Abstract: The present invention generally provides an apparatus and method for removing contaminants from a plating solution. The apparatus generally includes a plating cell having an electrolyte inlet and an electrolyte drain, an electrolyte storage unit in fluid communication with the electrolyte inlet, and an electrodialysis chamber in fluid communication with the electrolyte drain, wherein the electrodialysis chamber is generally configured to receive a portion of used electrolyte solution and remove contaminants therefrom. The method generally includes supplying an electrolyte solution to a copper plating cell, plating copper onto a substrate in the plating cell with the electrolyte solution, removing used electrolyte solution from the plating cell, and refreshing a portion of the used electrolyte solution with an electrodialysis cell.

Abstract: The invention disclosed relates to an electrochemical process for decreasing high levels of organic contaminants in metal plating baths. The process involves breaking down the organic contaminants in an electrochemical cell by electrochemical oxidation. The electrochemical cell includes an anode comprising an active material which is stable at low (acid) pH and at the high electrical potential required to break down the organic contaminants by oxidation. Typical examples of such anodes include a valve metal substrate coated with doped tin dioxide, lead dioxide, or platinum-based materials, the latter in some instances being coated on a high surface area valve metal substrate.

Abstract: The present invention provides a method and system for electrochemically processing a workpiece surface using a process solution that is degassed and deoxygenated. A deoxygenation step of the process solution substantially removes dissolved oxygen from the process solution by utilizing a treatment gas. In a following degassing step, remaining oxygen, the treatment gas and other gases are removed from the process solution by degassing the deoxygenated solution in a degasser. After degassing, the process solution is used to electrochemically process the workpiece surface.

Abstract: Embodiments of the invention provide a method for removing contaminants from a plating bath contained in a weir-type plater during idle times. The method broadly includes positioning a lower portion of a substrate support assembly into the plating bath and rotating the substrate support assembly at a rotation rate of between about 1 rpm and about 60 rpm for between about 5 seconds and about 30 seconds to circulate the plating solution such that contaminants accumulating on the surface of the plating solution are urged to flow over a weir of the weir-type plater.

Abstract: The invention deals with the technical problem to devise a process for the extended use of electrolytes which economically ensures a high electrolyte quality without having to accept production interruptions for regeneration. Especially, it is envisaged to conduct the process for the precipitation of non-glaring metal coatings in such a manner that work can proceed in three shifts for five days per week, without encountering production interruptions due to coagulation of the fine dispersal phase, respectively, and without the additional operating cost of a heating/cooling circuit. The invention solves the problem in that during the extended use of an electrolyte a partial flow is split off which is filtered and, if applicable, regenerated by the addition of active substances and reintegrated in the operating cycle.

Abstract: A method for galvanically depositing nickel, cobalt, nickel alloys or cobalt alloys in a galvanic bath includes using electrolytes containing nickel compounds or cobalt compounds. At least one anode and at least one cathode of the bath are subject to periodic current pulses. The IA/IC ratio of the anode current density IA to the cathode current density IC is selected to be greater than 1 and smaller than 1.5, where the anode current density IA and the cathode current density IC are defined as current densities with respect to a deposition body on which deposition occurs during the application of periodic current pulses where the deposition body serves as anode and cathode respectively. The charge ratio QA/QC=TAIA/TCIC of the charge QA, transported during anode pulse of duration TA, to the charge QC transported during a cathode pulse of duration TC, is between 30% and 45%.

Abstract: Disclosed are a process for producing a zinc oxide film comprising the steps of transporting a conductive long substrate via above at least one electrode comprised of zinc in an electrodeposition bath held in an electrodeposition tank and applying an electric field between the electrode and the conductive long substrate, thereby forming a zinc oxide film on the conductive long substrate, the process comprising a first step of forming the zinc oxide film on a part of the conductive long substrate; a second step of stopping the application of the electric field and the transportation; and a third step of bringing at least a region of a part of the conductive long substrate being in contact with the electrodeposition bath in the second step into non-contact with the electrodeposition bath, and an apparatus suitably used for the process. The process and apparatus enables high-quality zinc oxide films to be produced.

