Abstract: Process for the manufacture of alkali metal hydroxide, according to which an electrodialysis cell containing three compartments is used, an aqueous alkali metal halide solution is circulated in a saline compartment of the cell, delimited between an anionic membrane and a cationic membrane, an alkali metal halide is introduced into an acidic compartment of the cell, delimited between the anionic membrane and a cationic face of a bipolar membrane and an aqueous alkali metal hydroxide solution is extracted from an alkaline compartment of the cell, delimited between the cationic membrane and an anionic face of the bipolar membrane.

Abstract: Electrical conductor comprising a metallic bar (1) jacketed with a sheath (2) made from a metal different from that of the bar, in which the bar (1) exhibits at least one longitudinal groove (3, 3') containing a bead (4, 4') made from the same metal as the sheath (2), welded to the bar (1), and the sheath (2) exhibits an opening opposite the bead (4, 4'), the said opening containing a metallic mass (9, 9') welded to the bead (4, 4') and to the sheath (2). The conductor finds one application in electrodes comprising a metallic plate longitudinally fixed to an electrical conductor.

Abstract: Process for the manufacture of alkali metal sulphide, in which an electrolysis cell is used in which a membrane which is selectively permeable to cations separates an anode chamber containing an anode from a cathode chamber containing a cathode, an electrolyte containing alkali metal is electrolyzed in the anode chamber and an aqueous solution of alkali metal polysulphide is electrolyzed simultaneously in the cathode chamber.

Abstract: Cathode for the electrolytic production of hydrogen, having an active surface which comprises a nickel substrate and a coating film of dendrites of nickel or cobalt.This cathode can be used in a cell for the electrolysis of sodium chloride brine.

Abstract: An electrically conductive substrate is coated with a material containing an unsintered powder of a metal active for electrochemical proton reduction and colloidal silica and the said material is heated on the substrate successively in an oxidizing atmosphere and then in a reducing atmosphere.The electrode may be employed as a cathode for electrolytic production of hydrogen in an alkaline medium.

Abstract: Permeable diaphragm for a cell for the electrolysis of aqueous solutions of an alkali metal halide, the diaphragm being made from a hydrophobic organic polymeric material containing an oxide of a metal chosen from amongst group IIa of the periodic table of the elements, the oxide being in the form of particles having a mean diameter of at most 0.5 .mu.m.

Abstract: The invention relates to a cathode for the electrolytic production of hydrogen.The cathode comprises an active surface consisting of a metal oxide obtained by the thermal decomposition of a thermally decomposable compound of a metal chosen from amongst cobalt, iron, manganese or nickel.The cathode is particularly suitable for the electrolysis of aqueous sodium chloride solutions in cells with a permeable diaphragm.

Abstract: The invention relates to a process for the electrolytic production of hydrogen in an alkaline medium.The process consists in using a cathode, the active surface of which essentially consists of an oxide compound of the spinel type.The process is suitable, in particular, for the electrolysis of aqueous solutions of sodium chloride in cells with a permeable diaphragm.

Abstract: Pervious diaphragms for cells for the electrolysis of aqueous solutions of alkali metal halides and the method of manufacture thereof are disclosed; the pervious diaphragms comprise inorganic fibers and a polymer which is selected from polyelectrolytes insoluble in aqueous solutions of alkali metal halides.

Abstract: A diaphragm cell for use in the electrolysis of an aqueous solution of alkali metal chloride. The cell is provided with a chamber divided by a diaphragm into an anode compartment having at least one anode therein and a cathode compartment having at least one cathode therein. The cathode has a catalytic surface different from the active surface of the anode. The cathode surface is made of a material which catalyses the decomposition of hypochlorite ions.