Abstract: The invention relates to an electrolysis method that uses iron particles and an aqueous solution containing sodium hypochlorite. The method is characterized in that said method uses direct current, the iron particles form the anode (46) and the sodium hypochlorite concentration of the aqueous solution is at least 1 g/L. The invention further relates to a method and to a plant for the pretreatment of raw water for producing water that can then be easily treated in order to produce drinkable water or a so-called technical water that cannot be consumed but that can be used for household, agricultural or industrial applications such as cleaning, washing, laundry, flushing, garden watering or irrigation.

Abstract: The invention relates to an electrolysis method that uses iron particles and an aqueous solution containing sodium hypochlorite. The method is characterised in that said method uses direct current, the iron particles form the anode (46) and the sodium hypochlorite concentration of the aqueous solution is at least 1 g/L. The invention further relates to a method and to a plant for the pretreatment of raw water for producing water that can then be easily treated in order to produce drinkable water or a so-called technical water that cannot be consumed but that can be used for household, agricultural or industrial applications such as cleaning, washing, laundry, flushing, garden watering or irrigation.

Abstract: A method and apparatus for disinfecting sand with an electrolysate of sea water, whose concentration of chlorine equivalent is 200-2000 mg/l before redepositing sifted sand back on to the beach.

Abstract: In the electrolytic production of aluminum by electrowinning or electrorefining processes, cell components such as cathode current feeders which in use are normally covered with molten aluminum are made of a composite material of aluminum or an aluminum alloy or intermetallic compound with an aluminum oxycompound, usually alumina, and possibly containing minor amounts of additives such as borides carbides, nitrides or oxides. The composite material, which remains mechanically stable and electrically conductive at 1000.degree. C., may be prepared by hot pressing powders at 1000.degree.-1700.degree. C. possibly after surface treating the alumina to improve wettability by molten Al. The components are optionally coated, e.g. with TiB.sub.2. The composite materials are also useful as non-current carrying components, including separator walls, weirs, packing elements and baffles.

Abstract: A cermet is produced by providing a bulk reaction mixture of particulate reactants which react to produce a self-sustaining ceramic body, and carrying out the reaction with the bulk reaction mixture in contact with molten metal which moderates the reaction and infiltrates the resulting ceramic body. The method is particularly applicable for boride-based ceramics infiltrated with aluminum, suitable as components of electroytic cells for the production of aluminum by molten salt electrolysis.

Abstract: Metals such as lead, silver, copper, calcium, antimony, cadmium, nickel and zinc are electroplated onto a film-forming metal substrate from the group of aluminium, titanium, zirconium, niobium, molybdenum, tungsten, tantalum and alloys thereof, using an etching/electroplating solution comprising ions of the metal(s) to be plated, optionally alkali metal ions, aluminium halide and an aromatic hydrocarbon. Surface oxide is removed from the film-forming metal substrate by reaction with the aluminium halide and the metal(s) in solution to form soluble complexes, this possibly being assisted by anodization. This is followed by cathodically connecting the substrate and passing current to electroplate the metal(s) onto the oxide-free surface, directly in the same etching/electroplating solution.

Abstract: An electrode in particular an oxygen-evolving anode for metal electrowinning from an acid electrolyte comprises a body of aluminum or other metal coated with lead or a lead alloy by electroplating preferably from a non-aqueous electrolyte. The substrate can be a sheet of aluminium or compacted particles of aluminium plated with lead or a lead alloy. A sheet of lead or lead alloy is clad to the electroplated substrate and advantageously an electrocatalytic material such as surface-activated valve metal sponge is applied to the surface of the lead or lead alloy.

Abstract: The present invention provides a method for preparing an aqueous treatment solution containing at least hydrogen peroxide ions and hydroxyl ions in a predetermined concentration.The method according to the invention consists of using an electrolytic cell comprising a porous cathode, and circulating simultaneously in contact with said porous cathode an oxygen-containing compressed gas and a weakly alkaline initial aqueous solution, so as to cause the formation of hydrogen peroxide ions and hydroxyl ions by reduction of the oxygen, said circulation being continued until said solution attains said predetermined concentration, said solution having attained said concentration then being discharged to the outside for use as the treatment solution in various applications.Application in particular to bleaching, pollution control etc.

Abstract: Metal is electrodeposited on conductive granules in apparatus comprising a helical channel with a cathode at its radially outer side and an anode at its radially inner side. A suspension of the granules in an electrolysis solution is fed tangentially into an end of the channel so that the granules are urged by centrifugal force against the cathode and form a mass moving along the channel to its outlet. The emerging granules are separated from the used solution in a cyclone and the solution is recirculated along the axis of the helix.

Abstract: Heterogeneous enzymatic catalysis is carried out by means of an enzymatic electrode comprising an enzyme fixed to a solid, conductive support. To govern the reaction rate during continuous transformation of a substrate, the enzymatic activity is regulated by adjusting the potential of the enzyme support so as to transform the substrate at a given rate. The electrode is provided with a particulate enzymatic mass operatively associated with an inert working electrode for contact with this mass to thereby subject the particles thereof to the adjustable potential. Continuous movement of a liquid reaction system is produced so as to provide intimate contact thereof with each particle of the mass, which may be arranged as a fixed bed, an agitated bed or a fluidized bed. The potential of the enzyme support is caused to continually alternate between two levels while adjusting the mean value thereof so as to maintain a corresponding mean enzymatic activity for transforming the substrate at the desired rate.