Patents Examined by Paige C. Harvey
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Patent number: 5015452Abstract: An improved process for the preparation of monodispersed spherical colloidal particles from rare earth salts is disclosed. These colloidal particles are obtained in this process by homogeneous precipitation techniques involving the forced hydrolysis of rare earth salts in aqueous media. More specifically, this process initially involves the formation of hydrolyzed cations which are precursors or intermediate to precipitation of the desired colloidal particle. The objective in the formation of this precursor species is to reach critical supersaturation concentration of this particle forming species so that only one burst of nuclei occurs. Colloidal particle formation is then effected by diffusion of solutes onto the existing nuclei. The improvements of this process reside, in part, in the ability to control the kinetics of formation of this intermediate species. Such control permits the formation of colloidal dispersions having very narrow particle size distribution.Type: GrantFiled: January 16, 1987Date of Patent: May 14, 1991Assignee: Clarkson UniversityInventor: Egon Matijevic
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Patent number: 5011822Abstract: A method for producing uniform mixed metal oxides, such as superconducting mixtures including Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x, in which such metals are precipitated as their oxalates from alcoholic solutions of the metals as the salts of a carboxylic acid.Type: GrantFiled: January 10, 1989Date of Patent: April 30, 1991Assignee: Allied-Signal Inc.Inventor: Timothy J. Barder
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Patent number: 4994253Abstract: A process for the production of large boehmite crystal aggregates, useful for soft polishing applications is provided herein. A caustic aluminate liquor is contacted with an oxygen-containing gas at elevated temperatures and pressures in the presence of about 1-50 mg/L of copper ions. The liquor is oxidized until a molar ratio of Na.sub.2 O.sub.free to Al.sub.2 O.sub.3 of less than or equal to 1 is achieved, and the oxidized liquor is cooled under quiescent conditions of little or no agitation which causes the crystallization and precipitation or novel large boehmite particles.Type: GrantFiled: August 30, 1988Date of Patent: February 19, 1991Assignee: Vereinigte Aluminium-Werke AGInventor: Neil Brown
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Patent number: 4986742Abstract: High-grade titanium dioxide is produced by(a) reacting ilmenite or titanium-containing slag with sulfuric acid,(b) dissolving the material from (a) with water or dilute sulfuric acid,(c) separating insolubles from (b) to obtain a black solution containing titanyl sulfate and foreign metal salts,extracting titanyl sulfate from the black liquor with sulfuric acid and an organic medium containing an organophosphorus compound, separating the foreign metal salts in an aqueous extract phase, recovering titanyl sulfate from the organic extract phase, andhydrolyzing the titanyl sulfate to titanium oxide hydrate.Type: GrantFiled: August 17, 1989Date of Patent: January 22, 1991Assignee: Bayer AktiengesellschaftInventors: Gabriel Denecker, Werner Verhoeven, Joel Leuridan, Domien Sluyts
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Patent number: 4979986Abstract: A method of treating a gold-bearing ore to render the gold component of the ore more amenable to standard cyanidation treatment in a reduced amount of time is disclosed. An aqueous slurry of the gold-bearing ore is introduced into at least one vessel. An oxidizing agent, such as chlorine gas, an alkali metal hypochlorite and an alkaline earth metal hypochlorite, is rapidly introduced into the vessel so that it intimately contacts the aqueous slurry. While the oxidizing agent is being introduced into the vessel, the slurry is agitated with agitating means including a plurality of impeller blades that provide high shear agitation and a large interfacial surface area between the oxidizing agent and the liquid phase of the slurry to enhance the mass transfer of the oxidizing agent so that it becomes substantially completely adsorbed by the aqueous slurry in about 5 to about 15 minutes.Type: GrantFiled: February 22, 1988Date of Patent: December 25, 1990Assignee: Newmont Gold Company and Outomec U.S.A., Inc.Inventors: David L. Hill, Kenneth A. Brunk
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Patent number: 4976781Abstract: Noble metal or diamond values are recovered from ore slurries by contact with pellets of oil, coal and bitumen as a secondary binder. The pellets are of a size above 0.75 mm and contain 2% bitumen and 18% lighter oil fractions. The pellets do not disintegrate and size range remains constant.Type: GrantFiled: August 21, 1987Date of Patent: December 11, 1990Assignee: Charlton Mineral Associates Pty. Ltd.Inventors: David Mainwaring, Mark Cadzow
