Abstract: A metal amalgamatable with mercury, gold in particular, is extracted from a slurry in which it is dispersed in low concentration, in particular from alluvial sands, by contact with mercury the surface of which is continuously freed of the sulfides which form thereon as a secondary process and is renewed continuously by electrolytic deposit of mercury.

Abstract: The invention resides in an apparatus for the decontamination of radioactivated metallic waste by the electrolytic oxidation-reduction with an aqueous nitric acid solution containing trivalent cerium ions, i.e. the step of converting the trivalent cerium ions into tetravalent cerium ions through electrolytic oxidation and the step of dissolving the surface layer of the radioactivated metallic waste by oxidizing it with the electrolytic solution now vested with the oxidative power of the freshly produced tetravalent cerium ions and, at the same time, effecting regeneration of the tetravalent cerium ions.

Abstract: An electroplating system with improved water use efficiency and unique waste water treatment which enables operation without access to public sewers thereby permitting compliance with governmental regulations regarding disposal of waste water. Water use efficiency is achieved by means of limited use of overhead water sprays, multiple rinse tank backflow to the prior process tank and water evaporation from said process tanks. In addition, all waste water not returned to the prior process tank locally at each plating subassembly is transferred to an inplant sump for common evaporative treatment.

Abstract: An electroplating solution recovery system is disclosed which includes an electroplating tank containing an electroplating solution and one or more rinse tanks containing rinse solutions. A tubular interconnection extends between a first of the rinse tanks and the electroplating tank and is operative for transferring rinse solution from the first rinse tank to the electroplating tank by a siphoning process when the level in the plating tank is significantly lower than the level in the rinse tank. Additional tubular interconnections extend between the other rinse tanks for interconnecting them in series relation so that the solution in the tanks is automatically replenished as it is consumed, the solution level in the last tank in the series, however, being replenished from a continuous water supply. Maximum recovery of plating solution is assured by the system, and the pollution levels in the overflow effluent from the last rinse tank are minimized.

Abstract: A method and apparatus for rinsing electroplating solution from the surfaces of articles so that substantially complete recovery of the electroplating solution is achieved. The apparatus is preferably receivable on a wall of an electroplating tank and comprises an open housing-like structure having a splash wall and an open trough beneath the splash wall, and a rack for supporting at least one plated article in front of the splash wall above the trough. For use of the apparatus in accordance with the method, an article is supported on the rack in front of the splash wall, and a rinse solution, such as water, is sprayed onto the article in order to rinse electroplating solution from the surfaces thereof. The rinse solution and any plating solution intermixed therewith gravitate downwardly from the article and the splash wall and are received in the trough and then transferred to the plating tank.

Abstract: Chlorine dioxide is produced by electrolysis of a solution of chlorite and by using a compact apparatus which provides continuously a uniform concentration of chlorine dioxide, which can be operated easily, which discharges a spent electrolyte that can be treated easily and which achieves highly efficient use of chlorite and high current efficiency.

Abstract: A process for the production of sodium chlorate comprising electrolyzing an aqueous sodium chloride solution in a diaphragmless sodium chlorate cell, characterized in that an aqueous sodium chloride solution containing, as impurities, calcium, magnesium, barium and the like is contacted with a chelating ion exchange resin to remove the impurities and the resulting saline solution is supplied into a diaphragmless sodium chlorate cell, thereby enabling sodium chlorate to be produced at a stable electrolytic voltage.

Abstract: In an electrolysis cell, molten alkali hydroxide is decomposed into products which include alkali metal and water. The water dissolves in the electrolyte where it is decomposed by electrolysis or by reaction with alkali metal thereby reducing efficiency of the cell and yield of the alkali metal.According to the process of the invention, the electrolyte with water dissolved therein is drawn through openings in an anode, is depleted of the dissolved water by a dehydrating means which is separate from the cell, and the dehydrated electrolyte is returned to an anolyte portion of the operating electrolysis cell for further decomposition.According to the apparatus of the invention, the anode comprises a plurality of parallel elongated electrodes which alternate with parallel channels. The electrolyte flows from a return channel, over an electrode, and through a withdrawal channel for the depletion of water and return to operating portions of the electrolysis cell through the return channels.

Abstract: A method and apparatus for reducing electrowinnable metal ion concentration to a low level in a process stream and recovering the metal electrolytically. Low concentration metal ions from the process stream are recovered in an ion exchanger and then recaptured from the ion exchanger into a relatively small volume of regeneration fluid. The regeneration fluid, pregnant with the metal ions, is electrolyzed in a particulate bed electrolytic cell to a relatively low level of metal ion concentration, and the regeneration fluid is then available for reuse in a further ion exchanger regeneration.

Abstract: The invention provides an on-stream method and apparatus for analyzing of the concentrations of chemical components in a bath, especially in an electroplating bath, contained in one or more processing tanks. Moreover, the information obtained by such analysis of a single bath or of multiple baths may be efficiently employed to control such concentrations in the bath or respective baths, for example, by controlling the addition of one or more additives. The apparatus comprises a multi-steam sampling value and a computer for controlling the operation of said value. The computer also controls means for adding material to the baths in order to maintain the parameters thereof.

Abstract: An automatic electroplating apparatus which comprises a power-driven larger rotary drum containing plating solution therein, a plurality of power-driven smaller rotary drums disposed within the larger drum and immersed in the plating solution, and a plurality of through holes formed in each of the smaller drums for permitting the plating solution to interflow between insides of the larger and the smaller drums, each of the smaller drums being arranged so as to rotate on its own axis and synchronously to revolve orbitally around a vertical axis of the larger drum.

Abstract: An electrolytic cell comprising a rectangular tank divided into a plurality of adjacent compartments by a plurality of spaced apart parallel electrode plates. The outboard electrodes may form one pair of the opposite tank walls. Alternate electrodes are of opposite polarity. The intermediate electrodes terminate short of the tank ends so that the slurry or solution may pass around both ends of the electrode. An agitator is mounted in each compartment. The agitators are shaped and positioned to direct a predetermined volume of slurry against each electrode, the amount being directed against the cathode and anode respectively may be equal or unequal depending on the metal being recovered and the chemical reaction required at the electrode.

Abstract: This disclosure relates to a device for eliminating impure ions in chromium plating bath such as Sargent bath or Chromate bath. Also, the disclosure relates to specific anode used therein and chromium plating system combined with the device. According to the device, the impure ions such as those of Fe, Ni, Cu, Pb, Zn, etc. are eliminated from the bath in the form of slime which mainly precipitates on or around the anode under the condition of DC 1 to 10 volt between the electrodes and anode current density of 1 to 100 A/dm.sup.2.

Abstract: Metal articles are sequentially treated in a surface-treatment tank containing a solution of surface-treating agents, then rinsed in a plurality of series-connected water-washing tanks.The contents of the surface-treatment tank and water-washing tanks are cycled to a concentrator by way of a heat exchanger and concentrated solution is returned to the surface-treatment tank. Steam is condensed in the heat exchanger to cause evaporation of water in the concentrator and the steam condensate is transferred to the water-washing tanks.