Tanaka Kikinzoku Kogyo K.k.

Catalytica, Inc.

Kosaka Smelting & Refining Co., Ltd.

Chlorine Engineers Corp., Ltd.

Dowa Metals & Mining Co., Ltd.

Nippon Pgm Co., Ltd.

Dowa Mining Co., Ltd.

Nobuyasu Ezawa

Ralph Albert Dalla Betta

Kazunori Tsurumi

Hiroshi Inoue

Toru Shoji

Koji Yamada

Sarento George Nickolas

Nobutaka Goto

Masahiko Ogino

James C Schlatter

Hitoshi Masuda

Shoei Takada

Fabio H Ribeiro

Tsuyoshi Okazaki

Mamoru Hirako

Kenichi Tayama

Kazuma Takadate

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 &#x3bc;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 &#x3bc;m in the vertical depth direction from the electrode surface is 5 at % or less.

Electrolytic electrode, anode for electrolytic production of ozone, anode for electrolytic production of persulfuric acid and anode for electrolytic oxidation of chromium

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.

Apparatus for recovering platinum group elements

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.

Method and apparatus for recovering platinum group elements

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.

Catalyst structure for use in a partial combustion process

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.

Process for burning combustible mixtures

Partial combustion process and a catalyst structure for use in the

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.

Multistage process for combusting fuel mixtures

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.

Process of recovering platinum group metal

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.

Catalyst structure having integral heat exchange

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.

Multistage process for combusting fuel mixtures using oxide catalysts in

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.

Two stage process for combusting fuel mixtures

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.

Process for refining gold and apparatus employed therefor

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.

Growing community of inventors

Koto, Japan

Nobuyasu Ezawa