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EP1230436B1 - Cellule d'extraction electrolytique d'aluminium, dotee de parois resistantes a un electrolyte liquide - Google Patents

Cellule d'extraction electrolytique d'aluminium, dotee de parois resistantes a un electrolyte liquide Download PDF

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Publication number
EP1230436B1
EP1230436B1 EP00966360A EP00966360A EP1230436B1 EP 1230436 B1 EP1230436 B1 EP 1230436B1 EP 00966360 A EP00966360 A EP 00966360A EP 00966360 A EP00966360 A EP 00966360A EP 1230436 B1 EP1230436 B1 EP 1230436B1
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EP
European Patent Office
Prior art keywords
aluminium
cell
cathode
peripheral surface
molten
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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EP00966360A
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German (de)
English (en)
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EP1230436A1 (fr
Inventor
Jean-Jacques Duruz
Vittorio De Nora
Georges Berclaz
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Moltech Invent SA
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Moltech Invent SA
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Priority claimed from US09/431,023 external-priority patent/US6258246B1/en
Application filed by Moltech Invent SA filed Critical Moltech Invent SA
Publication of EP1230436A1 publication Critical patent/EP1230436A1/fr
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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

Definitions

  • the invention relates to drained-cathode cells for the electrowinning of aluminium from alumina dissolved in a molten fluoride-containing electrolyte having sidewalls resistant to molten electrolyte, and methods of operating the cells to produce aluminium.
  • the electrolytic cell trough is typically made of a steel shell provided with an insulating lining of refractory material covered by prebaked anthracite-graphite or all graphite carbon blocks at the cell floor bottom which acts as cathode.
  • the side walls are also covered with prebaked anthracite-graphite carbon plates.
  • US Patent 2,915,442 discloses interalia use of silicon carbide or silicon nitride as sidewall material.
  • US Patent 3,256,173 (Schmitt/Wittner) describes a sidewall lining made of a honeycomb matrix of coke and pitch in which particulate silicon carbide is embedded.
  • US Patent 5,876,584 (Cortellini) discloses sidewall lining material of silicon carbide, silicon nitride or boron carbide having a density of at least 95% and no apparent porosity.
  • An object of the invention is to provide a design for an aluminium electrowinning cell in which electrolyte is inhibited from freezing on the sidewalls.
  • Another object of the invention is to provide a cell configuration for crustless or substantially crustless molten electrolyte resistant sidewalls, in particular carbide and/or nitride-containing sidewalls, which leads to an increased sidewall lifetime.
  • a further object of the invention is to provide a cell configuration for crustless or substantially crustless molten electrolyte resistant sidewalls, in particular carbide and/or nitride-containing sidewalls, which leads to a reduced erosion, oxidation or corrosion of the sidewalls.
  • a major object of the invention is to provide a drained cathode cell configuration with sidewalls resistant to molten electrolyte, in particular carbide and/or nitride-containing sidewalls, for crustless or substantially crustless operation.
  • One main aspect of the invention concerns a drained-cathode cell for the electrowinning of aluminium from alumina dissolved in a fluoride-containing molten electrolyte.
  • the drained-cathode cell has a cell bottom which comprises an arrangement for collecting product aluminium and a peripheral upper surface that surrounds the arrangement for collecting product aluminium. At least the part of the cell bottom which is in contact with molten aluminium during operation is made of material resistant to molten aluminium.
  • Aluminium is produced on at least one drained cathode surface from which the produced aluminium drains into said arrangement for collecting the product aluminium during operation.
  • the drained-cathode cell further comprises one or more thermic insulating sidewalls extending generally vertically upwards from the peripheral surface of the cell bottom to form with the cell bottom a trough for containing during operation molten electrolyte and the product aluminium.
  • the or each thermic insulating sidewall is lined with a sidewall lining made of material resistant to molten electrolyte but liable to react with molten aluminium, the or each thermic insulating sidewall inhibits formation of an electrolyte crust or ledge on the sidewall lining that during operation remains permanently exposed to molten electrolyte above and around said peripheral surface.
