Forming Insoluble Substance In Liquid Patents (Class 423/158)
  • Patent number: 5167939
    Abstract: 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at least one second ion exchange stage and a solution which is virtually free of undissolved magnesium compounds is withdrawn from the fine purification means.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: Grant
    Filed: August 7, 1991
    Date of Patent: December 1, 1992
    Assignee: Metallgesellschaft Aktiengesellschaft
    Inventors: Karl Lohrberg, Rainer Dworak
  • Patent number: 5164171
    Abstract: 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: Grant
    Filed: July 1, 1991
    Date of Patent: November 17, 1992
    Assignee: GTE Products Corporation
    Inventors: Michael J. Miller, Martin C. Vogt, Thomas A. Wolfe
  • Patent number: 5152973
    Abstract: The invention process provides a metal oxide, or oxides of more than one more metal, wherein the oxides have a mean particle size less than 1 micron. The oxides are made by steps including (1) reacting an aqueous solution of a metal salt (or salts) that form insoluble carbonate(s), thereby to form a carbonate precipitate, followed by (b) recovering the precipitate, e.g., by filtration; (c) redispersing the precipitate in water to form a second very dilute slurry; (d) spray-drying said second slurry; (e) calcining the spray-dried product at a low temperature (e.g., 540.degree. C.), followed by a final calcination in atmosphere consisting of flowing oxygen initially under reduced pressure (e.g., 2 Torr). The spray-dried spheroids comprise particles having a mean particle size less than one micron, a property carried over into the products of both calcinations.
    Type: Grant
    Filed: May 8, 1990
    Date of Patent: October 6, 1992
    Assignee: W. R. Grace & Co.-Conn.
    Inventor: Nicholas D. Spencer
  • Patent number: 5132253
    Abstract: A method for synthesizing alkaline earth metal-containing ceramic materials by sol-gel processing is described, wherein a sol containing alkoxides or other soluble precursors for a selected ceramic composition, and additionally containing one or more dissolved alkaline earth metal/crown either complexes, is gelled, dried and fired to convert the precursors and complexes to a polycrystalline ceramic product. The crown ether complexes improve alkaline earth metal solubility and the homogeneous incorporation of these metals into the precursor gels and final crystalline products.
    Type: Grant
    Filed: December 17, 1990
    Date of Patent: July 21, 1992
    Assignee: Corning Incorporated
    Inventor: Steven B. Dawes
  • Patent number: 5102633
    Abstract: A method for reducing impurity levels of calcium, magnesium and/or silicon in hexammine cobalt halide compounds involves the addition of ferric ions and, optionally, soluble fluorides to an aqueous hexammine cobalt (III) chloride solution having a pH of at least 9. Insoluble compounds of magnesium fluoride, calcium fluoride, and/or ferric hydroxide and silicon coprecipitates are removed from the solution by filtration.
    Type: Grant
    Filed: May 20, 1991
    Date of Patent: April 7, 1992
    Assignee: GTE Products Corporation
    Inventors: Eric F. Husted, Michael J. Miller, Shellie K. Northrop, David T. Smith
  • Patent number: 4968498
    Abstract: Process for the manufacture of a mixed metal oxide powder, in which at least one metal alcoholate is hydrolyzed in the presence of at least one metal oxide or hydroxide and of an acidic organic compound containing more than 6 carbon atoms in the molecule. The process is applicable to the production of barium titanate powders.
    Type: Grant
    Filed: June 15, 1988
    Date of Patent: November 6, 1990
    Assignee: Solvay & Cie (Societe Anonyme)
    Inventors: Henri Wautier, Luc Lerot
  • Patent number: 4931133
    Abstract: A method of growing optical quality .beta.-BaB.sub.2 O.sub.4 crystals involves growing these crystals from a fluxed melt of BaB.sub.2 O.sub.4, Na.sub.2 O and NaCl, in certain proportions.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: June 5, 1990
    Assignee: Allied-Signal Inc.
    Inventors: Devlin M. Gualtieri, Bruce H. T. Chai
  • Patent number: 4904638
    Abstract: A process is disclosed for producing a homogeneous mixture of co-precipitated carbonate salts capable of reacting together in an oxygen atmosphere at an elevated temperature to form a superconducting ceramic which comprises forming a first solution by dissolving in a first solvent maintained at a temperature of from about 15.degree. to 35.degree. C. a rare earth compound, an alkaline earth metal compound, and a copper compound capable of reacting with a carbonate ion to form an insoluble precipitate of carbonate salts in the solvent used to form the solution; forming a second solution containing a carbonate-forming compound dissolved in a second solvent miscible with the first solvent; blending the first and second solutions together at a temperature of from about 0.degree. to 15.degree. C.
