Patents by Inventor Nobuyasu Ezawa

Nobuyasu Ezawa 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: 9353448
    Abstract: An electrolytic electrode includes an electrode surface layer formed by a high-temperature heat treatment under a low oxygen partial pressure of 100 Pa or less and includes a valve metal oxide film, the electrode surface layer having, just beneath, a layer which includes a valve metal and a noble metal excluding silver and the noble metal is precipitated and dispersed in a crystal grain boundary of the valve metal, wherein a crystal of the valve metal in a range of down to 30 ?m in a vertical depth direction from the electrode surface is a crystal grain being elongated in a vertical cross-section from the electrode surface and a content of the noble metal in a range of down to 10 ?m in the vertical depth direction from the electrode surface is 5 at % or less.
    Type: Grant
    Filed: September 14, 2011
    Date of Patent: May 31, 2016
    Assignee: Tanaka Kikinzoku Kogyo K.K.
    Inventors: Tsuyoshi Okazaki, Nobuyasu Ezawa
  • Publication number: 20130175165
    Abstract: An electrolytic electrode includes an electrode surface layer formed by a high-temperature heat treatment under a low oxygen partial pressure of 100 Pa or less and includes a valve metal oxide film, the electrode surface layer having, just beneath, a layer which includes a valve metal and a noble metal excluding silver and the noble metal is precipitated and dispersed in a crystal grain boundary of the valve metal, wherein a crystal of the valve metal in a range of down to 30 ?m in a vertical depth direction from the electrode surface is a crystal grain being elongated in a vertical cross-section from the electrode surface and a content of the noble metal in a range of down to 10 ?m in the vertical depth direction from the electrode surface is 5 at % or less.
    Type: Application
    Filed: September 14, 2011
    Publication date: July 11, 2013
    Applicant: TANAKA KIKINZOKU KOGYO K.K.
    Inventors: Tsuyoshi Okazaki, Nobuyasu Ezawa
  • Patent number: 8366991
    Abstract: An apparatus for recovering platinum group elements comprises a furnace body having an interior space substantially shot off from external air, a material charging port and an exhaust port provided in an upper half of the furnace body, at least two fluid discharge ports provided in a lower half of the furnace body at different height levels. a material charging chute connected to the material charging port. an exhaust unit connected to the exhaust port; and electrodes for passing electric current through and heating material charged into the furnace. The material charging chute is equipped with a vertical two stage shutter so as to maintain airtightness when material is charged into the interior space of the furnace.
    Type: Grant
    Filed: September 16, 2010
    Date of Patent: February 5, 2013
    Assignees: Dowa Metals & Mining Co., Ltd., Tanaka Kikinzoku Kogyo K.K., Kosaka Smelting & Refining Co., Ltd., Nippon PGM Co., Ltd.
    Inventors: Koji Yamada, Masahiko Ogino, Nobuyasu Ezawa, Hiroshi Inoue
  • Publication number: 20110001279
    Abstract: A method for recovering platinum group elements comprises charging into a closed electric furnace and melting, together with flux components and a reducing agent, a platinum group element-containing substance to be processed and a copper source material containing copper oxide, sinking molten metal of primarily metallic copper below a molten slag layer of primarily oxides, and enriching the platinum group elements in the molten metal sunk below, and is characterized in that molten slag whose copper content has decreased to 3.0 wt % or less is discharged from the electric furnace and that the copper source material charged into the electric furnace is a granular copper source material of a grain diameter of not less than 0.1 mm and not greater than 10 mm.
    Type: Application
    Filed: September 16, 2010
    Publication date: January 6, 2011
    Applicants: DOWA METALS & MINING CO., LTD., TANAKA KINKINZOKU KOGYO K.K., KOSAKA SMELTING & REFINING CO., LTD., NIPPON PGM CO., LTD.
