Abstract: Feed cathode for an electrolytic cell with a feed conduit suited to pass a metal compound therethrough from a source to an electrolyte in the cell. The feed cathode includes a member surrounding and substantially entirely enclosing at least an outlet of the conduit. The member is at least partially formed of an electrically conductive foraminous body suited to pass the electrolyte and ions of a multivalent metal compound therethrough. Preferably, the foraminous body has an electrical coefficient of greater than zero to about 1 and a flow coefficient of from about 0.1 to about 300.

Abstract: The covering sytem for a conventional fused salt electrolytic cell for the reduction of aluminum oxide to metallic aluminum comprises individual lids (4) butting onto each other at the sides and inclined downwards from the anode beam (1) to the edges (5) of the long sides of the reduction pot. The lids (4) are provided with a support (6) which rests on a rail (13) when the anode beam is in the raised position. As the anode beam (1) is lowered, the lids (4) slide over the long edges (5) of the pot, until they are supported by the stops (7) mounted on the lower third part of the lid (4). On lowering the beam (1) further, the supports (6) slide on the anode beam (1). The anode rods (2) are enclosed at the sides by the lids (4).

Abstract: Novel electrodes for oxygen ionization half-cell electrode reactions comprising an electrically conductive porous base having over at least a portion thereof a coating containing an electrocatalyst comprising (1) at least one metal selected from the group consisting of silver and a platinum group metal and (2) a hydrated oxide of at least one metal selected from the group consisting of manganese and nickel, electrochemical cells containing the said electrode at which oxygen is ionized and to novel electrolytic processes with such an electrode.

Abstract: An electrolytic process and an electrolytic cell for recovering metal values from low grade concentrates. The said concentrate is introduced into the cell containing an aqueous electrolyte so that it is retained in proximity to an anode or anodes and kept out of contact from the or each cathode. The cell is energized so that electrolysis takes place and acid is released at the anode(s) which dissolves the metal values which form cations which migrate to and are discharged at the cathode(s). The impurities in the concentrate form fine particles which are separated from the concentrate by screening, e.g. by means of a grid or grids separating the anodes from the cathodes.

Abstract: A bipolar current collector-separator for electrochemical cells consists of a molded aggregate of electro-conductive graphite and a thermoplastic fluoropolymer combined in a weight ratio of 2.5:1 to 16:1. The bulk resistivity of such a molded bipolar current collector-separator is less than 4.times.10.sup.-3 ohm inches (.OMEGA. in.). It has excellent corrosion resistance to a variety of feedstocks such as brine, aqueous HCl, etc. and to various electrolysis products such as caustic, chlorine, hydrogen, etc. In one alternative form the anodic side of a current collector-separator for a water electrolyzer is covered by a thin layer of a passivated metallic foil thus protecting the graphite current collector against attack by oxygen.

Abstract: The present invention relates to the continuous electrochemical treatment of a metal web and more particularly the continuous electrochemical graining and anodizing of aluminum metal webs for litho sheet and capacitor foil applications.

Abstract: The electrochemical working method according to the invention comprises the use of two electrodes whereof one oscillates with respect to the other. Voltage pulses are applied to the electrodes in synchronization with the oscillation and are continued to be applied thereto when the electrodes are found at a minimum distance from one the other. As the electrodes are brought apart, cavitation is produced in the interelectrode gap, which phenomenon is accompanied by a change in the relative resistance of the gap. A cavitation transducer is used to measure a parameter which unambiguously determines the cavitation intensity corresponding to a preset minimum gap. In order to control the electrochemical treatment process, a comparator produces a signal equal to the difference between a signal corresponding to the actual relative value of the parameter function and formed by a computing unit, and a signal corresponding to a predetermined value of the parameter.

Abstract: A capping board made of plastic material reinforced with fiberglass, for supporting the ends of a plurality of electrodes immersed in an electrolytic cell such as the cells used for the electrolytic refining of copper. This capping board is made of a plastic resin selected from the group consisting of polytetrafluoroethylene and acid resistant polyesters, vinylesters, epoxy and phenolic resins, and contains from 10 to 20% by weight of fiberglass, from 2 to 10% by weight of silica, from 2 to 10% by weight of mica and from 2 to 10% by weight of feldspar. Preferably, at least one wooden core is embedded in the capping board in order to reduce the quantity of resin required and the fabrication cost. Such capping boards made of reinforced plastic material allow for substantial increase in the productivity of electrolytic metal refining plants, in particular because they are resistant to corrosion and do not need to be frequently replaced.

Abstract: A method of etching a recrystallized aluminum foil which utilizes potentiostatic etching to roughen the foil to obtain a particularly high roughening factor. The etching preferably occurs in two stages in which the etching current density of the first stage is above the current density which creates an undesired pitting of the aluminum and a second stage which utilizes an etching current density which is below the density which creates pitting of the aluminum.

Abstract: A counterflow extraction column for the liquid-liquid extraction of two phases during simultaneous electrolysis, includes an elongated, upright column tube containing a cathode and an anode. Within the tube, a common chamber defines cathodic zones and anodic zones and is void of separating members between the zones. The common chamber constitutes the anode chamber and the cathode chamber of the column.

