    Assignee: Kernforschungszentrum Karlsruhe GmbH
    Inventors: Georg Petrich, Helmut Schmieder
  • Patent number: 4867951
    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).
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: September 19, 1989
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: Barbara F. Smith, Gordon D. Jarvinen, Robert R. Ryan
  • Patent number: 4855081
    Abstract: A method 20 for decontaminating plastic products and materials which have become radioactively contaminated. The treatment method 20 involves dissolving such plastics in a dissolution tank 28 in an organic solvent and treating the resulting solution by a solvent extraction technique in column 36 to remove particulate and dissolved radioactive contaminants from the plastic. The contaminants can be buried in a low level radioactive waste site and the separated plastic material can be disposed of in a sanitary landfill or recycled into other plastic products.
    Type: Grant
    Filed: June 7, 1988
    Date of Patent: August 8, 1989
    Assignee: Nutech, Inc.
    Inventor: James M. Wallace
  • Patent number: 4855080
    Abstract: A method 20 for decontaminating specially selected plastic materials comprised of polymers and copolymers of unsaturated organic acids and other specially selected plastic materials, which have become radioactively contaminated, includes dissolving such plastic materials in an aqueous solvent 34 and treating the resulting solution selectively via filtration 36, ion-exchange absorption 40, and precipitation 44 processes to remove particulate and dissolved radioactive contaminants. The treated aqueous stream may be discharged to a sewage stream and the separated plastic materials can be disposed of in a sanitary landfill or recycled into other plastic products.
    Type: Grant
    Filed: June 7, 1988
    Date of Patent: August 8, 1989
    Assignee: Nutech, Inc.
    Inventors: William J. McConaghy, James M. Wallace