Patents Examined by Edward Stern
  • Patent number: 4148867
    Abstract: In the production of a synthetic fluorspar of low silicon dioxide content wherein hexafluosilicic acid is added in an amount ranging from slightly below up to about stoichiometric amount to an aqueous calcium carbonate suspension at a temperature from about 0.degree. to 40.degree. C., and the calcium fluoride formed is separated off from the dilute silica sol and optionally washed out, the improvement which comprises reacting the calcium carbonate with the hexafluosilicic acid in such a way that the pH-value of the fully reacted solution amounts to between about 3.6 and 4.6, and adding a fast-reacting proton acceptor to the reaction mixture immediately before separation of the calcium fluoride in amount sufficient to raise the pH to about 5.0 to 6.4, preferably about 5.8 to 6.2. Suitable proton acceptors include the alkali metal and ammonium hydroxides carbonates and hydrogen carbonates or alkaline earth metal hydroxide.
    Type: Grant
    Filed: July 12, 1976
    Date of Patent: April 10, 1979
    Assignee: Bayer Aktiengesellschaft
    Inventors: Siegfried Schneider, Hans Niederprum
  • Patent number: 4127644
    Abstract: Hydrogen is produced from water by first reacting I.sub.2, SO.sub.2 and H.sub.2 O to make hydrogen iodide and sulfuric acid. A substantial molar excess of SO.sub.2 and I.sub.2 in the reaction zone creates a lighter sulfuric acid-bearing phase and a heavier polyiodic-acid-bearing phase. The heavier phase is separated, degassed and then contacted with phosphoric acid to permit distillation of HI of low water content and recovery of I.sub.2 as a separate fraction. Hydrogen is recovered from HI vapor, as by thermal decomposition.
    Type: Grant
    Filed: April 29, 1977
    Date of Patent: November 28, 1978
    Assignee: General Atomic Company
    Inventors: John H. Norman, Thomas S. Roemer, Bruce E. Kirstein, Karol J. Mysels
  • Patent number: 4117078
    Abstract: Concentrated magnesium chloride solutions are prepared from industrial liquors or brines by debrominating the liquor with chlorine, neutralizing the debrominated liquor up to a ph value of 3-6, adding a stoichiometric excess of calcium chloride to the neutralized liquor at temperatures in the range of 30.degree.-50.degree. C to form a calcium sulfate dehydrate crystallizate, separating the crystallizate from the mother liquor, adding a sufficient amount of carnallite to the mother liquor to increase the MgCl.sub.2 content thereof to 270-330 g/l after cold decomposition of the added carnallite and concentrating the resulting solution in two or more steps in the direct current in an evaporator with crystallization characteristics up to a final concentration of 440 to 470 g/l MgCl.sub.2 whereafter the concentrated magnesium chloride solution is separated from crude crystallized carnallite and sodium chloride formed during the concentration.
    Type: Grant
    Filed: March 29, 1977
    Date of Patent: September 26, 1978
    Assignee: Kali und Salz Aktiengesellschaft
    Inventor: Dietmar Kunze
  • Patent number: 4108968
    Abstract: In the production of aluminum chloride suitable for subsequent electrolytic reduction to metallic aluminum control of both the purity and the particle size is achieved by control of the entrance velocity of the aluminum chloride vapors in a fluidized bed, control of the fluidized bed temperature, and selective removal of the condensed particles from the bottom of the fluidized bed.
    Type: Grant
    Filed: July 21, 1977
    Date of Patent: August 22, 1978
    Assignee: Aluminum Company of America
    Inventors: Stanley C. Jacobs, Larry K. King, Bernard J. Racunas
  • Patent number: 4108967
    Abstract: Disclosed is a process for the production of sulphur hexafluoride comprising the steps of reacting fluorine and molten sulphur, removing lower-boiling by-products, separating a portion of the sulphur hexafluoride from higher-boiling by-products and treating the residue containing the higher-boiling by-products at a temperature between about 450.degree. and 800.degree. C. for a period of time between about 0.1 and 25 seconds. The treatment step may be carried out in the presence of elementary fluorine, and provision may be made for recycling the treated or untreated residue to the reaction stage. An apparatus for carrying out the process is also disclosed.
    Type: Grant
    Filed: June 15, 1977
    Date of Patent: August 22, 1978
    Assignee: Kali-Chemie Aktiengesellschaft
    Inventors: Joachim Massonne, Wilfried Becher
  • Patent number: 4107263
    Abstract: A process for the preparation of bromine and hydrogen bromide, which comprises reacting ammonium bromide with an oxygen containing gas at temperatures of from 200.degree. to 800.degree. C in the presence of oxidation catalysts is disclosed. Catalysts based on platinum group metals favor formation of HBr. Most other metal catalysts cause chiefly formation of bromine.
