Abstract: A fluorine gas generating apparatus for generating fluorine gas of high purity by electrolysis of a mixed molten-salt comprising hydrogen fluoride, the fluorine gas generating apparatus comprising an electrolytic cell which is separated into an anode chamber 5 and a cathode chamber 7 by a partition wall 28, and pressure keeping means 50 for supplying gas to the anode chamber 5 and the cathode chamber 7, respectively, to keep an interior of the anode chamber 5 and an interior of the cathode chamber 7 at a certain pressure.

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

Abstract: A drained-cathode cell for the electrowinning of aluminium comprises one or more anodes (14) suspended over one or more cathodes (16). The or each anode (14) and cathode (16) respectively have a sloped V-shaped active anode surface (22) and parallel sloped inverted V-shaped drained cathode surfaces (18) facing one another and spaced apart by two sloped inter-electrode gaps (20), arranged so the electrolyte circulates upwardly in the sloped inter-electrode gaps (20) assisted by anodically produced gas and then returns from a top part (22′) to a bottom part (22″) of each inter-electrode gap (20) along an electrolyte path (26,27,36,37).

Abstract: The present invention concerns a method and device for reducing emissions of process gases from Hall-Héroult cells to the ambient air. The cells comprise an anode superstructure (1) with covers which can be opened for access to the cell's anodes, among other things. The anode superstructure comprises an extraction system for the removal of process gases, which extraction system is adjusted to remove a standised quantity of process gases during normal operation of the cell. The extraction system is designed so that an increased quantity of process gases is removed when the covers of the anode superstructure are opened. One embodiment of the present invention includes a vertical partition wall (10′) which is located inside the anode superstructure and contributes to an improved flow pattern in the anode superstructure.

Abstract: A cell for the electrowinning of aluminum using anodes (10) made from a alloy of iron with nickel and/or cobalt is arranged to produce aluminum of low contamination and of commercial high grade quality. The cell comprises a cathode (20) of drained configuration and operates at reduced temperature without formation of a crust or ledge of solidified electrolyte. The cell is thermally insulated using an insulating cover (65,65a,65b,65c) and an insulating sidewall lining (71). The molten electrolyte (30) is substantially saturated with alumina, particularly on the electrochemically active anode surface, and with species of at least one major metal present at the surface of the nickel-iron alloy based anodes (10). The cell is preferably operated at reduced temperature from 730° to 910° C. to limit the solubility of these metal species and consequently the contamination of the product aluminum.

Abstract: A fluorine gas generator for generating fluorine gas by electrolysis of an electrolytic bath comprising a hydrogen fluoride-containing mixed molten salt in which generator the electrolytic bath will not corrode the upstream line even upon interruption of HF feeding or in case of emergency is provided. The generator has a hydrogen fluoride gas feed line for feeding hydrogen fluoride gas into the electrolytic bath, a first automatic valve disposed on the hydrogen fluoride gas feed line and capable of being closed on the occasion of interruption of hydrogen fluoride gas feeding, and an inert gas substitution means for eliminating the hydrogen fluoride gas remaining in the line on the side downstream from the first automatic valve on the hydrogen fluoride gas feed line and substituting an inert gas therefor when hydrogen fluoride gas feeding is interrupted.

Abstract: A method of electrochemically reducing a metal oxide to the metal in an electrochemical cell is disclosed along with the cell. Each of the anode and cathode operate at their respective maximum reaction rates. An electrolyte and an anode at which oxygen can be evolved, and a cathode including a metal oxide to be reduced are included as is a third electrode with independent power supplies connecting the anode and the third electrode and the cathode and the third electrode.

Abstract: An electrolysis cell includes an inner chamber containing a stack of porous anode and cathode plates with separators therebetween. Electrolyte is circulated through the porous anodes and cathodes in the inner chamber to generate hydrogen and oxygen gas. A plurality of electrolysis cells can be mounted together to form an electrolyzer unit.

