US3133008A - Furnace for electrolysis of aluminum operating at constant height of liquid levels - Google Patents

Furnace for electrolysis of aluminum operating at constant height of liquid levels Download PDF

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US3133008A
US3133008A US711577A US71157758A US3133008A US 3133008 A US3133008 A US 3133008A US 711577 A US711577 A US 711577A US 71157758 A US71157758 A US 71157758A US 3133008 A US3133008 A US 3133008A
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aluminum
furnace
receptacle
bath
molten
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Varda Giuseppe De
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
    • C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
    • C25C3/08—Cell construction, e.g. bottoms, walls, cathodes

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  • the quantity of metal removed by tapping is such as to restore said height level substantially to the same, minimum, starting value resulting after previous tappings.
  • the process of the present invention surprisingly eliminates, to av great extent, the aforesaid inconveniences, since it facilitates maintenance of the height level of the molten aluminum in the cells substantially constant during electrolysis (and pouring).
  • a device which also forms part of the present invention, permits the removal from the cell, automatically and expeditiously, and in a substantially continuous manner, of quantities of molten aluminum substantially equivalent to those being produced by the electrolysis.
  • the invention resides in replacing the periodic or intermittent aluminumtapping operation by a continuous, or nearly continuous, and automatically functioning overflow of the aluminum over a Weir, or other overflow or overfall device, and preferably down into a hot receptacle or channel preferably placed, enclosed, or formed within the heat insulated interior of the furnace.
  • the height of the Weir is predetermined so as to obtain the optimum amount of overflow of excess aluminum, coming from the bottom of the individual electrolysis gaps.
  • This receptacle is otherwise completely separated from the respective cell or cells which feed it.
  • the aluminum collected in said receptacle may be sucked, drawn, discharged, or removed ⁇ in any manner. It is always ready in the molten state, whenever needed. An important aspect is that its removal does not affect the level of the molten aluminum in the interior of the cell or cells feeding said receptacle to the last extent.
  • FIG. 1 is a vertical, longitudinal view, chiefly sectional, of a number of contiguous cells of a necklace-type multicell furnace having self-restoring anodes, as modified in accordance with the present invention; the partial section is on line 1 1 of FIG. 2;
  • FIG. 2 comprises two partial horizontal sectional-views taken at line A-A of FIG. 1, the sections being taken respectively at a lower level through the graphite bipolar electrodes, and at a higher level through the channels which ensure circulation of the bath from gap to the next;
  • FIG. 3 constitutes a top view at the right and a sectional view at the left, taken at B-B of FIG. l;
  • FIG. 4 is a transverse cross-section of the furnace of FIG.v 1;
  • FIG. 5 is a longitudinal vertical section of the said furnace taken parallel to and near its longitudinal axis,- at line D-D of FIG. 4;
  • FIG. 6 is a vertical section of a conventional furnace having horizontal layers and two self-baking electrodes, as modified in accordance with the present invention; FIG. 6 is taken at B-B of FIG. 7;
  • FIG. 7 is a horizontal section of the two-electrode furnace of FIG. 6, taken at A-A of FIG. 6.
  • FIG. 1 is a partial section of the furnace described in my application Serial No. 587,985, modified in accordance with my application Ser. No. 706,077 and in accordance with the present invention. 4
  • the reference numeral 2 (FIG. l) represents blocks ofinert refractory materials, which form one electrolysis the top head parts of the bipolar electrodes 1.
  • Blocks 2 rest on vertical walls 13 (FIGS. l and 2) of the same refractory. Two walls 13 divide the bipolar electrodes into three sections (FIG. 2).
  • Blocks ⁇ 2 are provided with vertical grooves 14 and are passed through by the conduits which permit the regulated ilow of the bath through the necklace circuit of cells.
  • Above blocks 2 are fixed layers 6 and mobile layers 8, each of heat-insulating material.
  • On the blocks 2 rest refractory pieces 3, of chimney shape. The chimneys pass through the external covering of the furnace 7 and are closed by mobile, preferably heat insulated, covers 5 arranged side by side.
  • the interstice between the fixed vand stationary bipolar electrodes 1, preferably comprising graphite, and the anodic layer l4 is lledup by a liquid lm 17 which may comprise molten aluminum.
