Alkali Metal Aluminate Patents (Class 423/119)
  • Patent number: 8282897
    Abstract: A process for the recovery of high purity boehmite with controlled pore size from spent hydroprocessing catalyst includes the step of treating the spent hydroprocessing catalyst composition in order to get recovery of the aluminas after extracting the valuable metals. The process permits easy and resourceful recovery of high quality boehmite from waste catalyst, which can be further used as hydroprocessing catalyst carrier having a pore structure almost identical or better than that used in heavy oil hydroprocessing catalysts. Such catalyst carrier is required to have high pore volume, macro-porosity, high strength and optimum surface area for active metal dispersion. The treating steps include process steps such as decoking, roasting, leaching, dissolving, digestion, precipitation, washing, stripping, and the like. The recovery steps include digestion, hydrothermal treatment, flocculation or precipitation, filtration, drying, calcination and the like.
    Type: Grant
    Filed: August 25, 2010
    Date of Patent: October 9, 2012
    Assignee: Kuwait Institute for Scientific Reaearch
    Inventor: Meena Marafi
  • Patent number: 8142709
    Abstract: The invention provides a rapid and economical process for manufacturing a transparent, spinel based ceramic. A transparent body of sintered magnesium aluminate spinel having excellent optical and mechanical properties is provided in a single-stage thermal process.
    Type: Grant
    Filed: May 27, 2009
    Date of Patent: March 27, 2012
    Assignee: Ben-Gurion University of the Negev Research & Development Authority
    Inventors: Nahum Frage, Moshe Dariel, Shai Meir, Sergei Kalabuchov
  • Publication number: 20110311419
    Abstract: The present invention relates to the use of lithium salts and/or magnesium salts for the precipitation of aluminum oxides present in aqueous media.
    Type: Application
    Filed: June 27, 2011
    Publication date: December 22, 2011
    Inventor: Donald Geniesse
  • Patent number: 7976799
    Abstract: The present invention relates to the use of lithium salts and/or magnesium salts for the precipitation of aluminum oxides present in aqueous media.
    Type: Grant
    Filed: February 24, 2010
    Date of Patent: July 12, 2011
    Assignee: Areva Federal Services, LLC
    Inventor: Donald Geniesse
  • Patent number: 7968067
    Abstract: The present invention relates to the use of lithium salts and/or magnesium salts for the precipitation of aluminum oxides present in aqueous media.
    Type: Grant
    Filed: April 14, 2010
    Date of Patent: June 28, 2011
    Assignee: Areva Federal Services, LLC
    Inventor: Donald Geniesse
  • Patent number: 7863471
    Abstract: The invention relates to a method for transesterification of at least one component comprising at least one ester group with at least one component comprising at least one hydroxyl group, wherein the red mud produced in the Bayer process used for producing aluminum is added to the method as a reaction-promoting component. The invention also relates to the use of carboxylic acid salts produced during the transesterification method as plant treating agents and as detergents in cleaning and washing agents. The invention also relates to the use of dealkalized red mud obtained by means of the method according to the invention as the iron-contributing component of an iron fertilizer which can be used in particular in agriculture and to which limestone can also be added.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: January 4, 2011
    Assignee: Krause-Rohm-Systeme AG
    Inventors: Eberhard Krause, Valentin Rohm
  • Patent number: 7863480
    Abstract: The invention relates to a process for alkaline hydrolysis of carboxylic acid derivatives, especially carboxylic esters, to carboxylic acids, wherein, for the alkaline hydrolysis of the carboxylic acid derivatives, red mud which is produced by the Bayer process used for aluminum production is used as a reaction-promoting component, especially as a hydroxide ion source.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: January 4, 2011
    Assignee: Krause-Rohm-Systems AG
    Inventors: Eberhard Krause, Valentin Rohm
  • Publication number: 20100189613
    Abstract: The present invention relates to the use of lithium salts and/or magnesium salts for the precipitation of aluminum oxides present in aqueous media.
    Type: Application
    Filed: April 14, 2010
    Publication date: July 29, 2010
    Applicant: AREVA FEDERAL SERVICES LLC
    Inventor: Donald GENIESSE
  • Patent number: 7666373
    Abstract: A process for recovering alumina values from a first liquor having an initial concentration of aluminate ions and hydroxyl ions in solution is described. The first liquor is treated with a hydroxide of a metal other than aluminium to form an aluminium-bearing layered double hydroxide and produce a treated stream of first liquor, the treated stream of first liquor having a final concentration of aluminate ions less than the initial concentration of aluminate ions. The aluminium-bearing layered double hydroxide is separated from the treated stream of first liquor. Thereafter the clarified treated stream of first liquor is returned to a first location within an alumina refinery. The separated aluminium-bearing layered double hydroxide is contacted with a solution containing carbonate ions to form a slurry comprising an insoluble salt of the metal other than aluminium and a second liquor comprising aluminate ions released from the aluminium-bearing layered double hydroxide.
    Type: Grant
    Filed: August 8, 2007
    Date of Patent: February 23, 2010
    Assignee: BHP Billiton Aluminium Australia Pty Ltd.