  • the peripheral surface of the cell bottom is arranged to keep molten aluminium away from the sidewall lining above and around the entire peripheral surface, whereby the molten aluminium is prevented from reacting with the sidewall lining above and around the entire peripheral surface.
  • the drained-cathode cell design according to the invention thus keeps the molten aluminium away from all cell sidewalls preventing it from contacting and reacting with the sidewall lining resistant to molten electrolyte, enabling use of a sidewall lining made of a carbide and/or a nitride, such as silicon carbide, silicon nitride or boron nitride, without risk of damage to the sidewall lining by reaction with molten aluminium as can occur with known designs.
  • a sidewall lining made of a carbide and/or a nitride, such as silicon carbide, silicon nitride or boron nitride
  • the cell comprises four of the above mentioned insulated sidewalls in a generally rectangular arrangement.
  • the invention can also be implemented with other sidewall configurations.
  • the upper surface of the cell bottom for example comprises opposed sloping surfaces leading from opposed sidewalls down into a central channel for the continuous removal of product aluminium, the central channel extending parallel to said opposed sidewalls.
  • This central draining channel (or a side channel or several channels in other embodiments) preferably leads into an aluminium storage sump or space which is internal or external to the cell and from which the aluminium can be tapped from time to time.
  • the upper surface of the cell bottom comprises a series of oppositely sloping surfaces forming therebetween recesses or channels that extend parallel to opposed sidewalls.
  • the recesses or channels can be of various shapes, for example generally V-shaped.
  • the peripheral surface slopes down to a flat or sloping main surface of the cell bottom which forms the drained cathode surface or which receives produced aluminium from a drained cathode surface located thereabove.
  • This main surface leads into the arrangement for collecting product aluminium.
  • the peripheral surface is usually inclined at a steeper slope than the main surface.
  • the main surface comprises downwardly converging inclined surfaces sloping down from first opposed sidewalls.
  • the converging surfaces are inclined along second opposed sidewalls.
  • the peripheral surface extends horizontally along the first opposed sidewalls and follows the inclination of the converging surfaces along the second opposed sidewalls.
  • the sloping peripheral surface can be of substantially uniform width around the entire cell bottom.
  • the main surface also comprises downwardly converging inclined surfaces sloping down from first opposed sidewalls
  • the converging surfaces are inclined along second opposed sidewalls
  • the peripheral surface extends horizontally along the first and second opposed sidewalls
  • the sloping peripheral surface extends down to the converging inclined surfaces around the entire cell bottom.
  • the sloping peripheral surface is of uniform width along the first opposed sidewalls and of non-uniform width along the second opposed sidewalls where it forms generally triangular surfaces whose sides follow the second opposed sidewalls and the converging inclined surfaces.
  • the main surface also comprises downwardly converging inclined surfaces sloping down from first opposed sidewalls, the converging surfaces are inclined along second opposed sidewalls, and the sloping peripheral surface extends horizontally along the first and second opposed sidewalls, the sloping peripheral surface is connected by at least one substantially vertical connecting wall to the main surface, i.e. at least to the converging inclined surfaces.
  • Such connecting wall(s) is/are resistant to molten aluminium.
  • the drained surface(s) is/are on one or more cathodes which are part of the cell bottom and so arranged that molten aluminium produced thereon drains away from the sidewall lining into the arrangement for collecting molten aluminium.
  • the drained cathode surface(s) can be on one or more cathodes located above the cell bottom, the molten aluminium draining from the cathodes onto the cell bottom and then into the arrangement for collecting molten aluminium.
  • the cathode and/or the cell bottom can be made of carbonaceous material, such as compacted powdered carbon, a carbon-based paste for example as described in U.S. Patent No. 5,362,366 (de Nora/Sekhar), prebaked carbon blocks, or graphite blocks, plates or tiles.
  • carbonaceous material such as compacted powdered carbon, a carbon-based paste for example as described in U.S. Patent No. 5,362,366 (de Nora/Sekhar), prebaked carbon blocks, or graphite blocks, plates or tiles.
  • Other suitable cathode materials which can also be used for the cell bottom are described in WO98/53120 (Berclaz/de Nora) and WO99/02764 (de Nora/Duruz).
  • This aluminium-wettable surface can be obtained by applying a top layer of refractory aluminium-wettable material over the upper surface (which can already have a precoating of the refractory aluminium wettable material) and over parts of the cell surrounding the cathode.
