Patents by Inventor Chanakya Misra

Chanakya Misra has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5435374
    Abstract: A method for wetting and bonding refractory alumina or aluminosilicate fibers or particles with molten aluminum or aluminum alloys by forming a boron oxidized interface between the fiber and the metal is exists. The method comprises the steps of (a) coating alumina fibers with an effective amount of a thermally decomposable precursor of boron oxide; (b) heating the coated fiber sufficiently to form a boron oxide; and (c) forming a composite with aluminum metal or an aluminum alloy. Thermally decomposable precursors of boron oxide include ammonium pentaborate, ammonium diborate and orthoboric acid.
    Type: Grant
    Filed: October 22, 1993
    Date of Patent: July 25, 1995
    Assignee: Aluminum Company of America
    Inventors: Maya Fishkis, Chanakya Misra, Karl Wefers
  • Patent number: 5348725
    Abstract: A method of making a pillared hydrotalcite and an associated products. The pillared hydrotalcite is made by calcining a hydrotalcite having the formula A.sub.w B.sub.x (OH).sub.y [C].sub.z .multidot.nH.sub.2 O, wherein A represents a divalent metal cation, B represents a trivalent metal cation, C represents a mono- to tetravalent anion and w, x, y, z and n satisfy the following:0<z.ltoreq.x.ltoreq.4.ltoreq.w.ltoreq.1/2y and 12.gtoreq.n.gtoreq.1/2(w-x).The method further comprises combining the calcined compound with a salt solution of an anion to make the pillared derivative of the compound and then separating the pillared derivative from the salt solution. A method of intercalating inorganic anions and resulting product is also disclosed.
    Type: Grant
    Filed: September 4, 1991
    Date of Patent: September 20, 1994
    Assignee: Aluminum Company of America
    Inventors: Chanakya Misra, Anthony J. Perrotta
  • Patent number: 5336480
    Abstract: In a process utilizing steam, the method of producing at least a portion of said steam includes heating a solid substance so as to generate steam, followed by capturing the generated steam at a pressure greater than one atmosphere gage pressure for use in the process at a pressure greater than one atmosphere gage pressure. Suitable solid substances are aluminum hydrate or aluminum fluoride. New hydrated aluminum containing products and uses for those products are obtained by the use of the process.
    Type: Grant
    Filed: June 26, 1992
    Date of Patent: August 9, 1994
    Assignee: Aluminum Company of America
    Inventors: Chanakya Misra, Steven W. Sucech
  • Patent number: 5286560
    Abstract: An aluminum alloy matrix composite containing alumina or aluminum silicate reinforcement whereby said composite material exhibits wetting between said reinforcement and said aluminum alloy. The composite comprises (a) alumina or aluminosilicate reinforcement; (b) a matrix of aluminum or aluminum alloy; and (c) an intelayer of mixed oxides of aluminum and boron wherein the interlayer of mixed oxides of aluminum and boron includes but is not limited to the following oxides, B.sub.2 O.sub.3, Al.sub.2 O.sub.3, 2Al.sub.2 O.sub.3.B.sub.2 O.sub.3 and 9Al.sub.2 O.sub.3 2B.sub.2 O.sub.3 at the interface between said reinforcement and said matrix.
    Type: Grant
    Filed: October 29, 1992
    Date of Patent: February 15, 1994
    Assignee: Aluminum Company of America
    Inventors: Maya Fishkis, Chanakya Misra, Karl Wefers
  • Patent number: 5275800
    Abstract: Zeolite is synthesized by reacting amorphous silica particles with NaOH and Al.sub.2 O.sub.3 under hydrothermal reaction conditions. The amorphous silica particles are preferably produced by reaction of fluosilicic acid and alumina to form aluminum fluoride and silica. The silica particles contain some residual fluorine and aluminum, and their surface area is about 1 to 3 m.sup.2 /g. Mordenite and ZSM-5 zeolites are obtained in preferred embodiments of the invention.
    Type: Grant
    Filed: December 30, 1992
    Date of Patent: January 4, 1994
    Assignee: Aluminum Company of America
    Inventor: Chanakya Misra
  • Patent number: 5270278
    Abstract: A hybrid adsorbent including particles of porous alumina having deposited thereon an ultrathin layer of carbon atoms which is essentially monomolecular. The carbon layer is produced by cracking a suitable hydrocarbon, preferably a gas, in contact with a hot turbulent fluidized bed of alumina particles. The hybrid adsorbent has the unique property of adsorbing more organic impurities than an equivalent weight of active carbon, and also oxalate ions which are not ordinarily adsorbed by carbon.
    Type: Grant
    Filed: February 21, 1992
    Date of Patent: December 14, 1993
    Assignee: Aluminum Company of America
    Inventors: Chanakya Misra, Joseph R. Genito
  • Patent number: 5258168
    Abstract: Disclosed is a method for preparing high purity alunite. In the method, a material selected from the group consisting of sodium sulfate, sodium bisulfate, ammonium sulfate, ammonium bisulfate, potassium sulfate and potassium bisulfate is provided and reacted with a source of aluminum hydroxide in a liquid. The reaction is carried out under acidic conditions, and alunite is recovered after separating, washing and drying.
