Abstract: Novel sintered electrodes comprised of a self-sustaining matrix of sintered powders of yttrium oxide and at least one electroconductive agent, the electrode being provided over at least a portion of its surface with at least electrocatalyst useful for electrolysis reaction and bipolar electrodes with the said matrix and electrolysis cells containing the said electrodes.

Abstract: The invention discloses a method of controlling the size distribution of electroconductive particles constituting a particulate electrode in an electrochemical cell. Particles are extracted from the particulate electrode and are subjected to elutriation, the flow of elutriating fluid being such that particles larger than a predetermined size settle against the flow of fluid, while the other particles are carried along by the elutriating fluid and are eventually returned to the electrochemical cell.

Abstract: Novel electrodes consisting essentially of a valve metal base or other electrically conductive material which is corrosion-resistant to the anodic conditions having on at least a portion of its outer surface an electrocatalytic coating of .beta.-manganese dioxide chemi-deposited by thermal decomposition of an alcoholic solution of manganese nitrate which are useful in electrolysis processes in which oxygen is formed at the anode such as electrowinning of metals from sulfuric acid solution or in the electrolytic production of perchlorates. Also included are electrodes where the .beta.-manganese dioxide coating is activated by doping with up to 5% by weight of at least one metal of the groups IB, IIB, IVA, VA, VB, VIB, VIIB, and VIII of the Periodic Table excluding the platinum group metals, gold and silver or activated by irradiation of the .beta.-manganese dioxide coating and/or stabilized by the addition of up to 20% by weight of silicon dioxide, tin dioxide or .beta.

Abstract: A novel process for the preparation of an alkali metal halate by electrolysis of an aqueous alkali metal halide solution comprising passing an alkali metal halide solution upwardly through a plurality of bipolar electrolysis units while passing an electrolysis current therethrough at a temperature of 90.degree. to 110.degree. C and at a current density to volume ratio of 15 to 30 A/liter to convert at least a portion of the alkali metal halide to alkali metal hypohalite, passing the resulting electrolyte while venting the hydrogen formed to a reaction zone whose volume is sufficient to provide a residence time to substantially complete the conversion of the alkali metal hypohalite to alkali metal halate and recovering the said halate from the electrolyte and an apparatus for performing the said process.

Abstract: Improved cathode starting blanks for metal electrowinning are produced when valve metal sheets are coated with a thin layer containing either silver or silver-valve metal alloys, particularly silver-yttrium alloys, and/or oxides thereof. Said blanks are used in the electro-deposition of strippable metal coatings such as in electrowinning and/or electro-refining of metals. The improved method of recovering a metal from an electrolyte using these cathode blanks and the electrowinning cells containing said cathode blanks are also a part of the invention.

Abstract: Electric storage batteries with titanium or other film forming metal anodes and cathodes are provided. The anodes are coated with mixed oxide coatings of a film forming metal oxide containing a platinum group metal oxide catalyst, which coatings may contain oxides of other metals to alter the breakdown voltage and increase the oxygen overpotential of the cathodes while preserving a low bromine and chlorine overpotential. The cathodes may be uncoated titanium or other film forming metals or film forming metals with a silver coating thereon. Bipolar film forming metal cathodes and anodes are provided carrying a mixed oxide coating on the cathodic face and either no coating or a silver coating on the anodic face. The invention is applicable to all types of electric storage batteries, either primary or secondary, and multiple batteries may be connected in series or in parallel to provide the desired amperage and voltage characteristics.

Abstract: Novel vertical multiunit electrolyzers with bipolar metallic electrodes for the electrolysis of halide containing electrolytes to produce oxidized halogen compounds and to a novel electrolysis of electrolytes which is designed to produce a gas lift effect to sweep solid deposits off the electrodes and out of the electrolyzer.

Abstract: There is disclosed an electrochemical apparatus including two or more electrochemical cells arranged in series. Each of the cells has at least one particulate electrode and is separated from its adjacent cells by a bipolar member which constitutes a current feeder for at least one particulate electrode. The apparatus is particularly useful in processes for the electrodeposition of metal onto the particles of a particulate cathode.