  • the layer 4 is of the selfrestoring type, kpreferably comprising electrode carbon, pre-baked or self-baking.
  • the bipolar electrodes rest on ledges or'sockets 18, 19 and 20 of said refractory material. This segregates or separates the lower chambers that collect the aluminum produced in the contiguous cells, for instance 16 and 22.
  • the lower, recess-free, chambers 11 are here reduced to minimum dimensions. The depth and Volume of chamber 11 are only minor or small portions of the corresponding dimensions of the electrode gap above it.
  • the fraction may range from about a fourth Vto a tenth or less.
  • a chamber of great capacity for collecting the aluminum since the present invention permits operation with liquid layers not subjected to sudden level variations, such as are caused, for example, by periodic tapping.
  • This surprising result is due to constancy of supply of all of the starting materials partaking in the production cycle (A1203 and auodes), and to constancy in removal of all of the products of electrolysis, the aluminum and gas evolved at the electrodes, although keeping the lower chambers and the metal therein electrically insulated, or at least not short circuited between each other.
  • the lower chamber 11 of each cell is connected, through the conduit 12, with a corresponding individual, vertical, or nearly vertical, tapping well or pocket 28 (FIG. 4), at a suitable level of which a slit serving as an overow weir is provided.
  • each cell the bath of the electrode gap 16, or 22, is in contact with the inclined, .upwardly facing cathode faces of the bipolar electrodes 1 and with the self-restoring anode assemblies '4.
  • the electrode gap is limited laterally by the walls 23 (FIGS. 2. and 3) of the already mentioned refractory material.
  • the fixed bipolar electrodes 1, the -self-restoring anodes 4 and the interposed liquid film 17, are subdivided by the refractory walls 13 (FIG. 2) so that in this example every cell actually comprises three anodes and three cathodes.
  • the restoring anodes 4 are visible in FIG. 2, in both sectionsof the furnace, taken at two levels, as explained above, while of the chimney-shaped piece 3 only the front-side submerged in the bath is visible.
  • FIG. 3 represents ahorizontal section of the cells taken at the level of the chambers for gas discharge, while the right half is a top View, as explained above.
  • FIG. 6 represents a top View ofthe fixed heat insulator arranged above the horizontal refractory block 2.
  • Numerals 3 and 4 respectively designate the section of the chimney-shaped piece and the section of the restoring anode.
  • S is the cover ofthe chimney and 8 is the mobile heat-*insulating layer interposed between the free bath surface below and the gas-discharge chamber above.
  • At 9 (FIGS. 1 and 3) is the supporting joist or the disposed under the mobile insulating layer.
  • FIG. 4 is a sectional view taken along line C-C of FIGS. l and 5. It is a cross section through two cells disposed yside by side and belonging to the two parallel branches of the above-described necklace-type furnace. The branches are separated by a longitudinal, dividing I wall structure in which is formed the longitudinal channel 29.
  • This figure illustrates how the chimney-shaped pieces 3 enclose the upper portions of each of the self-restoring anodes 4.
  • the bath layer 16 (cryolite for example) superimposed on the layer of molten metal 11 (aluminum).
  • the metal covers the bottom 21 of the lower chamber.
  • At 27 is a normally closed discharge at the bottom of the cell, directed towards the outside.
  • the lower chamber for the metal is in communication, at the side .opposed to the discharge 27, through channel 12, with the already described tapping pocket 28, closed at the top by heat-insulating cover 25.
  • Each pocket has a slit 24 which can act as an overflow or better overfall and puts the pocket in communication with the channel, ⁇ reservoir or receptacle 29 formed in the interior refractory dividing wall of the necklace furnace.
  • the channel is closed by heat insulated covers 26.
  • the height of said overflow slits above the Vbottom 21 of the lower aluminum collecting chamber should be so calculated that the static-pressures on bottom 21, and on the base of pocket 28 are equal.
  • the weight of the column of molten aluminum bearing upon the unit area of the base of the tapping pocket 28 is equal to the counter-pressure exerted by the liquid column on the unit of area of the 'bottom 21 of the corresponding lower aluminum chamber.