    Inventor: Steven Philip Rosenberg
  • Patent number: 7622190
    Abstract: The present invention relates to a particulate mixed metal hydroxide that includes nickel, cobalt and aluminium. The powder particles have a core of nickel/cobalt hydroxide, and a surface that is coated with amorphous aluminium hydroxide. A process for the continuous preparation of such mixed metal hydroxides is also described. The process includes precipitating aluminium hydroxide in the presence of a nickel/cobalt mixed hydroxide in a tube reactor. The mixed metal hydroxides of the present invention may be used to prepare active materials for positive electrodes of a secondary battery.
    Type: Grant
    Filed: September 12, 2005
    Date of Patent: November 24, 2009
    Assignee: Toda Kogyo Europe GmbH
    Inventors: Sven Albrecht, Michael Kruft, Armin Olbrich, Stefan Malcus, Wolfgang Wiezoreck, Trevor McLeod, Shuja Siddiqui, Rob Rops, Hirofumi Hori
  • Patent number: 7442846
    Abstract: Process for the regeneration of exhausted catalysts, containing one or more calcium aluminates, for steam cracking reactions, comprising treating said exhausted catalysts in a stream of water vapour at a temperature ranging from 700 to 950° C., preferably from 720 to 850° C., and at a pressure ranging from 0.5 to 2 atm.
    Type: Grant
    Filed: November 21, 2001
    Date of Patent: October 28, 2008
    Assignees: Polimeri Europa S.p.A., Enitecnologie S.p.A.
    Inventors: Carlo Perego, Paolo Pollesel, Massimo Soprani, Massimo Romagnoli
  • Patent number: 7247292
    Abstract: A method for producing aluminum hydroxide includes a step of elevating a temperature of a slurry of aluminum hydroxide suspended in a sodium aluminate solution from 70° C. or lower to 85° C. or higher, and a step of applying a centrifugal force to the slurry. The aluminum hydroxide constituting the slurry is obtained beforehand through the Bayer's process.
    Type: Grant
    Filed: June 21, 2002
    Date of Patent: July 24, 2007
    Assignee: Showa Denko K.K.
    Inventors: Akira Onishi, Shirou Tomitsuka, Seisuke Takahashi
  • Patent number: 6890647
    Abstract: Highly transparent alumina hydrate particles having a large pore volume, having a pore diameter which falls in a specified range and, when formed into a high-concentration dispersion sol, exhibiting a low viscosity are provided. Alumina hydrate particles having a composition represented by the general formula xM2O.y(NH4)2O.Al2O3.zH2O (2×10?4?x?25×10?4, 0.1×10?4?y?20×10?4, 0.6?z?2.5, M represents an alkali metal; when the alkali metal is in the form of M2O, x is the number of moles thereof per mol of Al2O3; when ammonia is in the form of (NH4)2O, y is the number of moles thereof per mol of Al2O3; and z is the number of moles of hydration water (H2O) per mol of Al2O3), the alumina hydrate particles having an average particle diameter of 0.02 to 0.2 ?m, a total pore volume of 0.5 to 1.5 ml/g, and a volume of pores whose diameter is from 15 to 30 nm ranging from 0.3 to 1.0 ml/g.
    Type: Grant
    Filed: August 9, 2000
    Date of Patent: May 10, 2005
    Assignee: Catalysts & Chemicals Industries Co., Ltd.
    Inventors: Hiroyasu Nishida, Naoyuki Enomoto, Michio Komatsu
  • Patent number: 6299846
    Abstract: The present invention provides a process for producing aluminum hydroxide with little contamination by silica at a high yield, while suppressing losses of consumed alumina and alkaline components. The process comprises the steps of mixing a first alumina-containing slurry with a preheated alkaline aqueous solution, extracting alumina from the mixture, separating a dissolution residue from the mixture to obtain a solution, mixing the solution with a second alumina-containing slurry, extracting alumina from the mixture, and precipitating aluminum hydroxide after a desilication treatment.
    Type: Grant
    Filed: November 15, 1999
    Date of Patent: October 9, 2001
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Takuo Harato, Toru Ogawa, Takahiro Ishida
  • Patent number: 6296817
    Abstract: Disclosed is the recycling of aluminum dross. Aluminum dross is crushed into particles which are size-classified on the basis of 1 mm. The aluminum dross particles equal to or smaller than 1 mm in size are leached with an aqueous sodium hydroxide solution to give a leachate which contains sodium aluminate as a result of the reaction the aluminum metal of the aluminum dross particles with sodium hydroxide. The aluminum dross particles greater than 1 mm in size are remelted to recover aluminum metal. In the leachate, a small quantity of aluminum hydroxide is seeded, followed by hydrolyzing the sodium aluminate to obtain aluminum hydroxide. Meanwhile, the leachate is filtered to obtain a residue. This residue is subjected to washing, drying and roasting. The mixing of the roasted residue with aggregate and alumina cement gives alumina castable refractories.
