Abstract: The invention provides an ion exchange membrane electrolyzer. An electric current is passed through at least one electrode while the electrode is in contact with a plurality of comb-like flat leaf spring tags extending at an angle from a flat leaf spring form of retainer member located on an electrode partition provided in an electrode chamber. Each pair of comb-like flat leaf spring tags are arranged in such a way that adjacent flat leaf spring tags extend in mutually opposite directions.

Abstract: The invention provides an ion exchange membrane electrolyzer ensuring a satisfactory circulation of electrolyte, high electrolytic efficiency and great ridigity. An anode chamber partition in a flat sheet form is joined to a cathode chamber partition in a flat sheet form. An electrode retainer member in a sheet form is joined to at least one partition at a belt-like junction. A projecting strip with an electrode joined thereto is located between adjacent junctions. A space on an electrode surface side of the electrode retainer member defines a path through which a fluid goes up in the electrode chamber, and a space that spaces away from the space defines a path through which an electrolyte separated from a gas at a top portion of the electrode goes down.

Abstract: An electrolytic cell using an oxygen cathode, for use in an ion-exchange membrane electrolytic soda process or the like, the electrolytic cell having; a structure, wherein, for effective supply and discharge of a caustic liquid and for an effective handling of a caustic liquid leakage, provided on an outer-side edge of the electrolytic cell are an upper chamber as a caustic liquid discharge outlet, a lower chamber as a caustic liquid introduction inlet, and a caustic-liquid room frame connected via a caustic liquid passage to thereby reduce a caustic liquid leakage; a structure, wherein a lower gas chamber is provided at the lower outer end of a cathode element to thereby handle a caustic liquid leakage from a gas diffusion electrode to a gas room; or a structure which uses a gas-liquid permeating gas diffusion electrode to supply an oxygen gas from an upper chamber communicating with a gas room and discharge a gas and a caustic liquid into a lower chamber.

Abstract: An electricity leading method for a gas diffusion electrode is provided, by which a gas diffusion electrode is easily fixed to a cathode current collecting frame, the contact part has reduced electrical resistance, even an electrically insulating mesh sheet can be utilized as a gas chamber, and only the gas diffusion electrode can be replaced in renewal of the electrode. The method includes preparing a gas diffusion electrode by sandwiching a conductor made of a highly conductive metallic mesh or spongy processed material in catalyst layers or attaching a catalyst layer onto the conductor while leaving the conductor exposed in the outer periphery of the electrode, and electrically connecting the exposed part of the conductor to a cathode chamber current collecting frame.

Abstract: A sodium chloride electrolytic cell is provided, comprising a gas diffusion electrode that allows smooth supply and discharge of catholyte for electrolyzing sodium chloride and allows oxygen gas to come in good contact therewith. The sodium chloride electrolytic cell comprises an anode chamber having an anode into which an aqueous solution of sodium chloride and a cathode chamber having the foregoing gas diffusion electrode for producing an alkaline aqueous solution, the anode chamber and the cathode chamber being divided by an ion exchange membrane. The sodium chloride electrolytic cell is arranged to effect electrolysis in such a manner that there occurs no pressure differential between the catholyte chamber and the gas chamber in the gas diffusion electrode. Further, a nickel mesh substance is fitted in a concave portion having the same size as that of the gas diffusion electrode formed in the central portion of a thin nickel plate.

Abstract: The present invention provides an ion exchange membrane type electrolyzer, which comprises electrodes at opposed positions via an ion exchange membrane, spacers are mounted in dot-like arrangement on openings of electrode surface to maintain spacing between the ion exchange membrane and surface of at least one of the electrodes.

Abstract: In a method of removing impurities, especially iodine and/or silica ions, from a salt solution to be used for electrolysis, the salt solution and zirconium hydroxide are brought into contact with each other under acidic conditions, and the zirconium hydroxide adsorbs the impurities. Thereafter, the zirconium hydroxide containing the adsorbed impurities is brought into contact with an aqueous solution at a higher pH value to desorb the impurities from the zirconium hydroxide, thereby enabling the zirconium hydroxide to be recycled.