    Type: Grant
    Filed: July 19, 1989
    Date of Patent: November 2, 1993
    Assignee: Aluminum Company of America
    Inventor: Chanakya Misra
  • Patent number: 5225115
    Abstract: A filler material for use in a polymer or paper system. The filler material is formed by heating hydrotalcite to less than approximately 600.degree. C. to remove most of the carbonate and water of hydration; submersing the hydrotalcite in a NaBr solution for 1-24 hours in a nitrogen atmosphere to form a bromide intercalated hydrotalcite; and adding the bromide intercalated hydrotalcite as a 25-65 wt % filler in a polymer system selected from the group of polypropylene, polybutylene terephtalate, nylon, and acrylonitrile-butadiene-styrene.
    Type: Grant
    Filed: October 15, 1990
    Date of Patent: July 6, 1993
    Assignee: Aluminum Company of America
    Inventors: Lawrence L. Musselman, Chanakya Misra, Donald K. Grubbs, Donald R. Smith
  • Patent number: 5182410
    Abstract: Disclosed is a crystalline compound and a method for forming the compound having a chemical composition expressed, in terms of molar ratios, by the formula:M.n[R(COOH).sub.x ]wherein M is aluminum hydroxide, n is the number of moles of organic material reacted with a mole of M, R is an organic functional group having carboxylic acid attached thereto, and x is equal to or greater than 2.
    Type: Grant
    Filed: December 14, 1990
    Date of Patent: January 26, 1993
    Assignee: Aluminum Company of America
    Inventor: Chanakya Misra
  • Patent number: 5141734
    Abstract: In a process utilizing steam, the method of producing at least a portion of said steam, including heating a water-containing, solid substance for generating steam and capturing the generated steam for said process. A suitable solid substance is Al(OH).sub.3 . New alumina products and uses therefor are obtained.
    Type: Grant
    Filed: April 24, 1990
    Date of Patent: August 25, 1992
    Assignee: Aluminum Company of America
    Inventors: Chanakya Misra, Steven W. Sucech
  • Patent number: 5093092
    Abstract: An economical process for the removal and destruction of organic impurities present in Bayer process liquor depends upon the use of a hybrid adsorbent. The hybrid adsorbent consists essentially of porous essentially anhydrous particles of alumina having deposited on the surfaces thereof including the pores, an ultrathin layer of carbon atoms which is essentially monomolecular. Such carbonization is effected by cracking a suitable hydrocarbon, preferably a gas, in contact with a hot turbulent fluidized bed of alumina particles. This layer has the unique property of adsorbing far more impurities than the equivalent weight of active carbon, and also oxalate ions which are known not to be adsorbed on carbon. As an ultrathin layer it is too thin to change either the average pore volume or the surface area of the alumina particles substantially, from before they are carbonized.
    Type: Grant
    Filed: February 28, 1991
    Date of Patent: March 3, 1992
    Assignee: Aluminum Company of America
    Inventors: Chanakya Misra, Joseph R. Genito
  • Patent number: 5075472
    Abstract: Disclosed is a crystalline compound and a method of making the compound. The composition is expressed in terms of molar ratios by the formula [Al.sub.2 (OH).sub.6 ].multidot.X[Li.sub.2 C.sub.2 O.sub.4 ] where X is in the range of 0.1 to 1. The method comprises the steps of adding Al(OH).sub.3 to an aqueous solution containing lithium oxalate to provide a mixture; and reacting said mixture to form said new compositions.
    Type: Grant
    Filed: September 28, 1990
    Date of Patent: December 24, 1991
    Assignee: Aluminum Company of America
    Inventors: Chanakya Misra, Anthony J. Perrotta
  • Patent number: 5075089
    Abstract: A method of making a pillared hydrotalcite and an associated products. The pillared hydrotalcite is made by calcining a hydrotalcite having the formula A.sub.w B.sub.x (OH).sub.y [C].sub.z .multidot.nH.sub.2 O, wherein A represents a divalent metal cation, B represents a trivalent metal cation, C represents a mono- to tetravalent anion and w, x, y, z and n satisfy the following:0<z.ltoreq.x.ltoreq.4.ltoreq.w.ltoreq.1/2y and 12.gtoreq.n.gtoreq.1/2(w-x)The method further comprises combining the calcined compound with a salt solution of an anion to make the pillared derivative of the compound and then separating the pillared derivative from the salt solution. A method of intercalating inorganic anions and resulting product is also disclosed.
    Type: Grant
    Filed: March 20, 1990
    Date of Patent: December 24, 1991
    Assignee: Aluminum Company of America
    Inventors: Chanakya Misra, Anthony J. Perrotta
  • Patent number: 5069889
    Abstract: Crystalline aluminum phosphorus compounds are provided which are useful as flame retardants and strength additives for organic polymeric materials. Typical compounds are formed from the reaction of aluminum hydroxide and a monobasic, dibasic or tribasic sodium phosphate.