    Type: Grant
    Filed: September 22, 1999
    Date of Patent: October 2, 2001
    Inventors: Hyung-Kyu Park, Hoo-In Lee, Eui-Pak Yoon
  • Patent number: 6231822
    Abstract: A method of recovering chloride and sulfate salts from spent potliner using acid digestion.
    Type: Grant
    Filed: November 30, 1998
    Date of Patent: May 15, 2001
    Assignee: Goldendale Aluminum Company
    Inventors: Robert J. Barnett, Michael B. Mezner
  • Patent number: 6086834
    Abstract: A process is described for removing dissolved silica from an alkaline solution containing sodium aluminate, e.g. a Bayer process solution. The process comprises contacting the alkaline solution with a slowly stirred bed of particles comprising coarse silica sand or a mixture of coarse silica sand and particles of sodalite, whereby the dissolved silica is precipitated out of solution to form a precipitation of desilication product dispersed in the solution and separating the desilication product solids from the alkaline solution to obtain a desilicated alkaline solution.
    Type: Grant
    Filed: June 19, 1998
    Date of Patent: July 11, 2000
    Assignee: Alcan International Limited
    Inventors: Guy Forte, Renald Dufour
  • Patent number: 5972506
    Abstract: An intercalation compound of general formula Na.sub.x K.sub.1-X Z.sub.y, wherein Z is a carbon or a polymer with a cyclic, particularly aromatic unit, as base unit; 0<x<1; and 2.ltoreq.y.ltoreq.6. A method for preparing the compound is also described, as well as the use thereof, particularly in pyrotechnics and in lithium batteries.
    Type: Grant
    Filed: January 2, 1998
    Date of Patent: October 26, 1999
    Assignee: Etienne LaCroix Tous Artifices S.A.
    Inventors: Genevieve Leichter, Jean-Claude Gachon, Daniel Guerard
  • Patent number: 5795559
    Abstract: A method for the preparation of new semi-crystalline, porous inorganic oxide compositions possessing uniform framework-confined mesopores in the range 2.0-10.0 nm. The method uses an interaction between various nonionic polyethylene oxide based surfactants (N.degree.) and neutral inorganic oxide precursors (I.sup..quadrature.) at ambient reaction temperatures. The materials formed exhibit a disordered assembly of worm-like channels of regular diameter owing to the specific mechanism of self-assembly, producing highly stable materials and particles incorporating large numbers of the channels. This (N.degree. I.degree.) templating approach introduces several new concepts to mesostructure synthesis. The application of the low-cost, non-toxic and biodegradable surfactants and ambient reaction temperatures, introduces environmentally clean synthetic techniques to the formation of mesostructures. Recovery of the template can be achieved through solvent extraction where the solvent may be water or ethanol.
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: August 18, 1998
    Assignee: Board of Trustees operating Michigan State University
    Inventors: Thomas J. Pinnavaia, Stephen A. Bagshaw
  • Patent number: 5776426
    Abstract: A process for treatment of a solid material containing fluoride and sodium, such as spent potlining from aluminum reduction cells, comprising the following steps: 1) contacting the solid material with recycled caustic liquor and source of calcium in a digestor; 2) passing the mixture to a separating device to separate into liquid and solid fraction; 3) recycling part of the liquid fraction containing caustic concentration of 75-200 g/l, calculated as Na.sub.2 CO.sub.3 to step (1); and 4) recovering concentrated caustic liquor from liquid fraction. The product of the process is a solid residue having low levels of leachable fluoride and a concentrated caustic liquor.
    Type: Grant
    Filed: October 17, 1996
    Date of Patent: July 7, 1998
    Assignee: Comalco Aluminium Limited
    Inventors: Ian Lewis Kidd, Darren Paul Rodda, Grant Ashley Wellwood
  • Patent number: 5711018
    Abstract: An industrial waste management facility (IWMF) for disposing of spent potlining includes a co-current gas-fired rotary kiln for containing a molten pool of spent potlining throughout the entire length of the rotary kiln from the inlet to the outlet, an ash quencher and cooler for receiving molten residue from the discharge end of the rotary kiln, a secondary combustion chamber, and a down-draft transition chamber for channeling discharge gases from the rotary kiln to the secondary combustion chamber. Pneumatic injection slingers feed and distribute spent potlining into the inlet end of the rotary kiln. A discharge dam provides a predetermined average depth of molten bath material in the rotary kiln over its entire length. A blended ratio of comminuted materials injected through the pneumatic injection slinger feeder is adjusted and controlled in response to signals received from a radiative optical kiln bath temperature measurement system.