  • the latter liquid column is composed of aluminum in its lower portion and in its upper portion of bath, said aluminum and said bath having the same heights as the corresponding two liquid layers present in the lower chamber and in the electrode gap and the upper flared space (visible in FIG. 1) formed by the horizontal, refractory blocks 2 constituting the upper heads of the electrodes and the front walls of the chimney pieces.
  • the height of the liquid column in the cell is always higher than that in the tapping pocket, since the density of the bath is about 2.1 and that of the molten metal is about 2.3.
  • the receptacle may have at least sufficient capacity to accept all of the aluminum Vas currently produced in the cells connected thereto, during the period between two successive operations of removing from the furnace the metal thus separated.
  • the aluminum that overows falls down preferably in form of separate drops and collects at the bottom of the twolongitudinal compartments of the receptacle is rfurnace and not shown in the drawing, sible to lift and to lower the electrodes, for example by the amount needed for compensating,
  • Cell lining 23 may be made of refractory material based on MgO, silicon carbide, etc.
  • FIG. 5, taken along line D-D of FIG. 4, is a longitudinal section of the same closed circuit, multicell furnace. It is taken near the center line of the furnace, and thus longitudinally sections the receptacle or channel 29 employed for collecting the molten aluminum produced. The aluminum is removed from said receptacle when desired, for further processing by known methods.
  • the conduits 32 and 35 connect the two parallel branches of the necklace-type multicell furnace to ensure the circulation of the bath in a closed circuit enclosed Within the furnace. The circulation is carried out with the aid of a device for lifting the bath not shown in the drawing, for example of the kind described in the application of G. Calabria, Serial No. 670,785, led Iuly 9, 1957, now U.S. Patent No.
  • 2,991,240 describing an oscillating dipping bucket raising molten bath from one terminal chamber to a second, the rst chamber having a lower bottom wall than the second and serving to receive molten bath liquid from a longitudinally disposed battery of cells, the bath liquid recirculating from the first terminal chamber through another longitudinally disposed battery of cells and back to the other battery.
  • the lifting may also be accomplished by means of gas pressure as in the application of G. de Varda No. 587,985, led May 29, 1956, or by means of the linearly reciprocating, valveless graphite piston described in A. V. de Pava application 'Serial No. 705,373, filed December 26, 1957, now U.S. 'Patent No. 3,063,930 or by other known devices.
  • the valuminum 31 and 34 falling from the weirs of individual tapping pockets collects on the bottom wall of one of the two longitudinal compartments formed by Wall 30.
  • the aluminum forms one or more deposits at the lowest points of said bottom wall.
  • the longitudinal compartment may be divided by one or more transverse partitions 33 (FIG. to keep separate the product of individual groups of contiguous cells, if necessary, in view of the grade of the metal to be produced.
  • the transverse partitions, as well as the longitudinal partition 30, may have horizontal bottoms or bottoms of opposed inclinations. The partitions are useful but may be omitted.
  • Electrodes 40 are separated, by the electrode spacing 50, from the unrderlying layer of molten aluminum 60 produced electro- 'lytica1ly.
  • the electrodes are controlled by known mechanical devices, the control devices being outside the whence it is posprogressively, for the consumption by electrolysis of carbon anode 40, and of the bath layer, thus keeping the electrode spacing 50 It is preferable to replace hand .the level and the balance lThe vertical walls 131, 150 etc.
  • refractory walls 131 made preferably of silicon nitride bonded silicon carbide (refrax) or of magnesium oxide which have been rendered impermeable to the bath by an inert gas current as described in the application of G. Calabria Serial No. 706,381, tiled December 31, 1957, now abandoned or by impregnating with a solution of pitch, removing excess surface pitch, and therefore carbonizing, as described in my application Serial No. 705,374, filed December 26, 1957, now U.S. Patent No. 2,952,605. But any conventional material, for instance carbonaceous masses or blocks may be used too.
  • the thin walls 70 and 90 form an interspace which communicates, through holes provided at the base of the wall 70, with the bottom layer 60 of cathodic metal and, by means of the overflow weirs 100, with the receptacle 120 preferably provided in the pot zone intermediate and between the two self-baking electrodes 40.
  • the interspace formed by the walls 70 and 90 is closed by the cover 101, and the receptacle 120 by the covers 200.