Abstract: A process for the removal of primarily iron impurities from acidic aqueous electrolytic solutions used in the electro-winning of copper is described. Strong base Type 1 ion exchange resin is used to remove acid from the solution resulting in a treated solution that contains only a small amount the original acid but all of the dissolved salts. This low acid treated solution is then processed using standard processes such as adjustment of the pH or oxidation potential to remove the iron impurities and the solution containing valuable process cobalt is returned to the electrolyte solution to continue the extraction of copper.

Abstract: Embodiments of the invention generally provide a method and apparatus for plating a metal on a substrate. The electrochemical plating system generally includes a plating cell having an anolyte compartment and a catholyte compartment, the anolyte compartment having an insoluble anode and an anolyte therein. The catholyte compartment generally includes a substrate support member and a catholyte therein. In addition, the plating cell generally includes an ion-exchange membrane disposed between the anolyte compartment and the catholyte compartment and a pump in fluid communication with the anolyte compartment, the pump configured to provide an anolyte to the anolyte compartment having a linear velocity of between about 0.5 cm/sec to about 50 cm/sec. The method generally includes supplying an anolyte solution to an anolyte compartment disposed in a plating cell having an anolyte compartment and a catholyte compartment.

Abstract: A real-time and in-line process control system maintains stable plating performance in copper electrochemical plating IC devices by using a real time, on-line programmable controller. Two or more valves to direct the flow of the electrolyte from the electroplating cell back to the reservoir connect an alternative carbon-filter as well as a mirco-filter. The programmable controller controls the operation of at least two in-line valves to direct the flow of the electrolyte within the system.

Abstract: Stainless steel coatings are formed on metallic substrates by employing the metallic substrates as a cathode in an aqueous electrolyte containing chromium, nickel and iron in specified concentrations or ratios. A coumarin leveling agent is preferably used. A product is obtained having a coating comprising, in weight ratios, weight ratios chromium 6-15:nickel 3-5:iron 32-39; the product has the appearance and many of the properties of monolithic stainless steel.

Abstract: The present invention provides a filtration method of copper electrolyte that can remove minute electrolytic by-products and dirt and may improve filtration efficiency by improving a conventional filtration method, the so-called precoating method. In a filtration method of copper electrolyte for removing electrolytic by-products and dirt which affect copper electrolysis, by passing copper electrolyte through a filter element precoated with a filtering aid, in the present invention, a precoated layer of a filtering aid is formed on a filter element in advance. Activated carbon preliminary treatment solution containing powdery activated carbon is passed through the filter element formed with the precoated layer, and is also circulated until no powdery activated carbon leaks from an outlet of the filter element, thus forming a powdery activated carbon layer on the precoated layer. Subsequently, the copper electrolyte is passed through for filtration.

Abstract: A method is disclosed for treating a flushing solution from an ion exchanger used in electroplating operations by co-precipitating or selectively precipitating out metal hydroxides derived from metal ions from the structures being plated in the electroplating bath, metal ions from the electrodes use in the electroplating bath and metal ions from the plating metal used in the electroplating bath, and a pH raising agent having a cation with a valence of at least 2. After the metals are precipitated out of the flushing solution, the flushing solution is aerated with carbon dioxide to precipitate out the cation from the pH raising agent as a carbonate. The carbonate precipitate is removed from the flushing solution and the resulting solution consists essentially of water that may be recycled for use in the electroplating plant or safely discharged into the environment.

Abstract: A method and apparatus for removing degraded organics from an electroplating solution by passing at least a portion of electroplating solution through a filter. The apparatus generally includes a deposition cell including a fluid inlet, a fluid reservoir, and at least one filter disposed between the reservoir and the fluid inlet. The apparatus may further include a control valve disposed between the fluid reservoir and the fluid inlet for passing at least a portion of an electroplating solution to a recovery stream including the at least one filter.

Abstract: The present invention generally provides an apparatus and method for removing contaminants from a plating solution. The apparatus generally includes a plating cell having an electrolyte inlet and an electrolyte drain, an electrolyte storage unit in fluid communication with the electrolyte inlet, and an electrodialysis chamber in fluid communication with the electrolyte drain, wherein the electrodialysis chamber is generally configured to receive a portion of used electrolyte solution and remove contaminants therefrom. The method generally includes supplying an electrolyte solution to a copper plating cell, plating copper onto a substrate in the plating cell with the electrolyte solution, removing used electrolyte solution from the plating cell, and refreshing a portion of the used electrolyte solution with an electrodialysis cell.

