Abstract: Disclosed is a process for the preparation of lead compounds which comprises reacting lead monoxide according to the wet method with an inorganic acid or organic acid in the presence of hydroxylamine under such conditions that the initial pH value of the reaction system is not higher than 7.Lead monoxide according to the wet method has an excellent reactivity with an inorganic acid or organic acid, but it contains higher oxides such as lead dioxide and minium, which cause coloration in lead compound products. According to this process, this undesirable coloration can effectively prevented.
Abstract: A method for preparing stable non-stoichiometric cathode material to provide cathodes useful in non-aqueous electrochemical cells having an active metal (eg. lithium) anode. The method comprises reducing the non-stoichiometric cathode material (eg. manganese dioxide) with the active metal or a precursor compound of said active metal to form a compound of the active metal and stoichiometric active cathode material.
Abstract: The instant invention is related to the production of porous spinel materials which exhibit exceptional durability in both acid and basic solutions, and possess high porosity with high surface area and narrow range of pore size. More specifically, the present invention is directed to the production of porous spinel materials involving the impregnation of finely-divided trivalent metal oxides, usually Al.sub.2 O.sub.3, Fe.sub.2 O.sub.3, or Cr.sub.2 O.sub.3, with a solution of a divalent metal ion-containing compound, commonly selected from the group of Mg.sup.+2, Fe.sup.+2, Mn.sup.+2, and Zn.sup.+2, and thereafter firing the mixture to effect reaction, resulting in the conversion of the trivalent metal oxide to a spinel.
Abstract: Novel double chromate compositions having the general formula:MBi(Cr.sub.x O.sub.y).sub.2,wherein M is silver or thallium and x is 1 and y is between about 3.7 and 4 or x is 2 and y is 7. Methods of making MBi(Cr.sub.x O.sub.y).sub.2 are characterized by reacting silver dichromate or thallium dichromate with a bismuth salt to provide equal numbers of silver or thallium atoms and bismuth atoms. Non-stoichiometric compositions wherein y is less than 4 and greater than or equal to about 3.7 are obtained by heating MBi(CrO.sub.4).sub.2 to a temperature between about 200.degree. C. and about 425.degree. C., the resulting product having an unchanged radio crystallographic structure. These double chromate compositions have particular utility in batteries as active positive material. Due to the steadiness of discharge voltage and duration of discharge of batteries employing these double chromate compositions, such batteries are especially adapted for use in clocks and in cardiostimulators or pacemakers.
Type:
Grant
Filed:
April 13, 1979
Date of Patent:
November 11, 1980
Assignee:
SAFT-Societe des Accumulateurs Fixes et de Traction
Abstract: Ceramic material, and cryogenic refrigeration apparatus containing thermal energy absorbing elements made of the ceramic material, which is a dielectric insulator and has values of specific heat at selected temperatures below 15.degree. K. that are greater than or at least equal to the values of specific heat of pure lead at those same temperatures. Material consists essentially of a crystalline phase with a composition defined by the molar formula selected from: (1) AB.sub.2 O.sub.4 where A is Group 2b metal ions with or without other divalent metal ions and B is Cr ion with or without other trivalent metal ions, (2) AB.sub.2 O.sub.6 where A is Mn and/or Ni ion(s) with or without other divalent metal ions and B is Nb and/or Ta ion(s), and (3) A.sub.2 BCO.sub.6 where A is Pb ion with or without other divalent metal ions, B is Gd or Mn with or without other trivalent metal ions and C is Nb and/or Ta ion(s). Elements include regenerator packings, thermal dampers and dielectric insulation.
Abstract: Novel double chromate compositions having the general formula:MM'(CrO.sub.4).sub.2,wherein M and M' are silver and bismuth, respectively. Methods of making AgBi (CrO.sub.4).sub.2 are characterized by reacting silver dichromate with a bismuth salt to provide equal numbers of silver and bismuth atoms. These double chromate compositions have particular utility in batteries as active positive material. Due to the steadiness of discharge voltage and duration of discharge of batteries employing these double chromate compositions, such batteries are especially adapted for use in clocks and in cardiostimulators or pacemakers.BACKGROUND OF THE INVENTIONThis invention relates to a new chemical composition, and more particularly to a double chromate having the formula MM' (CrO.sub.4).sub.2 where M and M' represent metals, to methods of making it, and to its use as a positive active material in batteries.From the disclosure of French Pat. No.