    Type: Grant
    Filed: March 3, 1988
    Date of Patent: February 27, 1990
    Assignee: Hewlett-Packard Company
    Inventor: Stephen A. DiCarolis
  • Patent number: 4851036
    Abstract: There is disclosed a process and an apparatus for beneficiating a mineral ore, such as phosphate-containing ore, in a substantially vertical column. The feed subjected to the benefication preferably has a particle size of less than 20 mesh. The feed is introduced into the column, containing at least one baffle, into which there is also introduced a gas at the bottom portion thereof and a liquid through at least one column inlet at the top of the column. The baffle and the rates of introduction of the feed, the gas, and the liquid are such as to create relatively high turbulence conditions within the column. The enriched, beneficiated product is removed at the top of the column, while the waste products, such as silica-containing material, in the case of a phosphate ore, are recovered at the bottom of the column.
    Type: Grant
    Filed: September 18, 1987
    Date of Patent: July 25, 1989
    Assignee: Mobil Oil Corporation
    Inventors: Robert J. Anthes, Ross A. Kremer, Susanne Von Rosenberg
  • Patent number: 4839060
    Abstract: Modified starch compositions and their use for flocculating mineral waste residues, particularly the red mud containing alumina liquors from bauxite residues, comprising the addition to an alumina liquor of a flocculating amount of a methylated starch which, optionally, may be hydrolyzed, or a methylated starch which is also sulfonated and, optionally, may be hydrolyzed. Preferably, the methylated starch compositions are potato and dasheen starch derivatives prepared at temperatures of about 50.degree. to about 85.degree. C.
    Type: Grant
    Filed: October 21, 1987
    Date of Patent: June 13, 1989
    Assignee: Suncor, Inc.
    Inventors: Raymond N. Yong, Amar J. Sethi
  • Patent number: 4838922
    Abstract: Methods of producing monocalcium phosphate and products created therefrom are provided. The method includes the steps of mixing phosphoric acid and water with brown mud. Preferably, the phosphoric acid is added to water so that it comprises approximately 3% to about 50% of the phosphoric acid/water mixture by weight, and the water comprises approximately 50% to about 97% of the phosphoric acid/water mixture by weight. The brown mud is added to the phosphoric acid/water mixture in a weight ratio of approximately 1:1 to about 1:3. The method of the present invention results in improved monocalcium phosphate products.
    Type: Grant
    Filed: January 27, 1988
    Date of Patent: June 13, 1989
    Assignee: Green, Inc.
    Inventor: Billy J. Green
  • Patent number: 4804498
    Abstract: A soluble salt (sodium sulfate or sodium borate (Na.sub.2 SO.sub.4 or Na.sub.2 B.sub.4 O.sub.7) contained as the main component in a concentrated radioactive waste liquid generated in the BWR power plant or the PWR power plant is insolubilized and precipitated, sodium hydroxide (NaOH formed in the insolubilization is separated from the precipitate and the radioactive waste liquid slurry containing the precipitate is solidified with a hydraulic solidifying material. Since the separated caustic soda (NaOH) is free of radioactive substances, it can be easily utilized again, and since the radioactive substances are stably fixed in the solidified body, leakage of radioactivity from the solidified body can be greatly reduced.
    Type: Grant
    Filed: December 8, 1986
    Date of Patent: February 14, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Hiroko Mizuno, Makoto Kikuchi, Shin Tamata, Tatsuo Izumida, Tsutomu Baba
  • Patent number: 4800042
    Abstract: A volume-reducing solidification treatment method for radioactive waste liquid containing boron primarily in the form of boric acid or borates is disclosed.After an alkali is added to the waste water to adjust pH thereof, and optionally after evaporation concentration is carried out, soluble calcium compounds such as Ca(OH).sub.2 are added, the waste water is stirred at a specific temperature to form insoluble calcium borate aged at a lower temperature than that of forming borate, and evaporation and concentration is carried out, which raises the concentration of the solid component. The concentrated liquid obtained is solidified with cement.The concentrated liquid may also be dried into a powder using a thin film evaporator.
    Type: Grant
    Filed: January 27, 1987
    Date of Patent: January 24, 1989
    Assignee: JGC Corporation
    Inventors: Norimitsu Kurumada, Hiroshi Kuribayashi, Setsuo Shibata, Toshikatsu Wakabayashi, Akira Hasegawa, Mamoru Shibuya
  • Patent number: 4793947
    Abstract: The present invention relates to a method and an apparatus for producing a waste package of radioactive waste containing particles of radioactive waste material of low modulus of elasticity, particles of radioactive waste material of high modulus of elasticity, and a solidifying agent in which the particles of radioactive waste material of low modulus of elasticity and the particles of radioactive waste material of high modulus of elasticity are fixed in an almost uniformly dispersed state. According to this invention, the radioactive waste generated from nuclear power plants can be greatly reduced in volume and also a waste package of radioactive waste with high strength and excellent water resistance can be obtained.
