Abstract: A metallic oxygen evolving anode for electrowinning aluminum by decomposition of alumina dissolved in a cryolite-based molten electrolyte, and operable at anode current densities of 1.1 to 1.3 A/cm2, comprises an alloy of nickel, iron, manganese, optionally copper, and silicon. Preferably, the alloy is composed of 64-66 w % Ni; Iron; 25-27 w % Fe; 7-9 w % Mn; 0-0.7 w % Cu; and 0.4-0.6 w % Si. The weight ratio Ni/Fe is in the range 2.1 to 2.89, preferably 2.3 to 2.6, the weight ratio Ni/(Ni+Cu) is greater than 0.98, the weight ratio Cu/Ni is less than 0.01, and the weight ratio Mn/Ni is from 0.09 to 0.15. The alloy surface can comprise nickel ferrite produced by pre-oxidation of the alloy. The alloy, optionally with a pre-oxidized surface, can be coated with an external coating comprising cobalt oxide CoO.

Abstract: A cell for the electrowinning of aluminium has a cavity for containing electrolyte (20) and one or more non emerging active anode bodies (5) that are suspended in the electrolyte. The electrolyte's surface (21,21?) has an expanse extending over the cavity and is substantially covered by a self-formed crust (25) of frozen electrolyte. The crust is mechanically reinforced by at least one preformed refractory body (30, 30?,30?). The electrolyte crust is formed against the preformed refractory body and bonded thereto so as to inhibit mechanical failure of the crust and collapse of the crust into the cavity.

Abstract: Method for manufacturing anodes used for the production of aluminium by fused bath electrolysis, said anodes comprising an anode stem made of a conducting metal and at least one block made of carbonaceous material called an anode block, said method including at least the following steps: a) obtain an anode stem; b) obtain a new anode block; c) fix one end of the anode stem onto the anode block, so as to give good mechanical attachment and good electrical connection between said stem and said anode block; said method being characterised in that before, during or after step c), but before placement of said anode in the electrolytic cell, a protective layer with a controlled thickness, typically between 5 and 25 cm composed of a material resistant to temperature and corrosion by the medium above the electrolytic bath is at least partially deposited on the upper surface of said anode block.

Abstract: A cell for electrowinning a metal, in particular aluminium, from a compound thereof dissolved in an electrolyte (30) comprises an anode (40) and a cathode (10,11) that contact the electrolyte (30), the cathode (10,11) being during use at a cathodic potential for reducing thereon species of the metal to be produced from the dissolved compound. The electrolyte (30) further contains species of at least one element that is liable to contaminate the product metal (20) and that has a cathodic reduction potential which is less negative than the cathodic potential of the metal to be produced. The cell further comprises a collector (50) for removing species of such element (s) from the electrolyte (30).

Abstract: A method is described for making aluminum reduction cell components, e.g. cathodes having stabilized surfaces, which comprises mixing together a carbonaceous material, TiB2 and up to 25% by weight of a finely divided additive consisting of a combination of two intimately mixed compounds and forming the mixture into a cell component, wherein at least a first of the two compounds has a higher melting temperature than the baking temperature. When the cell component is contacted with molten aluminum, the aluminum reacts with the additive to form a dense phase at the surface of the cell component, having low solubility in aluminum.

Abstract: The purpose of the invention is a process for making a solid part designed to form all or part of an anode for the production of aluminium by fused bath electrolysis, containing a cermet formed from at least one metallic oxide such as a mixed oxide with spinel structure, and at least one metallic phase, in which a mixed oxide is used containing a metal R in the form of a cation in its chemical structure, the said metal R being fully or partly reducible by a reduction operation during the manufacturing process, so as to form all or part of the said metallic phase. This process can provide a cermet with a uniform distribution of fine metallic particles.

Abstract: A method of protecting an inert anode assembly (16) operating in an electrolysis cell (10) for producing metal when an adjacent assembly (16?) is removed exposing remaining assemblies to low ambient temperatures (40) by utilizing heat radiation shields (24) which can circumscribe every inert anode assembly (16), where the shields (24) remain intact and in place in the cell (10) while operating in molten electrolyte (15) at about 850° C.