    Type: Grant
    Filed: February 21, 1995
    Date of Patent: January 20, 1998
    Assignee: Aluminum Company of America
    Inventors: Herman J. Hittner, R. Lee Byers, John N. Lees, Jr., David W. Rierson, Ludmila Dinter-Brown
  • Patent number: 5691082
    Abstract: A beta-alumina solid electrolyte for use in a sodium-sulfur battery is composed of beta-alumina crystals having a degree of orientation toward the C axis thereof, of 0.2-0.4 and an aspect ratio of 4.0 or less. The beta-alumina solid electrolyte is composed of the beta-alumina crystals having a degree of orientation toward the C axis thereof, of 0.2-0.4 and has such a particle diameter distribution that the average particle diameter is 3 .mu.m or less, the proportion of the particles having a particle diameter of 5 .mu.m or less is 90% or more, and the maximum particle diameter is 300 .mu.m or less. A process for producing a beta-alumina solid electrolyte using an alumina source material, a magnesium source material and a sodium source material, uses a magnesium-aluminum spinel as the magnesium source material and subjects all materials to mixing, granulation, molding and firing to obtain a beta-alumina solid electrolyte without subjecting the materials to calcination.
    Type: Grant
    Filed: September 3, 1996
    Date of Patent: November 25, 1997
    Assignee: NGK Insulators, Ltd.
    Inventors: Masaharu Kajita, Takehiro Kajihara, Takao Totoki
  • Patent number: 5573582
    Abstract: The present invention discloses a process for preparing a fine-particulate metal hydroxide comprising aluminum hydroxide as a major component which comprises continuously supplying water and a mixture of an aluminum alkoxide and at least one alkoxide of a metal selected from Mg, Ca, La, Fe, Si, Ti and Zr, to a high shear rate stirring area and a process for preparing a fine-particulate metal oxide comprising aluminum oxide as a major component which comprises drying and then calcining said metal hydroxide at 500.degree.-1500.degree. C.
    Type: Grant
    Filed: June 23, 1995
    Date of Patent: November 12, 1996
    Assignee: Sumitomo Chemical Co., Ltd.
    Inventors: Masamichi Inui, Yoshiaki Takeuchi, Yasushi Teshima, Koji Yamamoto, Makio Kimura, Takahiro Ishida
  • Patent number: 5476990
    Abstract: An industrial waste management facility (IWMF) for disposing of spent potlining includes a co-current gas-fired rotary kiln for containing a molten pool of spent potlining throughout the entire length of the rotary kiln from the inlet to the outlet, an ash quencher and cooler for receiving molten residue from the discharge end of the rotary kiln, a secondary combustion chamber, and a down-draft transition chamber for channeling discharge gases from the rotary kiln to the secondary combustion chamber. Pneumatic injection slingers feed and distribute spent potlining into the inlet end of the rotary kiln. A discharge dam provides a predetermined average depth of molten bath material in the rotary kiln over its entire length. A blended ratio of comminuted materials injected through the pneumatic injection slinger feeder is adjusted and controlled in response to signals received from a radiative optical kiln bath temperature measurement system.
    Type: Grant
    Filed: June 29, 1993
    Date of Patent: December 19, 1995
    Assignee: Aluminum Company of America
    Inventors: Herman J. Hittner, R. Lee Byers, John N. Lees, Jr., David W. Rierson, Ludmila Dinter-Brown
  • Patent number: 5470559
    Abstract: A process for recycling spent potlining material from aluminum reduction cells contaminated with fluoride and aluminum values. The process comprises first reducing the average particle size of the spent potlining material to smaller than 28 Tyler mesh to form a powder. The powder is then treated with an aqueous sodium hydroxide solution containing about 10 to 60 g/L of sodium hydroxide at a temperature in the range of between 60.degree. and 90.degree. C. to form a solution containing fluoride and sodium aluminate and a residual solid. The solution is removed from the residual solid and the content of NaOH is adjusted in the solution to the range of about 10 to 60 g/L of NaOH, if the content differs from this range, to produce a solution suitable for cyanide destruction. This solution is then heated to a temperature in the range of about 160.degree. to 220.degree. C. at a pressure in the range of about 150 to 350 p.s.i. for a time of between about 1/2 and 3 hours to destroy cyanide values in the solution.
    Type: Grant
    Filed: February 26, 1993
    Date of Patent: November 28, 1995
    Assignee: Alcan International Limited
    Inventors: Robert J. Grolman, George C. Holywell, Frank M. Kimmerle, Gilles R. Turcotte
  • Patent number: 5346511
    Abstract: A method for defoaming a Bayer process liquor, the method comprising the steps of adding to the Bayer process liquor an effective amount of an antifoam/defoamer composition comprising a polyether surfactant and a polyhydric alcohol fatty acid ester.
    Type: Grant
    Filed: March 12, 1993
    Date of Patent: September 13, 1994
    Assignee: Nalco Chemical Company
    Inventor: Peter A. Dimas
  • Patent number: 5266201
    Abstract: The invention relates to a process for the purification of aqueous solutions polluted by nitrate ions. This process is characterised in that it consists in precipitating hydrated double or mixed calcium nitroaluminates, such as, in particular, hydrated calcium mononitroaluminate, by adding at least one agent supplying the element aluminium and at least one agent supplying the element calcium to the solutions to be treated, the overall mole ratio of the element aluminium to nitrate, Al/NO3, being superior to 1 and the overall mole ratio of calcium to nitrate, Ca/NO3, being superior to 2, and in that the precipitation reaction is performed with stirring and at a basic pH, preferably above 10.5.The process according to the invention is intende, in particular, to the treatment of polluted waters such as municipal waste water and factory effluents and to the treatment of liquid manure.