    Type: Grant
    Filed: April 16, 1986
    Date of Patent: December 27, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Tatsuo Izumida, Hideo Yusa, Kiyomi Funabashi, Makoto Kikuchi, Shin Tamata
  • Patent number: 4793979
    Abstract: The present invention is depicting a chemical separation of phorphorus ore. Phosphorus ore, especially calcareous and clacareous-sillicious phosphorus ore can be effectively converted into several products through chemical separation, which consists of two stages, namely ore pulp reaction and solution regeneration. In the first stage, phosphorus ore is disolved by mixed ammonium salts solvent, but the valence minerals, such as fluoride apatite and quartz don't take part in the reaction and retain their solid state. Thus phosphorus concentrate can be obtained through the separation, the by-products such as the filtrate and gases can be utilized in the solution regeneration. After ammoniation, sulfurization, carbonization and alkalization of the filtrate, the Ca.sup.2+, Mg.sup.2+, Fe.sup.3+, Al.sup.2+, M.sup.2+ ions in it will gradually come out and turn into products, the regenerated solution obtained can be used again and again, thus forming a complete enclosed circulation process.
    Type: Grant
    Filed: March 20, 1986
    Date of Patent: December 27, 1988
    Assignees: Shaaxi Chemical and Fertilizer Industry Company, Kemira Company of Finland
    Inventor: Lu Wenxing
  • Patent number: 4788046
    Abstract: This invention relates to glass-ceramic packages for integrated circuits containing multi-layer, interconnected thick film wiring patterns obtained by co-sintering a glass-ceramic composite and copper, silver, palladium or gold based conductors at temperatures not exceeding about 1000.degree. C. The dielectric systems disclosed herein contains composites of borosilicate glasses and crystalline fillers which are fabricated by either mixing glass frit and the filler or by a sol-gel coating process.
    Type: Grant
    Filed: August 13, 1987
    Date of Patent: November 29, 1988
    Assignee: Ceramics Process Systems Corporation
    Inventors: Eric A. Barringer, Sheldon I. Lieberman, Mark S. Schmidt, James D. Hodge
  • Patent number: 4760138
    Abstract: Dry, stable carbonating agents comprised of a carbohydrate/metal bicarbonate complex are disclosed. The complex is prepared by reacting a carbohydrate with a metal hydroxide or oxide at a temperature not exceeding 25.degree. C. to form a carbohydrate/metal hydroxide adduct to which carbon dioxide is then introduced to form the complex. The complex is then immediately dried, preferably by freeze drying. The carbonating agents are particularly useful as components of dehydrated beverage powders. Upon rehydration, the complex releases carbon dioxide and carbonates the beverage. Additionally, upon rehydration the complex promotes the solubilization of the carbohydrate components in the beverage.
    Type: Grant
    Filed: January 29, 1986
    Date of Patent: July 26, 1988
    Assignee: Nestec S. A.
    Inventors: Rebecca S. So, Albert A. Willi
  • Patent number: 4743347
    Abstract: A process for producing a substantially pure, concentrated MgCl.sub.2 solution suitable for subsequent molten salt electrolysis to magnesium metal from an impure magnesite ore or concentrate is disclosed. The process comprises the steps of calcining a magnesite ore or concentrate at a temperature greater than 600.degree. C. to decompose most of the magnesite and form a reactive magnesia, dissolving such reactive magnesia with either concentrated hydrochloric acid or hydrogen chloride gas with the addition of a surface active wetting agent to produce an impure concentrated MgCl.sub.2 solution, and reacting such impure concentrated MgCl.sub.2 solution with a minimum of excess magnesia to increase the pH of the solution to at least 5.5 to precipitate undesirable impurities from solution and produce a substantially pure MgCl.sub.2 solution.
    Type: Grant
    Filed: May 11, 1987
    Date of Patent: May 10, 1988
    Assignee: Pamour Inc.
    Inventors: G. Bryn Harris, John G. Peacey, Serge Monette
  • Patent number: 4710366
    Abstract: Wet process phosphoric acid, stabilized with respect to the precipitation of solids upon aging, and containing significantly reduced levels of magnesium and aluminum, is prepared by the controlled addition of fluosilicic acid to wet process filter grade phosphoric acid followed by a series of evaporation, crystallization and centrifugation steps. Sufficient fluosilicic acid is added to provide a fluorine to magnesium ratio of about 2.5:1 to 10.1:1, preferably 5:1. The final product, which has a P.sub.2 O.sub.5 content of at least 56 percent, contains low amounts of magnesium and aluminum, and exhibits low solids precipitation characteristics during shipment, storage and eventual processing into end products such a fertilizers.
    Type: Grant
    Filed: October 23, 1986
    Date of Patent: December 1, 1987
    Assignee: Freeport Minerals Company
    Inventors: Vivian C. Astley, Jody J. Taravella
  • Patent number: 4692323
    Abstract: The invention concerns a process for separating magnesium-based impurities contained in a wet-process produced phosphoric acid. This process comprises adding an ammonium compound R(NH.sub.4) soluble in the said phosphoric acid, and, where called for, a fluorine compound and an aluminum compound to this phosphoric acid so as to induce a reaction forming an insoluble complex (NH.sub.4).sub.x (Mg).sub.y (Al).sub.z (F, OH).sub.6 ; this complex crystallizes in large grains and is easily separated subsequently by filtration and decantation.
