Abstract: The electrochemical reduction of nitrates in aqueous solutions thereof in the presence of amides to gaseous nitrogen (N2) is described. Generally, electrochemical reduction of NO3 proceeds stepwise, from NO3 to N2, and subsequently in several consecutive steps to ammonia (NH3) as a final product. Addition of at least one amide to the solution being electrolyzed suppresses ammonia generation, since suitable amides react with NO2 to generate N2. This permits nitrate reduction to gaseous nitrogen to proceed by electrolysis. Suitable amides include urea, sulfamic acid, formamide, and acetamide.

Abstract: A refractory boride body or coating made of a boride of titanium, chromium, vanadium, ziconium, hafnium, niobium, tantalum, molybednum and cerium is produced from a slurry of the refractory boride or a precursor in a collidal carrier preferably composed of two more different grades of the same colloidal carrier selected from colloidal alumina, yttria, ceria, thoria, zirconia, magnesia, lithia, monoaluminum phosphate and cerium acetate. The slurry can also comprise an organic additive selected from polyvinyl alcohol; polyacrylic acid; hydroxyy propyl methyl cellulose; polythylene glycol; ethylene glycol, butyl benzyl phthalate; ammonium polymethacrylate and mixtures thereof. The retractory boride body or coated body is useful as a component of aluminum electrowinning cells.

Abstract: An apparatus for electroplating a wafer surface includes a cup having a central aperture defined by an inner perimeter, a compliant seal adjacent the inner perimeter, contacts adjacent the compliant seal and a cone attached to a rotatable spindle. The compliant seal forms a seal with the perimeter region of the wafer surface preventing plating solution from contaminating the wafer edge, wafer backside and the contacts. As a further measure to prevent contamination, the region behind the compliant seal is pressurized. By rotating the wafer during electroplating, bubble entrapment on the wafer surface is prevented. Further, the contacts can be arranged into banks of contacts and the resistivity between banks can be tested to detect poor electrical connections between the contacts and the wafer surface.

Abstract: The present invention relates to an aqueous plating bath for electrodeposition of tin-zinc alloys comprising at least one bath-soluble stannous salt, at least one bath soluble zinc salt, and a quaternary ammonium polymer selected from a ureylene quaternary ammonium polymer, an iminoureylene quaternary ammonium polymer or a thioureylene quaternary ammonium polymer. The plating baths also may contain one or more of the following additives: hydroxy polycarboxylic acids or salts thereof such as citric acid; ammonium salts; conducting salts; aromatic carbonyl-containing compounds; polymers of aliphatic amines such as a poly(alkyleneimine); and hydroxyalkyl substituted diamines as metal complexing agents. The plating baths of this invention deposit a bright and level deposit, and they can be adapted to provide plated alloys having high tin concentration over a wide current density range.

Abstract: An electrolytic cell for the electrowinning of aluminium comprises a cathode cell bottom provided with a series of sloped active cathode surfaces (11, 12) down which produced aluminium (60) is drained, and a series of recessed grooves or channels (20), below the bottom of the cathode active surfaces (11, 12) and extending therealong which collect and evacuate the drained produced aluminum (63). Preferably the active surfaces (11, 12) are V-shaped and the recessed grooves or channels (20) are provided with a sloping bottom and a constant cross-sectional area. Alumina is so fed into the cell as to supply alumina-rich electrolyte (62) into the recessed grooves or channels (20) which contain the alumina-rich electrolyte along substantially their entire length above the drained layer of aluminium (63).

Abstract: The present invention relates to a device and method for electrolytic deposition of metals on conducting particles. The conducting particles are completely immersed in a liquid and allowed to flow across a particle contacting surface of a cathode support. The particles flow across the surface and into a reservoir. Electrical contact is made between the negative pole of a DC power supply and the conducting particles. An anode mesh is placed above and parallel to the top face of the particle bed such that the mesh does not touch the particle bed but remains a controlled distance from it. The anode mesh is connected to the positive terminal of the DC power supply. A significant aspect of the present invention is that the device does not require a separator between the particle bed and the anode.