Abstract: The present invention provides a method of making a carbon electrode, suitable for use as an anode in an aluminum reduction cell, which comprises mixing an aggregate, comprising a mixture of particulate shot coke, and a particulate carbonaceous material other than shot coke with coal tar pitch or petroleum pitch or a combination of these pitches at an elevated temperature to form a paste wherein said aggregate comprises a combination of coarse, medium, and fine particles and said particulate shot coke may comprise a majority of said fine particles, and said paste comprises from about 80 to about 90%, by weight, of said aggregate and from about 10 to about 20%, by weight, of said pitch; forming said paste into a solid body; and baking said solid body at an elevated temperature to form said carbon electrode.

Abstract: A method for protecting anode assemblies in an electrolytic cell from thermal shock is disclosed. The method generally involves applying a thermal insulating layer (8, 16) to the anode (2) prior to preheating the anode assembly in a furnace, where the layer (8, 16) protects the anode (2) from thermal shock during transfer from the preheat furnace to the electrolytic cell. In a preferred embodiment the anode (2) is attached to a castable plate (4) that is also protected from thermal shock by an insulating layer.

Abstract: Electrolysis of alumina dissolved in a molten salt electrolyte employing inert anode and cathodes, the anode having a box shape with slots for the cathodes.

Abstract: A sintered electrode assembly is made of an inert electrode (15) containing a sealed metal conductor (20) having a surface feature (30) such as a coating or wrapping which aids in bond formation with the inert electrode (15) at their interface (45), where the metal conductor (20) is directly contacted by and is substantially surrounded by the inert electrode (15) without the use of metal foam or metal powders.

Abstract: An electrolytic cell for producing aluminum from alumina having a reservoir for collecting molten aluminum remote from the electrolysis.

Abstract: This cathode (3) contains, within the pores in its structure, a carbon-containing product fired at a temperature of less than 1600° C., improving the erosion resistance by protecting the graphitized binder.

Abstract: A method of producing aluminum from alumina in an electrolytic cell including using a cathode comprised of a base material having low electrical conductivity and wettable with molten aluminum to form a reaction layer having a high electrical conductivity on said base layer and a cathode bar extending from said reaction layer through said base material to conduct electrical current from said reaction layer.

Abstract: A thermal treatment system for thermally treating a sterile medium is controlled via a foot actuated switch to thermally treat the sterile medium to a desired temperature and/or form (e.g., slush). The thermal treatment system includes a basin recessed in a system top surface, while a surgical sterile drape is placed over the system and within the basin to form a drape container for containing the sterile medium. The basin may be configured to cool the sterile medium and form sterile surgical slush, or heat the sterile medium to provide warm sterile liquid. A dislodgment mechanism may be employed within a cooling basin to manipulate the drape and dislodge frozen pieces of sterile medium adhered to the drape. Information pertaining to the sterile medium and system operation may be displayed on a system display that has dimensions sufficient to provide visibility of the information to users located within extended ranges from the system.

Abstract: A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising the steps of providing a molten salt electrolyte at a temperature of less than 900° C. having alumina dissolved therein in an electrolytic cell having a liner for containing the electrolyte, the liner having a bottom and walls extending upwardly from said bottom. A plurality of non-consumable Cu—Ni—Fe anodes and cathodes are disposed in a vertical direction in the electrolyte, the cathodes having a plate configuration and the anodes having a flat configuration to compliment the cathodes. The anodes contain apertures therethrough to permit flow of electrolyte through the apertures to provide alumina-enriched electrolyte between the anodes and the cathodes. Electrical current is passed through the anodes and through the electrolyte to the cathodes, depositing aluminum at the cathodes and producing gas at the anodes.

Abstract: A method of inhibiting dissolution of a transition metal alloy anode (40) of an aluminium electrowinning cell comprises providing a sodium-inert layer (11,20,50,50′) on a sodium-active cathodic cell material (15), such as carbon, and electrolysing alumina dissolved in a sodium ion-containing molten electrolyte (30). Aluminium ions rather than sodium ions are cathodically reduced on the sodium-inert layer to inhibit the presence in the molten electrolyte (30) of soluble cathodically-produced sodium metal that constitutes an agent for chemically reducing the anode's transition metal oxides and anodically evolved oxygen, thereby inhibiting reduction of the anode's transition metal oxides by sodium metal and maintaining the evolved oxygen at the anode at a concentration such as to produce at the alloy/oxide layer interface stable and coherent transition metal oxides having a high level of oxidation.