  • the apparatus is thus arranged so that the liquid 300 (FIG. 6) penetrating into the interspace is formed exclusively of molten aluminum, and not of bath. If the level of the free surface of the bath is kept constant, the height of the overflow Weir determines the height or level of the metal in the zone under the electrodes. To keep the bath level constant it is necessary to supply the bath with alumina in a sufficiently continuous manner, and to keep, as already stated, the height of the lower base planes of the two electrodes substantially constant. Under these conditions, the aluminum produced by electrolysis will cause an equivalent quantity of aluminum to overflow from the interspace into the receptacle 120, on the bottom of which the layer of aluminum 111 forms.
  • This deposit of aluminum can be removed for subsequent known processing steps, being taken, when needed, without interfering to the least extent with the constancy of in or of the electrolysis operation in the cell proper.
  • the deposit is removed by lifting the cover 200 and sucking out by a known technique, for instance by means ⁇ of a mobile pipe submerged from above, allor part of the aluminum 111.
  • FIG. 7 is a horizontal section of the same furnace also illustrates atop view ofthe cathodic bottom part.
  • the continuous feeding of alumina is carried out according to known methods, the
  • alumina being preferably fed into zone 160 disposed internally with respect to the head walls 150 of the two indicated in the drawing.
  • a furnace for producing aluminum by'electrolyss alumina in a molten salt bath comprising a containing furnace wall structure at least in part lined internally lanode and cathode means therein, a lower chamber therein for receiving the aluminum produced, means in the furnace providing a refractory lined tapping pocket forY aluminum metal and a passage connecting the lower chamber with the lower portion of said pocket for ow of aluminum metal, a refractory lined hot receptacle for aluminum in the furnace, and an over-fall device by which the receptacle receives molten aluminum from said lower chamber, the body of molten aluminum in the receptacle having a free upper surface below the over-fall device,
  • the height of the overthe height of theoverflow weir fall device being such that the static liquid pressures on the bottom of the lower chamber and at the bottom of the tapping pocket are substantially equal, said receptacle being otherwise isolated from said bath, the tapping pocket and the receptacle being located within and inwardly removed from the refractory outer side walls of said furnace, and being in proximity to the molten salt bath.
  • a furnace for producing aluminum by electrolysis of alumina in a molten salt bath comprising a containing refractory furnace wall structure, anode and cathode means therein, the furnace providing a lower chamber for receiving the aluminum produced, means in the furnace providing a Vhot storage receptacle for aluminum and providing an overflow weir over which the molten aluminum flows down into the receptacle, said molten aluminum coming from said lower chamber, an upwardly-downwardly directed tapping pocket for the aluminum, the pocket communicating at its lower end portion with the said lower chamber, for removal of molten aluminum therefrom, and communicating, by means of the Weir, with the receptacle for flow of aluminum to the latter, being such that Ithe static liquid pressures on the bottom of the lower chamber and at the bottom of the tapping pocket are substantially equal, said receptacle being otherwise isolated from said bath, the tapping pocket and the receptacle being located within and inwardly removed from the refractory outer side walls of said furnace, and being in proximity to
  • a furnace for producing aluminum by electrolysis of alumina in a molten salt bath comprising a containing refractory furnace wall structure, a plurality of anode and cathode means therein providing a plurality of cells, said furnace providing passages for serial flowand serial circulation of the molten bath amongst the cells, the passages including over-ow conduits for determining the bath level in the cells, the furnace providing a lower chamber for receiving the aluminum produced, means in the furnace providing a hot storage receptacle for aluminum and providing an overilow Weir over which the molten aluminum flows down into the receptacle, said molten aluminum coming from said lower chamber, an
  • Aupwardly-downwardly directed tapping pocket for the aluminum the pocket communicating at its lower end ⁇ portion with the said lower chamber, for removal of molten aluminum therefrom, and communicating, by means of the Weir, with the receptacle for flow of aluminum to the latter, the height of the weir being such that the static liquid pressures on the bottom of the lower chamber and at the bottom of the tapping pocket are substantially equal, said receptacle being located Within the structure of the furnace in proximity to the molten salt -bath and being between, and receiving aluminum from, adjacent cells.