    Type: Grant
    Filed: April 26, 1993
    Date of Patent: November 30, 1993
    Assignee: Lafarge Fondu International
    Inventors: Jean-Pierre Letourneux, Alain Bourdeau
  • Patent number: 5232681
    Abstract: A process for the preparation of stabilized sodium beta"-aluminum oxide from aluminum transition oxides includes applying a phase-stabilizing doping component and another component promoting conductivity and affixing the doping component, to surfaces of aluminum transition oxides and interior areas of pores.
    Type: Grant
    Filed: December 27, 1991
    Date of Patent: August 3, 1993
    Assignee: ABB Patent GmbH
    Inventor: Rudiger Hartung
  • Patent number: 5118484
    Abstract: A process is described for removing dissolved silica from process solutions or slurries formed in the Bayer process for producing alumina from bauxite. In the novel process, a Bayer process solution or slurry is contacted with porous agglomerates of a material containing Bayer process desilication product and bonded together by a polymer resin which is resistant to chemical degradation by high concentrations of caustic present in Bayer process liquors. The desilication product is essentially complex hydrated sodium aluminum silicates and typical bonding resins are polyvinylchloride or polypropylene.
    Type: Grant
    Filed: August 17, 1990
    Date of Patent: June 2, 1992
    Assignee: Alcan International Limited
    Inventors: Kwat I. The, George D. Fulford
  • Patent number: 5051243
    Abstract: This invention provides an improved process for increasing the specific gravity of red mud. The process comprises mixing red mud in an acidic solution, such as sulfur dioxide solution, having a pH of between about 1.5 and about 3.0 to form an insoluble red mud residue. The specific gravity of the red mud residue can also be increased by heating the residue in air to a temperature of 250.degree. C. to about 300.degree. C. This process enables recovery of a treated red mud derivative having an increased specific gravity in excess of 4.0, which makes the product particularly useful as a weighting agent for drilling fluid, and as the solid phase of slurries used to fill crevices and fissures exposed by drilling or excavation.
    Type: Grant
    Filed: December 7, 1989
    Date of Patent: September 24, 1991
    Assignee: Alcan International Limited
    Inventors: George D. Fulford, Anwer M. Khan
  • Patent number: 5043077
    Abstract: A method of treating Bayer process red mud slurries to improve or facilitate the handling thereof, comprising adding to such a slurry a minor porportion of humic acids or humates effective to reduce the viscosity of the slurry.
    Type: Grant
    Filed: December 11, 1989
    Date of Patent: August 27, 1991
    Assignee: Alcan International Limited
    Inventors: John L. Chandler, Dirk Noteboom, Ronald D. Paradis, John C. Winch
  • Patent number: 4973464
    Abstract: A process for the treatment of ground, spent potlinings generated during the production of metallic aluminum to reduce cyanide content to environmentally nonhazardous levels. Potlinings are ground or otherwise suitably reduced in size to a particle size of not greater than about 2 inches in any dimension and roasted in a stream of air or nitrogen at a temperature between about 500.degree. F. and 1400.degree. F. Roasting for an appropriate time-temperature interval reduces cyanide content to desired levels without combustion of a major portion of carbonaceous material, resulting in an end product rich in carbon and fluorine which may be salable because of this content.
    Type: Grant
    Filed: February 21, 1989
    Date of Patent: November 27, 1990
    Assignee: Ogden Environmental Services
    Inventor: William S. Rickman
  • Patent number: 4957564
    Abstract: A process for preparing lactulose from lactose in which an aqueous lactose mixture is reacted with a sodium aluminate solution and the solution obtained is continuously neutralized by feeding this solution and a sulphuric acid solution to a reactor simultaneously in such a manner as to obtain a pH of between 4.5 and 8.By operating in this manner an aluminium hydroxide suspension is obtained which can be easily separated from the lactulose solution.
    Type: Grant
    Filed: November 17, 1988
    Date of Patent: September 18, 1990
    Assignee: SIRAC S.r.l.
    Inventors: Renato Carobbi, Franco Innocenti
  • Patent number: 4946664
    Abstract: The invention provides a method of making .beta."-alumina by heating aluminium oxide in the presence of Na.sub.2 O. A metal oxide dopant in the form of Li.sub.2 O, MgO, ZnO, CoO, NiO, FeO or mixtures thereof, or a precursor of the dopant, is dispersed in a cubic-close packed aluminium oxide or a precursor thereof to form a starting mixture which is calcined by heating to 250.degree.-1100.degree. C. in an oxygen-containing atmosphere. Na.sub.2 O is then dispersed in the calcined starting mixture to form a final mixture, and the final mixture is heated in an oxygen-containing atmosphere to above 1100.degree. C. to produce .beta."-alumina.
