Patents Represented by Attorney L. Rita Quatrini
  • Patent number: 5063021
    Abstract: A method is disclosed for preparing an intimate mixture of powders of nickel-boron-silicon alloy and molybdenum metal powder suitable for thermal spray coatings which comprises milling a starting mixture of the alloy and molybdenum powder to produce a milled mixture wherein the average particle size is less than about 10 micrometers in diameter, forming an aqueous slurry of the resulting milled mixture and a binder which can be an ammoniacal molybdate compound or polyvinyl alcohol, and agglomerating the milled mixture and binder. The intimate mixture and binder are preferably sintered in a reducing atmosphere at a temperature of about 800.degree. C. to about 950.degree. C. for a sufficient time to form a sintered partially alloyed mixture wherein the bulk density is greater than about 1.2 g/cc.
    Type: Grant
    Filed: May 23, 1990
    Date of Patent: November 5, 1991
    Assignee: GTE Products Corporation
    Inventors: Vidhu Anand, Sanjay Sampath, Clarke D. Davis, David L. Houck
  • Patent number: 5045121
    Abstract: A method is disclosed for removing carbon from the surface of a cemented tungsten carbide article which comprises contacting a cemented tungsten carbide article with an aqueous solution of hydrogen peroxide having a concentration of at least about 5% by volume hydrogen perioxide for a sufficient length of time to remove the major portion of the carbon from the surfaces of the article.
    Type: Grant
    Filed: February 4, 1991
    Date of Patent: September 3, 1991
    Assignee: GTE Products Corporation
    Inventors: Timothy J. Hoffman, Robert G. Mendenhall, Michael J. Cheresnowsky
  • Patent number: 5045277
    Abstract: A method for producing metal carbide grade powders which comprises forming a wax mixture consisting essentially of in percent by weight about 5 to about 15 paraffin oil, with the balance being an esterified wax and paraffin, heating the wax mixture to a temperature above the melting point to melt the wax mixture and maintain it in the molten state, forming a powder-wax mixture consisting essentially of metal carbide powder, a binder metal, and the wax mixture while heating to a temperature above the melting point of the wax mixture to maintain the wax mixture in the molten state to result in a uniform distribution of the wax mixture on the carbide and binder metal particles, forming a slurry of the powder-wax mixture and water, attritor milling the slurry at a temperature below the melting point of the wax mixture, and removing water and agglomerating to produce metal carbide grade powder wherein a densified article made therefrom exhibits less linear shrinkage than articles made from carbide grade powder abs
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: September 3, 1991
    Assignee: GTE Products Corporation
    Inventors: Joseph J. Penkunas, Theodore E. Smith, Jr.
  • Patent number: 5021133
    Abstract: A method is disclosed for producing ammonium paratungstate from cemented tungsten carbide which comprises subjecting the cemented tungsten carbide to electrolysis by passing about 0.5 to about 20 volts through an ammoniacal solution selected from the group consisting of ammonium hydroxide-ammonium chloride solution, ammonium hydroxide-ammonium carbonate solution, and ammonium hydroxide-ammonium sulfate solution, wherein platinum and the cemented tungsten carbide serve as the anode and wherein the anode is immersed in the solution, to decompose the cemented tungsten carbide and form a solution of ammonium tungstate from which is crystallized ammonium paratungstate.
    Type: Grant
    Filed: April 4, 1990
    Date of Patent: June 4, 1991
    Assignee: GTE Products Corporation
    Inventors: Clarence D. Vanderpool, Tai K. Kim
  • Patent number: 5013582
    Abstract: A process is disclosed for making a rare-earth oxysulfide phosphor resistant to hydrolysis, which comprises forming a slurry of the phosphor in water, adding to the slurry, a zinc compound in an amount sufficient to result in a zinc ion concentration in the water of from about 0.01 molar to about 0.05 molar, separating the resulting zinc-treated phosphor from the liquid portion of the slurry, heating the zinc-treated phosphor in air at a temperature of from about 500.degree. C. to about 600.degree. C. for a sufficient time to enhance the brightness of the phosphor, and screening the resulting heated phosphor to remove non-luminescent material therefrom. The phosphor has a resistance to hydrolysis that is at least about 50% greater than phosphors produced without the zinc treatment.