Abstract: The present invention provides a system and method for selectively removing one or more organic and also preferably one or more inorganic contaminants from plating baths. More particularly, the invented method relates to the use of a source of energy in combination with chemical oxidants, alone or in conjunction with a catalyst to oxidize organic contaminants in the plating bath to a level such that the electroplating bath can be recovered and reused after appropriate chemical adjustment. The oxidative treatment method may be a continuous process or a batch process that is performed in a single pass and the endpoint of the oxidative process detected by a sensor. Residual organics, if desired, and chloride ions in the bath are removed from the solution by a chemisorption or physisorption treatment.

Abstract: A system for use with a plating cell configured to plate objects in a plating process. At least one byproduct is created in a plating substance used in the plating cell. The system includes a purification system configured to remove at least a portion of the at least one byproduct from the plating substance. The purification system comprises at least a first processing vessel, a second processing vessel, and a flow path providing flow from the first processing vessel to the second processing vessel. The flow path may be configured such that the flow from the first vessel to the second vessel is caused by gravity. A method is also provided for removing at least a portion of at least one byproduct from a plating substance used in a plating cell.

Abstract: Disclosed are methods for analyzing additive breakdown products in electroplating baths as well as methods of controlling the presence of such breakdown products in electroplating baths.

Abstract: The object of this invention is a method by which arsenic is removed from sulfuric acid solution, in which the sulfuric add concentration is at least 300 g/l, at a temperature of 50-105° C. by reducing the arsenic in the solution with the aid of sulfur dioxide. The arsenic trioxide produced is crystallized from the sulfuric acid solution by cooling. The method is particularly suitable for use in connection with the electrolytic refining of metals, as in copper refining.

Abstract: A system for electroplating a semiconductor wafer is set forth. The system comprises a first electrode in electrical contact with the semiconductor wafer and a second electrode. The first electrode and the semiconductor wafer form a cathode during electroplating of the semiconductor wafer. The second electrode forms an anode during electroplating of the semiconductor wafer. A reaction container defining a reaction chamber is also employed. The reaction chamber comprises an electrically conductive plating solution. At least a portion of each of the first electrode, the second electrode, and the semiconductor wafer contact the plating solution during electroplating of the semiconductor wafer. An auxiliary electrode is disposed exterior to the reaction chamber and positioned for contact with plating solution exiting the reaction chamber during cleaning of the first electrode to thereby provide an electrically conductive path between the auxiliary electrode and the first electrode.

Abstract: A method of purifying an electrolyte by bringing the electrolyte into contact with a first effective surface of a separating unit that is permeable to contaminants to be removed from the electrolyte, and bringing a purifying liquid into contact with a second effective surface of the separating unit. A concentration level of contaminants in the purifying liquid is maintained to maintain a contaminant driving force gradient between the electrolyte and the purifying liquid so contaminants transfer from the electrolyte into the purifying liquid. An apparatus for purifying an electrolyte having a first volumetric region for holding the electrolyte, a second volumetric region for holding a purifying liquid, and a separating unit that is permeable to the contaminants to be removed from the electrolyte and which fluidically separates the first and second volumetric regions.

Abstract: The present invention provides a filtration method of copper electrolyte that can remove minute electrolytic by-products and dirt and may improve filtration efficiency by improving a conventional filtration method, the so-called precoating method. In a filtration method of copper electrolyte for removing electrolytic by-products and dirt which affect copper electrolysis, by passing copper electrolyte through a filter element precoated with a filtering aid, in the present invention, a precoated layer of a filtering aid is formed on a filter element in advance. Activated carbon preliminary treatment solution containing powdery activated carbon is passed through the filter element formed with the precoated layer, and is also circulated until no powdery activated carbon leaks from an outlet of the filter element, thus forming a powdery activated carbon layer on the precoated layer. Subsequently, the copper electrolyte is passed through for filtration.

