Patents Examined by Edward Squillante
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Patent number: 5207996Abstract: Improved methods of heap leaching of copper ore with aqueous sulfuric acid solutions comprising a fluoroaliphatic surfactant are disclosed. The fluoroaliphatic surfactant increases the amount of copper values leached and recovered.Type: GrantFiled: October 10, 1991Date of Patent: May 4, 1993Assignee: Minnesota Mining and Manufacturing CompanyInventors: Michael J. Sierakowski, Frank A. Lee
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Patent number: 5207995Abstract: Recovery of cerium values from fluoride-containing ores such as bastnasite is enhanced. The ore is ground, roasted, and leached with dilute hydrochloric acid to produce an ore concentrate. The concentrate is treated with a solution of hydrochloric acid and boric acid to solubilize cerium values and convert fluoride to tetrafluoroborate ion. Tetrafluoroborate is removed from the solution, e.g., by precipitation, and the solution is further processed for recovery of cerium values. Removal of tetrafluoroborate avoids loss of cerium as insoluble cerium tetrafluorborate during said further processing.Type: GrantFiled: September 19, 1990Date of Patent: May 4, 1993Assignee: Union Oil Company of CaliforniaInventor: Paula J. Bosserman
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Patent number: 5207997Abstract: The processing of leaching residues from barium sulfide leaching is described. Sodium sulfide as well as a solid which is useful as an additive for fired clay products, particularly bricks, are obtained as valuable reaction products.Type: GrantFiled: December 20, 1990Date of Patent: May 4, 1993Assignee: Kali-Chemie AGInventor: Jacopo Porta
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Patent number: 5204074Abstract: Gallium values are recovered from basic aqueous solutions thereof, e.g., Bayer liquors, by (i) contacting such basic aqueous solution (A) with a medium (I) containing a gallium extractant, whereby the gallium values are transferred to the medium (I), (ii) contacting such gallium-enriched medium (I) with a basic aqueous solution (B) and back-extracting the gallium values into the basic aqueous solution (B), (iii) contacting such gallium-enriched basic aqueous solution (B) with a second medium (II) containing a gallium extractant, whereby the gallium values are transferred to the medium (II), and (iv) contacting such gallium-enriched medium (II) with an aqueous solution (C), which may be acidic or basic, and back-extracting the gallium values into the aqueous solution (C); such gallium-enriched aqueous solution (C) may, for example, be directly electrolyzed to produce gallium metal.Type: GrantFiled: November 15, 1990Date of Patent: April 20, 1993Assignee: Rhone-Poulenc ChimieInventors: Yvette Pescher, Jean-Louis Sabot
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Patent number: 5196178Abstract: In order to produce dustfree silver nitrate which can be readily dosed, silver nitrate is atomized in a molten state. A purity of the silver nitrate of greater than 99%, a pH of 2 to 6, and the exclusion of light during the atomizing are necessary.Type: GrantFiled: October 8, 1991Date of Patent: March 23, 1993Assignee: Degussa AktiengesellschaftInventors: Dieter Hollmann, Roland Gerner
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Patent number: 5194232Abstract: Fluorine content of tantalum and niobium hydroxides is reduced to under 0.5 weight % by washing such hydroxide precipitates (as obtained by HF digestion and solvent extraction) with dilute ammonia (1 to 10%) and then water in two washing stages. The first washing stage includes a partial neutralization and the used wash water of the second stage is advantageously recycled, after adjustment of its ammonia concentration, for use as the first stage washing liquid.Type: GrantFiled: August 27, 1991Date of Patent: March 16, 1993Assignee: Hermann C. Starck Berlin GmbH & Co. KGInventors: Walter Bludssus, Erk-Rudiger Feuerhahn, Horst Zimmermann
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Patent number: 5188736Abstract: A new chemical separation process was developed in this invention using 2-methoxyethanol or methyl collosolve (MCS) and ethylene glycol (EG) as separation agents, to separate the valuable extractants such as di(2-ethylhexyl) phosphoric acid(D2EHPA), tri n-octyl-phosphine oxide (TOPO) from spent solvent and to recover the extractants. The process comprises separation and recovery sections. In the separation section the extractants were removed by the polar solution from spent solvent based on the difference of miscibilities. In the recovery section, the polar solution loaded with extractants was distillated under vacuum to remove MCS as a distillate and water was added to the bottom product to facilitate the separation of the extractants. By using this novel process, 99% of D2EHPA and 70% of TOPO in the spent solvent were separated and 98% of D2EHPA was recovered. MCS and EG can be regenerated and reused in the process.Type: GrantFiled: August 27, 1991Date of Patent: February 23, 1993Assignee: Institute of Nuclear Energy ResearchInventors: Ben-Li Pen, Dah-Ping Wang, Ying-Chu Hoh, Kuo-Hao Tsao
