Abstract: The process for preparation of semipermeable polymer layers with ion-exchanging and ion-conducting capabilities comprises the steps of making and depositing a polymer layer in situ by electrochemical polymerization on an electrically conductive substrate and subsequently cross-linking, by heating or irradiating. The electrochemically formed polymer layers are built up of poly(oxyphenylene) or poly(naphthylene) chains, in which the aromatic units contain the ion-exchanging and ion-conducting groups. These polymer layers are suitable for use as a semipermeable membrane in an electrode/membrane unit, as a selective layer or as a component of a selective layer of potentiometric and amperometric sensors and as a solid polymer electrolyte in electrochemical cells.

Abstract: A geothermal brine containing recoverable metals is contacted with at least two electrodes, across which an electrical potential is applied to cause the metals to deposit upon said electrodes. The invention is particularly useful for the recovery of iron, zinc, lead, and manganese from a brine from a geothermal aquifer such as is found at the Salton Sea in California.

Abstract: A vanadium electrolytic solution containing highly concentrated and dissolved vanadium is produced by a method wherein a vanadium compound selected from the group consisting of ammonium metavanadate and vanadium pentaoxide is subjected to a reduction operation in the presence of inorganic acids. At this time, by repeating the addition of the concentrated inorganic acids and the vanadium compound, a tetravalent and pentavalent vanadium solution of 3.4 mol/l is obtained.In addition, the resulting vanadium electrolytic solution is electrolyzed, whereby tetravalent vanadium is reduced to be trivalent on the negative electrode and is oxidized into pentavalent vanadium on the positive electrode, and then pentavalent vanadium is reduced into tetravalent vanadium by a reducing agent to form a discharged couple of trivalent and tetravalent vanadium, and an electrolytic solution is obtained which is capable of being charge-discharged.

Abstract: Methods for the electrolysis of aqueous solutions of alkali metal carbonates and bicarbonates for the production of alkali metal hydroxides at current efficiencies of >85 percent without the simultaneous co-production of halogen or acid can be performed at very low, commercially attractive cell voltages and at high current densities in single or two solution compartment cells with carbon dioxide as the only substantive co-product by maintaining cell pH at >7. The methods are also especially suitable for retrofitting existing chlor-alkali facilities for shifting the balance of production in favor of caustic soda at peak demands. The methods may also be performed with fuel cell configurations for even more attractive operating economics.

Abstract: An aqueous solution of chloric acid and alkali metal chlorate is produced in an electrolytic cell having an anode compartment, a cathode compartment, and at least one ion exchange compartment between the anode compartment and the cathode compartment.

Abstract: A process which incorporates the recovery of silver from photographic film into the recovery of silver from photographic development waste solution is provided. In the process, a silver bearing emulsion layer coated on the surface of the photographic film is dissolved in the waste solution which is in turn subjected to an electrolysis treatment to recover metallic silver therefrom.

Abstract: An electrochemical process for the production of sulphuric acid and sodium hydroxide by the electrolysis of an aqueous solution of sodium sulphate in which the concentration of the aqueous sodium sulphate solution which is electrolysed is greater than that of a saturated solution of sodium sulphate under neutral conditions and at the temperature employed.The process may be effected in a two-compartment electrolytic cell comprising an anode compartment and a cathode compartment separated by a cation-exchange membrane.

Abstract: Nickel (or other transition metal) contaminated with about 5 ppm technetium is decontaminated by dissolving the nickel and the technetium into an aqueous acid solution while introducing a graphite or activated carbon powder into the acid to immediately adsorb the dissolving technetium. The technetium-contaminated powder is separated from the aqueous acid solution and the nickel is then electrowon from the solution. The depleted acid solution is then recycled back to the dissolution step.