  • the electric current to the cathode may arrive through an inner cathode holder shell or plate placed between the cathode and the outer shell, usually made of steel, as disclosed in WO98/53120 (Berclaz/de Nora).
  • the sidewall lining can be made of tiles containing carbide and/or nitride and/or can comprise a carbide and/or nitride based coating which during cell operation is in contact with the product aluminium.
  • the sidewall lining may be coated and/or impregnated with one or more phosphates of aluminium, as disclosed in US Patent 5,534,130 (Sekhar).
  • the phosphates of aluminium may be selected from: monoaluminium phosphate, aluminium phosphate, aluminium polyphosphate, and aluminium metaphosphate.
  • the cells according to the invention can make use of traditional consumable prebaked carbon anodes, continuously-fed S ⁇ derberg-type anodes, as well as non-consumable or substantially non-consumable anodes.
  • Non-consumable anodes may comprise an electrochemically active structure made of a series of horizontal anode members, each having an electrochemically active surface on which during electrolysis oxygen is anodically evolved.
  • the anode members may be in a parallel arrangement connected by at least one connecting cross-member or in a concentric arrangement connected by at least one generally radial connecting member as described in WO00/40781 and WO00/40782 (both in the name of de Nora).
  • Suitable materials for oxygen-evolving anodes include iron and nickel based alloys which may be heat-treated in an oxidising atmosphere as disclosed in WO00/06802, WO00/06803 (both in the name of Duruz/de Nora/Crottaz), WO00/06804 (Crottaz/Duruz), PCT/IB99/01976 (Duruz/de Nora) and PCT/IB99/01977 (de Nora/Duruz).
  • the invention also relates to a cell trough for containing molten electrolyte and product aluminium, having a cell bottom fitted with insulating cell sidewalls which are protected with a molten electrolyte resistant lining as described above.
  • a further aspect of the invention relates to a method of producing aluminium using the cell as outlined above which contains alumina dissolved in a fluoride-containing molten electrolyte.
  • the method involves electrolysing the dissolved alumina to produce aluminium on the or each drained cathode surface and draining the produced aluminium from the or each drained cathode surface into the arrangement for collecting the product aluminium, the produced aluminium being kept from contacting and reacting with the sidewall lining above and around the entire peripheral surface.
  • the surface of the cell bottom is maintained at a temperature corresponding to a paste state of the electrolyte whereby the cell bottom is protected from chemical attack.
  • the cryolite-based electrolyte is at about 950°C
  • the surface of the cell bottom can be cooled by about 30°C, whereby the electrolyte contacting the cathode surface forms a viscous paste which protects the cell bottom.
  • Figs. 1 and 6 schematically show an aluminium electrowinning cell according to the invention wherein a plurality of anodes 10 are suspended by yokes 11 connected to an anode suspension and current supply superstructure (not shown) which hold the anodes 10 suspended above a cathode cell bottom 20 enclosed in an outer steel shell 21 forming, with its insulating lining of refractory bricks 40, a cell trough or cathode pot.
  • a cathode 30 comprising an inner steel cathode holder shell 31 containing a cathode mass 32.
  • the inner shell 31 has a flat bottom, sidewalls 33 and outwardly-directed side flanges 34 at its top.
  • the inner shell 31 forms an open-topped container for the cathode mass 32.
  • the top of the cathode mass 32 has inclined surfaces 35 extending over the cathode 30 and leading down into a central channel 36 for draining molten aluminium.
  • the central channel 36 advantageously leads into an aluminium storage sump 36' which is centrally located in the cell, as shown in Figure 6.
  • a coating 37 of aluminium-wettable material preferably a slurry-applied boride coating as described in U.S. Patent 5,651,874 (de Nora/Sekhar) or WO98/17842 (Sekhar/Duruz/Liu).
  • Such coating 37 can also be applied to the inside surfaces of the bottom and sides 33 of the cathode holder shell 31, to improve electrical connection between the inner shell 31 and the cathode mass 32.
  • the periphery of the cathode mass 32 extends to the top of the sidewall 33 of the inner shell 31, from where it slopes down to the central channel 36.
  • a sidewall lining 50 formed for example of plates of carbon or silicon carbide.
  • the insulating sidewalls 55 extend generally vertically upwards from the cell bottom 20.
  • the insulating sidewalls 55 inhibit during operation formation of an electrolyte crust on the sidewall lining 50, whereby the lining is exposed to molten electrolyte 60.
  • the peripheral surface 35' from which the insulating sidewalls 55,55' extend is arranged to drain molten aluminium away from the sidewall lining 50, to keep the product aluminium from contacting and reacting with the sidewall lining 50, as shown in Figures 1 to 3 and 6.