    Type: Grant
    Filed: January 25, 1989
    Date of Patent: August 7, 1990
    Assignee: Lilliwyte Societe Anonyme
    Inventors: Arnold Van Zyl, Graham K. Duncan, Peter Barrow, Michael M. Thackeray
  • Patent number: 4816122
    Abstract: Fluoride-containing wastes, arising in the aluminium industry, particularly spent cell linings from reduction cells, are digested with caustic soda for conversion of sodium cryolite to NaF.By use of very strong caustic soda NaF may be left in the solid residues after removal of the residual liquor and recovered from such residues by water leaching.As an alternative weaker caustic soda may be used in the digestion stage and subsequently be crystallised out from the residual liquor, after separation from the solid residues, by evaporating and/or cooling the liquor. The precipitated NaF is then conventiently redissolved in water.The NaF solution prepared by either route is then preferably subjected to electrodialysis to recover a solution of HF from it. Such HF is conveniently converted to AlF.sub.3 by reaction with alumina.
    Type: Grant
    Filed: September 13, 1985
    Date of Patent: March 28, 1989
    Assignee: Alcan International Limited
    Inventor: Gordon Lever
  • Patent number: 4810682
    Abstract: A process for production of useful materials including a product of similar composition to nepheline involves contacting a slurry of red mud with sulphur dioxide to dissolve components of the red mud that are soluble in sulphurous acid, removing residual undissolved solids by filtration, and recovering a filtrate containing soda, alumina and silica values, removing free water from the filtrate to produce a crystallized residue, and calcining the crystallized residue.
    Type: Grant
    Filed: June 10, 1987
    Date of Patent: March 7, 1989
    Assignee: Comalco Aluminum Limited
    Inventor: William H. Andrews
  • Patent number: 4792377
    Abstract: A method for growing crystals of sodium beta" alumina is described. The crystals are grown by Czochralski type processes or analogous methods wherein single crystals are formed from a flux or melt. The melt is a eutectic type liquid primarily containing Na or K, (Li, Mg or other divalent element, e.g. Ni.sup.2+, Co.sup.2+, Cr.sup.2+, Fe.sup.2+, etc.) Al, in proportions to produce beta" alumina. To lower the melt temperature to where e.g. Na.sub.2 MgAl.sub.10 O.sub.17 beta" or Na.sub.2 Li.sub.1/2 Al.sub.11/2.degree.17 beta" can crystallize in its stability region (approximately less than 1700.degree. C. for the Mg version and approximately less than 1600.degree. C. for the Li version) high valent ions, which do not enter the structure, particularly V.sup.5+, Nb.sup.5+, Ta.sup.5+, Zr.sup.4+ and/or Hf.sup.4+ are added to the melt. The method has allowed the growth of single crystals of the Li-stabilized sodium and potassium varieties for the first time.
    Type: Grant
    Filed: February 9, 1987
    Date of Patent: December 20, 1988
    Assignee: The Regents of the University of California
    Inventors: Bruce S. Dunn, Peter E. D. Morgan
  • Patent number: 4732741
    Abstract: A method of making beta"-alumina comprises dispersing in a precursor of aluminum oxide a member of the group comprising sodium oxide and its precursors, and dispersing in the precursor of aluminum oxide a spinel stabilizer which is a member of the group comprising spinel-forming oxides and the precursors thereof, to form a mixture. The mixture is then heated to a temperature at which at least some of the precursor of aluminum oxide is converted to beta"-alumina. The precursor of aluminum oxide is one which, when calcined in air by itself, has a calcination product which, when subjected to X-ray diffraction, displays a predetermined X-ray diffraction trace. The X-ray diffraction trace is one whose peak with the highest intensity in the 2 (theta) range of 44.degree.-48.degree. and whose peak with the highest intensity in the 2 (theta) range of 63.degree.-69.degree. respectively have maximum intensities and integrated intensities which comply with equations (I) and (II):A/S is greater than 0.
    Type: Grant
    Filed: May 21, 1986
    Date of Patent: March 22, 1988
    Assignee: Lilliwyte Societe Anonyme
    Inventors: James H. Duncan, Peter Barrow, Arnold Van Zyl, Angus I. Kingon
  • Patent number: 4732742
    Abstract: A process for the production of pure aluminum trihydroxide having a controlled median diameter of less than 4 microns with a unimodal distribution and a minimum deviation. The process comprises contacting, for a short time, sodium aluminate solution with a small quantity of ground aluminum trihydroxide having a specific BET surface area of at least 8 m.sup.2 /g, separating the sodium aluminate solution from the solid phase comprising ground aluminum trihydroxide and aluminum trihydroxide precipitate containing impurities, then decomposing the purified sodium aluminate solution in the presence of a quantity of pure ground aluminum trihydroxide from a preceding decomposition operation to precipitate a very pure aluminum trihydroxide having the specified median diameter.