    Inventors: Koji Yamada, Masahiko OGINO, Nobuyasu EZAWA, Hiroshi INOUE
  • Patent number: 7815706
    Abstract: A method for recovering platinum group elements comprises charging into a closed electric furnace and melting, together with flux components and a reducing agent, a platinum group element-containing substance to be processed and a copper source material containing copper oxide, sinking molten metal of primarily metallic copper below a molten slag layer of primarily oxides, and enriching the platinum group elements in the molten metal sunk below, and is characterized in that molten slag whose copper content has decreased to 3.0 wt % or less is discharged from the electric furnace and that the copper source material charged into the electric furnace is a granular copper source material of a grain diameter of not less than 0.1 mm and not greater than 10 mm.
    Type: Grant
    Filed: August 4, 2003
    Date of Patent: October 19, 2010
    Assignees: Dowa Metals & Mining Co., Ltd., Tanaka Kikinzoku Kogyo K.K., Kosaka Smelting & Refining Co., Ltd., Nippon PGM Co., Ltd.
    Inventors: Koji Yamada, Masahiko Ogino, Nobuyasu Ezawa, Hiroshi Inoue
  • Publication number: 20060213323
    Abstract: A method for recovering platinum group elements comprises charging an oxide raw material entraining platinum group elements, copper oxide, solid carbonaceous reducing agent and flux into a closed electric furnace equipped with at least one electrode for heating material and a roof for substantially shielding material charged into the furnace from the exterior atmosphere. The charged material is melted and reduced to form a layer of molten metal under a molten slag layer and enrich platinum group elements in this molten metal. The oxide raw material, copper oxide, solid carbonaceous reducing agent and flux are prepared as powdery or particulate materials, premixed and then charged into the electric furnace. The heat-melted material in the furnace is allowed to stand at a temperature of 1200° to 1500° C. for at least 5 hours, with the molten metal containing platinum group elements then being discharged outside the furnace.
    Type: Application
    Filed: March 11, 2004
    Publication date: September 28, 2006
    Inventors: Koji Yamada, Kenichi Tayama, Nobuyasu Ezawa, Hiroshi Inoue, Masahiko Ogino, Kazuma Takadate
  • Publication number: 20050166707
    Abstract: A method for recovering platinum group elements comprises charging into a closed electric furnace and melting, together with flux components and a reducing agent, a platinum group element-containing substance to be processed and a copper source material containing copper oxide, sinking molten metal of primarily metallic copper below a molten slag layer of primarily oxides, and enriching the platinum group elements in the molten metal sunk below, and is characterized in that molten slag whose copper content has decreased to 3.0 wt % or less is discharged from the electric furnace and that the copper source material charged into the electric furnace is a granular copper source material of a grain diameter of not less than 0.1 mm and not greater than 10 mm.
    Type: Application
    Filed: August 4, 2003
    Publication date: August 4, 2005
    Inventors: Koji Yamada, Masahiko Ogino, Nobuyasu Ezawa, Hiroshi Inoue
  • Patent number: 5511972
    Abstract: This invention is both a partial combustion process in which the fuel is partially combusted using specific catalysts and catalytic structures and also a catalyst structure for use in the process. The choice of catalysts and supports solves problems in the art dealing with the stability of the overall catalyst structure and ease of catalyst operation. The catalyst structure is stable due to its comparatively low operating temperature, has a low temperature at which catalytic combustion begins, and yet is not susceptible to temperature "runaway". The combustion gas produced by the catalytic process typically is below the autocombustive temperature for the gas mixture; the gas may be used at that temperature, or fed to other combustion stages for ultimate use in a gas turbine, furnace, boiler, or the like.
    Type: Grant
    Filed: January 11, 1995
    Date of Patent: April 30, 1996
    Assignees: Catalytica, Inc., Tanaka Kikinzoku Kogyo K.K.
    Inventors: Ralph A. Dalla Betta, Toru Shoji, Kazunori Tsurumi, Nobuyasu Ezawa
  • Patent number: 5425632
    Abstract: This invention is a process for catalytically burning a combustible mixture of a fuel and an oxygen-containing gas. In particular, the invention is a process for producing a combustion gas at a selected temperature, preferably between 1050.degree. C. and 1700.degree. C., by introducing all of the fuel necessary to attain that temperature to a combustion catalyst, partially combusting the combustible within the combustion catalyst, and homogeneously combusting the remainder of the fuel outside the catalyst. By controlling the temperature within the catalyst, deterioration of that catalyst is prevented.
