Abstract: The etching rate of an alkaline ammonium copper etching bath is accelerated by inclusion therein of an etchant accelerating amount of a mixture comprising an ammonium halide, a water-soluble salt containing sulfur, selenium or tellurium in the anion, an organic thio compound containing the group ##STR1## and, optionally, a water-soluble salt of a noble metal (e.g. silver).

Abstract: A cathode suitable for use in an electrochemical process evolving hydrogen (for example the chloralkali process) in which the cathode comprises an electrically conductive substrate (1) made of a non-ferrous metal or having a coherent coating of non-ferrous metal on which is provided an electrocatalyst (4) comprising platinum and ruthenium and wherein the cathode is made more poison-resistant by a deposition of gold or silver and, optionally, a further deposition of PTFE. The cathode is particularly resistant to poisoning by iron.

Abstract: Improved articles are disclosed having a polymeric substrate containing a polymer, such as polyamide, and a metallic sulfide, such as copper sulfide, and a thin, uniform, and firmly adherent overlayer of an eletrodepositable metal, such as nickel. The metal overlayer may be continuous or selectively patterned over the polymeric substrate. The metal layer provides the articles with decorative, protective and electrically conductive characteristics without significantly diminishing polymeric properties.

Abstract: A process and an apparatus for producing an alloy containing terbium (Tb) and/or gadolinium (Gd). The process includes the steps of: (a) preparing a bath of molten electrolyte which consists essentially of 20-95% by weight of TbF.sub.3 and/or GdF.sub.3, 5-80% of LiF, up to 40% of BaF.sub.2 and up to 20% of CaF.sub.2 ; (b) reducing the TbF.sub.3 and/or GdF.sub.3 in the bath, with carbon anode and with cathode made of a metal such as iron or cobalt, so as to electrodeposit Tb and/or Gd on the cathode, and alloying the electrodeposited Tb and/or Gd with metal of the cathode so as to produce the alloy containing Tb and/or Gd in a liquid state on the cathode; (c) adding the TbF.sub.3 and/or GdF.sub.3 to the bath so as to maintain the composition of the bath, for compensating for consumption of the TbF.sub.3 and/or GdF.sub.

Abstract: A chlorine generating apparatus is disclosed herein by which chlorine gas or sodium hyperchlorite is generated in small quantities from a brine solution economically enough to be practical for use in the backyard swimming pool. The apparatus includes a free standing unit and cell utilizing only salt as its raw material to generate the chlorine required. The chlorine generating cell incorporates a chemical pump for forcibly urging the resulting product to the pool without the use of mechanical pumps or membranes. A device is included whereby hardness minerals are prevented from being deposited within the cell. New methods of reducing maintenance and increasing reliability are also disclosed.

Abstract: An electronic control circuit for a vehicle cathodic protection system is disclosed. A battery of the vehicle is utilized to supply electrical energy to the circuit. The circuit includes a first voltage comparator which compares the voltage level of the vehicle battery with a predetermined reference level. If the voltage level of the vehicle battery falls below the reference level, the first voltage comparator disables the control circuit so as to prevent an undesirable drain on the vehicle battery form occurring. An oscillator provides a pulsating output signal. When the output pulses from the oscillator are positive, a transistor switch is turned on to cause electric current to flow to one or more sacrificial anodes. When the output pulses are negative, the transistor switch is turned off, thereby preventing electric current from flowing to the sacrificial anodes. Thus, the control circuit is only energized intermittently.

Abstract: The present invention provides a process for recovering lithium from an aluminum-lithium alloy scrap including heating a lithium chloride-potassium chloride-lithium fluoride salt mixture in a separate bath melter vessel to form a molten salt bath reservoir; fluxing the molten salt with chlorine or hydrogen chloride gas to remove moisture; drying the aluminum-lithium scrap; heating the dried aluminum-lithium alloy scrap to form a molten reservoir of aluminum-lithium alloy; feeding low moisture molten salt and aluminum-lithium alloy to a three-layered electrolysis cell comprising a most dense lowest layer of molten aluminum-lithium alloy, a middle layer of molten salt electrolyte, and an uppermost layer of molten lithium; passing direct current through the cell with the aluminum-lithium alloy anodic; reducing lithium ions to lithium metal at a cathode suspended in the molten salt electrolyte; and removing lithium from said uppermost layer in said three-layered electrolysis cell.

