Abstract: An electrolytic generator is disclosed for use in treating water in swimming pools, baths, reservoirs, sewage, etc., and in bleaching chemical pulp. The generator is of the type consisting of two sealed compartments separated by an ion-permeable membrane and having a cathode in one compartment and an anode in the other. Hydrogen is evolved from the cathode compartment and a chlorine/chlorine dioxide mixture from the anode compartment. In this generator, an electrically neutral or bipolar electrode (one not connected in the anode-cathode circuit) is positioned adjacent to the anode or between the anode and the cathode adjacent to the ion-permeable membrane in the anode compartment. This electrolytic generator is characterized by a more rapid start up and generates a mixture of chlorine and chlorine dioxide at both the anode and the neutral electrode.

Abstract: In an anode of a cell for alkali metal chloride electrolysis by the amalgam method and comprising a grid-like or net-like level titanium anode surface, optionally current distributing rails, a bridge acting as a primary conducting rail and at least one copper bolt as a current supply means, the improvement wherein the copper bolt has a screw thread, the bridge having a threaded passage for receiving the screw thread and a conical passage for receiving the conical portion of the copper bolt, the copper bolt and bridge being screwed together in a force- and form-locking manner.

Abstract: Method of supporting a preformed membrane in an electrolytic cell, and apparatus therefor, which comprises casting in situ support plates about the open edges of the membrane.

Abstract: An intercell connector system is disclosed. The system includes two adjacent terminals attached to two adjacent cells and intercell connector selectively overlapping the adjacent ends of the terminals. The intercell connector includes a conductive first member and a second member which are held together by a fastening device which can be selectively loosened and tightened. When the fastening device is loosened, the two members are adapted to be moved out of engagement with one of the terminals thereby disconnecting the electrical circuit between the terminals.

Abstract: A method for high resolution maskless chemical and electrochemical machining is described. Preferential etching results from exposing those regions where machining is sought to an energy beam. Such exposures can increase the ething rate in the case of electrochemical machining by a factor of 10.sup.3 to 10.sup.4. Such enhancement is sufficient to make masking unnecessary.

Abstract: Device for selective electrodeposition of metal flat stock, on laddered or bandoliered component strips having at least one station filled with electrolyte through which the component strips are transported lengthwise. The device includes a longitudinal guide means for the component strips-the guide means is provided with a slot shaped chamber. The chamber, at its lower side is in open contact with a plating bath filled with electrolyte on a level lower than the electrolyte level in the plating bath. The guide means has apertures for introducing pressurized gas or air. The plating bath contains tubes with holes in such a position that during operation electrolyte recirculated through a transport pump can be jetted onto the portion of the metal or component strip which extends below the slot-shaped chamber of the guide means into the electrolyte.

Abstract: An electrochemical cell is disclosed for eliminating and/or recovering dissolved metals from waste liquors or winning dissolved metals from waste solutions having a low concentration of such metals. The cell has a three dimensional electrode with a geometrical bed depth that is increased from the electrolyte inlet to outlet so that the bed depth increases along the flow direction corresponding to the concentration decrease within the cell. Thus, the geometrical bed depth is essentially equal to the effective bed depth at each point within the electrode where the electrochemical conversion takes place.

Abstract: An electrolytic diaphragm or membrane cell is disclosed in which flexible clamp members are arranged to provide sealing engagement between the diaphragm or membrane and its associated support elements.

Abstract: An electroflotation device for treating contaminated water includes cathode electrodes which are self-cleaning with respect to lime deposits. Each anode electrode of the device is associated with a pair of cathode electrodes. During operation of the device, a negative potential is applied to only one of the two electrodes of each cathode pair, while the other electrode has either a zero potential or a weak positive potential applied thereto. The lime deposit formed on the non-negative electrode is dissolved by the action of the carbonic acid which is present in the water, through the formation of bicarbonates.

Abstract: An air/oxygen electrode substrate for use as a cathode in alkali metal halide electrolysis processes is formed by compressing a prefused mixture of carbon black and a hydrophobic polymer such as polytetrafluoroethylene under high pressures and at a temperature in excess of the sintering temperature of the polymer and below its decomposition temperature. Optionally, the electrode may be formed having a core comprised of a metal mesh which acts to better distribute the applied voltage and to reinforce the electrode. Further, a sheet of hydrophobic backing material such as TEFLON fabric may be incorporated into the compressed mixture to increase the hydrophobic properties of the cathode. Electrocatalysts may then be deposited on the surface of the electrode substrate to produce an oxygen electrode having a significant voltage advantage over mild steel cathodes in alkali-halide electrolysis cells.