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Patent number: 4968503Abstract: A process for the production of sodium dichromate comprising reacting sodium chromate with acids, the acids being sulfuric acid and NaHSO.sub.4 formed as a waste product in the production of CrO.sub.3 and thus being contaminated with chromium compounds, adding PO.sub.4 ions in excess to the NaHSO.sub.4 contaminated with chromium compounds and precipitating the Cr(III) present therein as CrPO.sub.4 at a temperature of 50.degree. to 100.degree. C. and at a pH value of 3 to 6.Type: GrantFiled: April 24, 1989Date of Patent: November 6, 1990Assignee: Bayer AktiengesellschaftInventor: Albert E. B. Glissmann
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Patent number: 4966688Abstract: A process for separating and recovering minerals, such as molybdenum or graphite, from ores with which they occur by addition of an amino mercaptothiadiazole to an ore flotation process.Type: GrantFiled: June 23, 1988Date of Patent: October 30, 1990Assignee: Phillips Petroleum CompanyInventor: M. D. Bishop
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Patent number: 4966760Abstract: A method for recovering chromium from chromium-bearing material which comprises heating the material which can contain any one or combination of Co, Ni, Fe, Mo, and W with solid alkali metal hydroxide in an oxidizing atmosphere at 600.degree. C.-1000.degree. C. to form a fused material containing water soluble compounds of Cr, Mo, and W contained therein. The fused material is cooled and contacted with water to form a leach solution and a residue. The leach solution is adjusted to a pH of from about 5-8 with sulfuric acid, and a water soluble calcium salt is added. The chromium-rich liquor is then adjusted to a pH of 1-3 with sulfuric acid. Sodium metabisulfite is added to the chromium-rich liquor to reduce the chromium to the trivalent state after which the pH is adjusted to 5-8 with a base to form a precipitate of essentially all of the chromium.Type: GrantFiled: September 5, 1989Date of Patent: October 30, 1990Inventors: Judith A. Ladd, Joseph E. Ritsko
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Patent number: 4965116Abstract: A method is disclosed for separating cobalt from nickel which consists essentially of adjusting the pH of a cobalt chloride solution containing nickel to about 3 to about 5 with a base, adding hypochlorite to the resulting pH adjusted solution in an amount equal to at least the stoichiometric amount required to oxidize essentially all of the cobalt to the .sup.+3 state, while maintaining the pH at about 3 to about 5 by addition of a base, to form a solid containing at least about 60% by weight of the cobalt in the .sup.+3 state and a liquor containing essentially all of the nickel, and removing the solid from the liquor.Type: GrantFiled: September 11, 1989Date of Patent: October 23, 1990Assignee: GTE Products CorporationInventors: Michael J. Miller, Richard A. Scheithauer
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Patent number: 4965057Abstract: Morphologically improved ceric oxide particulates having a grain size distribution such that the mean diameter of the aggregates thereof ranges from 0.2 to 1 .mu.m, are conveniently prepared by (i) hydrolyzing an aqueous solution of a cerium (IV) salt in an acid medium, (ii) adding an aqueous colloidal dispersion of a cerium (IV) compound to the product of step (i), (iii) separating the precipitate from step (ii), and then (IV) heat treating said separated precipitate, advantageously by calcination at elevated temperatures.Type: GrantFiled: June 27, 1988Date of Patent: October 23, 1990Assignee: Rhone-Poulenc ChimieInventors: Claire David, Francoise Seon
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Patent number: 4965056Abstract: A method of preparing PLZT powder with a carbonate process employing Pb(NO.sub.3).sub.2, zirconium oxychloride and chlorides of La and Ti as starting materials. Solutions of each are blended together and added to a solution consisting of NH.sub.4 OH and (NH.sub.4).sub.2 CO.sub.3. The resulting solution undergoes refluxing at proper conditions for a period of time to coprecipitate a majority of particles which form nuclei covered by the carbonates of La, Ti and Pb, and a minority of particles which form nuclei which are covered by the hydroxides of La, Ti and Pb, which are calcined and ground to form PLZT powder.Type: GrantFiled: April 11, 1990Date of Patent: October 23, 1990Assignee: Ming-Chin WuInventor: Yen-Hwei Chang
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Patent number: 4962279Abstract: An improvement is disclosed applicable to the production of calcined and hydrous kaolins in particulate form. A process and system are disclosed in which the calciner is integrated with a filtration process and a preceding spray dryer by passing the dust-laden calciner hot off-gases to the spray dryer to achieve savings in energy. Waste heat from the calciner, and concomitantly dustlike clay particles carried in the off-gas, are thereby passed to the dryer and subsequently treated and their values recovered.Type: GrantFiled: February 3, 1989Date of Patent: October 9, 1990Assignee: ECC America Inc.Inventors: Charles D. Anderson, Carl S. Cummings, J. Richard Hudson