  • a heat insulated, refractory lined furnace for producing aluminum by electrolysis of alumina in a fused fluorinated bath comprising therein two groups of cells, k
  • the furnace providing a bottom wall and structure for collection of an individual molten aluminum layer below the upper bath layer of each cell, upwardly extending tapping pockets communicating below with the individual aluminum layers on the bottom wall for Yreception of aluminum therefrom, weir means over which the aluminum flows from the pockets and falls down into the receptacle means, so that molten aluminum is removable at will from the receptacle means without disturbing the level of the molten aluminum on the bottom wall of each cell, said furnace providing over-flow con- -duits ⁇ serially connecting 'the electrolysis gaps of the cells .to determine the maximum height of the bath in said gaps.
  • a heat insulated, refractory lined furnace for producing aluminum by electrolysis of alumina in a fused fluorinated bath comprising therein two groups of cells, an intermediate refractory wall separating the groups, the wall providing therein receptacle means for the aluminum produced, the groups each comprising upwardlydownwardly extending electrode structures providing opposed pairs of anodic and cathodic surfaces, each pair defining therebetween an upwardly-downwardly extending electrolysis gap, the furnace providing a bottom wall for collection of a molten aluminum layer-below the upper bath layer, upwardly extending tapping pockets cornmunicating below with the layer on the bottom wall for reception of aluminum therefrom, each electrolysis gap having an individual tapping pocket, the lower portions of the gaps being isolated from communication with each other to ensure separate removal of the aluminum Vto the respective tapping pocket, weir means over which the aluminum flows from the pocket down into the receptacle means, the effective height of the overflow weir being such that the static pressure of the bath layer andmetal layer on said bottom wall
  • a heat insulated, refractory lined furnace .for producing aluminum by electrolysis of alumina in a fused fluorinated bath comprising therein two groups of cells, an intermediate refractory wall separating the groups, the wall providing therein receptacle means for the aluminum produced, the groups each comprising upwardlydownwardly extending electrode structures providing opposed pairs of anodic and cathodic surfaces, each pair defining therebetween an upwardly-downwardly extending electrolysis gap, the furnace providing a bottom wall for collection of a molten aluminum layer below the upper bath layer, upwardly extending tapping pockets communieating below with the layer on the bottom wall for reception of aluminum therefrom, each electrolysis gap having an individual tapping pocket, the lower portions o'f the gaps being isolated by transversal partitions of refractory material having poor electric conductivity from communication with each other to avoid by-passage of electric current and to ensure separate removal of the aluminum to the respective tapping pocket, weir means over which the aluminum flows from the pockets down into the receptacle means.
  • a heat insulated, refractory lined furnace for prov ducing aluminum by electrolysis ⁇ of alumina, whose content, in a fused iiuorinated bath is kept practicallyconstant, comprising therein two groups of cells, an intermediate refractory wall separating ythe groups, the wall providing therein receptacle means for the aluminum produced, the groups each comprising upwardly-downwardly extending bipolar intermediate electrode structures each cell, upwardly extending tapping pockets communicating below with the bottom wall for reception of aluminum therefrom, each electrolysis gap having an individual tapping pocket, the lower portions of the gaps being isolated from communication with each other for separate removal of the aluminum to the respective tapping pocket, weir means over which the aluminum flows from the pockets to the receptacle means, whereby continuous anode surface restoration, controlled removal of aluminum from the gaps to maintain the liquid levels constant in the cells, and substantially constant spacing between the anodic and cathodic surfaces is maintained.