Abstract: A cell for the electrowinning of aluminium comprises a plurality of metal-based anodes facing and spaced part from an aluminium-wettable drained cathode surface on which aluminium is produced. The drained cathode surface is formed along the cell by upper surfaces of juxtaposed carbon cathode blocks, the cathode blocks extending across the cell. The drained cathode surface is divided into quadrants by a longitudinal aluminium collection groove along the cell and by a central aluminium collection reservoir across the cell. Pairs of quadrants across the cell are inclined in a V-shape relationship, the collection groove being located along the bottom of the V-shape and arranged to collect molten aluminium draining from the drained cathode surface and evacuate it into the aluminium collection reservoir during cell operation.

Abstract: A fluorine gas generator for generating highly pure fluorine gas in a stable and safe manner by electrolyzing an electrolytic bath 2 comprising hydrogen fluoride in the form of a molten mixed gas is provided which comprises an electrolytic cell 1 divided, by a partition wall 16, into an anode chamber 3 in which an anode is disposed and a cathode chamber 4 in which a cathode is disposed, pressure maintenance means for maintaining the anode chamber 3 and cathode chamber 4 at atmospheric pressure, and liquid level sensing means 5, 6 capable of sensing the levels of the electrolytic bath 2 in the anode chamber 3 and in the cathode chamber 4, respectively, at three or more level stages.

Abstract: An electrochemical generator of pure pressurized high pressure hydrogen comprising a molten hydroxide or eutectic mixture electrolyte electrochemical pressurizing chamber bounded by a hydrogen-selective anode and a hydrogen-selective otherwise gas impermeable cathode respectively connected to a D.C. power supply, with the pressurizing chamber maintained at a temperature between the melting point of the electrolyte and about 600° C., wherein, upon passing D.C. current between the anode and cathode, pure hydrogen arriving on the electrolyte bounding with the anode substantially instantaneously reacts with hydroxyl ions from the electrolyte to form water and electrons and evolves pressurized pure hydrogen gas on the cathode, with such substantially instantaneous reaction at the anode creating a suction effect which effectively pumps pure hydrogen permeating through said anode.

Abstract: A method and apparatus for adding a metal, for example sodium, to a melt of a material, for example aluminum, in a vessel, in which a molten compound of the metal or a solution of a compound of the metal is provided in a container (12), the container being positioned outside the vessel, the compound is electrolytically decomposed and ions of the metal are caused to pass through a wall of a solid-state electrolyte (14) which is a conductor therefor, from a first side of the wall to an opposite second side thereof, and to combine with electrons at the second side of the wall and then to flow as molten metal from the container into the melt in the vessel.

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: An electrolytic cell for the electrowinning of aluminium comprises a cathode cell bottom provided with a series of sloped active cathode surfaces (11, 12) down which produced aluminium (60) is drained, and a series of recessed grooves or channels (20), below the bottom of the cathode active surfaces (11, 12) and extending therealong which collect and evacuate the drained produced aluminum (63). Preferably the active surfaces (11, 12) are V-shaped and the recessed grooves or channels (20) are provided with a sloping bottom and a constant cross-sectional area. Alumina is so fed into the cell as to supply alumina-rich electrolyte (62) into the recessed grooves or channels (20) which contain the alumina-rich electrolyte along substantially their entire length above the drained layer of aluminium (63).

Abstract: A non-carbon, metal-based slow-consumable anode of a cell for the electrowinning of aluminium self-forms during normal electrolysis an electrochemically-active oxide-based surface layer (20). The rate of formation (35) of the layer (20) is substantially equal to its rate of dissolution (30) at the surface layer/electrolyte interface (25) thereby maintaining its thickness substantially constant, forming a limited barrier controlling the oxidation rate (35). The anode (10) usually comprises an alloy of iron with at least one of nickel, copper, cobalt or zinc which during use forms an oxide surface layer (20) mainly containing ferrite.