Type:
Grant
Filed:
October 17, 1978
Date of Patent:
January 15, 1980
Assignee:
Saft-Societe des Accumulateurs Fixes et de Traction
Abstract: Zinc oxide is interacted with an aqueous solution containing a chromium chromate complex obtained through partial reduction of an aqueous solution of chromic acid with an organic reducing agent. The resulting product is dried and the residual solid ground to suitable size for use as a pigment.
Abstract: Aqueous process streams or waste waters destined for merging with public waters sometimes contain deleterious amounts of heavy metals, e.g., lead (Pb) compounds. The heavy metal compounds may be substantially removed or reduced to harmless levels by treating the acidic aqueous streams with chromate or dichromate ions, then heating the solution to oxidize organics and/or heavy metal-organics, then raising the pH to an alkaline pH to precipitate the heavy metal chromate, and separating the heavy metal chromate from the aqueous stream.
Abstract: A process of recovering and exploiting wastes from chromic anhydride production, wherein the slurry comprising a water suspension of solid waste residue from chromic anhydride processing is subjected to a first reaction stage with sodium chromate solution at a constant flow rate and such a density as to avoid precipitation of sodium sulfate, setting pH to 2-8 by adjusting the slurry flow rate, and finally separating by filtering insoluble chromium chromate formed from the sodium bichromate and sodium sulfate solution.
Abstract: Method for manufacturing pure silver chromate in which a soluble chromate is made to react with a silver salt in a bichromate medium. The bichromate medium stabilizes the pH and makes it possible to operate in a concentrated medium. The pure product obtained may be used more particularly as a positive active substance in an electrochemical generator having a non-aqueous electrolyte, for it enables avoidance of losses in capacity during idle and storage periods of the generator.
Type:
Grant
Filed:
September 15, 1976
Date of Patent:
June 28, 1977
Assignee:
Saft-Societe des Accumulateurs Fixes et de Traction
Abstract: Novel rhenium oxides of the formulas MReO.sub.4 and M'.sub.2 ReO.sub.6, where M is Mg, Zn, Mn, Al, Ga, Fe, Co, or Ni and M' is Cr or Fe, are prepared by heating powder mixtures containing precursor oxides with or without some of the metals selected to give the proper stoichiometry, under a pressure of at least 25 kbars. The new oxides are useful in electrical elements, e.g., resistors.
Abstract: Hydrogen is produced by the reaction of water with chromium sesquioxide and strontium oxide. The hydrogen producing reaction is combined with other reactions to produce a closed chemical cycle for the thermal decomposition of water.
Type:
Grant
Filed:
January 27, 1976
Date of Patent:
December 7, 1976
Assignee:
The United States of America as represented by the United States Energy Research and Development Administration
Inventors:
Carlos E. Bamberger, Donald M. Richardson
Abstract: This invention relates to the method for preparing oxygen compounds of antimony with metals.According to the invention, the method for preparing oxygen compounds of antimony with metals consists in oxidation of antimony trioxide by hydrogen peroxide at a temperature from 40.degree. to 100.degree.C to form a suspension of hydrated antimony pentoxide and interaction of the obtained suspension of hydrated antimony pentoxide with metal compounds with subsequent drying ad calcining at temperatures from 300.degree. to 700.degree.C.The invention can be employed in the manufacture of metal oxide-antimony catalysts and metal-oxide resistor materials.
Type:
Grant
Filed:
February 25, 1974
Date of Patent:
October 5, 1976
Inventors:
Vladimir Nikolaevich Sergunkin, Georgy Konstantinovich Boreskov, Vera Alexandrovna Dzisko, Viktor Petrovich Karlov, Vsevolod Valentinovich Klimov, Jury Vladimirovich Pugachev, Nadezhda Mikhailovna Samokhvalova, Dzhema Vladimirovna Tarasova
Abstract: An improved copper chromite catalyst having high density, low monovalent ion content, high activity and resistance to poisoning is prepared by reacting a soluble copper salt with chromic acid or a dichromate in solution in the presence of ammonia and urea to precipitate a copper-chromium-nitrogen complex, washing, drying and calcining the precipitate.
Type:
Grant
Filed:
December 30, 1974
Date of Patent:
January 27, 1976
Assignee:
Dart Industries Inc.
Inventors:
Marvin Michael Fein, Paul Alexander Colgate, Ronald Allan Kent