Abstract: A method is disclosed for treating a flushing solution from an ion exchanger used in electroplating operations by co-precipitating or selectively precipitating out metal hydroxides derived from metal ions from the structures being plated in the electroplating bath, metal ions from the electrodes use in the electroplating bath and metal ions from the plating metal used in the electroplating bath, and a pH raising agent having a cation with a valence of at least 2. After the metals are precipitated out of the flushing solution, the flushing solution is aerated with carbon dioxide to precipitate out the cation from the pH raising agent as a carbonate. The carbonate precipitate is removed from the flushing solution and the resulting solution consists essentially of water that may be recycled for use in the electroplating plant or safely discharged into the environment.

Abstract: A process for controlling the micelle size distribution of an alkylene oxide dispersion in a nickel-plating electrolyte is used to maintain the electrolyte in a condition suitable for producing nickel coatings having a uniform satin finish in which finish characteristics such as roughness depth are maintained within desired limits. The process involves steps of removing a portion of the electrolyte from the electroplating bath, filtering the alkylene oxide from the electrolyte removed from the electroplating bath, adding alkylene oxide to the electroplating bath, and returning the filtered electrolyte to the electroplating bath. The process removes larger alkylene oxide micelles from the electrolyte and replaces them with smaller micelles to maintain a desired micelle size distribution.

Abstract: An electroplating formulation and process is provided for electroplating an iron layer onto an aluminum or aluminum alloy substrate. The method entails immersing an iron-containing anode and an aluminum containing cathode in an electroplating bath including boric acid in a concentration of at least about 50 grams per liter, and ferrous ions, and then applying electrical current to the cathode. A preferred electroplating bath solution includes the following: (1) Fe+2 having a concentration ranging from about 0.65 to about 2.5 moles per liter of solution; (2) at least one anion associated with the Fe+2 ion; (3) a reducing agent in an amount sufficient to prevent oxidation of Fe+2 to Fe+3; (4) Cl− in an amount sufficient to promote dissolution of the anode and increase the conductivity of the solution; (5) a wetting agent in an amount sufficient to prevent pitting of the aluminum electroplated surface; and (6) boric acid in a concentration of at least about 50 grams per liter.

Abstract: A system for electroplating a semiconductor wafer is set forth. The system comprises a first electrode in electrical contact with the semiconductor wafer and a second electrode. The first electrode and the semiconductor wafer form a cathode during electroplating of the semiconductor wafer. The second electrode forms an anode during electroplating of the semiconductor wafer. A reaction container defining a reaction chamber is also employed. The reaction chamber comprises an electrically conductive plating solution. At least a portion of each of the first electrode, the second electrode, and the semiconductor wafer contact the plating solution during electroplating of the semiconductor wafer. An auxiliary electrode is disposed exterior to the reaction chamber and positioned for contact with plating solution exiting the reaction chamber during cleaning of the first electrode to thereby provide an electrically conductive path between the auxiliary electrode and the first electrode.

Abstract: A process for electrochemical oxidation of aldehydes to esters is provided. The invention includes electrooxidation at a pH where an intermediate hemiacetal is favored, thereby providing for maximum selectivity to the desired ester and for maximum reaction efficiency. In particular, the invention provides for the electrooxidation of acetaldehyde to methyl acetate. The invention is illustrated with reference reactants native to the carbonylation process for the manufacture of acetic acid. Processes described herein are readily adapted to an industrial scale, particularly for the removal of acetaldehyde from process streams.

Abstract: An anode assembly including a perforated anode. A perforated anode holder holds the anode. The anode holder includes perforations at least in a bottom wall such that plating solution may flow through perforations in the anode holder and perforations in the anode. An anode isolator separates the anode and a cathode. The anode isolator includes at least one curvilinear surface.

Abstract: A process for recycling a reaction system of electroplating passivation of wafers, in which lanthanum hydroxide (La(OH)3) or magnesium hydroxide (Mg(OH)2) is added to supplement the lanthanum ion or magnesium ion consumed in an electroplating solution when the pH of the electroplating solution decreases to a range from 0.1 to 0.4.