  • the peripheral surface 35' is inclined at a steeper slope than the inclined cathode surfaces 35, as shown in Figures 1 to 5, forming a small wedge sloping down from the end sidewalls 55' and extending across the cathode mass 32, so that the entire periphery 35' around the sloped cathode surfaces 35 slopes away from all cell sidewalls 55,55' to drain molten aluminium away from the sidewall lining 50, as shown in Figure 6.
  • Figures 3 and 6 show different configurations of the peripheral surface 35'.
  • the sloped cathode surfaces 35 are made of downwardly converging inclined surfaces 35 sloping down from opposed lateral sidewalls 55 to the central channel 36 and which are inclined along opposed end sidewalls 55' as shown in the upper part of Figure 6.
  • the peripheral surface 35' extends horizontally along the lateral sidewalls 55 and follows the inclination of the converging surfaces 35 along the opposed end sidewalls 55', the sloping peripheral surface 35 being of substantially uniform width around the entire cell bottom as shown in the upper part of Figure 6.
  • a variation of the configuration of the peripheral surface 35' is shown in Figure 3 by dotted line 35" and on the lower part of Figure 6.
  • the peripheral surface 35' extends horizontally along the lateral sidewalls 55 and the end sidewalls 55'. Furthermore, the sloping peripheral surface 35' extends down to the converging inclined surfaces around the entire cell bottom.
  • the peripheral surface 35' is of uniform width along the lateral sidewalls 55 and of non-uniform width along the end sidewalls 55' where, as shown on the lower part of Figure 6, it forms a generally triangular surface.
  • FIG. 3 Another variation of the configuration of the peripheral surface 35' is shown in Figure 3 by dotted line 35" and 35"' and on the upper part of Figure 6.
  • the peripheral surface 35' extends horizontally along the lateral and end sidewalls 55' as shown by dotted line 35".
  • the sloping peripheral surface 35' is connected to the converging inclined cathode surfaces 35 by substantially vertical connecting walls, the top of the connecting wall being indicated by line 35"' in Figures 3 and 6.
  • the sloping peripheral surface 35' is of uniform width all around the sidewalls 55,55'.
  • This connecting wall is resistant to molten aluminium and can be coated with aluminium-wettable material as mentioned above.
  • the cathode 30 is supported as a removable unit in the cell bottom 20 in a central recess of corresponding shape in the refractory bricks 40 lining the outer steel shell 21.
  • These refractory bricks 40 are the usual types used for lining conventional cells.
  • Transverse conductor bars 41 welded to the bottom of the inner shell 31. These conductor bars 41 are connected to current collector bars 42 which protrude laterally from the sides of the outer shell 21, as shown in Figure 1, these collector bars 42 being connected to external buswork (not shown).
  • current could be supplied to the cathode 30 of Fig. 1, by a series of vertical current collector bars 41 extending down through vertical openings in the bottom of the lining formed by the refractory bricks 40 (see Figures 2 and 3).
  • the space between the cathode 30 and the sidewall lining 50 is filled with a molten electrolyte 60 such as cryolite containing dissolved alumina at a temperature usually about 950-970°C, and into which the anodes 10 dip.
  • a molten electrolyte 60 such as cryolite containing dissolved alumina at a temperature usually about 950-970°C
  • aluminium is formed on the sloping cathode surfaces 35 coated with the refractory boride coating 37, and the produced aluminium continuously drains down the sloping surfaces 35 into the central channel 36 from where it is removed permanently into the storage sump 36' from which the aluminium can be tapped from time to time.
  • the inclination of these anode surfaces 12 facilitates the release of bubbles of the anodically-released gases.
  • the anode 10 As the anode 10 is consumed, it maintains its shape, keeping a uniform anode-cathode spacing.
  • the same cell bottom 20 and its cathode 30 it would be possible for the same cell bottom 20 and its cathode 30 to be used with non-consumable or substantially non-consumable anodes.
  • the aluminium electrowinning cell shown in Fig. 2 is similar to that of Fig. 1 and like references have been used to designate like parts.
  • the current collector bars 42 instead of being horizontal are vertical and extend through vertical apertures 43 in the lining of bricks 40. These collector bars 42 are welded centrally to the bottom of the inner shell 31. As illustrated in Fig. 4, several collector bars 42 are spaced apart from one another along the bottom of the inner shell 31. These collector bars 42 can have any desired cross-sectional shape : circular, rectangular, T-shaped, etc. Because the inner metal shell 31 keeps the collector bars 42 at practically the same potential, fluctuations in the current supply are avoided.