Abstract: A process for preparing sodium and aluminum chloride electrochemically is described in which, in an electrolytic cell containing aluminum as an anode and sodium as a cathode which are separated from one another by a sodium ion-conducting solid electrolyte, a fused electrolyte essentially containing sodium tetrachloroaluminate is electrolyzed in the anode compartment, aluminum chloride formed in this process is evaporated from the electrolytic cell and sodium is removed from the cathode compartment.

Abstract: An apparatus for electrolytic production of magnesium includes a plurality of upright anode elements interspread with a plurality of cathode elements situated within at least one electrolysis compartment. At least one section, defined between two adjacent anodes and having an elongated loading inlet, is provided for receiving and melting of a substantially solid raw material. A gas discharging outlet is formed for discharging of chlorine gas developed at the plurality of anodes. A baffle is supported by the receiving anodes in the vicinity of the gas discharging outlet. The baffle prevents direct flow of a mixture of chlorine gas and fine dust particles resulted from loading of the solid raw material between the section and gas discharging outlet.

Abstract: A cell of advanced design for production aluminum by the electrolysis of an aluminum compound dissolve in a molten ectrolyte, 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 feeders (42) which connect the cathode carrier (31) to the negative busbars.

Abstract: An electrolytic cell for aluminum production, including a cell wall, a bus bar, a carbonaceous cathode block, and a collector bar connecting the bus bar with the cathode block. The collector bar comprises a ferrous metal body including a solid spacer and a sheath defining a cavity containing a copper insert. The spacer has an external end portion connected with the bus bar and an internal end portion that is preferably spaced inwardly of the cell wall. The spacer separates the copper insert from the bus bar, thereby reducing heat loss from the cell.

Abstract: An electrolysis cell for recovery of metals that are lighter than the electrolyte used in the cell. The cell makes use of multiple electrode assemblies, and each assembly is provided with an individual hood at the top forming a gas collection chamber. The hood of each assembly collects gas generated by the assembly and isolates the gas thus generated from gas generated by other assemblies and from metal collecting in the cell outside the hoods. The invention also relates to an integrated unit made up of an electrode assembly and an associated hood for use in a cell of the above kind, and a method of recovering metal by operating a cell of the above kind.

Abstract: An apparatus for electrolytic production of magnesium includes a plurality of upright anode elements interspread with a plurality of cathode elements situated within at least one electrolysis compartment. At least one section, defined between two adjacent anodes and having an elongated loading inlet, is provided for receiving and melting of a substantially solid raw material. A gas discharging outlet is formed for discharging of chlorine gas developed at the plurality of anodes. A baffle is supported by the receiving anodes in the vicinity of the gas discharging outlet. The baffle prevents direct flow of a mixture of chlorine gas and fine dust particles resulted from loading of the solid raw material between the section and gas discharging outlet.

Abstract: An electrolytic pot for the production of aluminum by the Hall-Héroult electrolysis process includes a cooling device for blowing air with localized jets, advantageously with variable flow, in order to evacuate and dissipate thermal energy from the pot. An aluminum production plant using the Hall-Héroult electrolysis process has at least some pots which, either individually or in common, include at least one cooling device.

Abstract: A non-carbon, metal-based slow-consumable anode of a cell for the electrowinning of aluminium self-forms during normal electrolysis an electrochemically-active oxide-based surface layer (20). The rate of formation (35) of the layer (20) is substantially equal to its rate of dissolution (30) at the surface layer/electrolyte interface (25) thereby maintaining its thickness substantially constant, forming a limited barrier controlling the oxidation rate (35). The anode (10) usually comprises an alloy of iron with at least one of nickel, copper, cobalt or zinc which during use forms an oxide surface layer (20) mainly containing ferrite.

Abstract: The aluminum smelting from alumina in the Hall-Heroult cells can be dramatically improved by using one or a combination of the following features together or in alternative to the Bayer alumina as feedstock: Al+++ alumina, sawtooth shaped electrodes, and lower temperatures. Laboratory experiments have shown that higher rates of dissolution of the Al+++ alumina in molten fluoride baths combined with lower voltage drops and improved design of electrodes can allow the operation of the cells at even higher current density, thus increasing overall productivity and efficiency of the cells.

