Abstract: The present invention relates to nonferrous metallurgy, in particular to the process equipment for electrolytic production of primary aluminum, namely to methods for lining cathode assemblies of reduction cells. A method for lining a cathode of a reduction cell for production of aluminum includes filling a cathode device shell with a thermal insulation layer and leveling said layer; filling, leveling and compacting a refractory layer; installing bottom and side blocks followed by sealing joints therebetween with a cold ramming paste. Prior to filling a shell bottom with the thermal insulation layer, a layer of fine carbonized particles is formed. The inventive method for lining a cathode assembly of a reduction cell for production of primary aluminum allows to reduce the cost of lining materials and energy consumption for reduction cell operation by means of improved heat resistance of a base and to increase the service life of reduction cells.

Abstract: And objective of the present invention is to provide an improved method and system for use for control of layer formation in an aluminium electrolysis cell and exploitation of the heat. The present invention attains the above-described objective by a reordering of the fundamental structure of a Hall-Héroult cell, providing two alternatives, eliminating the need for thermal insulation. In a first embodiment the ordering from the inside to the outside is: Electrolyte-sidelining-heat tubes-steel shell. In a second embodiment the ordering from the inside to the outside is: Electrolyte-sidelining-steel shell-heat tubes.

Abstract: A system and method is provided for control of layer formation by use of sidelining provided with heat tube.

Abstract: The invention relates to an electrolytic cell for obtaining aluminum, including a pot shell, at least one cathode block arranged at least partially in the pot shell, at least one anode suspended above the cell and dipping into the upper portion of the electrolytic cell, and an insulation at least partially covering the internal surface of the pot shell and located between the cathode block and the pot shell, the pot shell and the elements that it contains delimiting a crucible intended to receive an electrolytic bath in contact with the cathode block, characterized in that the insulation is at least partially made of carbon-based blocks having a heat conductivity lower than 1 W/m/K.

Abstract: A method of providing a safety lining in an industrial processing container, such as an aluminum electrolytic cell, is provided comprising providing a container having an interior and a at least one primary lining in juxtaposition to said interior of said shell, and adding a calcium aluminate clinker and/or castable layer between the primary lining and the shell of the container. Further, a method of trapping one or more gasses, elements or compounds produced from industrial processes is provided using the container having the calcium aluminate layer as herein described. An electrolytic cell is disclosed comprising a shell having an interior, one or more primary linings in juxtaposition to the interior of the shell, and one or more safety linings located between the primary lining and the shell, wherein at least one of the safety linings comprises a calcium aluminate clinker and/or castable.

Abstract: A slurry comprises suspended aluminum particles in a colloid having dispersed colloidal particles of a metal oxide such as a hydroxide. The metal oxide is reducible by metallic aluminum. The slurry has such a basic pH that dissolution of the aluminum particles in the slurry is inhibited so that when the slurry is subjected to a heat treatment, the undissolved aluminum particles are reactable with the colloidal particles to form an aluminum-based mixture resistant to chemical attack made of aluminum oxide, metal aluminum and the metal of the colloidal particles. The slurry can be used to form an aluminum-based protective coating on a component, in particular of an aluminum electrowinning cell or an apparatus for treating molten aluminum.

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 cell of advanced design for the production of aluminium by the electrolysis of an aluminium compound dissolved in a molten electrolyte, has a cathode (30) of drained configuration, and at least one non-carbon anode (10) facing the cathode both covered by the electrolyte (54). The upper part of the cell contains a removable thermic insulating cover (60) placed just above the level of the electrolyte (54). Preferably, the cathode (30) comprises a cathode mass (32) supported by a cathode carrier (31) made of electrically conductive material which serves also for the uniform distribution of electric current to the cathode mass (32) from current feeders (42) which connect the cathode carrier (31) to the negative busbars.

Abstract: An aluminum production cell includes an inert anode and an insulating lid comprising alumina and at least one metal fluoride. The insulating lid preferably comprises about 35-90 wt. % of a mixture of sodium fluoride and aluminum fluoride and about 10-65 wt. % alumina.

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 drained cathode cell for the electrowinning of aluminium comprises a cell bottom (20) arranged to collect product aluminium and thermic insulating sidewalls (40) lined with a molten electrolyte resistant sidewall lining (50), in particular containing silicon carbide, silicon nitride or boron nitride. The thermic insulating sidewalls (40) inhibit formation of an electrolyte crust on the lining (50), whereby the lining (50) is exposed to molten electrolyte. The cell bottom (20) has a peripheral zone from which the insulating sidewalls (40) extend generally vertically to form, with the cell bottom, a trough for containing molten electrolyte and aluminium produced on at least one drained cathode (32). The peripheral zone of the cell bottom (20) is arranged to keep the product aluminium from contacting and reacting with the molten electrolyte resistant sidewall lining 50).

Abstract: A method of producing aluminum, comprising the steps of:a) providing an aluminum reduction Hall cell for reduction of alumina in molten fluoride electrolyte containing cryolite, the cell comprising a cathode, an anode and a sidewall, the sidewall having a thickness and comprising:i) a lining consisting essentially of a material selected from the group consisting of silicon nitride, silicon carbide, and boron carbide, and having a density of at least 95% of theoretical density, and no apparent porosity, andii) an insulating layer backing the lining,b) contacting the lining with an electrolyte comprising at least 60% cryolite and having a temperature of between 650.degree. C. and 1100.degree. C.

Abstract: Carbon-containing components of cells for the production of aluminum 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 treatment composition which consists essentially of a solution of one or more phosphates of aluminum. The treatment composition may alternatively consist essentially of one or more phosphates of aluminum, and one on more colloidal carriers.

Abstract: A method for producing a metal in an electrolysis cell comprising an anode, a carbon cathode, and a chamber containing a metal oxide dissolved in a molten salt bath, said method comprising: coating an outer surface portion of the cathode with a coating composition consisting of a refractory metal, a paint comprising an organic polymeric binder, and aluminum powder, and optionally an organic solvent and an oil; and optionally a boron source; curing the coating composition by heating it to an elevated temperature, producing an aluminum-wettable coating on the cathode outer surface portion; and electrolyzing the metal oxide to a metal bypassing an electric current in the molten salt bath between the anode and the coated cathode.