    Type: Grant
    Filed: July 20, 1990
    Date of Patent: December 3, 1991
    Assignee: Aluminum Company of America
    Inventor: Chanakya Misra
  • Patent number: 5055199
    Abstract: A method for reducing the amount of anionic metal-ligand complex in a solution comprises: (a) contacting the solution with a substance selected from: a compound having the formula: A.sub.w B.sub.x (OH).sub.y C.sub.z.nH.sub.2 O, wherein A represents a divalent metal cation, B represents a trivalent metal cation, C represents a mono- to tetravalent anion, and w, x, y, z and n satisfy the following: 0.ltoreq. z.ltoreq.x.ltoreq.4.ltoreq.w.ltoreq.1/2y and 12.gtoreq.n.gtoreq.1/2(w-x); a calcined product of said compound and mixtures thereof; and (b) separating the substance from the solution. A method for removing substantially all metal-cyanide, -thiocyanate, -thiosulfate, -citrate and/or -EDTA complex from a solution containing one or more of said complexes is also disclosed.
    Type: Grant
    Filed: September 28, 1989
    Date of Patent: October 8, 1991
    Assignee: Aluminum Company of America
    Inventors: Gary A. O'Neill, Chanakya Misra, Abraham S. C. Chen
  • Patent number: 5034206
    Abstract: Disclosed is a method of making aluminum borate fibers comprising the steps of preparing an aluminum borate gel by reacting aluminum salt in a solution with ammonium borate and heating the gel to form the aluminum borate fibers.
    Type: Grant
    Filed: July 1, 1988
    Date of Patent: July 23, 1991
    Assignee: Aluminum Company of America
    Inventor: Chanakya Misra
  • Patent number: 4956172
    Abstract: A novel crystalline aluminum ammonium phosphate, characterized by predominantly equiaxed crystals, is provided of the formula: Al.sub.2 (NH.sub.4)OH(PO.sub.4).sub.2.2H.sub.2 O. The phosphate is useful as a dentifrice polishing agent and filler for plastics. The novel product can be prepared by reacting aluminum trihydroxide with diammonium orthophosphate or monobasic ammonium phosphate. By heating at elevated temperature, the product can be converted to the tridymite form of aluminum phosphate.
    Type: Grant
    Filed: August 24, 1989
    Date of Patent: September 11, 1990
    Assignee: Aluminum Company of America
    Inventor: Chanakya Misra
  • Patent number: 4904457
    Abstract: Disclosed is a method for producing hydrotalcite in high yield including reacting activated magnesia with an aqueous solution containing aluminate, carbonate, and hydroxyl ions. The method further includes a first step of heating magnesium carbonate or magnesium hydroxide to a temperature between about 500.degree.-900.degree. C. to form activated magnesia or magnesium oxide. The method is suited to producing synthetic hydrotalcite from industrial Bayer liquor.
    Type: Grant
    Filed: October 18, 1985
    Date of Patent: February 27, 1990
    Assignee: Aluminum Company of America
    Inventor: Chanakya Misra
  • Patent number: 4867882
    Abstract: A method for reducing the amount of anionic metal-ligand complex in a solution comprises: (a) contacting the solution with a substance selected from: a compound having the formula: A.sub.w B.sub.x (OH).sub.y C.sub.z .multidot.nH.sub.2 O, wherein A represents a divalent metal cation, B represents a trivalent metal cation, C represents a mono- to tetravalent anion, and w, x, y, z and n satisfy the following: 0.ltoreq.z.ltoreq.x.ltoreq.4.ltoreq.w.ltoreq.1/2y and 12.gtoreq.n.gtoreq.3/2x; a calcined product of said compound and mixtures thereof; and (b) separating the substance from the solution. A method for removing substantially all metal-cyanide, -thiocyanate, -thiosulfate, -citrate and/or -EDTA complex from a solution containing one or more of said complexes is also disclosed. The latter method comprises contacting the solution with a sufficient amount of substance consisting essentially of a compound selected from: hydrotalcite, calcined hydrotalcite and mixtures thereof.
    Type: Grant
    Filed: November 9, 1987
    Date of Patent: September 19, 1989
    Assignee: Aluminum Company of America
    Inventors: Gary A. O'Neill, Chanakya Misra, Abraham S. C. Chen
  • Patent number: RE34164
    Abstract: Disclosed is a method for producing hydrotalcite in high yield including reacting activated magnesia with an aqueous solution containing aluminate, carbonate, and hydroxyl ions. The .[.method further includes a first step of.]. .Iadd.activated magnesia is produced by .Iaddend.heating magnesium carbonate or magnesium hydroxide to a temperature between about 500.degree.-900.degree. C. .[.to form activated magnesia or magnesium oxide..]. The method is suited to producing synthetic hydrotalcite from industrial Bayer liquor.
    Type: Grant
    Filed: February 4, 1991
    Date of Patent: January 19, 1993
    Assignee: Aluminum Company of America
    Inventor: Chanakya Misra