EP1392892B1 - Enceintes d'electro-extraction d'aluminium comprenant un fond de cathode draine et un reservoir de collecte d'aluminium - Google Patents
Enceintes d'electro-extraction d'aluminium comprenant un fond de cathode draine et un reservoir de collecte d'aluminium Download PDFInfo
- Publication number
- EP1392892B1 EP1392892B1 EP02730626A EP02730626A EP1392892B1 EP 1392892 B1 EP1392892 B1 EP 1392892B1 EP 02730626 A EP02730626 A EP 02730626A EP 02730626 A EP02730626 A EP 02730626A EP 1392892 B1 EP1392892 B1 EP 1392892B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- aluminium
- cathode
- cell
- wettable
- recess
- 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.)
- Expired - Lifetime
Links
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims abstract description 102
- 229910052782 aluminium Inorganic materials 0.000 title claims abstract description 101
- 239000004411 aluminium Substances 0.000 title claims abstract description 101
- 238000005363 electrowinning Methods 0.000 title claims abstract description 14
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 24
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 23
- 150000001721 carbon Chemical class 0.000 claims abstract description 3
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 24
- 239000003792 electrolyte Substances 0.000 claims description 24
- 239000010410 layer Substances 0.000 claims description 9
- 238000000034 method Methods 0.000 claims description 9
- 239000000463 material Substances 0.000 claims description 7
- 239000011241 protective layer Substances 0.000 claims description 6
- XVVDIUTUQBXOGG-UHFFFAOYSA-N [Ce].FOF Chemical compound [Ce].FOF XVVDIUTUQBXOGG-UHFFFAOYSA-N 0.000 claims description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 5
- 150000001785 cerium compounds Chemical class 0.000 claims description 5
- 238000000576 coating method Methods 0.000 claims description 5
- 238000005868 electrolysis reaction Methods 0.000 claims description 5
- 229910052760 oxygen Inorganic materials 0.000 claims description 5
- 239000001301 oxygen Substances 0.000 claims description 5
- 239000011248 coating agent Substances 0.000 claims description 4
- 239000007789 gas Substances 0.000 claims description 4
- 229910002804 graphite Inorganic materials 0.000 claims description 4
- 239000010439 graphite Substances 0.000 claims description 4
- RHZUVFJBSILHOK-UHFFFAOYSA-N anthracen-1-ylmethanolate Chemical compound C1=CC=C2C=C3C(C[O-])=CC=CC3=CC2=C1 RHZUVFJBSILHOK-UHFFFAOYSA-N 0.000 claims description 3
- 239000003830 anthracite Substances 0.000 claims description 3
- 229910052684 Cerium Inorganic materials 0.000 claims description 2
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims description 2
- 239000011253 protective coating Substances 0.000 claims description 2
- 210000004027 cell Anatomy 0.000 description 57
- 238000004519 manufacturing process Methods 0.000 description 9
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 239000003575 carbonaceous material Substances 0.000 description 5
- 238000004090 dissolution Methods 0.000 description 5
- 238000010079 rubber tapping Methods 0.000 description 5
- 239000011159 matrix material Substances 0.000 description 4
- 229910010293 ceramic material Inorganic materials 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 125000006850 spacer group Chemical group 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- HCHKCACWOHOZIP-UHFFFAOYSA-N Zinc Chemical compound [Zn] HCHKCACWOHOZIP-UHFFFAOYSA-N 0.000 description 2
- 239000010405 anode material Substances 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 239000011810 insulating material Substances 0.000 description 2
- 229910044991 metal oxide Inorganic materials 0.000 description 2
- 150000004706 metal oxides Chemical class 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 239000010936 titanium Substances 0.000 description 2
- 239000000080 wetting agent Substances 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- 239000011701 zinc Substances 0.000 description 2
- 229910017083 AlN Inorganic materials 0.000 description 1
- 229910017109 AlON Inorganic materials 0.000 description 1
- PIGFYZPCRLYGLF-UHFFFAOYSA-N Aluminum nitride Chemical compound [Al]#N PIGFYZPCRLYGLF-UHFFFAOYSA-N 0.000 description 1
- 229910052582 BN Inorganic materials 0.000 description 1
- PZNSFCLAULLKQX-UHFFFAOYSA-N Boron nitride Chemical compound N#B PZNSFCLAULLKQX-UHFFFAOYSA-N 0.000 description 1
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910000640 Fe alloy Inorganic materials 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 1
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 description 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 1
- 229910003564 SiAlON Inorganic materials 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000004645 aluminates Chemical class 0.000 description 1