  • a heat insulated, refractory lined furnace for producing aluminum by electrolysis of alumina in a fused fluorinated bath comprising therein two groups of cells, an intermediate refractory wall separating the groups, the walls providing therein receptacle means for the aluminum produced, the groups each comprising upwardly-downwardly extending electrode structures providing opposed pairs of anodic and cathodic surfaces, each pair defining therebetween an upwardly-downwardly extending electrolysis gap, the furnace providing a bottom wall for collection of a molten aluminum layer below the upper bath layer, upwardly extending tapping pockets communicating below with the layer on the bottom Wall for reception of aluminum therefrom, each electrolysis gap having an individual tapping pocket, the lower portions of the gaps being isolated from communication with each other to permit separate removal of the aluminum to the respective tapping pocket, Weir means over which the aluminum flows from the pockets down into the receptacle means, the receptacle means comprising an elongated channel having a bottom wall, the weir means being formed in opposite longitudinally directed walls
  • a multicell furnace for production of molten aluminum by electrolysis of alumina in a molten salt bath comprising a series of upwardly-downwardly extending, longitudinally spaced bipolar electrode structures each having opposite walls providing anodic and cathodically active surfaces, the anodic surfaces comprising self-restoring carbonaceous material consumable in the electrolysis, the opposed active surfaces of each pair of contiguous bipolar electrodes remaining at a constant distance, delining between them upwardly-downwardly extending electrolysis gaps, the bottom of the furnace having a refractory, inert, impervious lining, the lining being formed to provide upwardly extending ledges upon which the bipolar electrodes rest, the ledges serving to separate and isolate the lower parts of the adjacent electrolysis gaps from each other, the ledges and the parts of the respective bipolar electrode resting thereon being of substantially the same longitudinal dimension, the ledges providing aluminum collecting spaces therebetween, the said spaces each having a height and a volume each of which is not more than about a fourth of
  • a furnace for producing aluminum by electrolysis of alumina in a molten salt bath comprising a containing furnace wall structure at least in part lined internally by a refractory lining, a plurality of anode and cathode means therein providing a plurality of cells, the furnace providing passages for serial flow and re-circulation of bath liquid amongst the cells and to determine the liquid level of the bath in the cells during operation, and providing kindividual lower chambers therein for receiving the aluminum produced by each cell, means in the furnace providing a hot receptacle for aluminum and providing overflow means through which the receptacle receives molten aluminum from said lower chambers, the body of molten aluminum in the receptacle having a free upper surface below the overflow means, the molten aluminum dropping down into and being caught in the receptacle, and being removable at will from the receptacle without disturbing the level of molten aluminum in the lower chamber, said receptacle being lo- .cated
  • 11.1A furnace for producing aluminum by electrolysis of alumina in a molten salt bath comprising a containing refractory furnace wall structure, anode and cathode means therein providing a cell, the furnace providing passages for re-circulation of bath liquid from and to the cell and to determine the liquid level of the bath in the cell during operation, the furnace providing a lower chamber for receiving aluminum produced, means in the furnace providing a hot storage receptacle for aluminum and providing an overflow weir over which the molten aluminum drops down into thevreceptacle, said molten 'aluminum coming from said lower chamber, said receptacle being located in heat exchange relation with the molten bath.
  • a furnace for producing aluminum by electrolysis of alumina in a molten salt bath comprising a containing refractory furnace wall structure, anode and cathode means therein, the furnace providing a lower chamber for receiving the aluminum produced, means in the furnace providing a hot storage receptacle for aluminum and providing an over-flow weir over which the molten aluminum drops down into and is caught in the receptacle, the body of molten aluminum in the receptacle having a free upper surface below the over-flow Weir, said molten aluminum coming from said lower chamber, an upwardlydownwardly directed tapping pocket for the aluminum, the pocket communicating at its lower end portion with the said lower chamber, for removal of molten aluminum therefrom, and communicating, by means of the weir, with the receptacle for flow of aluminum to the latter, said receptacle being located in heat exchange relation with the molten ba 13.