  • the assembly method is illustrated in Fig. 3. It is possible to install the entire cathode 30 by lowering it using a crane until the bottom of the cathode holder shell 31 comes to rest on the top 44 of the lining of bricks 40 and its side flanges 34 come to rest on shoulders 45 of the cell lining. Then, the plates 50 can be installed on top of the flanges 34.
  • This assembly method is simple and labour saving, compared to the usual cell lining methods used heretofore.
  • FIG. 4 shows the cathode 30 ready to be installed as a unit in an aluminium electrowinning cell (not shown) which is fitted with insulating sidewalls protected with a carbide and/or nitride containing lining according to the invention.
  • This cathode 30 comprises a metal cathode holder shell 31 made of a flat base plate to which sidewalls 33 are welded substantially at right angles along its side edges. These sidewalls 33 can extend around the entire periphery of the base plate, or only along its opposite side edges.
  • a series of conductor bars 42 are welded, spaced equally apart from one another along the length of the shell 31. These conductor bars 42 protrude vertically down from the shell 31, so they can pass through corresponding vertical openings in the cell bottom, for connection to an external negative busbar.
  • a cathode mass 32 formed of a series of blocks, for example of carbon.
  • the cathode blocks have sloping upper surfaces 35 and are fitted together to form a series of generally V-shaped recesses.
  • parts of the cathode blocks protrude above the top of the sidewalls 33 which are embedded in the sides of the end blocks.
  • the upper surface 35 is made up of a series of sloping surfaces in generally V-configuration, formed by placing the adjacent blocks together.
  • the end blocks on each side of the shell 31 are shown with a sloping peripheral surface 35' from which the insulating sidewalls extend when placed in a cell.
  • the peripheral surface 35' surrounds the cathode 30 and is arranged to drain molten aluminium away from the sidewall lining 50 above and around the entire peripheral surface 35', to keep the product aluminium from contacting and reacting with the sidewall lining 50 above and around the entire peripheral surface 35'.
  • Each conductor bar 42 corresponds to the junction between two adjacent blocks forming the lower part of each V. As shown, the conductor bars 42 protrude through the shell 31 and extend part of the way up the blocks 42. Alternatively, the conductor bars 42 could be welded externally to the bottom of the shell 31.
  • This cathode 30 can be produced as a unit and installed in an aluminium electrowinning cell (as illustrated in Fig. 3) by lifting it with a crane, and lowering it into the cell.
  • the aluminium electrowinning cell shown in longitudinal cross-section in Fig. 5 comprises a cathode 30 with a series of spaced-apart vertical current conductors 42 welded to the bottom of its inner cathode holder shell 31, these conductors 42 protruding from the lower face of the cell bottom 20 for connection to the cathode buswork.
  • the upwardly-sloping side parts of the faces 35 are extended by bevelled parts of the edges 32a and by ramming paste 51, forming wedges along the edges of the cathode mass 32 on which the aluminium wettable boride layer 37 extends to form with the peripheral edge 32a a peripheral surface 35' of steeper slope which is arranged to drain molten aluminium away from the sidewall lining 50 above and around the entire peripheral surface according to the invention.
  • the sloping faces 35 of cathode mass 32 are inclined alternately to form flattened V-shaped recesses above which the anodes 10 are suspended with corresponding V-shaped inclined faces 11 of the anodes facing the V-shaped recesses in the cathode mass 32.
  • the anodes 10 are suspended by steel rods 14 held at an adjustable height in attachments 15 by an anode bus 16, enabling the anodes 10 to be suspended with a selected anode-cathode gap.
  • the cathode 30 is assembled first, outside the cell, then lowered using a crane into the cell bottom 20, passing the conductor bars 42 through corresponding openings 43 in the bricks 40. Then the gaps around the edges of the cathode mass 32 are filled with ramming paste 51 which is formed into the side wedges. Next, a slurry of refractory boride is applied to the sloping cathode faces 35, usually on top of a pre-coating already applied thereto, and also over the sloping wedge surfaces of the edges 32a and ramming paste 51.
  • the cell After drying and heat treatment of the boride coating 37, the cell is ready for start-up.
  • the central recess in the cell above the cathode mass 32 contains a molten electrolyte 60, such as cryolite containing dissolved alumina, into which the anodes 10 dip.
  • the molten contents are removed from the cell, and the ramming paste 51 is broken to enable the entire cathode unit 30 to be lifted out of the cell using a crane, after having disconnected the conductor bars 42 from the cathode busbar.

