Abstract: An electro-chemical machine supplies pulses to a spaced workpiece and electrode in a working tank through an electrolyte in order to finish the workpiece, while eliminating electrolytic products produced in a gap between the workpiece and electrode by supplying clean electrolyte to the gap. This machine includes: an electrolyte filtering apparatus for removing dirty electrolyte containing electrolytic products from the working tank and filtering it; an electrolyte supplying apparatus for intermittently supplying the filtered electrolyte to the gap through a supply hole formed in the electrode; and a power supply apparatus for supplying the pulses to the workpiece and electrode when the flow of electrolyte to the gap stops. Clean electrolyte can be supplied to the gap almost simultaneously with the removal of dirty electrolyte, and then the finishing work is started. A glossy mirror surface on the workpiece can be automatically obtained by repeating those operations.

Abstract: A process and an apparatus for coating a printed circuit board in a horizontal position in a coating chamber by flooding the chamber while the printed circuit board is suspended horizontally in a coating chamber between at least two anodes with adjustable power applied to the anodes provides for a uniform coating of the board and the aperture therein.

Abstract: An electrode is positioned with a predetermined gap between the electrode and a surface of a work in an electrolyte tank. Pulses are applied to the electrode. Electrolyte including residual products is discharged from the tank. Clean electrolyte is supplied to the electrolyte tank for next machining. After predetermined time, pulses for the next machining are applied to the electrode.

Abstract: An electrolytic pool chlorinator produces chlorinated pool water that is added to the cathode chamber to continuously dilute the caustic concentration of the catholyte before being returned to the pool. The cathode chamber includes a series of baffle plates between the primary cathode and the chlorinated pool water entry port in order to maintain the hydroxyl ion concentration near the primary cathode high enough to provide good current efficiency, yet low enough to avoid significant back-migration of hydroxyl ions. The baffle plates also cause metal hardness ions such as calcium to precipitate before reaching the primary cathode. A negatively-charged second cathode spaced apart from the primary cathode also helps to prevent precipitation of metal hardness ions upon the primary cathode.

Abstract: A cathode (10) surrounding an anode (14) stands on the bottom (11) of a tank (12) that can hold a varying volume of liquid (25) for electrolytic processing. A pump (18) circulates liquid from a drain (17) outside the cathode into a space between the cathode and anode; and although liquid can drain from inside the cathode back into the tank under the bottom of the cathode, the flow rate of the pump is larger so that the pump fills the cathode to overflowing, independently of the level of liquid in the tank. This allows widely varying batch sizes to be processed in a simple and inexpensive way; and it ensures that when tank (12) is drained, liquid (25) within cathode (10) also drains.

Abstract: The invention is a device and method for electroplating a metal workpiece having axial symmetry, such as a circular workpiece. In this invention the workpiece, which is the cathode, is rotated inside an anode structure submerged in the plating solution. Part of the rotating cathode continuously moves through a region of intense current fluxes created by passing DC current between the anode and cathode. The rotating cathode stirs the plating solution, which speeds up the plating rate. At the same time, with only part of the cathode passing continuously through the intense current flux region, the deposition process is periodically slowed down and intensified.

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 apparatus for the production of hydrogen peroxide is disclosed. In one preferred embodiment, high surface area circulating elements derivatized with a quinone catalyst are reduced in an electrolytic cell where the cathode may also be derivatized with a quinone catalyst and a solution quinone at low concentration is used as a mediator. Once reduced, the circulating elements are separated and used to form hydrogen peroxide from molecular oxygen in an aqueous, electrolyte-free, environment. The circulating elements can be cycled repeatedly. Particular, novel naphthoquinone compounds are also disclosed.

Abstract: Apparatus for removing radioactive contamination from metal objects is disclosed, consisting of three of three separate pieces. The first is an electro-polishing tank, pump and filter assembly, ventilation duct and filter assembly, and DC power supply. The second is a rinse tank and a pump and filter assembly therefor. The third is a divot crane. The electro-polishing tank assembly and the rinse tank assembly are each separately mounted on pallets to facilitate moving. The filter systems of the electro-polishing tank and the rinse tank are designed to remove the radioactive contamination from the fluids in those tanks. Heavy items or highly contaminated items are handled with the divot crane constructed of stainless steel. The electro-polishing tank and the rinse tank are also made of stainless steel. The ventilation system on the electro-polishing tank exhausts acid fumes resulting from the tank heaters and the electro-polishing process.