    Type: Grant
    Filed: June 12, 1986
    Date of Patent: September 8, 1987
    Assignee: Centre National de la Recherche Scientifique (C.N.R.S.)
    Inventors: Gilbert Bonel, Jean C. Heughebaert, Mohamed Chaabouni, Hassine Ayedi
  • Patent number: 4685935
    Abstract: A process for producing a pure magnesium sulphite from crude crystalline magnesium sulphite. Into a full suspension or flow containing magnesium sulphite crystals at least one further water-containing and heat-supplying flow is led. The heat-supplying flow rapidly increases the temperature of the suspension to above 80.degree. C. in less than 10 seconds, preferably in less than 2 seconds. The solid water-insoluble fraction is then separated from the resulting flow, and the pure product is recrystallized from the solution. The solution may be recycled into the process either for further purification or for use as at least one heat-supplying flow.
    Type: Grant
    Filed: June 26, 1986
    Date of Patent: August 11, 1987
    Assignee: Vysoka Skola chemicko-technologicka
    Inventors: Stanislav Najmr, Zdenek Jerman, Jaroslav Kralicek
  • Patent number: 4684512
    Abstract: The invention is a process for recovering phosphorus value from magnesium pyrophosphate containing filter media in the wet superphosphoric acid purification process. The invention comprises treating the filter cake with a salt to remove the adhering phosphoric acid without solubilizing magnesium acid pyrophosphate. The filter cake, after phosphoric acid removal, can be utilized as commercial or technical grade magnesium acid pyrophosphate.
    Type: Grant
    Filed: August 25, 1986
    Date of Patent: August 4, 1987
    Assignee: Stauffer Chemical Company
    Inventors: John M. Stewart, Teddy R. Clark, Thomas E. Edging
  • Patent number: 4640828
    Abstract: A process for separating and removing substantial amounts of magnesium and other ion impurities from wet process phosphoric acid of 35-45% P.sub.2 O.sub.5 content is provided. The process steps comprise: (a) heating the acid while maintaining the acid at a concentration of 35-45% P.sub.2 O.sub.5 by the addition of water for a time sufficient to effect removal of silicon as fluosilicic acid and/or silicon tetrafluoride, thereby forming a stripped acid; (b) precipitating ralstonite from the heated stripped acid; and (c) separating the precipitated ralstonite from the acid.
    Type: Grant
    Filed: October 22, 1985
    Date of Patent: February 3, 1987
    Assignee: International Minerals & Chemical Corp.
    Inventor: Arthur N. Baumann
  • Patent number: 4639359
    Abstract: A method of removing aluminum, magnesium, iron and other impurities from wet process phosphoric acid is provided. The method comprises partially ammoniating the acid and reacting the acid with a fluoride ion donating compound to precipitate aluminum- and magnesium-containing ralstonite and ammonium fluorosilicate which can be easily separated from the acid thereby producing a partially ammoniated wet process phosphoric acid of reduced impurities content.
    Type: Grant
    Filed: December 16, 1985
    Date of Patent: January 27, 1987
    Assignee: International Minerals & Chemical Corp.
    Inventors: Dennis H. Michalski, Viswanathan Srinivasan
  • Patent number: 4610722
    Abstract: A process is provided for hydrometallurgical processing of steel plant dusts containing cadmium, lead, zinc, and iron values, along with impurities such as chloride and fluoride salts of sodium, potassium, magnesium, etc. The first step in the process involves leaching the dust in a mixed sulfate-chloride medium that dissolves most of the zinc and cadmium. Any iron and aluminum dissolved in this step is precipitated by oxidation and neutralization. Zinc is recovered from the resulting solution by solvent extraction which provides a raffinate which is recycled to the leaching step with a bleed stream also provided for recovery of cadmium and removal of other impurities from the circuit. The lead sulfate residue from the leaching step is leached with caustic soda, and zinc dust is used to cement the lead out from the caustic solution, which then joins the main solution for zinc recovery.
    Type: Grant
    Filed: January 31, 1985
    Date of Patent: September 9, 1986
    Assignee: AMAX Inc.
    Inventors: Willem P. C. Duyvesteyn, Robert F. Hogsett
  • Patent number: 4571263
    Abstract: A process for recovering gold from refractory auriferous iron-containing concentrate includes feeding the concentrate as an aqueous slurry to an acidic pretreatment step and treating the concentrate in the acidic pretreatment step with aqueous sulphuric acid solution to decompose carbonate and other acid consuming gangue compounds. The treated slurry is oxidized in a pressure oxidation step at a temperature in the range of from about 135.degree. to about 250.degree. C. under a pressurized oxidizing atmosphere while maintaining a free acid concentration of from about 5 to about 40 g/L sulphuric acid to cause dissolution of iron, formation of sulphuric acid and oxidation of substantially all oxidizable sulphide compounds to sulphate form with less than about 20% of oxidized sulphur being present as elemental sulphur during the oxidation step.