    Type: Grant
    Filed: July 6, 1993
    Date of Patent: June 20, 1995
    Assignees: Catalytica, Inc., Tanaka Kikinzoku Kogyo K.K.
    Inventors: Kazunori Tsurumi, Nobuyasu Ezawa, Ralph A. Dalla Betta
  • Patent number: 5326253
    Abstract: This invention is both a partial combustion process in which the fuel is partially combusted using specific catalysts and catalytic structures and also a catalyst structure for use in the process. The choice of catalysts and supports solves problems in the art dealing with the stability of the overall catalyst structure and ease of catalyst operation. The catalyst structure is stable due to its comparatively low operating temperature, has a low temperature at which catalytic combustion begins, and yet is not susceptible to temperature "runaway". The combustion gas produced by the catalytic process typically is below the autocombustive temperature for the gas mixture; the gas may be used at that temperature, or fed to other combustion stages for ultimate use in a gas turbine, furnace, boiler, or the like.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: July 5, 1994
    Assignees: Catalytica, Inc., Tanaka Kikinzoku Kogyo K.K.
    Inventors: Ralph A. Dalla Betta, Toru Shoji, Kazunori Tsurumi, Nobuyasu Ezawa
  • Patent number: 5281128
    Abstract: This invention is a combustion process having a series of stages in which the fuel is stepwise combusted using specific catalysts and catalytic structures and, optionally, a final homogeneous combustion zone. The choice of catalysts and the use of specific structures, including those employing integral heat exchange, results in a catalyst support which is stable due to its comparatively low temperature and yet the product combustion gas is at a temperature suitable for use in a gas turbine, furnace, boiler, or the like, but has low NO.sub.x content.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: January 25, 1994
    Assignees: Catalytica, Inc., Tanaka Kikinzoku Kogyo K.K.
    Inventors: Ralph A. Dalla Betta, Kazunori Tsurumi, Nobuyasu Ezawa
  • Patent number: 5252305
    Abstract: A process of recovering a platinum group metal from a waste catalyst comprising a first step which comprises heating and melting the catalyst impregnated with the platinum group metal, copper and/or the oxide of copper, a flux component and a reductant component to form a layer containing the metal copper into which the platinum group metal is absorbed and another layer of the oxide, and then separating the metal copper; and a second step which comprises supplying air or oxygen as an oxidant to the separated metal copper for oxidizing under heating and melting to form a layer of partially oxidized metal copper and another layer of the metal copper containing the concentrated platinum group metal, and separating it. This process enables the economical recovery of the platinum group metal from the waste catalyst in a short period of time with high recovery rate.
    Type: Grant
    Filed: April 9, 1992
    Date of Patent: October 12, 1993
    Assignees: Tanaka Kikinzoku Kogyo K.K., Dowa Mining Co., Ltd., Kosaka Smelting & Refining Co., Ltd.
    Inventors: Nobuyasu Ezawa, Hiroshi Inoue, Shoei Takada, Hitoshi Masuda
  • Patent number: 5250489
    Abstract: This invention is a catalyst structure having integral heat exchange surfaces and a method for using the structure in highly exothermic processes, such as a combustion process, while maintaining the catalyst and the structure wall at a temperature below the adiabatic combustion temperature.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: October 5, 1993
    Assignees: Catalytica, Inc., Tanaka Kikinzoku Kogyo K.K.
    Inventors: Ralph A. Dalla Betta, Fabio H. Ribeiro, Toru Shoji, Kazunori Tsurumi, Nobuyasu Ezawa, Sarento G. Nickolas
  • Patent number: 5232357
    Abstract: This invention is a combustion process having a series of stages in which the fuel is combusted stepwise using specific catalysts (desirably palladium-bearing catalysts in the first two zones and metal and oxygen-bearing catalysts in the hot catalytic zone) and catalytic structures and, optionally, a final homogeneous combustion zone. The choice of catalysts and the use of specific structures, including those employing integral heat exchange, results in a catalyst support which is stable due to its comparatively low temperature and yet the product combustion gas is at a temperature suitable for use in a gas turbine, furnace, boiler, or the like, but has low NO.sub.x content.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: August 3, 1993
    Assignees: Catalytica, Inc., Tanaka Kikinzoku Kogyo K.K.