Abstract: Nitrates, such as alkali metal nitrates and ammonium nitrate, are electrolytically reduced to the corresponding nitrites by a process wherein an aqueous solution containing a nitrate is supplied into a cathode chamber of an electrolytic cell including cathode and anode chambers separated by a cation exchange membrane and an electric current is applied to the electrolytic cell, while maintaining the pH of the aqueous solution at a value of at least about 4. This process can be advantageously applied not only to the manufacture of nitrites but, also, to the treatment of waste nitrates. In the treatment of waste ammonium nitrate, the ammonium nitrite so formed is conveniently further treated by subjecting the electrolytically reduced catholyte to thermal decomposition outside the electrolytic cell, and removing the so formed nitrogen and water from the reaction system.

Abstract: A simplified, safe, fast and economical method of refining gold and a versatile apparatus for practicing the method are disclosed. The process and the apparatus are ideally suited for reclaiming substantially pure gold from gold jewelry and gold alloy scrap. Gold alloy to be refined is inquarted with a non-ferrous metal or metal alloy and the resulting gold alloy is cast into slab anodes which are suspended in an electrolytic cell containing a mild nitric acid solution as the electrolyte. The cell includes a stainless steel container cathode to retain gold mud or slime precipitated from the slab anode during the electrolytic process. If platinum and/or palladium are present in the gold alloy to be refined inquartation with silver is carried out, and these platinum metals are dissolved in the electrolyte solution. If iridium or any other platinum metals are present in the gold alloy to be refined, they will remain in the resulting gold mud and subsequent treatment with aqua regia is necessary.

Abstract: The washings in a plating process is continuously circulated to an electrolytic cell in communication with the washing vessel. A metal contained in the washings is deposited on a cathode of the electrolytic cell.

Abstract: A method and apparatus for treating aqueous rinse mixtures containing organic brightener additives having sulfur therein of nickel electroplating processes by adding acid to the rinse mixture, passing the rinse and acid mixture through a carbon filter to remove the brighteners and decrease the sulfur content of the mixture, and adding the filtered mixture to and reusing it in the semi-bright and bright nickel baths of the nickel electroplating process.

Abstract: Method for treating metal containing waste water employing a vessel containing the waste water in which there is provided at least one anode and a cathode comprised of a plurality of electrically conductive elements and in which the waste water is subjected to electrolysis during which the cathode elements are being moved. The cathode elements are provided in the form of rods which are arranged in the vessel by means of at least two holding devices so that the rods extend parallel to one another and can be moved in the holding devices relative to one another. The holding devices are moved during the electrolysis process so that the rods strike one another again and again at spaced intervals. An apparatus is provided for practicing the method.

Abstract: Method for recovering metals from cyanide and hexavalent chromium plating baths comprising immersing plated articles in a reclaiming bath containing an aldehyde or an aldehyde percursor, and optionally an oxidizing agent, to precipitate the excess metal in the residual plating bath in the form of free metal or metal hydroxide and to decompose the cyanide and to reduce the hexavalent chromium to trivalent chromium. The plating bath and reclaiming bath are regenerated. Apparatus is provided to effect this process.

Abstract: Method for recovering metals from cyanide and hexavalent chromium plating baths comprising immersing plated articles in a reclaiming bath containing an aldehyde or an aldehyde percursor, and optionally an oxidizing agent, to precipitate the excess metal in the residual plating bath in the form of free metal or metal hydroxide and to decompose the cyanide and to reduce the hexavalent chromium to trivalent chromium. The plating bath and reclaiming bath are regenerated. Apparatus is provided to effect this process.

Abstract: A device for applying by way of electrolysis a metal coat onto a cylinder-shaped body, especially for coppering a cylinder, with an outer tank and a process tank arranged above the outer tank, as well as with a circulation and filtering apparatus for the electrolyte. Two anode supports are installed in the process tank and connected to spray pipes. The supports are controlled by adjusting means arranged above the process tank. This latter is designed at its longitudinal ends with pockets whose inner walls are fitted with self-acting sealing elements for the projecting shaft ends of the cylinder.

Abstract: Apparatus for continuous electrowinning of copper bearing slurries, including an electrowinning cell wherein a slurry composed of a suitable electrolyte and a copper-bearing solid material, is subjected to the simultaneous reactions of dissolving the copper material and plating out elemental copper as a relatively pure copper product. The apparatus and process also includes means to purify the copper-bearing material before passage to the electrowinning cell so as to prevent contamination of the electrolyte in the cell and, also, a means to recover sulfur which is released during the electrowinning and unreacted copper material.