Abstract: A method and apparatus for enriching the chromium concentration in an operating chrome plating from a spent chrome plating solution containing hexavalent chromium, trivalent chromium and extraneous metal ions is dislosed. A spent platining solution vessel is divided into an anode chamber and a cathode chamber by a porous container. A hollow primary anode is provided in the anode chamber and a plurality of cathodes are provided in the cathode chamber. A circularly shaped secondary anode is provided in the cathode chamber surrounding the cathodes and porous container. The primary anode and cathodes are connected to a primary electric circuit and the secondary anode and the cathodes are connected to a secondary electric. Operating solution from an operating plating vessel containing hexavalent chromium at a pre-enriched concentration is pumped to the anode compartment and hexavalent chromium enriched anolyte is flowed from the anode compartment to the operating plating vessel.

Abstract: An electroplating apparatus comprising: an electroplating tank assembly for receiving an electroplating solution; transfer structure for transferring a substrate to be electroplated along a transfer passage within the electroplating tank assembly; at least one pair of sparger assemblies for dispersing the electroplating solution in the direction of the substrate; at least one pair of anode baskets for containing anode material; electricity feeding circuitry for feeding electricity to the anode material contained in the at least one pair of anode baskets; and at least one pair of anode shield assemblies positioned to direct a current flux toward the substrate to provide for a uniform distribution of plating material thereon.

Abstract: The invention relates to a process for electrolytic treatment of copper foil, comprising the steps of: (A) applying a voltage across an anode and cathode, wherein the anode and cathode are in contact with an electroplating composition containing a gelatin component; (B) removing organic particulate matter by contacting the electroplating solution containing the organic particulate matter with an adsorbent polymer; and (C) electrolytically treating the copper foil. The electroplating composition can additionally contain an active sulfur-containing component, such as thiourea.

Abstract: A process for the treatment of a hydrated mixture of a salt which comprises an inorganic fluoride and hydrogen fluoride to remove water from the mixture wherein the salt mixture contains an excess of hydrogen fluoride, which process comprises forming a liquid phase of the said mixture by melting the salt therein and feeding an inert gas through the liquid phase of the mixture.

Abstract: A method of purifying a copper electrolytic solution circulated in a copper electrorefining system, wherein a portion of the solution is withdrawn and recycled to the system after purification treatment. The purification treatment includes the addition of a hydrosulfide to the withdrawn solution to generate only the necessary quantity of hydrogen sulfide gas required in the reaction. The hydrogen sulfide gas generated is utilized for purification treatment. One process comprises dividing the solution withdrawn into two portions. Sodium hydrosulfide is added to the first portion to precipitate and separate metals as sulfides. Excess sodium hydrosulfide is further added to the first portion for reaction with residual sulfuric acid in the solution to generate hydrogen sulfide gas, then contacting the second divided portion with the hydrogen sulfide gas thus produced to precipitate and separate metals in the form of sulfides. The filtrate is then recycled to an electrorefining system.

Abstract: The present invention is to provide a method for treating sludge as a by-product of a process of tin electroplating a steel plate by means of a plating bath containing haloid ions, together with an equipment therefor. More specifically, by immersing the sludge in water prior to filtration, the residual sludge is subjected to alkali hydrolysis in the presence or absence of the ions of an alkali earth metal within a temperature range of 100.degree. to 400.degree. C., whereby cyanide compounds and fluoride compounds contained therein under environmental regulations are prepared into environmentally non-hazardous matters. By adjusting the filtrate to pH 7.5 to 10, the precipitate with the principal component of tin hydroxide is deposited to recover the tin components contained in the sludge. Furthermore, the recovered tin is refined into the metal tin, for recycling and use as the electrode by the plating.

Abstract: A process and apparatus for electrolytically surface-coating special metal workpieces in which the electrolyte is conveyed in a controlled circuit in and around the electrolysis region in that most of it is conveyed at a high flow rate, at a higher inlet pressure, through the space between a cathodically connected workpiece and an anode and a smaller proportion of it is conveyed at a lower flow rate upwards to the rear of the anode away from the cathode. After leaving the electrolysis region the electrolyte is taken into a separate overflow tank and/or in the feed back system.