    Type: Grant
    Filed: March 4, 1985
    Date of Patent: February 18, 1986
    Assignee: Sherritt Gordon Mines Limited
    Inventors: Donald R. Weir, Roman M. Genik-Sas-Berezowsky
  • Patent number: 4571264
    Abstract: A process for recovering gold from refractory auriferous iron-containing sulphidic ore which comprises feeding ground ore as an aqueous slurry to an acidic pretreatment step. The ground ore in the acidic pretreatment step is treated with aqueous sulphuric acid solution to decompose carbonate and acid consuming gangue compounds, and subjecting the treated slurry to a first liquid-solids separation step to produce a sulphate solution and separated solids. Water is added to the separated solids in a first repulping step to form a slurry having a pulp density in the range of from about 25 to about 60% by weight solids. The first repulped slurry is oxidized in a pressure oxidation step at a temperature in the range of from about 135.degree. to about 250.degree. C.
    Type: Grant
    Filed: March 4, 1985
    Date of Patent: February 18, 1986
    Assignee: Sherritt Gordon Mines Limited
    Inventors: Donald R. Weir, Roman M. Genik-Sas-Berezowsky
  • Patent number: 4564507
    Abstract: A method is described for decontaminating magnesium fluoride resulting from the reduction of uranium fluoride to the metal by reaction with magnesium. This decontamination employs reactions with magnesium and carbon to remove radioactive components from the said magnesium fluoride in its molten state.
    Type: Grant
    Filed: October 24, 1983
    Date of Patent: January 14, 1986
    Inventor: Guy R. B. Elliott
  • Patent number: 4557748
    Abstract: A process for treating wet-process weak phosphoric acid solution is disclosed which significantly lowers the magnesium impurities in the acid (as well as certain other impurities) permitting subsequent concentration of the acid to levels for use in preparation of liquid fertilizers which are less prone to settling out of the impurities during storage than would be the case without such treatment. It has unexpectedly been found that by limiting evaporation of water from the initial 26% to 32% P.sub.2 O.sub.5 wet-process acid to a level such that the acid has a P.sub.2 O.sub.5 content of from about 42% to about 45% and thereafter maintaining the semi-concentrated acid at a temperature within the range of from about 145.degree. F. to about 270.degree. F.
    Type: Grant
    Filed: August 24, 1984
    Date of Patent: December 10, 1985
    Assignee: Farmland Industries, Inc.
    Inventors: Norman L. Stewart, Jr., Ken E. Kranz
  • Patent number: 4554144
    Abstract: Magnesium and aluminum impurities are removed from aqueous phosphoric acid by treatment with a fluorine material and an alkali metal containing material in such a manner that the atomic ratio of fluorine to aluminum is adjusted so that it is greater than about 2 and the alkali metal plus magnesium to aluminum atomic ratio to a value no greater than about 2. In one embodiment the fluorine to aluminum ratio is below about 11, preferably between about 4 and about 8. By controlling such atomic ratios in the limits prescribed, a more purified aqueous phosphoric acid can be produced having a substantial reduction in the magnesium and aluminum content thereof. The process is useful for wet-process phosphoric acids. The process is also particularly useful for acids having low P.sub.2 O.sub.5 content and/or high aluminum concentration. The purification process does not require evaporation for the removal of impurities, as for example fluorine as silicon tetrafluoride.
    Type: Grant
    Filed: January 6, 1984
    Date of Patent: November 19, 1985
    Assignee: Occidental Research Corporation
    Inventor: Fernando Ore'
  • Patent number: 4521397
    Abstract: A process for producing calcium hypochlorite hydrate crystals, which comprises continuously supplying a basic calcium hypochlorite slurry and chlorine gas, and reacting them at a temperature of from 20.degree.-50.degree. C. and at a chlorination rate of from 92 to 98.5% to precipitate calcium hypochlorite crystals at a crystallization velocity of not greater than 200 kg/m.sup.3 per hour.
    Type: Grant
    Filed: July 20, 1983
    Date of Patent: June 4, 1985
    Assignee: Asahi Glass Company, Ltd.
    Inventors: Keiichi Nakaya, Kunio Sato
  • Patent number: 4500498
    Abstract: Anhydrous zinc chloride is produced from an aqueous feed solution containing zinc chloride from an aqueous feed solution containing zinc chloride. The zinc chloride is extracted onto an organic extractant known to the art such as tributyl phosphate, primary, secondary or tertiary amines, and quaternary amine salts. The loaded extractant is then stripped with aqueous stripping solution containing ammonium chloride and ammonium hydroxide. The zinc ammine chloride formed in this aqueous stripping solution is separated from the stripping solution and can then be heated to form anhydrous zinc chloride and ammonia. This anhydrous zinc chloride is suitable as a feed material to a fused salt electrolysis process for the production of zinc.
    Type: Grant
    Filed: January 19, 1984
    Date of Patent: February 19, 1985
    Assignee: Cato Research, Inc.