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Claims (23)

  1. Cuvette d'une cuve cathodique drainée pour l'électro-obtention d'aluminium à partir d'alumine dissoute dans un électrolyte fondu contenant du fluorure, comprenant :
    un fond de cuve comprenant un agencement pour recueillir l'aluminium produit (36) et une surface supérieure périphérique (35) qui entoure l'agencement pour recueillir l'aluminium produit, au moins la partie du fond de la cuve qui est en contact avec l'aluminium fondu pendant le fonctionnement étant réalisée en un matériau résistant à l'aluminium fondu ;
    au moins une surface cathodique drainée (35) sur laquelle de l'aluminium est produit et à partir de laquelle l'aluminium produit s'écoule dans ledit agencement pour recueillir l'aluminium produit pendant le fonctionnement ;
    une ou plusieurs parois latérales à isolation thermique (55, 55') s'étendant généralement verticalement vers le haut à partir de ladite surface périphérique pour former avec le fond de la cuve, une cuvette pour contenir, pendant le fonctionnement, l'électrolyte fondu et l'aluminium produit ; et
    un garnissage (50) de paroi latérale réalisé en un matériau résistant à l'électrolyte fondu mais apte à réagir avec l'aluminium fondu et lequel matériau recouvre la (ou les) paroi latérale à isolation thermique au-dessus de ladite surface périphérique, la (ou les) paroi latérale à isolation thermique inhibant la formation d'une croûte ou d'un rebord d'électrolyte sur le garnissage de paroi latérale qui, pendant le fonctionnement, reste exposée de façon permanente à l'électrolyte fondu au-dessus et autour de ladite surface périphérique,
    ladite surface périphérique étant agencée pour maintenir l'aluminium fondu éloigné du garnissage de paroi latérale au-dessus et autour de la totalité de la surface périphérique, grâce à quoi l'aluminium fondu est empêchée de réagir avec le garnissage de paroi latérale au-dessus et autour de la totalité de la surface périphérique.
  2. Cuve à cathode drainée pour l'électro-obtention d'aluminium à partir d'alumine dissoute dans un électrolyte fondu contenant du fluorure, comprenant une cuvette telle que définie dans la revendication 1.
  3. Cuve selon la revendication 2, comprenant quatre desdites parois latérales selon un agencement généralement rectangulaire.
  4. Cuve selon la revendication 3, dans laquelle le fond de la cuve comprend des surfaces en pente opposées menant des parois latérales opposées jusque dans un canal central pour le retrait de l'aluminium produit, le canal central s'étendant parallèlement auxdites parois latérales opposées.
  5. Cuve de la revendication 3, dans laquelle le fond de la cuve comprend une série de surfaces en pente de façon opposée formant entre elles une série d'évidements ou de canaux qui s'étendent parallèlement aux parois latérales opposées.
  6. Cuve selon une quelconque des revendications 2 à 5, dans laquelle ladite surface périphérique descend en pente jusqu'à une surface principale plate ou en pente du fond de la cuve, qui forme la surface cathodique drainée ou qui reçoit l'aluminium produit à partir d'une surface cathodique drainée située au-dessus, ladite surface principale menant dans ledit agencement pour recueillir l'aluminium produit.
  7. Cuve de la revendication 6 quand elle dépend de la revendication 3, dans laquelle ladite surface principale comprend des surfaces inclinées convergeant vers le bas descendant en pente à partir de premières parois latérales opposées, lesdites surfaces convergentes étant inclinées le long de secondes parois latérales opposées, ladite surface périphérique s'étendant horizontalement le long desdites premières parois latérales opposées et suivant l'inclinaison desdites surfaces convergentes le long desdites secondes parois latérales opposées.
  8. Cuve de la revendication 6 quand elle dépend de la revendication 3, dans laquelle ladite surface principale comprend des surfaces inclinées convergeant vers le bas descendant en pente à partir de premières parois latérales opposées, lesdites surfaces convergentes étant inclinées le long de secondes parois latérales opposées, ladite surface périphérique s'étendant horizontalement le long desdites premières et secondes parois latérales opposées, ladite surface périphérique en pente s'étendant jusqu'auxdites surfaces inclinées convergentes autour de la totalité du fond de la cuve.