    Type: Grant
    Filed: April 24, 1989
    Date of Patent: May 7, 1991
    Assignee: GTE Products Corporation
    Inventor: Ramon L. Yale
  • Patent number: 5007957
    Abstract: A method for producing metal carbide grade powders suitable for isostatic compaction which comprises combining a binder metal powder with an esterified wax and heating the wax to a temperature above the melting point of the wax to melt the wax and maintain it in the molten state to form a first mixture, with the amount of wax being sufficient to result in a level of wax in the subsequently produced second mixture of no greater than about 1/2% by weight, combining a metal carbide powder component with the first mixture while maintaining the wax in the molten state, forming a slurry of the second mixture and water, attritor milling the slurry at a temperature below the melting point of the wax, and removing water from the resulting attritor milled mixture to form the metal carbide grade powder.
    Type: Grant
    Filed: September 10, 1990
    Date of Patent: April 16, 1991
    Assignee: GTE Products Corporation
    Inventors: Joseph J. Penkunas, Theodore E. Smith, Jr.
  • Patent number: 5007181
    Abstract: A method for making stir-in type halophosphate phosphors to obtain a fluffy, deagglomerated powder is disclosed. A wet phosphor filter cake is fed into a toroidal-shaped direct-fired glass flash dryer in which a hot gaseous stream is circulating. The wet phosphor particles are suspended in the stream while the remaining liquid is evaporated. The dried phosphor powder is ejected from the dryer by centrifugal force and collected. Recovery efficiency of the process is about 99.9 percent.
    Type: Grant
    Filed: January 22, 1990
    Date of Patent: April 16, 1991
    Assignee: GTE Products Corporation
    Inventors: Douglas M. Jackson, John A. Arbie, Sr.
  • Patent number: 5000785
    Abstract: A method is disclosed for controlling the level of oxygen in molybdenum metal powder, which comprises agglomerating and sintering the molybdenum powder, classifying the resulting agglomerated and sintered molybdenum powder to obtain a particle size of from about -200 to about +325 mesh, contacting the resulting classified powder with a sufficient amount of an aqueous solution of hydrogen peroxide containing from about 1% to about 10% by weight of hydrogen peroxide to yield a molar ratio of H.sub.2 O.sub.2 :Mo of from about 2 to about 5 for sufficient time to achieve an oxygen content in the powder of from about 1% to about 15% by weight wherein the major portion of the oxygen is on the surface of the agglomerates, and removing the resulting hydrogen peroxide-treated molybdenum powder agglomerates from the resulting solution.
    Type: Grant
    Filed: March 20, 1989
    Date of Patent: March 19, 1991
    Assignee: GTE Products Corporation
    Inventors: David J. Port, Joseph E. Ritsko
  • Patent number: 4999169
    Abstract: A method of separating tungsten from molybdenum wherein impure acid leached molybdenum trioxide containing tungsten is combined with ammonium hydroxide to form an ammonium molybdate solution, the solution is contacted with tin (IV) oxide hydrate to cause sorption of essentially all of the tungsten contained therein without causing sorption of molybdenum, the tin (IV) oxide hydrate with the sorped tungsten is separated from the ammonium molybdate solution, and the ammonium molybdate solution is dried and fired to obtain purified molybdenum trioxide.
    Type: Grant
    Filed: October 26, 1988
    Date of Patent: March 12, 1991
    Assignee: GTE Products Corporation
    Inventor: Michael J. Cheresnowsky
  • Patent number: 4983354
    Abstract: A tungsten carbide powder and cemented tungsten carbide article made from the powder are disclosed. The powder has a particle size of greater than 20 micrometers in diameter and no particles less than one-half the average particle size or greater than two and one-half times the average particle size.
    Type: Grant
    Filed: February 10, 1989
    Date of Patent: January 8, 1991
    Assignee: GTE Products Corporation
    Inventors: David A. Reeder, Carlos Lopez, Jack L Burwick
  • Patent number: 4976948
    Abstract: A process is disclosed for producing chromium oxide powders, which comprises forming an aqueous slurry wherein the solids content is a mixture which consists essentially of in percent by weight about 5 to 15 chromium acetate and the balance chromium oxide, agglomerating the mixture, sintering the resulting agglomerated mixture in a hydrogen atmosphere at a temperature at about 1400.degree. C. to about 1550.degree. C. in metallic vessels, entraining the sintered chromium oxide powder in a carrier gas, passing the sintered chromium oxide powder and the carrier gas through a plasma flame at a power of about 10 to about 80 KW using an inert gas as the plasma gas, and cooling the resulting plasma heated chromium oxide powder to produce free flowing chromium oxide powder having a free chromium content of less than about 1% by weight.