Abstract: The present invention provides an electrolyzer, which comprises vertical type electrolyzer units with irregular surfaces formed on partition walls on anode side and on partition walls on cathode side, said irregular surfaces being overlapped on each other and integrated, and electrode plates being connected to convex portions of the partition walls, whereby said irregular surfaces are formed as troughs and ridges extending in vertical direction of the electrolyzer units, said irregular surfaces are divided into a plurality of sectors in height direction, said trough in each sector extends along the same straight line as the ridge of another sector, a liquid junction is provided to connect adjacent troughs in the same sector in the connecting portion of the adjacent sector and to connect the troughs in adjacent sectors, and an internal circulation member is provided between the partition wall and the electrode surface, using inclined surfaces of the trough on the partition wall or a member parallel to the incl

Abstract: In removal of sulfate groups and chlorate groups from brine used for electrolysis, concentrated brine used in an electrolysis process or dilute brine whose concentration is decreased by electrolysis is fed to an anode chamber divided by a cation exchange membrane in a brine treating electrolyzer, where the concentrated or dilute brine is electrolyzed to recover chloride ions therein. The concentrated brine is electrolyzed at a rate of decomposition of salt higher than that in the ion exchange membrane electrolysis process of brine. Thereafter, the concentrated or dilute brine is discharged out of the electrolysis process.

Abstract: CMPO is safely, reliably and rapidly decomposed under mild conditions. A CMPO-containing substance is emulsified in an electrolyte comprising an oxidation promoter (silver ion) by an emulsifier in an emulsifying tank, this electrolyte comprising the CMPO-containing substance is supplied to an anode chamber, and an electrolytic oxidation reaction is performed by passing an electric current. By emulsifying the CMPO-containing substance, the surface area of CMPO in contact with electrolyte is increased, and electrolytic decomposition is thereby promoted. As sufficient CMPO decomposition is not obtained by passing the emulsion only once through an electrolysis tank 1, a batch oxidation method is employed wherein an anolyte is recirculated by a recirculating pump 3a through the anode chamber, a constant temperature bath 7a and an emulsifying tank 6, so that electrolysis is performed with the CMPO-containing substance permanently emulsified in the electrolyte.

Abstract: In an activated cathode and a method for manufacturing the activated cathode, a first layer which contains nickel or cobalt as a main component is formed on a metal substrate, and a second layer which contains platinum or ruthenium as a main component is formed on the first layer. It is preferable that the first layer is formed of Raney nickel and the second layer has a large cathode working area, or it is also preferable that the first layer is formed of nickel oxide or cobalt oxide, and the second layer is formed of fine platinum or ruthenium particles and has a large cathode working area.

Abstract: The present invention provides an apparatus for producing hypochlorite of any concentration as desired by electrolysis and being easy to maintain. A hypochlorite reaction chamber is provided integrally with an electrolyzer, which is divided by a cation exchange membrane, and introducing means for introducing an anode chamber product and a cathode chamber product is provided between the hypochlorite reaction chamber and the anode chamber or the cathode chamber. As a result, it is possible to obtain an apparatus for producing hypochlorite and being easy to handle, and there is no need to install pipings for chlorine outside the apparatus.

Abstract: The method of removing a film from a substrate (wafer) comprises a step of injecting ozone (13) into an acid aqueous solution (12) (e.g., a mixed liquid of dilute hydrogen fluoride aqueous solution and dilute hydrochloric acid); and a step of bringing bubbles (18) formed by the ozone injection step into contact with a film (17) (e.g., organic or metal contaminated film) adhering on to the substrate to remove the film (17) from the substrate (16). Therefore, the organic film or metal contaminated film adhering onto the substrate surface can be removed easily and effectively. Further, the film removing agent is bubbles formed when ozone (13) is injected into an acid aqueous solution. Each bubble is composed of an inside ozone bubble and an outside acid aqueous solution bubble. Therefore, when the bubbles are brought into contact with the film, an intermediate between ozone and the film is first formed, and then the formed intermediate can be removed from the substrate by the acid aqueous solution.

Abstract: The present invention provides a method for manufacturing hypochlorite efficiently, using an anode, which has a coating containing palladium oxide by 10 to 45 weight %, ruthenium oxide by 15 to 45 weight %, titanium dioxide by 10 to 40 weight %, and platinum by 10 to 20 weight % as well as an oxide of at least one metal selected from cobalt, lanthanum, cerium or yttrium by 2 to 10 weight % being formed on a conductive base, and a cathode comprising a coating having low hydrogen overvoltage and covered with a reduction preventive film and being formed on a conductive base, and an aqueous solution of a chloride is electrolyzed without a diaphragm.