Abstract: The present invention is directed to a method of minimizing shunt currents in electrochemical devices which have a plurality of cells connected, at least in part, in series and which have a common electrolyte which is fed to at least two of the cells as a shared electrolyte from a common manifold via individual inlet channels, whereby an electrical electrolytic conductive bypass path is created around such cells and through said shared electrolyte, resulting in undesirable shunt currents. This method involves providing electrolyte tunnels which connect the individual inlet channels and applying a protective current through said electrolyte tunnels and thus through said shared electrolyte, the protective current being of a magnitude which effectively at least reduces said shunt currents. Thus, a single protective current may be applied such that shunt currents are minimized, and preferably are totally eliminated.

Abstract: An apparatus for producing hydrogen and oxygen or oxides wherein electrolysis of an aqueous system is carried out using, in the cathode compartment of the electrolysis cell, a hydride-forming liquid metal, the resulting hydride being thermally decomposed to produce the hydrogen.

Abstract: An electrode package is disclosed which comprises a substantially flat elrode (32) surrounded by two substantially flat inner frames (1) which are surrounded by a substantially flat outer frame (20) with holes (21, 22) for supply of electrolyte to and holes (23, 24) for discharge of electrolyte from the electrode. Each of the inner frames is provided with a grid (13) that improves the electrolyte flow and serves as a support for a membrane when used in membrane cells, and furthermore with flow-distributing projections and possibly barriers, making it possible to achieve varying flow patterns for the electrolyte with the same basic construction. The outer frame is preferably provided with ridges, going all the way round, for the simple fitting and sealing of a membrane against it. The electrode package will, thus, be particularly suitable for use in membrane cells in electrolyzers of the filter-press type, said use also being described herein.

Abstract: An apparatus for use in extracting primary zinc metal from ore concentrates is described. The apparatus includes first and second electrolytic cells, the first cell receiving an acid zinc sulfate solution derived from an ore concentrate, and having an anode which is insoluble in said solution, and the second cell containing an alkaline electrolyte and having a cathode which is insoluble in said electrolyte. A common electrode is also provided which is insoluble both in the acid zinc sulfate solution and in the alkaline electrolyte. The common electrode can be transferred between the first cell, in which it acts as a cathode, and the second cell, in which it acts as an anode. The zinc sulfate solution is subjected to electrolysis in the first cell with the common electrode acting as a cathode, thereby causing primary zinc metal to be deposited as a coating on the common electrode.

Abstract: A process and apparatus for electrolytic etching of aluminum or its alloy is disclosed wherein an electric current is passed between an anode and a cathode which are spaced opposed in an electrolytic bath with a workpiece removably supported on an insulating frame so that the side of the workpiece to be etched faces the cathode, the insulating frame being disposed between the anode and the cathode and having at least one opening formed therein.

Abstract: An electrochemical cell comprises a housing (1,2) divided by a perforated generally horizontal plate (3) into an upper chamber (4) and a lower chamber (5). Bipolar electrodes (19, 21) are disposed in the upper chamber (4) above perforations (23) in the plate (3), between electrolyte inlet and outlet weirs (11, 13) for flowing electrolyte over the plate (3). The lower chamber (5) is a gas-supply chamber for passing a gas, e.g. propylene, up through the perforations (23), so as to bubble the gas through electrolyte (e.g. NaBr solution) on the plate (3) and into the upper gas-collection chamber (4). A reactor may be formed by stacking several cells with their electrolyte flows in cascade. The cell is particularly suitable for electro-organic syntheses involving a gaseous reactant.

Abstract: Disclosed is an electrolytic cell having an electrolyte tank, planar first electrodes substantially parallel to and spaced from each other and electrically in parallel with each other in the tank, and a series of hollow second electrodes of opposite polarity to and interleaved between the planar first electrodes. The hollow second electrodes are substantially parallel to and spaced from each other and electrically in parallel with each other. An ion permeable separator is on the electrically active external surfaces of the hollow second electrodes between the planar first electrodes and the hollow second electrodes. Reactant feed and gaseous product recovery, as well as bus bars, are above the electrolyte tank thereby allowing ease of assembly and disassembly and flexibility in the number of units to be utilized.

Abstract: A hanger bar for use in electrolytic copper or zinc production cells comprising a steel reinforced bar with extra reinforcement at the contact points, the extra reinforcement being provided by a block of copper or a copper alloy having greater strength than the remainder of the bar.

Abstract: Anodic deburring or brightening of steel articles is carried out in an alkaline solution containing, per liter of the solution, at least 200 grams of water, at least 300 grams of polyhydric alcohol and at least 200 grams of alkali sulphamate.

Abstract: Disclosed is a solid polymer electrolyte bipolar electrolyzer having an anode facing surface of the bipolar electrolyzer of enhanced resistance to crevice corrosion and hydrogen uptake.