Patents by Inventor Raj P. Singh
Raj P. Singh 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: 7300492Abstract: A novel molybdenum compound, ammonium dodecamolybdomolybdate (AMM), is described which may be used in the manufacture of molybdenum metal and molybdenum carbide powders. The molybdenum compound is a dodecaheteropoly acid salt having a Keggin-type structure wherein molybdenum resides in both the hetero as well as peripheral atomic positions. The novel compound has the general formula (NH4)2Mo12MoO40ยท6H2O. Because of its low solubility, the compound can be crystallized efficiently and at a high purity from ammonium molybdate solutions.Type: GrantFiled: September 1, 2004Date of Patent: November 27, 2007Assignee: Osram Sylvania Inc.Inventors: Raj P. Singh, Thomas A. Wolfe, David L. Houck
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Patent number: 7182925Abstract: A method for the dissolution and purification of tantalum ore and synthetic concentrates is described. The method preferably uses ammonium bifluoride as the fluoride source in place of the hydrofluoric acid used in the conventional methods. Other fluoride compounds such as NaF, KF, and CaF2 may be used alone or in combination with ammonium bifluoride. The tantalum concentrate and fluoride source are combined with sulfuric acid to form a solution containing tantalum values and impurities. The tantalum values are then separated from the impurities by solvent extraction.Type: GrantFiled: April 22, 2004Date of Patent: February 27, 2007Assignee: Osram Sylvania Inc.Inventors: Raj P. Singh Gaur, Robert G. Mendenhall
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Publication number: 20040213716Abstract: A method for the dissolution and purification of tantalum ore and synthetic concentrates is described. The method preferably uses ammonium bifluoride as the fluoride source in place of the hydrofluoric acid used in the conventional methods. Other fluoride compounds such as NaF, KF, and CaF2 may be used alone or in combination with ammonium bifluoride. The tantalum concentrate and fluoride source are combined with sulfuric acid to form a solution containing tantalum values and impurities. The tantalum values are then separated from the impurities by solvent extraction.Type: ApplicationFiled: April 22, 2004Publication date: October 28, 2004Applicant: OSRAM SYLVANIA INC.Inventors: Raj P. Singh Gaur, Robert G. Mendenhall
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Patent number: 6793907Abstract: A novel molybdenum compound, ammonium dodecamolybdomolybdate (AMM), is described which may be used in the manufacture of molybdenum metal and molybdenum carbide powders. The molybdenum compound is a dodecaheteropoly acid salt having a Keggin-type structure wherein molybdenum resides in both the hetero as well as peripheral atomic positions. The novel compound has the general formula (NH4)2Mo12MoO40.6H2O. Because of its low solubility, the compound can be crystallized efficiently and at a high purity from ammonium molybdate solutions.Type: GrantFiled: July 29, 2002Date of Patent: September 21, 2004Assignee: Osram Sylvania Inc.Inventors: Raj P. Singh, Thomas A. Wolfe, David L. Houck
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Patent number: 6780219Abstract: A method for spheridizing silicon metal particles is described. The method involves injecting irregular silicon metal particles into a high-temperature plasma reactor to melt at least 50 weight percent of the particles. The molten droplets are solidified to form substantially spherical silicon particles having a thin SiO coating which may be removed by treating with a weak hydroxide solution.Type: GrantFiled: July 3, 2002Date of Patent: August 24, 2004Assignee: Osram Sylvania Inc.Inventors: Raj P. Singh, David L. Houck, Nelson E. Kopatz, Michael R. Pierce, Scott A. Braymiller
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Patent number: 6737035Abstract: A high-surface-area heterogenite (HCoO2) material is described for use in making submicron cobalt metal powders. The HCoO2 material has a surface area of at least about 90 M2/g and is preferably produced by dehydrating a cobalt hydroxide precipitate at 110° C.Type: GrantFiled: August 31, 2000Date of Patent: May 18, 2004Assignee: Osram Sylvania Inc.Inventors: Raj P. Singh, Robert G. Mendenhall
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Publication number: 20040004301Abstract: A method for spheridizing silicon metal particles is described. The method involves injecting irregular silicon metal particles into a high-temperature plasma reactor to melt at least 50 weight percent of the particles. The molten droplets are solidified to form substantially spherical silicon particles having a thin SiO coating which may be removed by treating with a weak hydroxide solution.Type: ApplicationFiled: July 3, 2002Publication date: January 8, 2004Applicant: OSRAM SYLVANIA Inc.Inventors: Raj P. Singh, David L. Houck, Nelson E. Kopatz, Michael R. Pierce, Scott A. Braymiller