Abstract: An apparatus is provided wherein, in a static condition a lower phase liquid is covered by an upper phase liquid which is non-miscible with the lower phase liquid. In operation, the upper phase liquid is removed from a selected area of the lower phase liquid by raising the upper phase liquid to pass over a weir into a second chamber. Simultaneously a portion of the lower phase liquid is circulated over a second weir and caused to pass through a portion of the upper phase liquid to provide a scrubbing or cleansing action. When operation ceases the liquids automatically return to the static condition levels wherein the lower phase liquid is completely covered by the upper phase liquid. During operation articles or materials may be caused to enter and exit the lower phase liquid in the selected area, for treatment therein without contacting the upper phase liquid. The apparatus is useful in cleaning, degreasing, plating, pre-plating treatments and the like.

Abstract: The present invention discloses an improved electrode assembly and electrochemical drilling machine for drilling small diameter holes. The electrode assembly includes a metallic working electrode tube having an inlet end for electrolyte entry and an outlet end for drilling, the tube having preselected dimensions to provide the desired diameter and depth of hole. The assembly also includes a filter tube one end portion of which defines a plurality of individual access openings for electrolyte entry from an electrolyte source, each opening having a smaller cross section than the bore of the working electrode tube to filter out particles in the electrolyte which could clog the electrode tube and the other end of which is in fluid communication with the inlet end of the electrode tube for delivering filtered electrolyte thereto.

Abstract: An electrolytic solution containing chromium (VI) compound is admixed with an aqueous solution of ferrous nitrate or ferrous chloride and pH of the mixture is adjusted to 8 to 8.5 with an aqueous solution of sodium hydroxide and the sludge containing chromium (III) compound is separated.

Abstract: An improved filter assembly is advantageously utilized in association with an apparatus which electrolytically removes material from a workpiece. The apparatus includes one or more nozzles each of which tapers from a relatively large inside diameter to a relatively small inside diameter to direct a flow of electrolyte toward a workpiece. The improved filter assembly is utilized to remove particles from the electrolyte before it is conducted to the nozzles. The filter assembly includes a housing which is divided into an inlet chamber and an outlet chamber by a transverse wall. A plurality of tubes extend through the wall and are effective to conduct electrolyte from the inlet chamber to the outlet chamber along a plurality of spaced apart flow paths. Each of these tubes has an inlet end portion with a cross sectional area which is less than the minimum cross sectional area of each of the nozzles.

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: A tank is provided in which a lower solution is covered by an upper solution which is non-miscible with the lower solution. In the operating condition the apparatus automatically uncovers a small area of lower solution by raising the level of lower solution in that area and having the upper solution pass over a weir into a holding chamber. When the operating condition ceases, the solution automatically returns to the same levels as in the static condition.

Abstract: A water recycle treatment system comprising two main treatment sub-systems for treatment of contaminated water from a plurality of concentrated solutions and rinse baths to separate out the impurities therein. A first sub-system treats less concentrated solutions used for the rinse baths by channeling the flow therefrom to a first neutralizing tank which provides for pH control to produce a mixed output solution having a substantially constant pH factor, which is filtered to remove gross particles, the filtered solution being cooled in a holding tank and passed through a reverse osmosis process and carbon bed to produce clean water. The second sub-system treats highly concentrated solutions obtained from a plurality of chemical processes, mixes them in a second neutralizing tank which is utilized to produce a substantially constant pH output, which is fed to an evaporator to precipitate the metals and salts in sludge and also forms a water vapor output.

Abstract: A method of making a flexible seamless brass cylinder which comprises forming a thin continuous layer of brass of uniform thickness on the surface of a cylindrically shaped vertical rotating mandrel by electrolitic deposition in an electrolic bath containing at least one brass anode. Apparatus for carrying out the electroforming process is also disclosed.

Abstract: This method of copper plating aluminum and aluminum alloy wire or strip applies an adherent and ductile plating while the wire is moving rapidly and continuously through the plating apparatus. An improved chemical zincating step followed by a copper pyrophosphate strike plating, within critical thickness limits, reduces the plating time and makes practical plating of the wire while moving at speeds of about 100 feet per minute or more in relation to the processing solution.