  9. Cuve de la revendication 6 quand elle dépend de la revendication 3, dans laquelle ladite surface principale comprend des surfaces inclinées convergeant vers le bas, descendant en pente à partir de premières parois latérales opposées, lesdites surfaces convergentes étant inclinées le long de secondes parois latérales opposées, ladite surface périphérique s'étendant horizontalement le long desdites premières et secondes parois latérales opposées, ladite surface périphérique en pente étant reliée, par au moins une paroi de liaison sensiblement verticale, auxdites surfaces inclinées convergentes, ladite paroi de liaison étant résistante vis-à-vis de l'aluminium fondu.
  10. Cuve selon une quelconque des revendications 2 à 9, dans laquelle la ou chaque surface cathodique drainée est sur une cathode qui fait partie du fond de la cuve, la cathode étant agencée de sorte que l'aluminium produit sur celle-ci s'éloigne du garnissage des parois latérales selon l'agencement pour recueillir l'aluminium produit.
  11. Cuve selon une quelconque des revendications 2 à 9, dans laquelle la ou chaque (ou les) surface cathodique drainée est sur une cathode située au-dessus du fond de la cuve, la cathode étant agencée de sorte que l'aluminium produit sur celle-ci s'écoule au loin du garnissage des parois latérales selon l'agencement pour recueillir l'aluminium produit.
  12. Cuve de la revendication 11, dans laquelle le fond de la cuve est enrobé d'un revêtement en un matériau réfractaire mouillable par l'aluminium.
  13. Cuve selon une quelconque des revendications 2 à 12, dans laquelle la ou chaque surface cathodique drainée est enrobée d'un revêtement en un matériau réfractaire mouillable par l'aluminium.
  14. Cuve de la revendication 12 ou 13, dans laquelle le revêtement en matériau réfractaire mouillable par l'aluminium comprend un borure réfractaire.
  15. Cuve de la revendication 14, dans laquelle le revêtement en matériau réfractaire mouillable par l'aluminium comprend du diborure de titane.
  16. Cuve selon une quelconque des revendications 2 à 15, dans laquelle le garnissage des parois latérales comprend un carbure et/ou un nitrure.
  17. Cuve de la revendication 16, dans laquelle le garnissage des parois latérales comprend au moins l'un du carbure de silicium, du nitrure de silicium et du nitrure de bore.
  18. Cuve de la revendication 16 ou 17, dans laquelle le garnissage des parois latérales est réalisé en des tuiles contenant du carbure et/ou du nitrure.
  19. Cuve de la revendication 16 ou 17, dans laquelle le garnissage des parois latérales est enrobé d'un revêtement à base de carbure et/ou de nitrure.
  20. Cuve selon une quelconque des revendications 2 à 19, dans laquelle le garnissage des parois latérales est enrobé et/ou imprégné d'un ou de plusieurs phosphates d'aluminium.
  21. Cuve de la revendication 20, dans laquelle lesdits phosphates d'aluminium sont choisis parmi : le phosphate de monoaluminium, le phosphate d'aluminium, le polyphosphate d'aluminium et le métaphosphate d'aluminium.
  22. Procédé pour produire de l'aluminium en utilisant une cuve telle que définie dans l'une quelconque des revendications 2 à 21, contenant de l'alumine dissoute dans un électrolyte fondu à base de fluorure, le procédé consistant à électrolyser l'alumine dissoute pour produire de l'aluminium sur la ou chaque surface cathodique drainée et à évacuer l'aluminium produit à partir de la ou de chaque surface cathodique drainée selon l'agencement pour recueillir l'aluminium produit, l'aluminium produit étant maintenu éloigné du contact et de la réaction avec le garnissage des parois latérales au-dessus et autour de la totalité de la surface périphérique.
  23. Procédé de la revendication 22, consistant à maintenir la surface du fond de la cuve à une température qui correspond à un état de pâte de l'électrolyte grâce à quoi le fond de la cuve est protégé vis-à-vis d'attaque chimique.
EP00966360A 1999-10-26 2000-10-16 Cellule d'extraction electrolytique d'aluminium, dotee de parois resistantes a un electrolyte liquide Expired - Lifetime EP1230436B1 (fr)