    Type: Grant
    Filed: June 15, 1977
    Date of Patent: August 15, 1978
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Lothar Schulz, Hans-Jurgen Arpe
  • Patent number: 4105752
    Abstract: A process for the production of aluminum chloride comprises providing a mixture of high purity activated carbon and alumina and bubbling chlorine gas therethrough, the mixture being kept at a temperature in the range of 500.degree. to 775.degree. C. Aluminum chloride is removed from the mixture as a vapor and condensed.
    Type: Grant
    Filed: December 20, 1976
    Date of Patent: August 8, 1978
    Assignee: Aluminum Company of America
    Inventors: Aaron J. Becker, Subodh K. Das
  • Patent number: 4105753
    Abstract: A process for the preparation of bromine and hydrogen bromide, which comprises reacting ammonium bromide with an oxygen containing gas at temperatures of from 200.degree. to 800.degree. C. in the presence of oxidation catalysts is disclosed. Catalysts based on platinum group metals favor formation of HBr. Most other metal catalysts cause chiefly formation of bromine.
    Type: Grant
    Filed: January 28, 1975
    Date of Patent: August 8, 1978
    Assignee: Hoechst Aktiengesellschaft
    Inventors: Lothar Schulz, Hans-Jurgen Arpe
  • Patent number: 4102985
    Abstract: A process for the production of high purity silicon characterized by the employment of an electric arc heater in which a silicon halide is reacted with hydrogen to produce liquid silicon and gaseous co-products.
    Type: Grant
    Filed: January 6, 1977
    Date of Patent: July 25, 1978
    Assignee: Westinghouse Electric Corp.
    Inventor: Francis J. Harvey, II
  • Patent number: 4101645
    Abstract: A process for the production of hydrogen/deuterium-containing gas in which the enriched condensate obtained from the production of a hydrogen/deuterium-containing gas mixture is collected and subjected to a direct exchange of isotopes with the feedsteam admitted to the process. Such condensate can be brought into direct exchange of isotopes with the gas water vapor mixture within the process, viz. ahead of the CO conversion section. The exchange of isotopes may be performed according to the counter-current principle. If it is intended to maintain in the hydrogen/deuterium-containing gas a certain definite content of water vapor whose phase condition is superior to the condition achieved when using normal cooling water, this gas, at least 0.6 kg/m.sup.3 of gas, is subjected to an exchange of isotopes with the water fed additionally into the process.
    Type: Grant
    Filed: November 8, 1976
    Date of Patent: July 18, 1978
    Assignee: Friedrich Uhde GmbH
    Inventors: Eberhard Nitschke, Arvind Desai, Hartmut Ilgner
  • Patent number: 4098873
    Abstract: A solid, particulate reactant is continuously added to a first zone and a liquid reactant is continuously added to a second zone. A conduit between the zones allows the solid and liquid reactants to pass counter-currently between the zones, the reaction being accomplished on contact between the reactants. During steady state operation, a clear layer is established in each zone above a slurry layer of the particles in solution. The clear layer is withdrawn from the top of each zone and introduced at the bottom thereof causing agitation in the slurry layer which promotes the reaction. The solid reactant is withdrawn from the second zone while the spent liquid reactant is withdrawn from the first zone.
    Type: Grant
    Filed: August 18, 1975
    Date of Patent: July 4, 1978
    Assignee: Borden, Inc.
    Inventor: Clinton Allen Hollingsworth
  • Patent number: 4097574
    Abstract: Synthetic rutile is made from ilmenite by pre-oxidizing it, reducing it in a fluid bed, thereafter aeration leaching it, optionally acid leaching, and drying.
    Type: Grant
    Filed: June 16, 1976
    Date of Patent: June 27, 1978
    Assignee: United States Steel Corporation
    Inventors: Robert G. Auger, Edward F. Restelli, Jr.
  • Patent number: 4097584
    Abstract: Technical-grade silicon is purified to produce silicon having less than 1 ppm of electrically effective impurities therein, particularly boron and phosphorus, by treating molten technical silicon with a hydrogen containing gas in the presence of water so as to remove such impurities from the molten silicon.
    Type: Grant
    Filed: May 19, 1977
    Date of Patent: June 27, 1978
    Assignee: Siemens Aktiengesellschaft
    Inventors: Konrad Reuschel, Norbert Schink
  • Patent number: 4094956
    Abstract: The content of sodium sulfate (and less soluble sulfates) in rock salt (halite) can economically be reduced from levels as high as 5 weight percent to levels as low as about 0.1 weight percent by the process of the invention. The halite is crushed to a certain particle size range and particles less than 0.5 mm in effective diameter are removed while (or after) the crushed material is subjected to attrition washing with a low sulfate, high NaCl brine. The washed, coarse particles are rinsed with a low sulfate brine, drained and dried to an extent appropriate to their contemplated use.