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Patent number: 5186920Abstract: The iron content of the TiO.sub.2 -containing precursor is subjected to a direct reduction to effect a metallization of at least 90%. The reduced product is separated into magnetic and nonmagnetic fractions by magnetic separation. To oxidize the metallic iron, the magnetic fraction is subjected to an oxidation in an acid medium with agitation at a pH value below 2, under a pressure of 12 to 24 bars, and at a temperature from 150.degree. to 210.degree. C. with a supply of an oxygen-containing gas that contains at least 90% oxygen. When the suspension has been pressure-relieved, the hematite which has been formed is separated from the TiO.sub.2 concentrate.Type: GrantFiled: November 19, 1991Date of Patent: February 16, 1993Assignee: Metallgesellschaft AktiengesellschaftInventors: Rudolf Heng, Walter Koch, Ali-Naghi Beyzavi
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Patent number: 5178848Abstract: Lithium metatungstate as a new composition of matter and the production thereof are disclosed. A solution of lithium monotungstate is treated with an extractant to remove sufficient lithium ions to produce a dilute solution of lithium metatungstate and the dilute solution is then concentrated. Lithium metatungstate solutions are more dense than other alkali metal metatungstates and have lower viscosities which properties make the solutions highly useful for heavy media separations.Type: GrantFiled: June 25, 1991Date of Patent: January 12, 1993Assignee: BHP-Utah International Corp.Inventors: Willem P. C. Duyvesteyn, Houyuan Liu, Nicholas L. Labao, Purusotam L. Shrestha
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Patent number: 5174971Abstract: The thermal neutron capture cross-section of zirconium may be altered by altering its natural isotope distribution through a steady state chromatographic separation of these isotopes using an anion exchange resin as the stationary phase of the chromatographic column. Zirconium is dissolved in a very strong acid which causes the formation of a zirconium anion, such as the ZrOCl.sub.4.sup.-2 anion formed in six normal hydrochloric acid, and eluted off the column with a weaker acid. Distinct elution volumes representative of each isotope are collected. In a preferred embodiment, the process also separates the zirconium from hafnium and the other impurities normally present in the product obtained by chlorinating zircon sand and utilizes a continuous annular chromatograph.Type: GrantFiled: October 10, 1990Date of Patent: December 29, 1992Assignee: Westinghouse Electric Corp.Inventors: Thomas S. Snyder, Michael C. Skriba, Edward J. Lahoda, Ernest D. Lee
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Patent number: 5174812Abstract: A process for the separation and recovery of nickel from an ammoniacal ammonium carbonate liquor containing nickel II ions and cobalt III ions by liquid-liquid extraction where ammoniacal ammonium carbonate solutions are the only aqueous phases involved in the process. The process includes the successive steps of: (a) oxidizing the majority of any cobalt II ammines in the ammoniacal liquid to cobalt III; (b) extracting nickel from the ammoniacal liquor with an organic reagent, which reagent may also contain a suitable modifying reagent, to form a nickel loaded organic phase and an ammoniacal ammonium carbonate phase containing cobalt; (c) stripping the nickel loaded organic phase characterized by contacting the organic phase with an ammoniacal ammonium carbonate solution to form a nickel loaded aqueous strip liquor.Type: GrantFiled: May 14, 1990Date of Patent: December 29, 1992Assignee: MEQ Nickel Pty., Ltd.Inventors: Malcolm J. Price, John G. Reid
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Patent number: 5173277Abstract: The present invention is directed to improved methods for processing battery wastes, batter casing debris and other lead contaminated materials. The improved processes of the present invention provide less environmentally stressful methods for recovering lead from such materials while at the same time producing scrap or recyclable ebonite and plastics having reduced and environmentally acceptable lead and leachable lead levels. Most of the lead is first removed by trommel scrubbing. In another aspect of the present invention ebonite and other hard surface materials to which are adhered lead contaminants are mixed with water and abraded in a high energy scrubber to remove the adhered contaminants prior to separation of the cleaned ebonite from solution. This simple and environmentally preferred hydromechanical process provides clean scrap or recyclable ebonite.Type: GrantFiled: February 22, 1991Date of Patent: December 22, 1992Assignee: NL Industries, Inc.Inventors: Alistair H. Montgomery, Wolfram H. Kube
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Patent number: 5171547Abstract: The present invention is directed to a method for treating a sludge containing substantial amounts of chromium, aluminum, calcium, iron, and phosphorous. The method comprises forming a slurry of the sludge; reacting the slurry with an acid to dissolve substantially all the aluminum and chromium and provide a solids residue comprising mostly calcium sulfate; separating the chromium/aluminum-containing solution from the solids residue; raising the pH of the chromium/aluminum solution to precipitate chromium as chromium hydroxide; and separating the chromium hydroxide from the remaining aluminum-containing solution. The chromium hydroxide is then enriched with an alkali or earth alkali compound and calcined in an oxidizing atmosphere to convert the chromium to a chromate. The calcine is leached in an aqueous medium at a controlled pH to yield a high concentration, high purity chromate solution suitable for producing metallic chromium or a variety of chromium chemicals.Type: GrantFiled: September 19, 1990Date of Patent: December 15, 1992Assignee: Amax, Inc.Inventors: Ranko Crnojevich, Andrew B. Case, Felix D. Rando, John D. Sweeney