Abstract: A process and an apparatus for electrowinning metal from metal bearing solutions is disclosed. A support solution containing a predetermined metal concentration is continuously recirculated through a cell having a porous grid supporting a bed of particulate conducting particles at a sufficiently high flow rate so as to fluidize and expand the bed by 5 to 25%. A gas is continuously fed through the bed of conducting particles so as to strongly agitate the particles at low bed expansion to maintain good mixing and uniform fluidization of the bed of particles. The cell includes an electrode arrangement suspended from the top of the cell and immersed into the bed of fluidized conducting particles.

Abstract: Equipment for controlling, monitoring, determining the most effective operating conditions and operating, and for displaying data in, alkali metal chloride electrolysis plants which are operated by the amalgam process, wherein the equipment has, for each electrolytic cell or for each group of electrolytic cells, a data collecting and processing device for controlling, monitoring and determining the most effective operating conditions the electrolytic cell or group, and all the data collecting and processing devices are connected to a central data collecting and processing device for central operation and for displaying data.

Abstract: A dual current supply system for aluminum-producing electrolyzers longitudinally arranged in a series-connected row comprises at least four anode risers in each space between next-adjacent electrolyzers. The system includes anode systems and anode buses electrically connected to the anode risers for supplying current from the anode risers to the anode systems. Two of the anode risers of one of a pair of next-adjacent electrolyzers are coaxially positioned in the space between the next-adjacent electrolyzers and two of the anode risers of the other of the pair of next-adjacent electrolyzers are positioned in the space between the next-adjacent electrolyzers in coplanar relation with the anode risers of the one of the next-adjacent electrolyzers. The arrangement of the anode risers enables a more uniform distribution of the magnetic field and permits the total length of the electrolyzer body and current supply buses to be reduced.

Abstract: This invention relates to the recovering of metallic silver from photographical bleach-fix baths. An electric current is passed through a bleach-fix solution containing silver ions and ferric ions, which solution has been brought to a predetermined redox potential by the addition of a reducing agent. The cathode is of the type wherein reduced silver ions can deposit thereon as metallic silver. The redox potential of the electrolyte solution is continuously monitored and a reducing agent is added automatically when the redox potential rises above a predetermined level. When the redox potential drops below a predetermined level the addition of the reducing agent is automatically stopped.

Abstract: An improved anode and base assembly for diaphragm type electrolytic cells is disclosed. In the present embodiment, downwardly facing annular portions at the base of the anode risers of dimensionally stable anodes of the type well-known in the art are welded from below directly to a metal cell base cover which seals the electrolyte contained within the cell from the cell base which is generally of copper or aluminum, thereby eliminating corrosion problems associated with leaks in the rubber gaskets or blankets formally used between the anode risers and the cell base.

Abstract: A unique, current conducting, separator element with controlled anolyte flow distribution is incorporated in an electrolysis cell having anode and cathode electrodes bonded to an ion transporting membrane. The current conducting-fluid distributing separator has a plurality of parallel conductive ribs which contact the anode electrode and also define a plurality of fluid distribution channels through which an anolyte such as water, is brought to the electrode and through which gaseous electrolysis products and the spent anolyte are removed from the anolyte chamber. A pressure dropping flow restrictor is provided in the channel inlets to prevent gases generated at the anode from flowing backward and blocking the anolyte distribution inlet manifold. The pressure dropping element can take the form of a restrictor to reduce the dimension of the channel. Alternatively the separator is molded so that the inlets of the channels have a reduced cross section.

Abstract: Electrode elements are provided for monopolar electrolysis cells useful in chlor-alkali electrolysis and having two vertical, planar, opposed electrode surfaces, said surfaces being substantially parallel and spaced apart from one another and being electrically fastened to an electrode frame, said electrode element being characterized in that at least one electrode rod is connected in electrically conductive fashion to the side portion of said electrode frame, extending through the space between said opposed electrode surfaces substantially parallel to said electrode surfaces, the diameter of said rod being smaller than the distance between said opposed electrode surfaces, said electrode rod being provided with conductive members distributed over the length thereof and connected in electrically conductive fashion to both the electrode surfaces and the electrode rod.

Abstract: Electrolysis apparatus and electrode structure comprising a solid polymer electrolyte membrane, a porous cathode plate, and a porous anode plate which is electrochemically compatible with the cathode, so that the anode plate and cathode plate are substantially immune from galvanic corrosion. The solid polymer electrolyte membrane is disposed between the anode plate and cathode plate, and means are provided for holding the anode and cathode plates in firm contact with the opposite sides, respectively, of the membrane. In an embodiment employing a plurality of sets of electrode structures means are provided for securing the anode plate, solid polymer electrolyte membranes, and cathode plate of each electrode structure in side-by-side relationship and to secure the respective electrode structures in spaced series arrangement, with a spacer plate positioned between the individual sets of spaced electrode structures. A series of grooves is provided between the anode plate and the plate in contact therewith.

Abstract: A pneumatic anode positioning apparatus is disclosed for positioning any number of a plurality of anodes relative to a cathode in an electrolytic cell. This apparatus comprises a means for determining the desired anode position for each of the anodes and converting the amount of movement necessary to attain such position to a number of increments of predetermined displacement.

Abstract: Disclosed is a cathodic element for a chlor-alkali electrolytic cell. The cathodic element has a hollow electrolyte permeable nonconductive finger with a permionic membrane on the outer surface of the finger and a cathodic electrode inside the finger, spaced from and substantially parallel to the walls of the finger.