Abstract: A hydrogen replenishment system for providing hydrogen to a hydrogen-receiving apparatus, the system comprising (i) an electrolytic cell for providing source hydrogen; (ii) a compressor means for providing outlet hydrogen at an outlet pressure; (iii) means for feeding the source hydrogen to the compressor means; (iv) means for feeding the outlet hydrogen to the hydrogen-receiving apparatus; (v) central processing unit means for controlling the cell and the compressor; and (vi) user activation means for operably activating the central processing unit means. The invention provides a practical user interface in the treatment of data provided, computed, measured and stored, to offer a convenient, essentially self-contained, hydrogen fuel replenishment system for vehicles based on water electrolysis. The apparatus has virtually no stored hydrogen and provides pressurized hydrogen on the demand of a user.

Abstract: In a process for the electrolytic polishing of surgical needles, a plurality of unfinished needles, which are arranged side by side and are secured to at least one web (6, 7) in their end-regions lying opposite the needle tips, are moved with the help of the web (6, 7) through an acid-containing polishing bath (22) which is electrically connected to an electrode. The web (6, 7) is guided above the polishing bath (22). The unfinished needles dip at least with the needle tips into the polishing bath (22). Above the polishing bath (22) and alongside the web (6, 7), a metal ribbon (40) connected as a counter-electrode provides an electrical connection with the unfinished needles.

Abstract: A process for electrolyzing Al2O3 to produce aluminum in a low temperature bath containing AlCl3 and an alkali metal chloride. The bath is maintained at a temperature of less than about 300 ° C. Solid aluminum is produced at the cathode in a frozen layer of the alkali metal chloride.

Abstract: Disclosed is a technique for manufacturing a Ni—Fe alloy thin foil using a single-step electrodeposition-based plating process without requiring processes such as melting, casting, forging, and rolling. A manufacturing apparatus is provided which includes an electrolyzer adapted to receive an electrolyte containing, as a major component thereof, a solution of nickel and iron compounds, a cathode partially dipped in the electrolyte and arranged in such a fashion that it is rotatable, an anode completely dipped in the electrolyte and arranged in such a fashion that it faces the cathode while being spaced apart from the cathode by a desired distance, and a current supply device adapted to generate a flow of current between the cathode and the anode, whereby a Ni—Fe alloy thin film is electrodeposited to a desired thickness over a surface of the cathode facing the anode, and then peeled off from the surface of the cathode, so that a continuous Ni—Fe alloy thin foil is manufactured.

Abstract: This plating apparatus 4 includes a plating bath 15 filled up with a plating solution, a first O ring 17 arranged on a top part of the plating bath 15, for electrical connection with an underlying electrode 18 formed on a wafer 2, a second O ring 20 arranged on the top part of the plating bath 15 so as to prevent the plating solution in the plating bath 15 from contact with the first O ring 17, an anode plate 24 disposed in the plating bath 15 and an ultrasonic oscillating element 26 arranged in the plating bath 15. The plating apparatus 4 is capable of forming a plating film having an uniform thickness on the semiconductor wafer.

Abstract: This invention relates to an electrolytic method for the selective recovery and recycling of silver from a nitric acid solution containing it in the form of Ag(I), this method comprising successive steps of electro-deposition of the silver in the form of silver metal Ag(0), and then of redissolution of the deposited silver Ag(0), to give a final solution of Ag(I) in which the step of electro-deposition is carried out at a prescribed current and the successive steps of electro-deposition of the silver and of redissolution of the deposited silver are carried out in the same apparatus. The invention is applicable particularly to the selective recovery of Ag(I) by reduction to Ag metal from nitric acid solutions arising from the processing of plutonium containing waste in plants for the reprocessing of nuclear fuels and to the redissolution of the silver metal to form Ag(I) with the purpose of recycling it to an upstream point of the method.

Abstract: A process for the removal of galvanic electrolytic residues from galvanically reinforced fiber structure frames, where the fiber structure frame is produced through chemical metallization of a textile substrate based on fleeces or felts made of synthetic fibers and then through galvanic reinforcement of the metallized textile substrate in a galvanic bath containing a galvanic electrolyte. The invention provides that the galvanic electrolytic residues are removed by suction from the fiber structure frame. The fiber structure frame then makes contact at least once under high pressure with the wash liquid in a wash station, and subsequently the wash liquid is removed by suction from the fiber structure frame. In order to remove by suction, the galvanic electrolytic residues or the wash liquid, a belt-shaped porous supporting device is inserted between the suction port and a main area of the fiber structure frame.