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Patent number: 5171549Abstract: An improved halogenator process and system is provided which significantly and economically decreases the level of impurities in the processing of various refractory metals and their halides and particularly hafnium tetrachloride which is condensed from gases produced by the chlorination of Zircon.Type: GrantFiled: May 22, 1991Date of Patent: December 15, 1992Assignee: Teledyne Wah Chang AlbanyInventors: Ronald E. Walsh, Jr., Peter W. Krag, Roy E. Blackstone, Duane L. Hug
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Patent number: 5169610Abstract: An efficient method is proposed for decolorizing a rare earth oxysulfide, which is usually slightly colored in grey as prepared by the sulfiding reaction of a rare earth oxide with hydrogen sulfide, by removing sulfur impurity. The method comprises two steps of heat treatmentof which the first step is conducted in air at 450.degree. to 550.degree. C. for 2 to 5 hours and the second step is conducted in an inert gas, e.g., argon, at 800.degree. to 950.degree. C. for 2 to 5 hours.Type: GrantFiled: October 7, 1991Date of Patent: December 8, 1992Assignee: Shin-Etsu Chemical Ltd.Inventors: Kasuhiro Yamada, Norifumi Yoshida
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Patent number: 5169619Abstract: There is provided a method of producing titanium oxides which comprises: admixing an aqueous solution of titanium tetrachloride with sulfuric acid in a molar ratio of sulfuric acid to titanium tetrachloride of at least 0.5 adding an alklai to the resultant solution to produce titanium hydroxide; and drying and calcining the titanium hydroxide. A further method is provided which comprises: adding a solution of an alkali to an aqueous solution of titanium tetrachloride having a concentration of not more than 2.5 moles/l at temperatures of not less than 50.degree. C., thereby to substantially thermally hydrolyze the titanium tetrachloride and to produce titanium hydroxide; and drying and calcining the titanium hydroxide.Type: GrantFiled: February 12, 1991Date of Patent: December 8, 1992Assignee: Sakai Chemical Industry Co., Ltd.Inventors: Masafumi Yoshimoto, Tadao Nakatsuji, Kazuhiko Nagano
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Patent number: 5167939Abstract: The aqueous alkali chloride solution is coarsely purified first. In the succeeding fine purifier the solution, which contains calcium ions, magnesium ions and undissolved magnesium compounds, is passed through a plurality of purification stages (ion exchange stages), which contain cation exchange granulate. In the fine purifier the solution having a pH value of about 10 to 11 is passed through a first ion exchange stage and the solution coming from the first ion exchange is acidified to decrease its pH value by at least 0.5. The solution is subsequently passed through at least one second ion exchange stage and a solution which is virtually free of undissolved magnesium compounds is withdrawn from the fine purification means. The acidified solution fed to the second ion exchange stage has preferably a pH value of 5 to 10.Type: GrantFiled: August 7, 1991Date of Patent: December 1, 1992Assignee: Metallgesellschaft AktiengesellschaftInventors: Karl Lohrberg, Rainer Dworak
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Patent number: 5165901Abstract: Rhodium and certain other PGM's in oxidation state III complex with chloride is precipitated from a solution by mixing with a polyamine, especially diethylene-triamine, in the presence of a protonating agent for the polyamine. High selectivity and high yields, in comparison to known reagents, are observed.Type: GrantFiled: September 10, 1991Date of Patent: November 24, 1992Assignee: Johnson Matthey Public Limited CompanyInventors: William D. Crozier, Richard A. Grant
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Patent number: 5164171Abstract: In the manufacture of ammonium paratungstate, sulfide is added to a tungsten-containing solution in order to precipitate molybdenum sulfide. Volatiles, including sulfides, evolved during this process are collected in a caustic scrubbing solution. The sulfide values in the caustic scrubbing solution may be reused to precipitate molybdenum sulfide by first treating the caustic scrubbing solution with alkaline earth chloride or sulfate to precipitate out alkaline earth carbonate.Type: GrantFiled: July 1, 1991Date of Patent: November 17, 1992Assignee: GTE Products CorporationInventors: Michael J. Miller, Martin C. Vogt, Thomas A. Wolfe
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Patent number: 5160711Abstract: A method for recovering platinum group metals from a catalyst material comprises leaching the material with a cyanide solution at a temperature greater than about 100.degree. C. to form soluble platinum group metal-cyanide complexes in solution. Solids are removed from the resulting pregnant leach solution, and the pregnant leach solution is then heated to a temperature sufficient to decompose the platinum group metal-cyanide complexes and precipitate the platinum group metals.Type: GrantFiled: May 10, 1991Date of Patent: November 3, 1992Assignee: The United States of America as represented by the Secretary of the InteriorInventors: Gary B. Atkinson, Robert J. Kuczynski, Dennis P. Desmond