    Type: Grant
    Filed: December 12, 1986
    Date of Patent: March 22, 1988
    Assignee: Aluminum Pechiney
    Inventor: Jean-Philippe Puig
  • Patent number: 4704266
    Abstract: A method for producing .gamma.-form lithium aluminate powders usable as a material for an electrolyte tile of molten carbonate fuel cells which comprises mixing aluminum alkoxide with one member selected from the group consisting of the lithium salts of inorganic and organic acids, lithium hydroxide and lithium oxide in the presence of a non-aqueous solvent, carrying out reaction with addition of water of 1.5 to 20 moles (including water of crystallization contained in the lithium compound) based on 1 mole of aluminum alkoxide with stirring, and removing the solvent to obtain a solid matter which is then calcined at a temperature in a range of from 650.degree. C. to 1000.degree. C.
    Type: Grant
    Filed: June 11, 1986
    Date of Patent: November 3, 1987
    Assignee: Sumitomo Chemical Company, Limited
    Inventors: Hidekimi Kadokura, Hiroshi Umezaki, Hideaki Murakami, Toshiyuki Mizoe
  • Patent number: 4668485
    Abstract: A process for recovery of valuable products from Bayer process red mud comprises the steps: (a) digesting red mud with sulphur dioxide in the presence of water to dissolve soda, alumina and silica therein; (b) heating the product of step (a), with or without prior removal of insolubles, to selectively precipitate silica, and removing solids including the precipitated silica, to produce a liquor containing soda and alumina; (c) causticizing the liquor to precipitate calcium sulphite; and (d) separating the precipitated calcium sulphite from the liquor to produce calcium sulphite and sodium aluminate solution as products. In a preferred embodiment calcium sulphite produced in step (c) is calcined to regenerate lime and sulphur dioxide for recycle to the liquor causticization and red mud digestion stages respectively, and sodium aluminate produced in step (d) is returned to the Bayer process.
    Type: Grant
    Filed: December 10, 1985
    Date of Patent: May 26, 1987
    Assignee: Comalco Aluminum Limited
    Inventors: Pearson J. Cresswell, Ian L. Grayson, Andrew H. Smith
  • Patent number: 4663132
    Abstract: In a method of processing contaminated sodium oxalate which becomes available in a separating stage succeeding the digestion of bauxite in accordance with the Bayer process, chemicals used in the digesting process are recovered in that moist sodium oxalate which has been separated is dried with the hot exhaust gases from a rotary kiln jointly with aluminum hydroxide or aluminum oxide hydrate and/or reactive alumina at a mole ratio of aluminum to sodium of at least 0.8 and the dried product is decomposed in said rotary kiln at a temperature of 780.degree. to 1000.degree. C. to form sodium aluminate. Suitably drying is effected by spray drying in direct contact with the exhaust gases of the rotary kiln and decomposition is effected at a temperature in the range from 850.degree. to 950.degree. C. and with an Al:Na ratio not in excess of 1.2.
    Type: Grant
    Filed: March 19, 1985
    Date of Patent: May 5, 1987
    Assignee: Metallgesellschaft AG
    Inventors: Hans-Werner Schmidt, Walter Koch, Martin Hirsch, Karlheinz Rosenthal, Yilmaz Yetmen
  • Patent number: 4643885
    Abstract: In a method for processing contaminated sodium oxalate which becomes available in a separating stage succeeding the digestion of bauxite in accordance with the Bayer process, chemicals used in the digesting process are recovered in that the moist sodium oxalate which has been separated is dried with the hot exhaust gases from a fluidized bed, particularly a circulating fluidized bed, jointly with aluminum hydroxide or aluminum oxide hydrate and/or reactive alumina at a mole ratio of aluminum to sodium of at least 0.8 and the dried product is decomposed in said fluidized bed at a temperature of 780.degree. to 1000.degree. C. to form sodium aluminate. Suitably drying is effected by spray drying in direct contact with the exhaust gases of the fluidized bed and decomposition is effected at a temperature in the range from 850.degree. to 950.degree. C. and with an Al:Na mole ratio not in excess of 1.2.
    Type: Grant
    Filed: March 19, 1985
    Date of Patent: February 17, 1987
    Assignee: Metallgesellschaft AG
    Inventors: Hans-Werner Schmidt, Walter Koch, Martin Hirsch, Karlheinz Rosenthal, Yilmaz Yetmen
  • Patent number: 4609534
    Abstract: A process for cleaning lime having undesirable levels of contaminants, particularly manganese oxide, is disclosed. The process includes leaching the contaminants from the lime with an aqueous means, preferably spent Bayer liquor, to form a slurry containing said impurities and cleaned lime. The cleaned lime is then removed from the slurry containing the contaminants.
    Type: Grant
    Filed: October 9, 1984
    Date of Patent: September 2, 1986
    Assignee: Aluminum Company of America
    Inventors: Paul J. The, William V. Felix
  • Patent number: 4587005
    Abstract: Disclosed is a process for removing mineral matter from Rundle oil-shale by contacting the oil-shale with (a) an ammonium salt solution and (b) an organic solvent, at a temperature from about 0.degree. C. to about 300.degree. C. for a time which is sufficient to substantially separate at least about 80 wt. % of the carbonate mineral matter from the oil-shale.