    Type: Grant
    Filed: August 12, 1977
    Date of Patent: June 13, 1978
    Assignee: The Dow Chemical Company
    Inventor: Barrie H. Bieler
  • Patent number: 4093706
    Abstract: Method of production of synthetic fluorite with a selected specified grain size to be obtained, by submitting the calcium carbonate to a reaction with fluoride ions present in an aqueous solution, consists therein that calcium carbonate is used having a grain size substantially the same as the selected grain size for the synthetic fluorite to be obtained. The fluoride ions for the reaction with the calcium carbonate are supplied in the form of a solution of ammonium fluoride and/or potassium fluoride and/or sodium fluoride. The process is conducted at a temperature chosen within the range of 50.degree. C to 150.degree. C, under a pressure reduced, atmospheric or elevated, within the range of 0.5 to 10 atm, and preferably at the boiling temperature or at a temperature not too far from the boiling point, especially in a reaction system containing ammonium fluoride.
    Type: Grant
    Filed: October 21, 1976
    Date of Patent: June 6, 1978
    Assignees: Politechnika Slaska, Instytut Chemii Nieorganicznej
    Inventors: Wladyslaw Augustyn, Maria Dziegielewska, Andrzej Kossuth
  • Patent number: 4092446
    Abstract: A balanced closed cycle silicon refinery has been developed for producing electronic silicon from industrial grade silicon. Impurities comprising approximately 1% of the industrial grade silicon are removed during the refinery process to produce the purified silicon, while only a relatively small percentage of make-up chemicals are added to the system. In the refinery, hydrogen chloride is reacted with the impure silicon in a halide reactor to provide trichlorosilane and silicon tetrachloride and hydrogen. The trichlorosilane and/or silicon tetrachloride are purified to remove the impurities, and then reacted with the hydrogen from the halide reactor in a fluidized bed reactor to produce the purified silicon and an effluent comprised of unreacted trichlorosilane, silicon tetrachloride, hydrogen, and the by-product hydrogen chloride.
    Type: Grant
    Filed: July 31, 1974
    Date of Patent: May 30, 1978
    Assignee: Texas Instruments Incorporated
    Inventors: Francois A. Padovani, Michael Brant Miller, James A. Moore, James H. Fowler, Malcolm Neville June, James D. Matthews, T. R. Morton, Norbert A. Stotko, Lewis B. Palmer
  • Patent number: 4092401
    Abstract: Process for the recovery of pigment-grade iron oxide and technical hydrochloric acid of predetermined molarity, from iron chloride solutions such as pickling solutions containing hydrochloric acid. The iron chloride solution is concentrated until the molarity of the chloride ion therein is the same as the molarity of the hydrochloric acid which it is desired to produce. Concentrated sulfuric acid in slight stoichiometric excess relative to the iron, is then added to the iron chloride solution, which solution is thereafter evaporated to dryness. The distillation from this evaporation is hydrochloric acid of the predetermined molarity, and the dry residue is iron sulfate. The iron sulfate is calcined to drive off sulfur dioxide and sulfur trioxide and to leave iron oxide which may contain sulfates; and to remove these latter, the iron oxide is leached with dilute hydrochloric acid and is thereafter washed with water. The washed iron oxide is dried and micropulverized to produce a red iron oxide pigment.
    Type: Grant
    Filed: January 10, 1977
    Date of Patent: May 30, 1978
    Assignee: Compagnie Royale Asturienne des Mines
    Inventor: Noel Dreulle
  • Patent number: 4091084
    Abstract: A process for purification of mercuric iodide (HgI.sub.2) to be used as a source material for the growth of detector quality crystals. The high purity HgI.sub.2 raw material is produced by a combination of three stages: synthesis of HgI.sub.2 from Hg and I.sub.2, repeated sublimation, and zone refining.
    Type: Grant
    Filed: June 6, 1977
    Date of Patent: May 23, 1978
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: Michael M. Schieber
  • Patent number: 4089940
    Abstract: Hydrogen is thermochemically produced from water in a cycle wherein a first reaction produces hydrogen iodide and H.sub.2 SO.sub.4 by the reaction of iodine, sulfur dioxide and water under conditions which cause two distinct aqueous phases to be formed, i.e., a lighter sulfuric acid-bearing phase and a heavier hydrogen iodide-bearing phase. After separation of the two phases, the heavier phase containing most of the hydrogen iodide is treated, e.g., at a high temperature, to decompose the hydrogen iodide and recover hydrogen and iodine. The H.sub.2 SO.sub.4 is pyrolyzed to recover sulfur dioxide and produce oxygen.
    Type: Grant
    Filed: April 8, 1977
    Date of Patent: May 16, 1978
    Assignee: General Atomic Company
    Inventors: John H. Norman, John L. Russell, Jr., John T. Porter, II, Kenneth H. McCorkle, Thomas S. Roemer, Robert Sharp
  • Patent number: 4089936
    Abstract: Ammonium fluoride is converted into a bifluoride by reaction with KF to form KF.HF, converting the latter to NaF.HF and heating said sodium bifluoride to form a solid product comprising NaF.
    Type: Grant
    Filed: September 20, 1976
    Date of Patent: May 16, 1978
    Assignee: Goulding Chemicals Limited
    Inventors: William Henry Thompson, Ralph Eric Worthington, David John Stamper