Abstract: A method of preparing carbonaceous blocks or bodies for use in a cathode in an electrolytic cell for producing aluminum wherein the cell contains an electrolyte and has molten aluminum contacting the cathode, the cathode having improved wettability with molten aluminum. The method comprises the steps of providing a carbonaceous block and a boron oxide containing melt. The carbonaceous block is immersed in the melt and pressure is applied to the melt to impregnate the melt into pores in the block. Thereafter, the carbonaceous block is withdrawn from the melt, the block having boron oxide containing melt intruded into pores therein, the boron oxide capable of reacting with a source of titanium or zirconium or like metal to form titanium or zirconium diboride during heatup or operation of said cell.

Abstract: A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising the steps of providing a molten salt electrolyte at a temperature of less than 900° C. having alumina dissolved therein in an electrolytic cell having a liner for containing the electrolyte, the liner having a bottom and walls extending upwardly from said bottom. A plurality of non-consumable anodes and cathodes are disposed in a vertical direction in the electrolyte, the cathodes having a plate configuration and the anodes having a flat configuration to compliment the cathodes. The anodes contain apertures therethrough to permit flow of electrolyte through the apertures to provide alumina-enriched electrolyte between the anodes and the cathodes. Electrical current is passed through the anodes and through the electrolyte to the cathodes, depositing aluminum at the cathodes and producing gas at the anodes.

Abstract: An improved method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte, the method comprising the steps of providing a molten salt electrolyte at a temperature less than 900° C. having alumina dissolved therein in an electrolytic cell having a liner for containing the electrolyte, the liner having a bottom and walls extending upwardly from the bottom, the liner being substantially inert with respect to the molten electrolyte. A plurality of non-consumable anodes and cathodes are disposed in the electrolyte and an electric current is passed through the anodes and through the electrolyte to the cathodes depositing aluminum on the cathodes and generating oxygen bubbles at the anodes, the bubbles stirring the electrolyte. Periodically, the electric current flow to the cell is reduced for extended periods.

Abstract: A bipolar cell for the electrowinning of aluminium has bipolar electrodes each comprising a carbon cathode body having on one side an active surface on which aluminium is produced and connected on the other side through an oxygen impermeable barrier layer to an electrochemically active anode layer having an oxygen evolving iron oxide-based outer surface. The anode layer may comprise a metal-based anode substrate and a transition metal oxide-based outside layer, in particular an iron oxide-based outside layer, which either is an applied layer or is obtainable by oxidising the surface of the anode substrate which contains iron. During operation, the anode layer can be kept dimensionally stable by maintaining in the electrolyte a concentration of transition metal species which are present as one or more corresponding transition metal oxides in the electrochemically-active layer.

Abstract: This invention relates to the use of bubble-driven flow to enhance the dissolution and distribution of alumina in an aluminum electrolysis cell operating with inert anodes. By harnessing the driving force of bubbles rising along the sides of a sloped anode to induce circulation in a cell and by using a group of anodes to amplify the effect, alumina distribution can be maintained close to or at saturation without formation of muck/sludge. Alumina fed through point feeders at specific locations can be distributed throughout the entire cell rather than sinking to the bottom of the cell below the feed location. For a given circulation pattern, feeder locations can be optimized.

Abstract: The present invention is directed to methods for preheating a molten salt electrolysis cell having inert anodes (24) using recuperative gas heating by combusting a first gas outside the cell chamber (20) in a combustion chamber (2) and using to heat a second gas in recuperator (8) which second gas us passed to the cell chamber (20). The inert anode can be a cermet inert anode.

