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).
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Patent number: 5435374Abstract: 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: GrantFiled: October 22, 1993Date of Patent: July 25, 1995Assignee: Aluminum Company of AmericaInventors: Maya Fishkis, Chanakya Misra, Karl Wefers
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Patent number: 5348725Abstract: 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: GrantFiled: September 4, 1991Date of Patent: September 20, 1994Assignee: Aluminum Company of AmericaInventors: Chanakya Misra, Anthony J. Perrotta
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Patent number: 5336480Abstract: 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: GrantFiled: June 26, 1992Date of Patent: August 9, 1994Assignee: Aluminum Company of AmericaInventors: Chanakya Misra, Steven W. Sucech
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Patent number: 5286560Abstract: 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: GrantFiled: October 29, 1992Date of Patent: February 15, 1994Assignee: Aluminum Company of AmericaInventors: Maya Fishkis, Chanakya Misra, Karl Wefers
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Patent number: 5275800Abstract: 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: GrantFiled: December 30, 1992Date of Patent: January 4, 1994Assignee: Aluminum Company of AmericaInventor: Chanakya Misra
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Patent number: 5270278Abstract: 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: GrantFiled: February 21, 1992Date of Patent: December 14, 1993Assignee: Aluminum Company of AmericaInventors: Chanakya Misra, Joseph R. Genito
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Patent number: 5258168Abstract: 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: GrantFiled: July 19, 1989Date of Patent: November 2, 1993Assignee: Aluminum Company of AmericaInventor: Chanakya Misra
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Patent number: 5225115Abstract: 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: GrantFiled: October 15, 1990Date of Patent: July 6, 1993Assignee: Aluminum Company of AmericaInventors: Lawrence L. Musselman, Chanakya Misra, Donald K. Grubbs, Donald R. Smith
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Patent number: 5182410Abstract: 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: GrantFiled: December 14, 1990Date of Patent: January 26, 1993Assignee: Aluminum Company of AmericaInventor: Chanakya Misra
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Patent number: 5141734Abstract: 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: GrantFiled: April 24, 1990Date of Patent: August 25, 1992Assignee: Aluminum Company of AmericaInventors: Chanakya Misra, Steven W. Sucech
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Patent number: 5093092Abstract: 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: GrantFiled: February 28, 1991Date of Patent: March 3, 1992Assignee: Aluminum Company of AmericaInventors: Chanakya Misra, Joseph R. Genito
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Patent number: 5075472Abstract: 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: GrantFiled: September 28, 1990Date of Patent: December 24, 1991Assignee: Aluminum Company of AmericaInventors: Chanakya Misra, Anthony J. Perrotta
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Patent number: 5075089Abstract: 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: GrantFiled: March 20, 1990Date of Patent: December 24, 1991Assignee: Aluminum Company of AmericaInventors: Chanakya Misra, Anthony J. Perrotta
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Patent number: 5069889Abstract: 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: GrantFiled: July 20, 1990Date of Patent: December 3, 1991Assignee: Aluminum Company of AmericaInventor: Chanakya Misra
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Patent number: 5055199Abstract: 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: GrantFiled: September 28, 1989Date of Patent: October 8, 1991Assignee: Aluminum Company of AmericaInventors: Gary A. O'Neill, Chanakya Misra, Abraham S. C. Chen
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Patent number: 5034206Abstract: 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: GrantFiled: July 1, 1988Date of Patent: July 23, 1991Assignee: Aluminum Company of AmericaInventor: Chanakya Misra
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Patent number: 4956172Abstract: 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: GrantFiled: August 24, 1989Date of Patent: September 11, 1990Assignee: Aluminum Company of AmericaInventor: Chanakya Misra
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Patent number: 4904457Abstract: 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: GrantFiled: October 18, 1985Date of Patent: February 27, 1990Assignee: Aluminum Company of AmericaInventor: Chanakya Misra
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Patent number: 4867882Abstract: 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: GrantFiled: November 9, 1987Date of Patent: September 19, 1989Assignee: Aluminum Company of AmericaInventors: Gary A. O'Neill, Chanakya Misra, Abraham S. C. Chen
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Patent number: RE34164Abstract: 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: GrantFiled: February 4, 1991Date of Patent: January 19, 1993Assignee: Aluminum Company of AmericaInventor: Chanakya Misra