Abstract: Disclosed is a liquid filter device for effectively eliminating impurities from liquid.Voltage is applied to liquid to break electrostatic coupling of liquid molecules and impurity molecules. The impurity molecules are electrostatically adsorbed by an electrode containing adsorbent having charges different in polarity from those of the impurity molecules.Voltage is applied to liquid to break electrostatic coupling of liquid molecules and impurity molecules. Adsorbent having charges different in polarity from those of the impurity molecules on its surface is provided between a pair of electrodes to electrostatically adsorb the impurity molecules. After the impurity molecules are electrostatically adsorbed, the liquid is filtrated by a filter.Voltage is applied to liquid to eliminate zeta potentials which are potential difference at electric double layers having charges different in polarity from those of impurity particles in interfaces between the impurity particles and the liquid.

Abstract: Electrolytes and plating solutions for use in processes for electroplating and electroforming pure magnesium and alloys of aluminum and magnesium and also electrodeposition processes. An electrolyte of this invention is comprised of an alkali metal fluoride or a quaternary ammonium halide, dimethyl magnesium and/or diethyl magnesium, and triethyl aluminum and/or triisobutyl aluminum. An electrolyte may be dissolved in an aromatic hydrocarbon solvent to form a plating solution. The proportions of the component compounds in the electrolyte are varied to produce essentially pure magnesium or magnesium/aluminum alloys having varying selected compositions.

Abstract: A gas and electrolyte permeable metal layer is bonded to an ion-permeable membrane by electroless deposition to produce a permeable metal deposit upon the membrane or diaphragm. Advantageously, the membrane surface to be coated is pretreated with an amphoteric material. Thereafter, the treated surface is treated to deposit the coating. Typical metals deposited include platinum group metals, iron group metals, such as nickel, cobalt and others including gold and silver. The coatings are very thin, rarely in excess of about 50 to 100 microns.The coated membrane may be installed in an electrolytic cell used for producing chlorine and alkali by electrolysis of alkali metal chloride with the coating serving as one electrode and another opposed electrode on or adjacent to the opposite side of the membrane. It may also be used in water electrolysis and for other purposes.The coatings may be thickened by depositing other coatings of the same or different composition by suitable coating techniques.

Abstract: In an electrolytic method for removing metal from solution, a "plating" voltage applied to the electrodes is reduced to a lower, "standby" value if the current drawn by the solution falls below a threshold value. This "standby" voltage, however, is periodically restored to its higher, "plating" value for brief intervals so that the current at the higher voltage can periodically be sampled. If it is found that the current drawn by the solution at the higher voltage is once again above the threshold value (indicating that new metal has been added to the solution), the electrode voltage is kept at the higher level until the solution is again depleted of metal to the point that the current drops below the threshold. If, during the brief sampling interval, the current is still below the threshold, the electrode voltage is returned to its lower, "standby" value and another current sample is taken at the next interval.

Abstract: A process is disclosed for the preparation of potassium nitrate by means of the reaction of nitric acid with potassium carbonate, wherein potassium carbonate is obtained by means of an electrochemical process.

Abstract: A process for electrolytically recovering mercury from mercury compounds is provided. In one embodiment, Hg is recovered from Hg.sub.2 Cl.sub.2 employing as the electrolyte solution a mixture of HCl and H.sub.2 O. In another embodiment, Hg is electrolytically recovered from HgO wherein the electrolyte solution is comprised of glacial acetic acid and H.sub.2 O. Also provided is an apparatus for producing isotopically enriched mercury compounds in a reactor and then transporting the dissolved compounds into an electrolytic cell where mercury ions are electrolytically reduced and elemental mercury recovered from the mercury compounds.