    Type: Grant
    Filed: December 27, 1984
    Date of Patent: May 6, 1986
    Assignee: Exxon Research and Engineering Co.
    Inventors: Michael Siskin, Glen Brons
  • Patent number: 4587111
    Abstract: The process of liquid-liquid extraction of gallium from sodium aluminate liquor used in the Bayer alumina process, uses an organic extractant comprising a diluent and a substituted hydroxyquinoline such that gallium and some aluminum are extracted into the organic phase.In five successive steps, the organic extractant solution loaded with gallium and aluminum is first contacted with an aqueous mineral acid solution, during which the acid solution strips the loaded solution of gallium and aluminum. Next, the phases are separated and a chloride salt or hydrochloric acid is dissolved in the acidic solution of gallium and aluminum which is then contacted with an organic solvent, e.g. n-butyl acetate. Aluminum remains in the aqueous acid solution whereas the organic solvent becomes loaded with gallium.After the phases have been separated, the organic solvent is separated from gallium chloride, which forms the feed for producing pure gallium.
    Type: Grant
    Filed: November 7, 1984
    Date of Patent: May 6, 1986
    Assignee: Sulzer Brothers Limited
    Inventor: Nicholas P. Wynn
  • Patent number: 4587004
    Abstract: Disclosed is a process for beneficiating oil-shale wherein the oil-shale is treated in a first stage with an aqueous ammonium salt solution and in a second stage and optionally a third stage in the presence of a solution containing ammonium ions/ammonia, or both. The pH of the first stage is from about 5 to 9, and the pH of the second and third stages are from about 0.5 to 5 or about 9 to 12 with the proviso that the pH of the second and third stage is not in the same range.
    Type: Grant
    Filed: December 27, 1984
    Date of Patent: May 6, 1986
    Assignee: Exxon Research and Engineering Co.
    Inventors: Michael Siskin, Glen Brons
  • Patent number: 4557907
    Abstract: A process for hydrothermally disintegrating wastes or residues having a high content of calcined aluminum oxides by reacting said wastes or residues with an aqueous sodium hydroxide solution having a concentration of sodium hydroxide of from about 20 to about 50% by weight at a temperature in the range of from about 180.degree. to about 250.degree. C. under a saturated steam pressure corresponding to said temperature. The sodium aluminate solution obtained is separated off and optionally filtered.
    Type: Grant
    Filed: May 27, 1983
    Date of Patent: December 10, 1985
    Assignee: Henkel Kommanditgesellschaft auf Aktien
    Inventors: Peter Christophliemk, Jurgen von Laufenberg, Rudolf Novotny, Siegfried Staller, Friedrich W. Diekotter
  • Patent number: 4518571
    Abstract: The process consists of two desilication stages. In the first stage the aluminate liquor resulting from digestion of the sinter is subjected to an autoclave treatment to remove the major portion of impurities of SiO.sub.2 and Fe.sub.2 O.sub.3. In the second stage the aluminate liquor is treated with a desilication agent comprising a lime pulp containing oxides CaO, Al.sub.2 O.sub.3, SiO.sub.2, Fe.sub.2 O.sub.3, Na.sub.2 O in a mass ratio of CaO:(SiO.sub.2 +Fe.sub.2 O.sub.3)=1,000 to 5,000:1 and Na.sub.2 Al.sub.2 O.sub.3 =0.25-0.60:1, wherein CaO is active, Na.sub.2 O--in the carbonate form. This lime pulp is employed in such an amount as to ensure the content of active CaO in the aluminate liquor within the range of from 5 to 10 g/l . The impurities of SiO.sub.2 and Fe.sub.2 O.sub.3 present in the liquor pass into the solid phase with the formation of calcium hydrogarnets of the formula 3 CaO(Al,Fe).sub.2 O.sub.3 mSiO.sub.2 (6-2m)H.sub.2 O, wherein m=0.01-0.5 which are separated as a mud.
    Type: Grant
    Filed: February 27, 1984
    Date of Patent: May 21, 1985
    Assignees: Vsesojuzny Nauchno-Issledovatelsky I Proektny Institut Aljuminievo Magnievoi I Elektrodnoi Promyshlennosti, Leningradsky Tekhnologichesky Institut Imeni Lensoveta
    Inventors: Nikolai A. Kaluzhsky, Viktor M. Sizyakov, Vladimir V. Andreev, Alexei I. Alexeev, Khoren A. Badaliants, Isaak A. Zatulovsky, Valentin I. Korneev, Ivan M. Kostin
  • Patent number: 4512809
    Abstract: Aluminous siliceous starting materials are mixed and ground with correction materials to produce a raw mixture comprising oxides of aluminium, silicon, calcium and alkali metal having certain mole ratios, preheating the raw mixture by suspending the raw mixture in a hot gas, and sintering the preheated material to clinker.
    Type: Grant
    Filed: January 25, 1984
    Date of Patent: April 23, 1985
    Assignee: Industrias Penoles S.A. de C.V.
    Inventors: Hans C. A. Nielsen, Roberto Schroeder