Abstract: A method of treating an electrolyte for use in the electrolytic reduction of alumina to aluminum employing an anode and a cathode, the alumina dissolved in the electrolyte, the treating improving wetting of the cathode with molten aluminum during electrolysis. The method comprises the steps of providing a molten electrolyte comprised of ALF3 and at least one salt selected from the group consisting of NaF, KF and LiF, and treating the electrolyte by providing therein 0.004 to 0.2 wt. % of a transition metal or transition metal compound for improved wettability of the cathode with molten aluminum during subsequent electrolysis to reduce alumina to aluminum.

Abstract: A method of preparing carbonaceous blocks or bodies for use in a cathode in an electrolytic cell for producing aluminum wherein the cell contains an electrolyte and has molten aluminum contacting the cathode, the cathode having improved wettability with molten aluminum. The method comprises the steps of providing a carbonaceous block and a boron oxide containing melt. The carbonaceous block is immersed in the melt and pressure is applied to the melt to impregnate the melt into pores in the block. Thereafter, the carbonaceous block is withdrawn from the melt, the block having boron oxide containing melt intruded into pores therein, the boron oxide capable of reacting with a source of titanium or zirconium or like metal to form titanium or zirconium diboride during heatup or operation of said cell.

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: 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 method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte. A plurality of non-consumable anodes are disposed substantially vertically in the electrolyte along with a plurality of monolithic hollow cathodes. Each cathode has a top and bottom and the cathodes are disposed vertically in the electrolyte and the anodes and the cathodes are arranged in alternating relationship. Each of the cathodes is comprised of a first side facing a first opposing anode and a second side facing a second opposing anode. The first and second sides are joined by ends to form a reservoir in the hollow cathode for collecting aluminum therein deposited at the cathode.

Abstract: Cathode connector means for low temperature aluminum smelting cell for connecting titanium diboride cathode or the like to bus bars.

Abstract: A method of producing aluminum in an electrolytic cell containing alumina dissolved in an electrolyte. The method comprises the steps of providing a molten salt electrolyte in an electrolytic cell having an anodic liner for containing the electrolyte, the liner having an anodic bottom and walls including at least one end wall extending upwardly from the anodic bottom, the anodic liner being substantially inert with respect to the molten electrolyte. A plurality of non-consumable anodes is provided and disposed vertically in the electrolyte. A plurality of cathodes is disposed vertically in the electrolyte in alternating relationship with the anodes. The anodes are electrically connected to the anodic liner. An electric current is passed through the anodic liner to the anodes, through the electrolyte to the cathodes, and aluminum is deposited on said cathodes. Oxygen bubbles are generated at the anodes and the anodic liner, the bubbles stirring the electrolyte.

Abstract: A method of producing commercial purity aluminum in an electrolytic reduction cell comprising ceramic inert anodes is disclosed. The method produces aluminum having acceptable levels of Fe, Cu and Ni impurities. The ceramic inert anodes used in the process may comprise oxides containing Fe and Ni, as well as other oxides, metals and/or dopants.

Abstract: An inert anode for the electrolytic production of metals such as aluminum is disclosed. The inert anode includes a ceramic oxide material preferably made from NiO, Fe2O3 and CoO. The inert anode composition may comprise the following mole fractions of NiO, Fe2O3 and CoO: 0.15 to 0.99 NiO; 0.0001 to 0.85 Fe2O3; and 0.0001 to 0.45 CoO. The inert anode may optionally include other oxides and/or at least one metal phase, such as Cu, Ag, Pd, Pt, Au, Rh, Ru, Ir and/or Os. The Ni—Fe—Co—O ceramic material exhibits very low solubility in Hall cell baths used to produce aluminum.

Abstract: A cell for the production of aluminium by the electrolysis of an aluminium compound dissolved in a molten electrolyte, in which an outer mechanical structure forming an outer shell (21) houses therein one or more inner electrically-conductive cathode holder shells or plates (31) which contain a cathode mass (32) and is/are connected electrically to the busbar. The cathode mass (32) has an aluminium-wettable top surface (37), preferably at a slope forming a drained cathode. The inner cathode holder shell or shells (31) is/are separated from the outer shell (21) by an electric and thermic insulation (40), the cathode holder shell(s) (31) also serving to distribute current uniformly to the cathode mass (32). The or each cathode (30) formed by the cathode holder shell (31) and cathode mass (32) is removable from the cell as a unit.