    Inventors: Paul R. Kruesi, William H. Kruesi
  • Patent number: 4495160
    Abstract: Magnesium is removed from brine by contacting the brine with calcium hydroxide at temperatures above about 80.degree. C. but below the boiling point of the brine. The contacting results in the formation of magnesium hydroxide precipitate which is substantially insoluble in the mother liquor at those temperatures and strontium hydroxide which is dissolved in the mother liquor. When the contacting is carried out at a temperature above about 90.degree. C., magnesium hydroxide precipitate is fast settling and filterable; accordingly, it is removed from the mother liquor by a conventional process, such as filtering. The mother liquor is then cooled to cause the precipitation of at least a substantial part of strontium hydroxide present in the mother liquor. The precipitate of strontium hydroxide is recovered by a conventional process such as filtering. If precipitation upon cooling is insufficient, carbon dioxide gas is introduced into the mother liquor to effect the precipitation of strontium hydroxide.
    Type: Grant
    Filed: March 28, 1983
    Date of Patent: January 22, 1985
    Assignee: The Standard Oil Company
    Inventors: Truman P. Moote, Robert L. Reed
  • Patent number: 4489045
    Abstract: A process for the recovery of calcium chloride produced in the conversion of metal chloride by-products of chlorination to hydrous metal oxides. The hydrous metal oxides and other by-products of chlorination are insoluble in an aqueous solution of at least about 75 weight percent calcium chloride having a generally neutral pH and temperature between about 174 degrees centigrade and about 200 degrees centigrade. Calcium chloride also is readily recovered from the above solution.
    Type: Grant
    Filed: June 17, 1983
    Date of Patent: December 18, 1984
    Assignee: Kerr-McGee Chemical Corporation
    Inventor: Theodore A. Rado
  • Patent number: 4435370
    Abstract: Monocalcium phosphate, phosphoric acid and/or potassium phosphate, calcium fluoride and gypsum are produced in a process involving acidulation of phosphate rock with phosphoric acid, and wherein monocalcium phosphate dissolved in phosphoric acid is formed during acidulation. In important features, insolubles and impurities are removed and a portion of the monocalcium phosphate may be separated and recovered. Alkali metal ion is added to the solution to form alkali metal fluosilicate, such as K.sub.2 SiF.sub.6, is separated and hydrolyzed with calcium ion to form CaF.sub.2 and the solution is recycled as RH.sub.2 PO.sub.4 /H.sub.3 PO.sub.4 for further reaction with fluorides, where R is alkali metal. A portion of the MCP/H.sub.3 PO.sub.4 solution and/or crystallized monocalcium phosphate can then be reacted with potassium sulfate, potassium bisulfate, or mixtures thereof, to form KH.sub.2 PO.sub.4 or KH.sub.2 PO.sub.4 /H.sub.3 PO.sub.4 solutions, and gypsum or with H.sub.2 SO.sub.4 to produce phosphoric acid.
    Type: Grant
    Filed: September 29, 1981
    Date of Patent: March 6, 1984
    Assignee: Pennzoil Company
    Inventors: Dysart E. Holcomb, Erhart K. Drechsel, John B. Sardisco
  • Patent number: 4431615
    Abstract: The recovery of substantially pure magnesium and/or nickel sulphite which is present in a solid starting meterial. The latter is treated with gaseous SO.sub.2 in water, the solution obtained is treated by a liquid-liquid extraction, to give an aqueous phase and an organic phase and the magnesium and/or nickel sulphite is recovered from the aqueous phase. With this process, it is possible to obtain a magnesium salt of high purity.
    Type: Grant
    Filed: September 29, 1982
    Date of Patent: February 14, 1984
    Assignee: Gouvernement du Quebec
    Inventor: Georges Gabra
  • Patent number: 4416779
    Abstract: The invention relates to a method of producing an aqueous solution rich in phosphorous and recovering metal compounds in the purification of sewage-water or raw-water, in a plant which includes at least one chemical treatment stage in which an iron compound is supplied to the water to precipitate phosphorous present therein. The method is characterized in that the sludge from the chemical treatment stage is treated with hydrogen sulphide under anaerobic conditions, phosphorous compounds being dissolved from the sludge and metal sulphide being formed. The metal sulphides are dissolved to form metal salt solutions, of which at least the iron salt solution is separated and recycled to the chemical treatment stage. It is also possible prior to separating the iron salt solutions to recycle the metal salt solutions one or more times. The dissolved phosphorous can be removed in the form of an aqueous solution and treated in accordance with the so-called Donnert-process, to form calcium phosphate.