Abstract: A process for removing or reducing the directionality or anisotropy of a surface and for making the surface specular on a substrate material consisting of aluminium or an aluminium alloy, by (a) chemically etching the substrate material, (b) subjecting the etched substrate material substrate material to electrochemical polishing by using a solution, and (c) subjecting the substrate material to additional chemical etching and electrochemical polishing directly after step (b), wherein the surface of the substrate material is not exposed to air between the etching and the electrochemical polishing.

Abstract: An improved anode, cup and conductor assembly for a reactor vessel includes an anode assembly supported within a cup which holds a supply of process fluid. The cup is supported around its perimeter within the reactor vessel. The anode assembly has an anode shield carrying an anode, the anode shield having upwardly extending brackets with radially extending members. A diffusion plate is supported above the anode by the anode brackets using first bayonet connections. The anode shield and the anode are supported from below by a delivery tube which also serves to deliver process fluid to the cup. A second bayonet connection is provided between a top portion of the delivery tube and the anode assembly. The fluid delivery tube has a fixed height within the vessel. The anode elevation is adjusted by the interposing of a spacer of desired thickness between the anode and the tube. An electrical conductor is connected to the anode, and passes through the tube to be electrically accessible outside the vessel.

Abstract: An improved anode, cup and conductor assembly for a reactor vessel includes an anode assembly supported within a cup which holds a supply of process fluid. The cup is supported around its perimeter within the reactor vessel. The anode assembly has an anode shield carrying an anode. The anode shield and the anode are supported from below by a delivery tube which also serves to deliver process fluid to the cup. A bayonet connection is provided between a top portion of the delivery tube and the anode assembly. The fluid delivery tube has a fixed height within the vessel. The anode elevation is adjusted by the interposing of a spacer of desired thickness between the anode and the tube. An electrical conductor is connected to the anode, and passes through the tube to be electrically accessible outside the vessel. The conductor is connected to the anode with a plug-in connection which is completed when the tube is coupled to the anode by the bayonet connection.

Abstract: An electroplating system is provided for seed layer covered semiconductor wafers. A plating chamber is provided with an inert primary anode connectible to a positive voltage source and a semiconductor wafer connector connectible to a negative voltage source. The plating chamber further contains a consumable ring secondary anode connectible to the positive voltage source such that, when the plating chamber is filled with a plating solution and a semiconductor wafer is connected to the semiconductor wafer connector and the voltages are connected, the seed layer on the semiconductor wafer will be plated by consuming the consumable ring secondary anode.

Abstract: A method for making semiconductor interconnect features in a dielectric layer is provided. The method includes depositing a copper seed layer over a barrier layer that is formed over the dielectric layer and into etched features of the dielectric layer. The copper seed layer is then treated to remove an oxidized layer from over the copper seed layer. The method then moves to electroplating a copper fill layer over the treated copper seed layer. The copper fill layer is configured to fill the etched features of the dielectric layer.

Abstract: A process for producing sodium gold sulfite in solution is described. The sodium gold sulfite solution is useful in gold electroplating baths, and can be used in applications which require pure, soft gold deposits.

Abstract: A method of making, by etching, depressions in selected portions of an etching surface of an electrically conductive etching material, the depressions forming an etching pattern, comprises the step of contacting the etching material with an etchant. A passivating layer is formed on the etching material which layer decreases or stops the etching capability of the etchant on the surface and which is dissolved in a chemical reaction when exposed to electromagnetic radiation. An electrode with electrically conductive electrode portions in selected portions of an electrode surface is provided, the electrode portions forming an electrode pattern corresponding to the etching pattern. The electrode is arranged in contact with the etchant and with the electrode portions facing the etching surface of the etching material, an electric voltage is applied between the electrode and the etching material, and the etching material is exposed to electromagnetic radiation essentially perpendicular to the etching surface.