    Type: Grant
    Filed: September 29, 1989
    Date of Patent: December 11, 1990
    Assignee: GTE Products Corporation
    Inventors: Vidhu Anand, David L. Houck, Dennis C. Smouse
  • Patent number: 4966710
    Abstract: A method for removing magnesium and calcium from sodium sulfate solutions to render the solutions suitable for membrane processing, which comprises adjusting the pH of the solutions to about 11 to 13 with sodium hydroxide to form a precipitate containing the bulk of the magnesium and the calcium, removing the precipitate from the resulting partially purified sodium sulfate solution, and contacting the partially purified sodium sulfate solution with a polystyrene divinyl benzene copolymer chelating cation exchange resin having an aminophosphonic functional group and having sodium as the exchangeable cation, to remove essentially all of the magnesium and the calcium from the partially purified sodium sulfate solution.
    Type: Grant
    Filed: April 4, 1990
    Date of Patent: October 30, 1990
    Assignee: GTE Products Corporation
    Inventors: Tai K. Kim, Robert P. McClintic
  • Patent number: 4965116
    Abstract: A method is disclosed for separating cobalt from nickel which consists essentially of adjusting the pH of a cobalt chloride solution containing nickel to about 3 to about 5 with a base, adding hypochlorite to the resulting pH adjusted solution in an amount equal to at least the stoichiometric amount required to oxidize essentially all of the cobalt to the .sup.+3 state, while maintaining the pH at about 3 to about 5 by addition of a base, to form a solid containing at least about 60% by weight of the cobalt in the .sup.+3 state and a liquor containing essentially all of the nickel, and removing the solid from the liquor.
    Type: Grant
    Filed: September 11, 1989
    Date of Patent: October 23, 1990
    Assignee: GTE Products Corporation
    Inventors: Michael J. Miller, Richard A. Scheithauer
  • Patent number: 4961910
    Abstract: Methods are disclosed for recovering one or more of the metals of tungsten and molybdenum from metal-cellulose material. One method involves digesting the material in a mineral acid selected from the group consisting of hydrochloric acid having a concentration of at least about 4 normal, and sulfuric acid having a concentration of at least about 9 normal at a temperature of at least about 50.degree. C. for a sufficient time to form a digestion solid containing the major portion of the tungsten and a digestion solution containing a portion of any molybdenum which is present in the material, and separating the solid from the solution. Another method involves having as the starting material a metal-cellulose material comprising one or more of the metals of tungsten and molybdenum and elements selected from the group consisting of arsenic, phosphorus, silicon, and combinations thereof.
    Type: Grant
    Filed: July 6, 1987
    Date of Patent: October 9, 1990
    Assignee: GTE Products Corporation
    Inventors: Clarence D. Vanderpool, John A. Powers
  • Patent number: 4946707
    Abstract: A method is disclosed for producing an aluminum oxide coated manganese activated zinc silicate phosphor which comprises forming a solution of Al.sup.+3 ions in water with the concentration of the aluminum being from about 0.01 to about 0.30 moles/l, adding manganese activated zinc silicate phosphor to the aluminum solution to form a slurry wherein the amount of phosphor is about 0.7 to about 1.0 moles per liter of slurry with agitation for a sufficient time to result in aluminum ions being adsorbed onto the surfaces of the particles of the phosphor, separating the resulting phosphor with adsorbed aluminum ions from the resulting liquor, drying the phosphor with the adsorbed aluminum ions, firing the resulting dried phosphor at a temperature of from about 750.degree. C. to about 850.degree. C.
    Type: Grant
    Filed: July 28, 1989
    Date of Patent: August 7, 1990
    Assignee: GTE Products Corporation
    Inventors: Anthony F. Kasenga, Bella M. Dorfman
  • Patent number: 4946634
    Abstract: A powder compacting press wherein one or more upper and one or more lower punches are respectively advanced toward each other in a die filled with an amount of powder to producing a pressed part in the shape of the die and punch configuration. The press including measuring device on the upper and lower punches to measure the peak forces applied to the upper and the lower punches and to generate a first signal proportional to the forces, calculating device for receiving the first signal and calculating the ratio of the forces of the upper and lower punches and transmitting a second signal that is proportional to the ratio, and adjusting device for receiving the second signal and adjusting the forces applied to each punch based upon the second signal to achieve a predetermined green density distribution in the pressed part whereby substantial uniformity in part dimensions is achieved.
