Abstract: A cermet inert anode having a reduced level of contaminating surface metal is disclosed. Methods for preparing cermet inert anodes and methods for treating cermet inert anodes are also disclosed. The methods generally use an oxidizing agent to convert metals on the surface of the anode to inert oxides and/or to otherwise remove the metal contaminants. The inert anodes of the present invention may be used in electrolytic reduction cells for the production of commercial purity aluminum, as well as other metals.

Abstract: A process for repairing a hole in the crust of an electrolytic cell. The hole is repaired by covering it with a receptacle containing solid particles. The receptacle comprises a polymeric material. More preferably, the receptacle comprises a cellulosic material, such as paper, polymer-impregnated paper, or cardboard. A closed paper bag having at least two paper layers and weighing about 15-20 lb. (6.8-9.1 kg) is particularly preferred. When the electrolytic cell produces aluminum by electrolysis of alumina, the solid particles comprise an aluminum compound such as alumina, aluminum fluoride, cryolite, or a mixture of such compounds. Two preferred forms of alumina include smelting grade alumina (SGA) and alumina dust collected by an electrostatic precipitator (ESP dust).

Abstract: A cermet anode of an electrolytic cell is protected from thermal shock during cell start-up by coating an outer surface portion of the anode with a coating composition comprising carbon or aluminum or a mixture thereof. A particularly preferred coating composition includes an aluminum underlayer adjacent the outer surface portion of the anode, and a carbon overlayer overlying the underlayer. A support structure assembly supporting the cermet anode includes a high alumina ceramic material. In a preferred embodiment, the high alumina ceramic material is protected from thermal shock and corrosion by the coating composition of the invention.

Abstract: An adherent protective coating of a refractory material is produced on the surface of carbonaceous, refractory, ceramic, metallic or other materials serving as components of electrolytic cells operating at high temperature, by applying to such surfaces a well chosen micropyretic reaction layer from a slurry, which when dried is ignited to initiate a self-sustaining micropyretic reaction, along a combustion front, to produce condensed matter forming such refractory protective adherent coating. The slurry is preferably applied in several layers, the first layer(s) to facilitate adherence and the last layer(s) to provide protection, and may contain some preformed non-reactant materials. The electrolytic cells whose components require such coatings are especially those operating at high temperature with a molten salt electrolyte, particularly those for the production of metals, aluminium being the most important.

Abstract: A method for winning the valuable metal content of a leaching solution acidified with sulphuric acid, by solvent extraction and electrowinning and a following final product winning stage, for instance an electrowinning stage, wherein the pH of the leaching solution is raised successively to precipitate out the iron and arsenic present in a first precipitation stage, removing said first precipitate, and precipitating the valuable metal content of the leaching solution substantially totally in a following precipitation stage. The resultant precipitate containing valuable metal and gypsum is removed and leached in an acid environment to re-dissolve the valuable metal content, and the thus formed acid solution and its metal content are delivered to a solvent extraction circuit in which the metal content is converted to a substantial degree to an acid electrolyte from which metal or some other end product is won.

Abstract: A low temperature alkali metal electrolysis process for carrying out the electrolysis in the presence of a co-electrolyte and an alkali metal halide. The co-electrolyte comprises (1) a nitrogen-containing compound and optionally one ore more Group IB halides, Group IIIA halides, Group VIII halides; (2) a Group IIIA halide, a Group VB halide, or combinations of a Group IIIA halide and a Group VB halide; or (3) water. Further provided is an electrolyte comprising an alkali metal halide and a co-electrolyte that comprises (1) a nitrogen-containing compound and optionally one ore more Group IB halides, Group IIIA halides, Group VIII halides or (2) a Group IIIA halide, a Group VB halide, or combinations of a Group IIIA halide and a Group VB halide.

Abstract: The invention provides a method for producing a sputtering target material including electrolyzing a molten salt mixture containing a precious metal salt and a solvent salt, to thereby deposit a precious metal or a precious metal alloy. The method enables simplification of production steps and produces high-purity target materials. In addition, the electrodeposited precious metal or precious metal alloy is heat-treated at a temperature of at least 800° C. but lower than the melting point of the precious metal, to thereby produce a target material of higher purity.

Abstract: An amperometric in situ apparatus and technique for measuring the concentrations and transport properties of easily dissociable oxides in slags is described. The technique consists of a combination of different measurements utilizing an electrolyte to separate a reference-gas compartment from the slag of interest. A method and apparatus for metals extraction is also described which includes a vessel for holding a molten electrolyte, the electrolyte comprising a mobile metallic species and an anionic species having a diffusivity greater than about 10−5 cm2/sec; a cathode and an anode, the cathode in electrical contact with the molten metal electrolyte, the cathode and molten electrolyte separated from the anode by an ionic membrane capable of transporting the anionic species of the electrolyte into the membrane; and a power source for generating a potential between the cathode and the anode.

Abstract: An electrolytic refining method for gallium by depositing refined gallium on a cathode in an electrolytic solution using a melted raw gallium material as an anode in an electrolytic cell is disclosed, comprising applying a centrifugal force to the melted raw gallium material and discharging out a scum gathered in the central portion of the cell.

Abstract: An electrolytic cell and electrolytic process for producing a metal by reduction of a metal oxide dissolved in a molten salt bath containing at least one chloride and at least one fluoride. A solid conductor of oxide ions is interposed between the anode and the cathode. The solid conductor preferably comprises zirconia, stabilized in cubic form by addition of a divalent or trivalent metal oxide such as yttria.