    Type: Grant
    Filed: September 28, 1982
    Date of Patent: November 22, 1983
    Inventors: Wilhelm K. Ripl, Bo L. Verner
  • Patent number: 4402850
    Abstract: A method is disclosed of producing a liquid agent for improving the quality of contaminated water, particularly water in pools, natural bodies of water and waste waters, characterized by introducing with agitation comminuted rock-salt clay or a mixture thereof with rock-salt deads into an aqueous solution or suspension of an inorganic base, stirring the resultant mixture for 2 to 5 (preferably 3) hours, thereupon adjusting the pH of the resultant solution to a value of between 7.5 and 10.5 (and preferably between 9.5 and 10.5) by means of the addition of acid or alkali, and removing undissolved portions from the solution.
    Type: Grant
    Filed: November 3, 1981
    Date of Patent: September 6, 1983
    Inventor: Karl P. Schorghuber
  • Patent number: 4389323
    Abstract: A process of making different grades of calcium magnesium acetate deicing agents, having substantially uniform but different calcium-to-magnesium mole ratios, from limestone having varying proportions of calcium carbonate and magnesium carbonate, is provided wherein limestone containing calcium and magnesium carbonates is finely divided, mixed with water to form an aqueous suspension of limestone, vigorously agitated and reacted with excess acetic acid. The reaction is completed by adding to the reaction batch about 30% of the molar equivalent of calcined finely divided limestone base to produce a calcium magnesium acetate salt solution having a calcium-to-magnesium mole ratio much greater than one. The insolubles from this first reaction are removed, calcined and reacted with acetic acid in a second reaction to produce a calcium magnesium acetate salt solution having a calcium-to-magnesium mole ratio substantially equal to one.
    Type: Grant
    Filed: November 2, 1981
    Date of Patent: June 21, 1983
    Inventor: Alan B. Gancy
  • Patent number: 4379132
    Abstract: Either commercial yellow phosphorus or a phosphorus sludge is reacted with a slurry of calcium hydroxide in aqueous sodium hydroxide to form a sodium hypophosphite solution containing calcium and hydroxide ions. The solution is neutralized with phosphoric acid or an acid phosphate salt with the co-production of an insoluble calcium phosphate. The neutral solution is contacted with an ion exchange resin charged with sodium ions to remove any remaining calcium ions.
    Type: Grant
    Filed: August 5, 1982
    Date of Patent: April 5, 1983
    Assignee: FMC Corporation
    Inventors: Dennis C. Annarelli, Richard E. Hall
  • Patent number: 4362709
    Abstract: In a process of preparing sinter magnesia from magnesium oxide in a sintering kiln evolving flue gases during sintering, the flue gases are washed before their removal from the kiln to the atmosphere with a portion of the magnesium chloride slurry formed during the preparation of the magnesium oxide and the magnesium chloride slurry used for washing the flue gases is recycled to the slurry wherefrom the magnesium sol for making the magnesium oxide is derived.
    Type: Grant
    Filed: November 2, 1981
    Date of Patent: December 7, 1982
    Assignee: Veitscheer Magnesitwerke-Actien-Gesellschaft
    Inventors: Helmut Grohmann, Peter Stadler
  • Patent number: 4289736
    Abstract: The addition of an excess of asbestos tailings in the course of the extraction of magnesium from asbestos tailings by digestion with an acid greatly facilitates the elimination of silica and other impurities by filtration of the resulting reaction mixture. The improvement reduces the filtration time and the filtration leaves a cake which is much easier to dispose.
    Type: Grant
    Filed: August 31, 1979
    Date of Patent: September 15, 1981
    Assignee: Universite de Sherbrooke
    Inventor: Jean M. Lalancette
  • Patent number: 4271131
    Abstract: Highly pure lithium chloride suitable for use in production of lithium metal by electrolysis is obtained directly from impure natural or other lithium chloride brines by an integrated process in which the brine is first concentrated by solar energy to a lithium chloride concentration of about 3%, after which the brine is treated with lime and calcium chloride to convert such impurities as boron, magnesium and sulfate to a calcium borate hydrate, magnesium hydroxide and calcium sulfate dihydrate, respectively, and separating the precipitated calcium sulfate dihydrate from the brine. The brine is then further concentrated to 40% or more lithium chloride by means of solar or other energy, during which concentration step the calcium borate hydrate, magnesium hydroxide and calcium sulfate dihydrate precipitate from the brine. The highly concentrated brine is subjected to evaporation at a temperature above 101.degree. C. to produce anhydrous lithium chloride which is further heated to a temperature of 200.degree.
    Type: Grant
    Filed: April 11, 1979
    Date of Patent: June 2, 1981
    Assignee: Foote Mineral Company
    Inventors: Patrick M. Brown, Susan R. Jacob, Daniel A. Boryta
  • Patent number: 4270944
    Abstract: A process where calcium borates are precipitated from an aqueous solution of ulexite is disclosed. The ulexite is dissolved in hydrochloric acid. Calcium chloride then is added to the acid solution and then neutralized to precipitate the calcium borates. The calcium borates so produced are useful as glass forming, batch ingredients that can be compacted into agglomerates and preheated.