Applications Claiming Priority (5)

Application Number Priority Date Filing Date Title
IBPCT/IB99/01739 1999-10-26
WOPCT/IB99/01739 1999-10-26
US431023 1999-11-01
US09/431,023 US6258246B1 (en) 1998-05-19 1999-11-01 Aluminium electrowinning cell with sidewalls resistant to molten electrolyte
PCT/IB2000/001483 WO2001031087A1 (fr) 1999-10-26 2000-10-16 Cellule d'extraction electrolytique d'aluminium, dotee de parois resistantes a un electrolyte liquide

Publications (2)

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EP1230436A1 EP1230436A1 (fr) 2002-08-14
EP1230436B1 true EP1230436B1 (fr) 2005-07-20

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EP00966360A Expired - Lifetime EP1230436B1 (fr) 1999-10-26 2000-10-16 Cellule d'extraction electrolytique d'aluminium, dotee de parois resistantes a un electrolyte liquide

Country Status (8)

Country Link
EP (1) EP1230436B1 (fr)
AT (1) ATE299959T1 (fr)
AU (1) AU770338B2 (fr)
CA (1) CA2387414A1 (fr)
DE (1) DE60021411T2 (fr)
NO (1) NO20021953L (fr)
NZ (1) NZ517674A (fr)
WO (1) WO2001031087A1 (fr)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
RU2282680C1 (ru) * 2005-04-05 2006-08-27 Общество с ограниченной ответственностью "Инженерно-технологический центр" Электролизер для производства алюминия
CN102400175A (zh) * 2011-10-08 2012-04-04 高伟 铝电解槽阴极导电结构
RU2485216C1 (ru) * 2012-02-21 2013-06-20 Федеральное государственное автономное образовательное учреждение высшего профессионального образования "Национальный исследовательский технологический университет "МИСиС" Электролизер для производства алюминия

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU7074598A (en) * 1997-05-23 1998-12-11 Moltech Invent S.A. Aluminium production cell and cathode
ES2165682T3 (es) * 1997-07-08 2002-03-16 Moltech Invent Sa Celda para la fabricacion de aluminio por electrolisis.
NO982585L (no) * 1998-06-05 1999-12-06 Navion As System for bruk ved arbeidsoperasjoner til havs, på innsjöer eaalaa

Also Published As

Publication number Publication date
EP1230436A1 (fr) 2002-08-14
DE60021411T2 (de) 2006-04-27
NO20021953D0 (no) 2002-04-25
NO20021953L (no) 2002-04-25
CA2387414A1 (fr) 2001-05-03
AU770338B2 (en) 2004-02-19
WO2001031087A1 (fr) 2001-05-03
NZ517674A (en) 2004-07-30
AU7679500A (en) 2001-05-08
ATE299959T1 (de) 2005-08-15
DE60021411D1 (de) 2005-08-25

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