Abstract: A fluorine generating cell apparatus, system, and method for the production of fluorine gas having an electrolyte melt flow circulation, a corrosion resistant anode connection, a separation skirt aiding in the circulation of the electrolyte melt, having a controlled gas recombination fail-safe, and a cathode arrangement enhancing efficiency and anode life by providing enhanced effective surface area for each anode.

Abstract: An electrochemical cell for the production of fluorine includes an anode having a carbon portion partially or fully impregnated with a polymeric material and a conductive centrally disposed internal channel that permits the anode to be run at high current with uniform current densities without undue resistance heating.

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: In a metallic Mg electrolyzing device provided with a plurality of electrolytic cells for forming metallic Mg, promotion of current efficiency in each electrolytic cell and decrease in electric power consumption rate are aimed at. In order to transport the Cl.sub.2 gas produced as a byproduct in the plurality of electrolytic cells to a Cl.sub.2 gas refining equipment, gas from the plurality of electrolytic cells is collectively sucked by use of a blower installed in the main pipe. And an automatic valve is installed in each of the branch pipes which branch out from the main pipe and introduce the Cl.sub.2 gas from each electrolytic cell to the main pipe. Each automatic valve is gate type, and its positioner is driven/controlled by air pressure. The suction pressure for sucking Cl.sub.2 gas in the plurality of electrolytic cells is detected and the opening degree of the automatic valves is automatically controlled so that each detected pressure is controlled to the target value.

Abstract: Described is a method and apparatus for producing high purity titanium and high purity titanium so produced. The process contemplates producing titanium sponge in a container and performing titanium fused salt electrolysis in situ in the same container to produce high purity titanium crystal, and where especially low oxygen content is desired, to treat the high purity titanium crystal as produced with iodine.

Abstract: Apparatus is disclosed for the production of nitrogen trifluoride (NF.sub.3), starting with an anhydrous molten flux including ammonia (NH.sub.3), a metal fluoride (MF), and hydrogen fluoride (HF). The apparatus includes an electrolyzer, an ammonia solubilizer, a hydrogen fluoride solubilizer, a nitrogen trifluoride reactor, two compressors, two pumps, three condensers a gas recycle loop, and, two flux loops of the same component ternary flux, but each loop with different concentration.

Abstract: A process for changing spent anodes while recovering the majority of the gaseous compounds evolved by the spent anodes and by the bath crust removed from the electrolytic pots during the cooling phase uses an effluent-collection device for electrolytic pots. A device for collecting gaseous effluents from pots for the production of aluminum by igneous electrolysis allows the recovery of the gaseous compounds evolved by the spent anodes and by the crust which they contain during the replacement and cooling of these anodes and this crust. The device preferably includes a degassing and cooling container located at one of the ends of the hooding device of the pots. The container can be made to communicate with the suction produced by the gas collection device.

Abstract: An electrolytic cell for reduction of a metal oxide to a metal and oxygen has an inert anode and an upwardly angled roof covering the inert mode. The angled roof diverts oxygen bubbles into an upcomer channel, thereby agitating a molten salt bath in the upcomer channel and improving dissolution of a metal oxide in the molten salt bath. The molten salt bath has a lower velocity adjacent the inert anode in order to minimize corrosion by substances in the bath. A particularly preferred cell produces aluminum by electrolysis of alumina in a molten salt bath containing aluminum fluoride and sodium fluoride.

Abstract: An electrolytic cell is provided that increases current efficiency in the fused alkali chloride salt electrolysis process for producing chlorine and sodium or lithium by improved design of the cell's product collector, diaphragm and graphite anode.