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Patent number: 4956340Abstract: A process for preparing compound metal oxides, superconductive compound oxides, is disclosed. The process comprises preparing an aqueous solution containing a predetermined content ratio of chloride, nitrate or acetate of a rare earth metal, an alkaline earth metal and copper, said content ration corresponding to the composition of the object compound metal oxide, adjusting the pH of the solution to 1.5-2.0, adding oxalic acid in an amount such that the concentration of the residual oxalic acid becomes 0.05 M/l-0.1 M/l, collecting the thus formed precipitate and firing it.Type: GrantFiled: November 3, 1989Date of Patent: September 11, 1990Assignee: Mitsubishi Kinzoku Kabsuhiki KaishaInventors: Etsuji Kimura, Nozomu Hasegawa, Yutaka Nishiyama
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Patent number: 4956159Abstract: Gallium-containing waste is chlorinated in the presence of gallium trichloride from the beginning. By this procedure, gallium is more efficiently chlorinated and gallium trichloride is more easily separated from other chlorides and recovered.Type: GrantFiled: August 15, 1989Date of Patent: September 11, 1990Assignee: Mitsubishi Kinzoku Kabushiki KaishaInventors: Takeyoshi Shibasaki, Etsuji Kimura, Yutaka Nishiyama
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Patent number: 4956154Abstract: Aqueous effluent solutions containing metal cations may be treated with an extractant comprising an organophosphinic acid, a di-2-ethylhexyl phosphoric acid and/or an aliphatic amine to selectively separate chromium, nickel, cobalt, copper and lead cations from the aqueous solution. Typical extraction techniques include liquid-liquid extraction employing either mixer settlers or columns, liquid membrane extraction and selective supported membrane extraction.Type: GrantFiled: March 9, 1988Date of Patent: September 11, 1990Assignee: UNC ReclamationInventors: Alex Magdics, Donald B. Stain
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Patent number: 4943418Abstract: In a method of preparing high-purity manganese compounds, wherein the method comprises adding a member selected from ferromanganese and metallic manganeses to an aqueous electrolyte-containing solution, dissolving said member while stirring and maintaining a pH of 2 to 9, and then removing insolubles by filtration and recovering solubles by precipitation, heavy metal elements as well as non-metllic elements, such as P, Si, etc. can be removed efficiently, and high-purity manganese compounds of stable quality can be prepared.Type: GrantFiled: May 30, 1989Date of Patent: July 24, 1990Assignee: Japan Metals & Chemicals Co., Ltd.Inventors: Koichi Kambe, Kiyoshi Matsuura, Tatsuo Seino, Yoshiyuki Kimura, Hiroshi Kemmochi, Koichi Yoshioka, Hideaki Hohnoki
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Patent number: 4942023Abstract: A process using an extractant, that consists on the one hand of an active component being substituted 8-hydroxyquinoline and on the other hand of by-products of the manufacture of said extractant, said process being characterized in that the extractant contains at least 90 wt % of the active component.Type: GrantFiled: December 21, 1988Date of Patent: July 17, 1990Assignee: Metallurgie Hoboken-OverpeltInventors: Achille J. De Schepper, Guy G. Haesebroek, Antoine L. Van Peteghem
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Patent number: 4937148Abstract: Transparent conductive coatings excellent in transparency are provided on substrates such as glass, plastics, etc. by the use of conductive coating materials obtained by maintaining aqueous solutions of hydrolyzable tin containing or indium containing compounds at pH of 8-12, and gradually hydrolyzing said compounds in the solutions to form sols containing colloidal particles, followed by drying and calcining.Type: GrantFiled: May 1, 1989Date of Patent: June 26, 1990Assignee: Catalysts & Chemicals Industries Co., Ltd.Inventors: Goro Sato, Michio Komatsu, Tsuguo Koyanagi, Masayuki Matsuda, Hiroo Yoshidome, Akira Nakashima, Kazuaki Inoue
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Patent number: 4937064Abstract: In the process for producing titanium dioxide by(a) reacting titanium tetrachloride and oxygen in the vapor phase to produce titanium dioxide, and(b) subsequently cooling the titanium dioxide in a flue,an improvement comprising utilizing for all or a portion of the flue a conduit having a plurality of internal, substantially longitudinal protuberances, depressions or both.Type: GrantFiled: September 29, 1988Date of Patent: June 26, 1990Assignee: E. I. Du Pont de Nemours and CompanyInventor: Raul A. Gonzalez