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Patent number: 6660184Abstract: A phosphor paste composition for plasma display panels (PDP) is provided which comprises a phosphor dispersed in an organic paste comprising a solvent, a binder, at least one dispersant comprising stearic acid, and a plasticizer. The paste compositions are very stable and have desirable screen-printing properties. In addition, the phosphor contained in the paste retains a high percentage of its initial brightness following binder burn-out.Type: GrantFiled: December 13, 2001Date of Patent: December 9, 2003Assignee: Osram Sylvania Inc.Inventors: Raj P. Singh, Robert G. Mendenhall, Diane C. Seymour
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Patent number: 6596051Abstract: A high-surface-area heterogenite (HCoO2) material is described for use in making submicron cobalt metal powders. The HCoO2 material has a surface area of at least about 90 m2/g and is preferably produced by dehydrating a cobalt hydroxide precipitate at 110° C.Type: GrantFiled: September 27, 2001Date of Patent: July 22, 2003Assignee: Osram Sylvania Inc.Inventors: Raj P. Singh, Robert G. Mendenhall
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Publication number: 20030111642Abstract: A phosphor paste composition for plasma display panels (PDP) is provided which comprises a phosphor dispersed in an organic paste comprising a solvent, a binder, at least one dispersant comprising stearic acid, and a plasticizer. The paste compositions are very stable and have desirable screen-printing properties. In addition, the phosphor contained in the paste retains a high percentage of its initial brightness following binder burn-out.Type: ApplicationFiled: December 13, 2001Publication date: June 19, 2003Inventors: Raj P. Singh, Robert G. Mendenhall, Diane C. Seymour
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Patent number: 6383459Abstract: A direct dissolution method for the purification of technical grade hydrated ammonium tantalum oxide (HATO), (NH4)2−xHxTa2O6.nH2O), and related compounds such as tantalum hydroxide and tantalum oxide is described. The method preferably uses ammonium bifluoride as fluoride source in place of the hydrofluoric acid used in the conventional methods. Other fluoride compounds such as NaF, KF, and CaF2 may be used.Type: GrantFiled: August 31, 2000Date of Patent: May 7, 2002Assignee: Osram Sylvania Inc.Inventors: Raj P. Singh, Michael J. Miller
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Publication number: 20020043132Abstract: A high-surface-area heterogenite (HCoO2) material is described for use in making submicron cobalt metal powders. The HCoO2 material has a surface area of at least about 90 m2/g and is preferably produced by dehydrating a cobalt hydroxide precipitate at 110° C.Type: ApplicationFiled: September 27, 2001Publication date: April 18, 2002Inventors: Raj P. Singh, Robert G. Mendenhall
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Patent number: 6051196Abstract: A method for purifying a phosphorus containing scheelite ore is described wherein the calcite phase is selectively dissolved prior to dissolution of the apatite phase. Selective dissolution of the calcite produces several benefits: (1) a usable calcium solution, (2) enhanced apatite dissolution, and (3) lower volumes of toxic acid solution for disposal.Type: GrantFiled: February 9, 1999Date of Patent: April 18, 2000Assignee: Osram Sylvania Inc.Inventors: Raj P. Singh, Michael J. Miller, Thomas A. Wolfe
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Patent number: 6010676Abstract: Highly pure tantalum compounds are made by slurrying hydrated ammonium tantalum oxide or tantalum hydroxide with concentrated sulfuric acid followed by dissolution with concentrated hydrofluoric acid. After diluting the concentrated acidic solution with water, a soluble potassium compound is added to precipitate a highly pure potassium fluorotantalate. Further steps are used to convert the highly pure potassium fluorotantalate into a highly pure tantalum oxide.Type: GrantFiled: September 12, 1997Date of Patent: January 4, 2000Assignee: Osram Sylvania Inc.Inventors: Raj P. Singh, Michael J. Miller
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Patent number: 5635146Abstract: A method is disclosed for the dissolution and purification of tantalum pentoxide. The impure tantalum pentoxide is reacted with a potassium-containing compound to form potassium tantalate. The potassium tantalate is optionally slurried with sulfuric acid and dissolved in an HF medium. The solution is suitable for purification by conventional ion exchange or solvent extraction methods. A potassium fluorotantalate precipitate may also be formed by adding KCl to the solution. The fluorotantalate precipitate may be further processed into a pure tantalum pentoxide by suspending the precipitate in an aqueous solution optionally containing a chelating agent and adding ammonium hydroxide to form ammonium tantalum oxide which can then be converted to tantalum pentoxide by calcining at high temperature.Type: GrantFiled: November 30, 1995Date of Patent: June 3, 1997Assignee: Osram Sylvania Inc.Inventors: Raj P. Singh, Michael J. Miller