Abstract: The present invention includes uranium-bearing ceramic phase electrodes and electrolysis apparatus and electrolysis methods featuring same, including methods of metal production and the like by the electrolytic reduction of oxides or salts of the respective metals. More particularly, the invention relates to an inert type electrode composition, and methods for fabricating electrode compositions, useful in the electrolytic production of such metals. The present invention also includes an inert-type electrode composition, and methods for fabricating electrode compositions, used in processes for generating energy from fossil fuels.

Abstract: A Process for the electrolytic production of metals particularly titanium and alloys starting from the corresponding compounds is disclosed, by means of an apparatus for the electrochemical extraction including: (1) a cathode-crucible containing a mass of solidified metal, a liquid electrolyte with a density which is lower than that of the metal and a pool of liquid metal produced; (2) one or more non-consumable anodes particularly immersed in the electrolyte with means for regulating their distance from the cathodic surface; (3) a feeding system to the electrolyte of the compounds of the metals, of the electrolyte constituents and of alloying materials; (4) a power supply which feeds direct current to the liquid metal, and through the electrolyte, to the anodes, and causes the cathodic reduction of the metal in liquid form and the evolution of anodic gas, with the heat generation which maintains the electrolyte in the molten state; and (5) an air-tight containment structure in which the anodic gases generate

Abstract: An amperometric in situ apparatus and technique for measuring the concentrations and transport properties of easily dissociable oxides in slags is described. The technique consists of a combination of different measurements utilizing an electrolyte to separate a reference-gas compartment from the slag of interest. A potentiometric measurement (type I) provides information on the thermodynamic properties of the slag; an amperometric measurement (type II) yields information concerning the type and transport properties of dissociable oxides; an electrolysis measurement (type III) determines the concentration of dissociable oxides. A method and apparatus for metals extraction is also described which includes a vessel for holding a molten electrolyte, the electrolyte comprising a mobile metallic species and an anionic species having a diffusivity greater than about 10.sup.-5 cm.sup.

Abstract: An inert electrode material is made by reacting at an elevated temperature a mixture preferably comprising iron oxide, at least one other metal oxide, copper and silver. The reaction produces a material having ceramic phase portions and alloy phase portions, wherein the alloy phase portions have copper-rich interior portions and silver-rich exterior portions. Inert anodes made with a reaction mixture containing copper and silver have lower wear rates than inert anodes made with copper and no silver.

Abstract: The present invention provides a new and useful process for the production of a molten metal by electrolysis in an electrolytic cell having an electrolysis compartment, a metal recovery compartment, and a partition separating upper parts of said compartments, said process comprising: electrolysing in said electrolysis compartment an electrolyte containing a fused salt of said metal said electrolyte being of greater density than said metal; continuously withdrawing the product metal mixed with said electrolyte in a stream from said electrolysis compartment to a top part of said metal recovery compartment; allowing said metal to form in said metal recovery compartment a pad floating on said electrolyte; maintaining said pad out of contact with said partition; and recovering said pad.

Abstract: A method of refining magma, which includes silicon carbide, basaltic clay, and other insoluble components, including the steps of blending the magma with monovalent alkali hydroxides and a chemical oxidizing agent, melting the magma, and injecting oxygen into the melted magma. The melted magma is electrolyzed to separate metals contained in the melt, which are recovered by gravity separation followed by centrifugation. Soluble silicates are recovered by crystallization.

Abstract: An anode positioning hoist supported on an overhead crane used in a smelting apparatus including a cathode with an upwardly facing surface and an anode with a downwardly facing surface. The anode positioning hoist includes a pair of channel members defining opposed vertical channels and a cylinder/piston assembly including a cylinder located between the channel members and a piston rod extending downwardly from the cylinder. A carrier is fixed to the piston rod for movement therewith and includes rollers guided in the channels. A connector assembly is mounted on the carrier to releasably secure the anode to the carrier. A control system including a counterbalance valve mounted on the cylinder and a pressure switch operates to cause extension of the piston rod until the downwardly facing surface of the anode engages the upwardly facing surface of the cathode. The control system thereafter causes retraction of the piston rod a predetermined distance to provide a desired anode-cathode gap.

Abstract: The present invention provides a new and useful process for the production of a molten metal by electrolysis in an electrolytic cell having an electrolysis compartment, a metal recovery compartment, and a partition separating upper parts of said compartments, said process comprising: electrolysing in said electrolysis compartment an electrolyte containing a fused salt of said metal said salt being of greater density than said metal; continuously withdrawing the product metal mixed with said electrolyte in a stream from said electrolysis compartment to a top part of said metal recovery compartment; allowing said metal to form in said metal recovery compartment a pad floating on said electrolyte; maintaining said pad out of contact with said partition; and recovering said pad.

Abstract: An electrolytic reduction cell for the production of metal is provided, in which liquid metal is deposited at or adjacent an upper surface of a cathode. The electrolytic reduction cell includes an anode structure and a cathode located beneath the anode structure, wherein an upper portion of the cathode comprises an aggregate of particles sized and shaped such that in operation of the cell liquid metal is present in at least an upper part of the aggregate and a slurry of liquid metal and particles is established, the slurry comprising a substantially uniform dispersion of the particles in a continuous liquid phase of the liquid metal, the slurry having a viscosity sufficiently high such that under operating conditions of the cell the slurry is relatively immobile. Methods for the production of a metal by electrolysis in the electrolytic cell are also provided.