Abstract: Carbon-containing components of cells for the production of aluminium by the electrolysis of alumina dissolved in a cryolite-based molten electrolyte are protected from attack by liquid and/or gaseous components of the electrolyte in the form of elements, ions or compounds, by a refractory boride coating applied from a slurry composed of pre-formed particulate refractory boride in a colloidal carrier which is dried and heated to consolidate the coating.

Abstract: A method of producing commercial purity aluminum in an electrolytic reduction cell comprising inert anodes is disclosed. The method produces aluminum having acceptable levels of Fe, Cu and Ni impurities. The inert anodes used in the process preferably comprise a cermet material comprising ceramic oxide phase portions and metal phase portions.

Abstract: A non-carbon, metal-based high temperature resistant anode of a cell for the production of aluminium has a metal-based substrate coated with one or more electrically conductive adherent applied layers, at least one electrically conductive layer being electrochemically active. The electrochemically active layer contains one or more electrocatalysts fostering the oxidation of oxygen ions as well as fostering the formation of biatomic molecular gaseous oxygen to inhibit ionic and/or monoatomic oxygen attack of the metal-based substrate. The electrocatalyst can be iridium, palladium, platinum, rhodium, ruthenium, silicon, tin, zinc, Mischmetal oxides and metals of the Lanthanide series. The applied layer may further comprise electrochemically active constituents from oxides, oxyfluorides, phosphides, carbides, in particular spinels such as ferrites.

Abstract: A dimensionally stable electrode is provided comprising a hollow substrate with an open upper end for confining a fluid containing a metal, a film covering portions of the external surface; and a mechanism for replenishing the film. Also provided is a method for maintaining the dimensions of an anode during electrolysis comprising adapting an interior surface of the anode to receive a fluid containing a metal, facilitating transport of the metal to an exterior surface of the anode, forming a protective film on the exterior surface, wherein the transported metal is a cation of the formed protective film, and maintaining the protective film on the exterior surface while the anode is in use.

Abstract: The present invention includes a conceptually new process to produce primary aluminum through the modification/adaptation for the HHC of a non-consumable anode of the type used for solid oxide fuel cells (SOFC) with the provision to electrochemically utilize/burn a fuel. The present invention is believed to work most effectively when the dissolution and fragility problems of the zirconia-base solid electrolyte can be sufficiently alleviated, e.g., through the use of a lower electrolysis temperature, through the use of melt additives to restrict dissolution, and/or through modem methods for the fabrication/deposition of the electrolyte onto an appropriate internal metal anode. The present invention thus achieves, through the use of the solid-electrolyte-coated anode, the long-sought non-consumable anode. The electrochemical oxidation, inside the NCA in accordance with the present invention, of an inexpensive fuel, e.g.

Abstract: Disclosed is an improved carbonaceous material suitable for use as a cathode in an aluminum producing electrolytic cell, the cell using an electrolyte comprised of sodium containing compounds. The carbonaceous material is comprised of carbon and a reactive compound capable of suppressing the formation or accumulation of sodium cyanide during operation of the cell, of reacting with sodium to reduce problems associated with sodium intercalation, and of reacting with one of titanium or zirconium to form titanium or zirconium diboride during operation of the cell to produce aluminum.

Abstract: The present invention includes a conceptually new process to produce primary aluminum through the modification/adaptation for the HHC of a non-consumable anode of the type used for solid oxide fuel cells (SOFC) with the provision to electrochemically utilize/burn a fuel. The present invention is believed to work most effectively when the dissolution and fragility problems of the zirconia-base solid electrolyte can be sufficiently alleviated, e.g., through the use of a lower electrolysis temperature, through the use of melt additives to restrict dissolution, and/or through modern methods for the fabrication/deposition of the electrolyte onto an appropriate internal metal anode. The present invention thus achieves, through the use of the solid-electrolyte-coated anode, the long-sought non-consumable anode. The electrochemical oxidation, inside the NCA in accordance with the present invention, of an inexpensive fuel, e.g.