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: An electrolysis cell for the production of aluminum by the electrolysis of alumina dissolved in a molten halide electrolyte using a multimonopolar arrangement of substantially non-consumable anodes and cathodes with facing operative surfaces which are upright or at a slope and are spaced in a substantially parallel relationship, enabling operation at low and/or current density with an acceptable production per unit self-lowered area. The operative surface area of the anodes and the cathodes is high due to their upright sloping configuration. Operative surfaces of the anodes and possibly of the cathodes can be increased by making them porous, preferably with their articulated skeletal structure, e.g. with a porous active part on opposite faces of a central current feeder.

Abstract: The present invention relates to a method for closing and cooling of the top of a Soderberganode for use in connection with electrolytic production of aluminum, which anode is equipped with an anode casing and vertical contact bolts for holding and for conducting operating current to the anode and where the top of the anode casing is equipped with at least one cover having openings for the contact bolts and at least one off-gas opening. The amount of gas removed from the top of the anode through the off-gas opening is regulated in such a way that a sufficient diminished pressure is provided on the top of the anode that surrounding air will flow through air gaps arranged between the cover and each of the contact bolts in such an amount that gas from the top of the anode does not escape through the air gaps and to keep the temperature of the top of the anode casing below a preset temperature.

Abstract: An on-demand fluorine cell is described together with the construction of a suitable anode and a means of mounting the anode within the cell. The fluorine cell comprises a cell container having a cathode compartment and an anode compartment, the anode compartment having an anode therein, the cathode compartment and the anode compartment having separation means therebetween so as to separate fluorine gas and hydrogen gas generated during operation of said fluorine cell but said separation means allowing passage of electrolyte between said compartments; said anode extending below a lower end of the separation means and being continuously in contact with the electrolyte, control sensor means in at least one of said compartments to sense the level of electrolyte in said at least one compartment; electric current supply means responsive to signals from said control sensor means so as to either start or stop current supply in accordance with said signals.

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 apparatus for electrochemical refining of a low carbon steel melt is provided.

Abstract: A carbonaceous, refractory or metal alloy substrate material coated with a refractory material, the refractory material including at least one of borides, silicides, nitrides, aluminides, carbides, phosphides, oxides, metal alloys, inter-metallic compounds and mixtures of one of titanium, chromium, zirconium, hafnium, vanadium, silicon, niobium, tantalum, nickel, molybdenum and iron and at least one refractory oxide of rare earth metals. An aluminum production cell including a component made up of a material coated with the coating described above is also disclosed.

Abstract: A process for electrolytically producing magnesium metal from MgCl.sub.2 dissolved in an electrolyte, by conversion to the product metal and chlorine gas, wherein the MgCl.sub.2 content of the electrolyte is replenished by supplying thereto a feed having as components one or more magnesium chloride ammoniates for decomposition by the heat of the electrolyte into MgCl.sub.2 and ammonia gas. The feed, which may also include uncombined MgCl.sub.2, is delivered to the electrolyte at a location at which the generated ammonia does not come into reactive contact with the chlorine gas. The temperature of the electrolyte as well as its MgCl.sub.2 content can be controlled by selection of feed components, relative proportions, and rate of supply. The ammoniate content of the feed can be produced by reaction of ammonia with magnesium chloride hydrates, using the ammonia gas generated by the decomposition.

Abstract: Automatized equipment for the replacement of the anodes in the cells for aluminum production, comprising two modular structures suspended from saddles sliding on a bridge crane provided in the cell room, the first structure being provided with devices for crust breaking, the removal and laying of worn anodes on a platform translable on a special vehicle placed on a side of the cells, and then for hooking new anodes placed on the same platform and positioning them into the hollow space of the removed worn anodes and the second structure being provided with a device for cleaning the hollow space, and for collecting and transferring slags into a special container placed at the opposite side of the cells on a special vehicle, as well as of means for covering with alumina and/or other powdery materials the new repositioned anodes.