    Type: Grant
    Filed: October 3, 1988
    Date of Patent: August 7, 1990
    Assignee: GTE Products Corporation
    Inventor: Kenneth H. Shaner
  • Patent number: 4943322
    Abstract: A powdered material and a process for producing the material are disclosed. The powdered material consists essentially of titanium based spherical particles which are essentially free of elliptical shaped material and elongated particles having rounded ends. The material has a particle size of less than about 50 micrometers. The process for making the spherical particles involves mechanically reducing the size of a starting material to produce a finer powder which is then entrained in a carrier gas and passed through a high temperature zone above the melting point of the finer powder to melt at least about 50% by weight of the powder and form spherical particles of the melted portion. The powder is then directly solidified.
    Type: Grant
    Filed: November 16, 1987
    Date of Patent: July 24, 1990
    Assignee: GTE Products Corporation
    Inventors: Preston B. Kemp, Jr., Walter A. Johnson
  • Patent number: 4933152
    Abstract: A process for purifying molybdenum, which comprises first leaching impure molybdenum trioxide containing potassium in a liquid medium of nitric acid, and an ammoniacal liquor, wherein the nitric acid concentration is about 3.5 to 4.0 moles per liter and the ammonium nitrate concentration is about 0.5 to 1.0 moles per liter, at greater than 50.degree. C. to solubilize the major portion of the potassium and produce a once-leached molybdenum trioxide and a first liquor, removing the once-leached molybdenum oxide from the first liquor, re-leaching the once-leached molybdenum trioxide in nitric acid having a concentration of about 3.5 to 4.0 moles per liter, at greater than 50.degree. C. to produce a twice-leached molybdenum trioxide and a second liquor, removing the twice-leached molybdenum oxide from the second liquor, water washing the twice-leached molybdenum trioxide, digesting the molybdenum trioxide in ammonium hydroxide at greater than 50.degree. C. at a pH of greater than 9.
    Type: Grant
    Filed: February 16, 1989
    Date of Patent: June 12, 1990
    Assignee: GTE Products Corporation
    Inventors: Judy L. Scheftic, James N. Christini
  • Patent number: 4929386
    Abstract: A process is disclosed for preparing a single phase M'YTaO.sub.4 :Nb X-ray phosphor which comprises firing a uniform milled mixture consisting essentially of the components of Y.sub.2 O.sub.3, Ta.sub.2 O.sub.5, and Nb.sub.2 O.sub.5 in an amount equal to the stoichiometric amounts to form the phosphor, with a flux consisting essentially of lithium sulfate and potassium sulfate in a mole ratio of about 80 to 20, wherein the flux makes up from about 25% to about 50% by weight of the mixture. The firing is done by heating in a furnace to a temperature of from about 1200.degree. C. to about 1300.degree. C. at a heating rate of from about 1.0.degree. C. per minute to about 1.5.degree. C. per minute and maintaining the temperature for about 10 to 14 hours to react the components and produce a fired material containing luminescent material.
    Type: Grant
    Filed: June 7, 1989
    Date of Patent: May 29, 1990
    Assignee: GTE Products Corporation
    Inventor: Vaddi B. Reddy
  • Patent number: 4929384
    Abstract: A process is disclosed for producing M' phase YTaO.sub.4 :Nb X-ray phosphor which comprises forming a mixture of the components Y.sub.2 O.sub.3, Ta.sub.2 O.sub.5, and Nb.sub.2 O.sub.5, and a flux which can be lithium chloride, lithium sulfate or a mix of lithium sulfate and potassium sulfate in a mole ratio of 80 to 20, the flux making up about 25% to 50% by weight of the mixture, the components being provided in an amount equal to approximately the stoichiometric amounts to form the phosphor, firing the mixture in a furnace by heating to a temperature of about 1200.degree. C. to 1300.degree. C. at a heating rate of about 1.0.degree. C./min. to 1.5.degree. C./min. and maintaining the temperature for about 10 to 14 hours to react the components and produce a fired material containing luminescent material, cooling the material by turning off the heat to the furnace and allowing the material to remain in the furnace until the temperature is no higher than about 300.degree. C.
    Type: Grant
    Filed: June 7, 1989
    Date of Patent: May 29, 1990
    Assignee: GTE Products Corporation
    Inventor: Vaddi B. Reddy