  • a furnace for producing aluminum by electrolysis of alumina in a molten salt bath comprising a containing refractory furnace wall structure, anode and cathode means therein, the furnace providing a lower chamber for receiving the aluminum produced, means in the furnace providing a hot storage receptacle for aluminum and providing an overflow weir over which the molten aluminum drops down into and is caught in the receptacle, the body of molten aluminum in the receptacle having a free upper surface below the over-flow Weir, said molten aluminum coming from said lower chamber, an upwardly-downwardly directed tapping pocket for the aluminum, the pocket communicating at its lower end portion with the said lower chamber, for removal of molten aluminum therefrom, and communicating, by means of the weir, with the receptacle for flow of aluminum to the latter, the height of the weir being such that the static liquid pressures on the bottom of the lower chamber and at the bottom of the tapping pocket are substantially equal, said receptacle being located in heat exchange relation
  • a heat insulated, refractory lined furnace for producing a metal by electrolysis of a compound of the metal in a molten salt bath comprising a plurality of opposed anode and cathode electrodes defining between them a plurality of upwardly-downwardly directed serially disposed electrolysis gaps, the furnace providing passages therewithin for serial flow and re-circulation of bath liquid amongst the cells and for determining the bath level in the cells, means providing a bottom portion for collecting metal, produced in the process, below an upper layer of bath, means Within the refractory forming an upwardly extending tapping well and a passage permitting flow of the metal to the well as it collects on the bottom portion, a hot refractory receptacle in the furnace serving as a common reservoir for the metal produced in said electrolysis gaps, the receptacle extending in a direction transverse to the series of electrolysis gaps, an overow device, the metal passing from the bottom portion upwardly in the Well and then over the overtlow device and dropping down into
  • the improvement comprising removing upwardly substantially continuously, a column of aluminum from the bottom layer, and permitting the top of .the column to overilow and fall downwardly, and collecting the downward overilow in a hot storage chamber, the body of aluminum in the storage chamber having a free upper surface below the top of the column, said column of aluminum and the downward overow being in heat exchange relation with the molten bath.

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  • Metallurgy (AREA)
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Publication number Priority date Publication date Assignee Title
US3352767A (en) * 1962-11-10 1967-11-14 Montedison Spa Multicell electrolytic furnace with suspended electrodes and method of aluminum production
WO2012038423A1 (de) * 2010-09-20 2012-03-29 Sgl Carbon Se Elektrolysezelle zur gewinnung von aluminium

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US995476A (en) * 1909-09-30 1911-06-20 Roessler & Hasslacher Chemical Electrolytic process.
DE484197C (de) * 1929-10-10 Vaw Ver Aluminium Werke Ag Ofen zur schmelzelektrolytischen Aluminiumherstellung
CH254311A (de) * 1942-04-27 1948-04-30 Szego Ladislaus Einrichtung zur Herstellung von Aluminium durch Schmelzflusselektrolyse.
US2480474A (en) * 1945-12-14 1949-08-30 Reynolds Metals Co Method of producing aluminum
FR1119832A (fr) * 1954-01-19 1956-06-26 Montedison Spa Four et procédé pour l'élaboration, par électrolyse, de l'aluminium
US2902415A (en) * 1956-10-03 1959-09-01 Leonard W Niedrach Purification of uranium fuels
US2952592A (en) * 1955-06-08 1960-09-13 Montedison Spa Multicell closed circuit furnace and fused salt electrolysis process for aluminium production from aluminium oxide

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE484197C (de) * 1929-10-10 Vaw Ver Aluminium Werke Ag Ofen zur schmelzelektrolytischen Aluminiumherstellung
US995476A (en) * 1909-09-30 1911-06-20 Roessler & Hasslacher Chemical Electrolytic process.
CH254311A (de) * 1942-04-27 1948-04-30 Szego Ladislaus Einrichtung zur Herstellung von Aluminium durch Schmelzflusselektrolyse.
US2480474A (en) * 1945-12-14 1949-08-30 Reynolds Metals Co Method of producing aluminum
FR1119832A (fr) * 1954-01-19 1956-06-26 Montedison Spa Four et procédé pour l'élaboration, par électrolyse, de l'aluminium
US2952592A (en) * 1955-06-08 1960-09-13 Montedison Spa Multicell closed circuit furnace and fused salt electrolysis process for aluminium production from aluminium oxide
US2902415A (en) * 1956-10-03 1959-09-01 Leonard W Niedrach Purification of uranium fuels

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3352767A (en) * 1962-11-10 1967-11-14 Montedison Spa Multicell electrolytic furnace with suspended electrodes and method of aluminum production
WO2012038423A1 (de) * 2010-09-20 2012-03-29 Sgl Carbon Se Elektrolysezelle zur gewinnung von aluminium
CN103180486A (zh) * 2010-09-20 2013-06-26 西格里碳素欧洲公司 用于提取铝的电解池
JP2013540898A (ja) * 2010-09-20 2013-11-07 エスゲーエル カーボン ソシエタス ヨーロピア アルミニウム生産のための電解セル

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GB881453A (en) 1961-11-01
DE1147389B (de) 1963-04-18
FR1213432A (fr) 1960-03-31
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