Abstract: A process for production of high purity quarternary ammonium hydroxides, comprising electrolyzing quarternary ammonium hydrogencarbonates represented by the general formula: ##STR1## (wherein the symbols are as defined in the appended claims) in an electrolytic cell comprising an anode compartment and a cathode compartment defined by a cation exchange membrane. In accordance with this process, high purity quarternary ammonium hydroxides can be produced with high electrolytic efficiency and further without causing corrosion of equipment. Since the quarternary ammonium hydroxides produced by the present invention are of high purity, they can be effectively used as, for example, cleaners, etchants or developers for wafers in the production of IC and LSI in the field of electronics and semiconductors.

Abstract: A process for the preparation of a water soluble food-grade diaminotriphenylmethane colorant containing from 2 to 4 sulfo groups, comprising anodically oxidizing the corresponding leuco compound in an electrolysis cell divided into an anode space and a cathode space in the presence of from 0.01 to 2% by weight, based on the solution being oxidized, of a C.sub.2 -C.sub.4 -alkanol, urea, a urea derivative or a mixture thereof, at a potential .epsilon..sub.h .ltoreq.1250 mV and at a temperature .ltoreq.+40.degree. C. The colorants obtained are produced in high yield and are of food quality.

Abstract: A method of improving the adhesion of metal applied on a polyimide surface is disclosed, in which the surface is first treated with an adhesion-promoting compound containing a nitrogen-oxygen moiety prior to plating of the metal thereon.

Abstract: Disclosed herein is a process for dissolving and recovering noble metals form used catalysts. Noble metal components are leached out from particles supporting or containing at least one noble metal or noble metal compound by subjecting particles them to electrolysis, with the electrolyte being an acid, in the anode compartment of an electrolytic cell which divided by a diaphragm into anode and cathode compartments, and the resulting solution containing noble metals is subjected to electrolysis in a fluidized bed electrolytic cell, thereby causing the noble metals to separate out on to the fluidizing cathode particles. The thus deposited noble metals are again leached out in an electrolytic cell.

Abstract: A process for dehalogenating halogenated organic compounds comprising:(1) combining in an electrochemical cell(a)(i) a halogenated organic compound or (ii) a solid or fluid containing a halogenated organic compound with(b) a compound capable of forming an iminium ion having the formula (I) ##STR1## wherein X represents an oxygen atom or a sulfur atom, R.sub.1 and R.sub.2, which may be the same or different, each represents an alkyl group, an aryl group or a heterocyclic group, and R.sub.1 and R.sub.2 may combine and form a carbocyclic ring or a heterocyclic ring, andR.sub.3 represents a hydrogen atom, an alkyl group, an aryl group, a heterocyclic group or a halogen atom, and(2) applying an electrical voltage and an electrical current to an electrode of the electrochemical cell as a working electrode; which voltage is such that a reaction occurs and the halogenated organic compound is partially or completely dehalogenated.

Abstract: The invention concerns a process and an apparatus for applying prestresses to carbonaceous cathodic blocks in the operation of sealing the cathodic bar in position with cast iron.The block (1) in the course of the sealing operation is lifted on two rollers (16A, 16B) in the vicinity of its ends (E) and stresses F1 and F3 are simultaneously applied respectively to the ends (10) of the lateral edges of the limb portions (3) of the block and to the central part (C) of the block. Such stresses must be applied during the sealing operation and maintained for 15 to 30 minutes after the end of the cast iron casting operation.That virtually totally suppresses the occurrence of cracks in the cathodic blocks.

Abstract: An apparatus for extraction of metals by electrolysis comprising a means for applying a cathodic current of sufficient magnitude with respect to the cross-sectional dimension of an opening in an insulating coating on a cathode so that a powder-like deposit of anode metal will be made on exposed cathode metal, said deposited metal acting to decrease the current density so that subsequent deposited metal will be in a non-powder like consistency.