Abstract: A method and a plant for regenerating zinc sulfate electrolyte in steel strip electrogalvanizing processes by precipitating dissolved iron from electrolyte circulating through a coating cell. A partial quantity of the circulating electrolyte to be regenerated is removed from the coating cell and the dissolved iron is oxidized to Fe.sup.3+ by a redox-controlled addition of oxidizing agents. Subsequently, by raising the pH value to the precipitation limit of Fe.sup.3+ by a controlled addition of a ZnO/water suspension or a ZnCO.sub.3 /water suspension, the dissolved iron is precipitated as sludge. Any excess ZnO or ZnCO.sub.3 is then dissolved by adding fresh electrolyte. The precipitated iron sludge is conducted through a suitable filter such as a filter press, a filter belt, a decanter, etc., and the precipitated iron is filtered out in this manner. Subsequently, the purified partial quantity of the electrolyte is returned to the coating cell.

Abstract: A plating cell for plating a flat substrate, for example, a stamper for a high-density compact disk recording, employs a sparger to introduce a flow of electrolyte across the surface of the substrate to be plated. A fluid-powered rotary blade or wiper within the cathode chamber has a rotary blade with an edge spaced a small distance, preferably about three-eighths inch, from the substrate, and an annular turbine which rotates under a flow of the electrolytic fluid that is also being fed to the sparger. The rotary wiper is run at a speed between about 35 and 80 rpm and draws the electrolyte away from the substrate. This helps remove hydrogen bubble that form during electroplating. A semipermeable weir separates the cathode chamber from an anode chamber that contains an anode basket that is filled with plating material. The plating cell is provided with a backwash flow regime so that impurities and inclusions from the anode chamber are kept out of the plating bath.

Abstract: The invention describes a process for the electrolytical coating of an object of steel on one or both sides. Preferably, the object is a steel strip with zinc or a zinc iron alloy. Zinc or a zinc iron alloy is deposited on the object when the object is connected to form the cathode of a galvanic cell in an aqueous solution of zinc chloride and iron chloride with a pH of 0.1 to 3.0. The zinc chloride solution has a concentration of 50 to 1000 g/l for the deposition of metallic zinc. A partial flow of electrolyte solution is past continuously into a column filled with metallic zinc, where the trivalent iron formed there during the electrolysis is reduced to a bivalent iron, and metallic zinc is dissolved simultaneously therewith. The invention also describes an apparatus for the electrolytical coating of an object of steel.

Abstract: A system automated for providing at least periodic removal of metal ions and contaminants from a chemical bath, consists of a microprocessor programmed for controlling fluid circuits of pumps and valves, for in one state of operation circulating a first predetermined quantity of the chemical bath from a first tank, through an ion exchange column, and back to the first tank; for in a second state of operation circulating deionized water from a second tank into the IEX column for displacing residual chemical bath therefrom for return to the first tank; for in a third state of operation circulating deionized water through the IEX column, and discharging the rinse water from a waste port; for in a fourth state of operation circulating regenerant acid through the ion exchange column, and discharging the used acid from a waste port; for in a fifth state of operation circulating deionized water through the IEX column for rinsing acid regenerant therefrom and discharging the same out of a waste port; and for in a six

Abstract: An apparatus for continuously dissolving metal powder for use in plating includes a dissolving tank for dissolving metal powder for used in plating solution in a solvent, a filter for separating the solution containing undissolved residue into an undissolved residue and a filtrate, a recovery tank of the filtrate, and a plating solution storing tank for supplying recovered filtrate to a plating tank. The filter is a porous substance having a plurality of liquid passages in the axial direction thereof, and the filter is provided with a circuit for returning a liquid solution containing the undissolved residue passed through the passages to the dissolving tank and a pipeline for leading the filtrate to the recovery tank.A method of dissolving a nickel metal, which has a specific surface of 0.003 m.sup.2 /g or more, is dissolved with the use of the above-described apparatus.

Abstract: A process is provided for the removal of fluoride from a metal sulphate solution, such as a zinc sulphate solution, which presents an option for the disposal of waste treatment sludge from the aluminum anodizing industry. The fluoride is removed from metal sulphate solution by mixing the sludge with the solution for a predetermined period of time and then performing a solid/liquid separation.

Abstract: A first pair electrodes consisting of an anode to which a plurality of wiring lines to be anodized are connected and a cathode that is opposed to the anode, and a second pair electrodes for collecting impurities in a forming solution are immersed in a forming solution. A voltage is applied to the plurality of wiring lines in such a manner that at least one of the plurality of wiring lines receives the voltage for a different period than the other wiring lines.