    Type: Grant
    Filed: January 11, 1980
    Date of Patent: June 2, 1981
    Assignee: Owens-Corning Fiberglas Corporation
    Inventors: Walter L. Eastes, Anna Tarantino
  • Patent number: 4261960
    Abstract: Boron, as well as magnesium and sulfate impurities, are removed from or at least substantially reduced in a lithium containing brine to minimize lithium losses on further concentration of the brine by adding to the brine an aqueous slurry of slaked lime and a solution of calcium chloride to form a calcium borate hydrate, magnesium hydroxide and calcium sulfate dihydrate, the last named compound being precipitated and separated from the brine. On further concentration of the brine, calcium boron hydrate and magnesium hydroxide precipitate and they are also removed from the brine. In an alternate procedure, the pH of the brine is adjusted to 8.0-8.4 by addition of hydrochloric acid to form a calcium borate hydrate, which on further evaporation, is also separated from the brine. The brine is then concentrated further to recover lithium values.
    Type: Grant
    Filed: April 11, 1979
    Date of Patent: April 14, 1981
    Assignee: Foote Mineral Company
    Inventor: Daniel A. Boryta
  • Patent number: 4229399
    Abstract: A process is provided wherein solid mixtures of metal chlorides of, for example, ferric chloride, ferrous chloride, vanadium chloride and chromium chloride are (1) mixed with an alkaline material such as, for example, calcium oxide, calcium hydroxide and calcium carbonate, followed (2) by adding water to the resulting mixture to granulate said mixture whereby the metal chlorides are rendered substantially insoluble in water.
    Type: Grant
    Filed: August 10, 1978
    Date of Patent: October 21, 1980
    Assignee: NL Industries, Inc.
    Inventors: Donald G. Cole, Achim Hartmann, Achim M. Kulling, Hermann B. Trub
  • Patent number: 4224290
    Abstract: Aqueous waste streams containing recoverable chlorine are reacted with an aqueous solution of an alkali metal hypohalite, such as sodium hypochlorite, to form an aqueous salt solution of an alkali metal halide, such as sodium chloride, and an alkaline earth metal hypohalite, such as calcium hypochlorite. Thereafter the aqueous salt solution is admixed with an organic alcohol to form an organic-aqueous salt solution. A gas containing chemically bound oxygen, such as carbon dioxide, is reacted with the organic-aqueous salt solution to form a slurry of solid particles of calcium carbonate suspended in a liquid mixture. The solid particles of calcium carbonate are separated from the liquid mixture.The aqueous phase containing sodium chloride may be recycled for use as a reactant in a chlor-alkali electrolytic cell. The organic phase containing organic hypochlorite may be used as a chlorinating agent or may be treated with an acid, such as hydrochloric acid, to reclaim free chlorine.
    Type: Grant
    Filed: September 28, 1978
    Date of Patent: September 23, 1980
    Assignee: Olin Corporation
    Inventor: Richard W. Lynch
  • Patent number: 4222989
    Abstract: A process for obtaining pure aluminum oxide (Al.sub.2 O.sub.3) from siliceous aluminum ore is disclosed. The aluminum ore is digested in a hydrochloric acid solution to obtain aluminum chloride, the aluminum chloride is crystallized as the hexahydrate, the aluminum chloride hexahydrate is purified and, subsequently, decomposed to give pure aluminum oxide and secondary products. The mother liquor of the crystallization step and the secondary products of the decomposition step are recycled.
    Type: Grant
    Filed: January 26, 1979
    Date of Patent: September 16, 1980
    Inventors: Milan Belsky, Albert Schwind, Gunter Winkhaus, Joseph Schierholt
  • Patent number: 4222990
    Abstract: A method is disclosed for the acidulation of phosphate rock and the production of substantially pure alkali metal phosphates, calcium phosphates, and phosphoric acid which are essentially free of fluorides and recovery of the fluorine values from the starting phosphate rock in useful form. The steps of the method comprise initial acidulation of phosphate rock with a phosphoric acid solution containing sufficient alkali metal values to provide R.sub.2 O in the system, where R is alkali metal, to solubilize the phosphates and form an insoluble precipitate comprising a mixture of impurities, sand (SiO.sub.2) and the fluorides, from which the fluorides can be recovered in usable form. In preferred embodiments, after removal of the precipitate containing the fluorides, a portion of the solution of phosphoric acid and calcium phosphate is reacted with sulfuric acid and RHSO.sub.4 or R.sub.2 SO.sub.4 where R is alkali metal, to form a solution of RH.sub.2 PO.sub.
    Type: Grant
    Filed: April 18, 1979
    Date of Patent: September 16, 1980
    Assignee: Pennzoil Company
    Inventor: Erhart K. Drechsel
  • Patent number: 4219360
    Abstract: Bone china is produced by including a boron-containing substance in the composition in water-insoluble form. Use of the boron-containing compound results in a lowering of the firing temperature and widening of the firing temperature range.
    Type: Grant
    Filed: August 9, 1979
    Date of Patent: August 26, 1980
    Assignee: United States Borax & Chemical Corporation
    Inventor: Raymond Thompson