Abstract: A metal surface, useful as an electrode in an electrolytic cell, is now described having enhanced adhesion of subsequently applied coatings combined with excellent coating service life. The substrate metal of the electrode, such as a valve metal as represented by titanium, is provided with a highly desirable rough surface characteristic for subsequent coating application. This can be achieved by various operations including etching and melt spray application of metal or ceramic oxide to ensure a roughened surface morphology. Usually in subsequent operations, a barrier layer is provided on the surface of enhanced morphology. This may be achieved by operations including heating, as well as including thermal decomposition of a layer precursor. Subsequent coatings provide enhanced lifetime even in the most rugged commercial environments.

Abstract: A process and an electrolytic cell for the production of fluorine. A fluorine-containing electrolyte is passed in non-turbulent flow between an anode and a cathode of the electrolytic cell. The electrolyte emerging from between the anode and the cathode is divided into two streams. One stream emerges adjacent to the anode and has fluorine entrained therein, the other stream emerges adjacent to the cathode and has hydrogen entrained therein. The fluorine and the hydrogen are subsequently separated from their respective streams of electrolyte.

Abstract: A multimonopolar cell for electrowinning aluminium by the electrolysis of alumina dissolved in a molten salt electrolyte, comprises electrode assemblies each having a non-consumable anode and a non-consumable cathode both resistant to attack by the electrolyte and by the respective product of electrolysis. The anode (2) is preferably of tubular form with an active anode surface (7) inside, and the cathode is made of one or more rods (1) or tubes placed in the middle of the tubular anode or between plate anodes, the cathode extending beyond the bottom of the anode. The active anode surface area is bigger than the facing active cathode surface area. In use, the electrode assembly is partly immersed vertically or at a slope in the electrolyte (3) with the cathode dipping in a layer (4) of aluminum on the cell bottom.

Abstract: An aluminium smelting cell comprising a floor defining a cathode surface (4) which is substantially horizontal in the longitudinal direction of an overlying anode (1), shaped structures (2,3) projecting from the cathode surface (4) and having exposed surfaces of aluminium wetted material, the shaped structures being positioned to cause preferential contouring of the anode (1), particularly at its longitudinal edges (5,6) to allow for improved bubble release and to minimize cell resistivity.

Abstract: A method for electrochemical refining of an impurity-containing melt using a solid electrolyte ionic conductor to remove the impurity from the melt is provided. Also provided are an apparatus for performing the method, and a batch and a continuous method for electrochemical refining of a melt.

Abstract: A molten salt reactor for potentiostatic electroplating that includes a rtor chamber defined by a peripheral wall, a bottom wall and a top cover. The bottom wall of the reactor chamber has an opening, to which a first end of a gas inlet conduit is attached so as to be in fluid communication with the reactor chamber. A crucible support platform is positioned within the reactor chamber, and a crucible for holding a molten salt is mounted thereon. A furnace substantially surrounds the peripheral wall of the reactor chamber and the first end of the gas inlet conduit. The crucible support platform is electrically insulated from the reactor chamber. An inert gas flows from the gas inlet conduit, through a lower portion of the reactor chamber, past the crucible support platform, through an upper portion of the reactor chamber, and to a gas outlet in the upper portion of the reactor chamber.

Abstract: The present invention relates to an arrangement for closing the top of a Soderberganode used in an electrolytic cell for production of aluminum. The anode comprises an anode casing and vertical contact bolts for holding and for conducting electric current to the anode. The top of the anode is closed by means of at least one central cover having openings for the contact bolts and at least one side cover which can be opened in order to charge anode paste to the anode.

Abstract: Improved methods and apparatus for carrying out the methods are disclosed for feeding alumina into a Soderberg type aluminum reduction cell (10), so as to maximize efficiency of the cell. The apparatus includes a continuous point feeder assembly (12) connected to the cell structure over an exposed peripheral portion of the cryolite bath. The feeder assembly includes as alumina feed hopper (40) and a pair of vertically disposed feeding bins (56). Each feeding bin receives alumina from the hopper. A piston and cylinder assembly (46) is connected to the feeder assembly and arranged to drive a crust breaking member (44) down through bath crust (17) to form a temporary opening.