    Inventors: Ralph A. Dalla Betta, Kazunori Tsurumi, Nobuyasu Ezawa
  • Patent number: 5183401
    Abstract: This invention is a comparatively high pressure combustion process having a two stages in which a fuel is stepwise combusted using specific catalysts and catalytic structures and, optionally, having a final homogeneous combustion zone. The choice of catalysts and the use of specific structures, including those employing integral heat exchange, results in an overall catalyst structure which is stable due to its comparatively low temperature. The product combustion gas is at a temperature suitable for use in a gas turbine, furnace, boiler, or the like, but has low NO.sub.x content.
    Type: Grant
    Filed: November 26, 1990
    Date of Patent: February 2, 1993
    Assignees: Catalytica, Inc., Tanaka Kikinzoku Kogyo KK
    Inventors: Ralph A. Dalla Betta, Nobuyasu Ezawa, Kazunori Tsurumi, James C. Schlatter, Sarento G. Nickolas
  • Patent number: 4859293
    Abstract: Disclosed are processes and an apparatus for refining gold. One of the processes comprises dissolving unrefined gold by use of iodine and/or an iodide compound to form a solution containing an iodide compound of gold, removing insoluble substances in the solution, reducing the ions containing the gold by use of an alkali to precipitate the gold of high purity. In this process, the iodine may be obtained by electrolyzing the iodide compound. The other process and the apparatus further comprise circulating the solution having been separated from the precipitated gold for reuse, and the alkali simultaneously produced by the above electrolysis is economically employed therein.
    Type: Grant
    Filed: July 15, 1987
    Date of Patent: August 22, 1989
    Assignee: Tanaka Kikinzoku Kogyo K.K.
    Inventors: Mamoru Hirako, Nobuyasu Ezawa
  • Patent number: 4626331
    Abstract: In an electrolytic cell of the type which includes a cylindrical electrolytic cell main body divided into a main electrode chamber and an auxiliary electrode chamber by a diaphragm, and having main electrode particles in the main electrode chamber, which are maintained in the fluidized state by an electrolyte supplied to the main electrode chamber, an improvement is disclosed wherein an electrolyte supply port and an electrolyte discharge port are provided to enable flow of electrolyte through said cell to maintain the fluidized state of said particles, and a porous auxiliary electrode is provided in contact with the diaphragm on the side thereof facing said auxiliary electrode chamber, to facilitate flow of gas generated on the auxiliary electrode in the direction of the auxiliary chamber.
    Type: Grant
    Filed: November 21, 1985
    Date of Patent: December 2, 1986
    Assignee: Chlorine Engineers Corp., Ltd.
    Inventors: Nobutaka Goto, Nobuyasu Ezawa
  • Patent number: 4569729
    Abstract: In an electrolytic cell of the type which includes a cylindrical electrolytic cell main body divided into a main electrode chamber and an auxiliary electrode chamber by a diaphragm, and having main electrode particles in the main electrode chamber, which are maintained in the fluidized state by an electrolyte supplied to the main electrode chamber, an improvement is disclosed wherein an electrolyte supply port and an electrolyte discharge port are provided to enable flow of electrolyte through said cell to maintain the fluidized state of said particles, and a porous auxiliary electrode is provided in contact with the diaphragm on the side thereof facing said auxiliary electrode chamber, to facilitate flow of gas generated on the auxiliary electrode in the direction of the auxiliary chamber.
    Type: Grant
    Filed: November 19, 1984
    Date of Patent: February 11, 1986
    Assignees: Chlorine Engineers Corp., Ltd., Tanaka Kikinzoku Kogyo K.K.
    Inventors: Nobutaka Goto, Nobuyasu Ezawa