Abstract: A method of recovering and reproducing a tinning liquid containing Fe ions and other detrimental cations by the steps of removing cations from the tinning liquid by passing the tinning liquid or a diluted liquid of the tinning liquid through a strong-acid cation exchange resin to obtain a recovered acid, thereafter reproducing the strong-acid cation exchange resin and desorbing adsorbed cations into a solution containing an acid by passing the acid through the exchange resin to which the cations have been adsorbed, precipitating and separating Sn ions in the form of a precipitate of an Sn compound from the solution into which the cations have been desorbed while maintaining Fe ions as ions in this solution, mixing and dissolving the precipitate of the Sn compound or a compound reduced from the same in the recovered acid to reproduce and reuse the mixture of the Sn compound and the recovered acid as a tinning liquid, and discharging the solution containing Fe ions out of the system of the tinning liquid.

Abstract: A method of recovering volatile ruthenium, which is separated and formed by constant potential electrolysis from high-level radioactive liquid waste discharged from the reprocessing step of spent nuclear fuel by purex process, in the form of stable solid. The method comprises electrolyzing at a constant potential a high-level radioactive liquid waste from which palladium has substantially been removed in advance, thereby vaporizing ruthenium, bringing the vaporized ruthenium into contact with an aqueous solution of formic acid to precipitate ruthenium oxide, and separating the precipitate from the aqueous solution of formic acid.

Abstract: This is to a process for chromium plating metal articles spray rinsing the metal article after it has been cleaned, acid treated, nickel plated, and chromium plated over rinse tanks which are empty except for the rinse collected therein. The rinse water is recirculated to the respective treating tanks as needed.

Abstract: An automated system is disclosed for providing at least periodic removal of metal ions from a chemical complex and contaminants from a chemical bath. The chemical bath is a latex solution containing charged latex particles and having an acidic pH to form a coating by autodeposition, the charged particles tending to coagulate when subjected to a high shear circulation. The system uses an ion exchange column containing an iminodiacetate ion exchange resin for removal of the metal ion contaminants. The chemical bath is passed through the ion exchange column at a low velocity to prevent coagulation of the latex particles. Conductivity measurement devices and controllers are used to automate the operation of the system. Also, additional sensors, such as pressure and level sensors, controllers, filters, circulation pumps and tanks are used for performing rinsing and regeneration of the ion exchange column.

Abstract: In a retardation installation having a container holding the adsorber material capable of accepting acid, in particular adsorber resin, and a feed for a watery acid-salt-solution, for example from an anodizing bath, a further feed for a regenerating solution to regenerate the adsorber material, in particular demineralized Water in opposite flow to the acid-salt-solution, as well as a drain for the treated acid-salt-solution which has passed the adsorber material and with at least one pump for the transport of the acid salt solution and/or the regenerating solution, precisely one pump is provided for which is configured as a compressed air-diaphragm pump and which exhibits a device for stroke counting as well as a device for the control of the volume flow of acid-salt-solution or regenerating solution on the a basis of the stroke count of the compressed air-diaphragm pump.

Abstract: Carbonates, and particularly sodium carbonate, are removed from cyanide containing plating baths by taking from said cyanide containing bath at least part of its bath liquid; stirring and cooling in a cooling container the token liquid while in the metastabile state until crystallization of the carbonates occurs; separating the crystallized carbonates from the liquid; and leading the residual liquor back to the plating bath. Preferably, the quantity of bath liquid taken from the plating bath and the moment of this taking are chosen so as to bring the carbonate content of said plating bath, after leading the residual liquor back to it, to a carbonate content of 25 to 45 grams/liter, and the cooling is continued until the exothermic reaction, which is caused by the liberation of the heat of crystallization, starts, and thereafter the mixture is still held for 2 to 4 minutes at 0.5.degree. C. to 1.degree. C. below this starting temperature.

Abstract: A process and apparatus for regenerating a plating bath comprising trivalent chromium cations (a trivalent chromium bath). The bath can be continuously, or more preferably, periodically with an ion exchange resin, preferably a cation exchange resin. A useful apparatus comprises a plating tank containing a trivalent chromium plating bath in communication with an ion exchange bed continuing ion exchange resin.