Abstract: In a brine treatment method of removing sulfate ions from sulfate-ion contained brine, sulfate-ion contained brine is brought into dispersive contact with granular ion exchange resin carrying zirconium hydrous oxide thereon in a fluid state under an acidic condition to thereby cause the sulfate ions to be adsorbed by the ion exchange resin and removed from the brine, then the granular ion exchange resin is washed with aqueous solution whose pH value is equal to or lower than a pH value in the adsorbing step, thereby removing chloride ions from the granular ion exchange resin, then in a fluid state, the granular ion exchange resin adsorbing the sulfate ions is brought into dispersive contact with aqueous solution of pH value higher than the pH value in the adsorbing step, thereby desorbing the adsorbed sulfate ions from the granular ion exchange resin, and then the granular ion exchange resin is washed with water.

Abstract: Sulfuric acid used in the process of fabricating semiconductor devices, etc., can be recycled to reduce the amount of sulfuric acid to be discarded. A sulfuric acid effluent is fed to an anode chamber of a sulfuric acid-concentrating electrolyzer partitioned by at least one cation exchange membrane to concentrate sulfuric acid and generate oxidizing substances, so that the sulfuric acid can be used at the step of using sulfuric acid, and, when the concentration of impurities built up in the system exceeds a certain level, a part of sulfuric acid in the system is fed to a unit for refining sulfuric acid, where the sulfuric acid is refined and whence the refined sulfuric acid is fed back to the system. According to this recycling process, it is possible to obtain sulfuric acid having high oxidizing power with no addition of an oxidizing substance such as hydrogen peroxide thereto.

Abstract: Electroplating is carried out in a nickel plating bath in which are dispersed active carbon particles supporting at least one platinum metal selected from the group consisting of platinum, rhodium, iridium, and palladium, thereby forming on an electrode substrate a nickel electrode active layer containing platinum metal-supporting active carbon particles and having such active carbon particles attached to a surface layer thereof, and thus producing a cathode exhibiting a high electrode activity and capable of stably sustaining a low hydrogen overvoltage for a long period of time.

Abstract: An electrolyzer having a partition plate produced by forming thin plates. The electrolyzer includes a vertical electrolyzer unit which has a partition plate formed by superimposing a pair of anode- and cathode-side partitions provided with mutually fittable recesses and projections, and an electrode plate connected to the projections on each side of the partition plate to define an electrolytic chamber. A gas-liquid separating chamber having a discharge opening is provided in the upper part of the electrolyzer unit such that the cross-sectional area of the gas-liquid separating chamber is larger at a part closer to the discharge opening than at a part remoter from the discharge opening, thereby preventing the fluctuation of pressure in the electrolytic chamber caused by pulsation occurring in the gas-liquid separating chamber.

Abstract: The present invention relates to a method for regenerating tetraalkylammonium hydroxide used as developer solution for positive type resist from waste developer solution. Waste solution from developer solution for positive type resist, which contains tetraalkylammonium hydroxide as principal component, is neutralized, and after depositing and removing alkali-soluble organic substances dissolved in it, it is electrolyzed in an anode chamber of an electrolytic cell partitioned by cation exchange membranes, and it is anodized in the anode chamber. Aqueous solution of tetraalkylammonium hydroxide obtained from the cathode chamber is further introduced to an anode chamber of the other electrolytic cell to perform multi-stage electrolysis or it is introduced into an anode chamber of an electrolytic cell partitioned into 3 chambers or more by two or more cation exchange membranes to perform multi-chamber electrolysis.

Abstract: A method for fabricating an electrode assembly for solid polymer electrolyte fuel cells comprising a cation exchange membrane as the electrolyte and electrode catalyst layers, which utilizes specific perfuluorosulfonic acid copolymers for the cation exchange membrane and a binder used for preparing the electrode catalyst layers or bonding the cation exchange membrane and the electrode catalyst layers and provides electrode assemblies for the fuel cells being capable of providing fuel cells having a high cell voltage with high efficiency.