- 239000002585 base Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- JLQUFIHWVLZVTJ-UHFFFAOYSA-N carbosulfan Chemical compound CCCCN(CCCC)SN(C)C(=O)OC1=CC=CC2=C1OC(C)(C)C2 JLQUFIHWVLZVTJ-UHFFFAOYSA-N 0.000 description 1
- 210000003850 cellular structure Anatomy 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 229910001610 cryolite Inorganic materials 0.000 description 1
- 238000007598 dipping method Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 238000009830 intercalation Methods 0.000 description 1
- 230000002687 intercalation Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 229910052746 lanthanum Inorganic materials 0.000 description 1
- FZLIPJUXYLNCLC-UHFFFAOYSA-N lanthanum atom Chemical compound [La] FZLIPJUXYLNCLC-UHFFFAOYSA-N 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 229910052750 molybdenum Inorganic materials 0.000 description 1
- 239000011733 molybdenum Substances 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 239000010955 niobium Substances 0.000 description 1
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 230000002940 repellent Effects 0.000 description 1
- 239000005871 repellent Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 238000009738 saturating Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 229910052715 tantalum Inorganic materials 0.000 description 1
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 1
- 229910052726 zirconium Inorganic materials 0.000 description 1
Images
Classifications
-
- 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
- This invention relates to a cell for the electrowinning of aluminium from alumina dissolved in a fluoride-containing molten electrolyte having a cell bottom with an aluminium-wettable drained cathode surface and an aluminium reservoir, and a method to produce aluminium in such an aluminium electrowinning cell.
- the technology for the production of aluminium by the electrolysis of alumina, dissolved in molten cryolite containing salts, at temperatures around 950°C is more than one hundred years old and still uses carbon anodes and cathodes.
- US Patent 5,683,559 (de Nora) proposed a new drained cathode design for aluminium production cells, where grooves or recesses were incorporated in the surface of blocks forming the cathode surface in order to channel the drained product aluminium.
- a specific embodiment provides an enhanced anode and drained cathode geometry where aluminium is produced between V-shaped anodes and cathodes and collected in recessed grooves.
- WO98/53120 (Berclaz/de Nora) discloses an aluminium production cell provided with a cathode mass supported on a cathode shell or plate, the cathode mass having a horizontal drained cathode surface and a central channel extending along the cell for draining molten aluminium.
- WO00/63463 discloses an aluminium production cell in which the drained cathode bottom is divided into four drained cathode sections by a longitudinally extending central aluminium evacuation groove and a central aluminium collection reservoir extending centrally across the cell on a spacer body located between and parallel to cathode blocks placed across the cell.
- US Patent 4,560,448 (Sane/Wheeler/Kuivila) discloses a porous component made of aluminium repellent material covered with an aluminium-wettable metal boride coating which during use is maintained by saturating the molten aluminium infiltrating the porous component with coating constituents.
- US Patent 4,650,552 (de Nora/Gauger/Fresnel/Adorian/Duruz) discloses an aluminium production cell component produced from a powder mixture of alumina and aluminium.
- US Patent 4,600,481 (Sane/Wheeler/Gagescu/Debely/Adorian/Derivaz) discloses a component of an aluminium production cell which is made of an openly porous matrix, e.g. an alumina matrix, filled with molten aluminium.
- the openly porous matrix may comprise an aluminium-wettable coating made of a boride or nickel.
- the infiltration of the matrix with aluminium is carried out at a temperature of 1000° to 1500°C.
- Another object of the invention is to provide an aluminium electrowinning cell having a cell bottom with an aluminium collection recess and an aluminium-wettable cathode surface of great surface area.
- a major object of the invention is to provide an aluminium electrowinning cell having a cell bottom with a drained cathode and an aluminium collection recess, the aluminium production yield relative to surface area of the cell bottom being maximised.
- a further object of the invention is to provide an aluminium electrowinning cell having an aluminium collection reservoir from which molten aluminium can be tapped, without the risk of aluminium freezing in the reservoir, and which can be easily retrofitted in existing cells.
- the invention provides a cell for the electrowinning of aluminium from alumina, in particular alumina dissolved in a fluoride-containing molten electrolyte.
- the cell has a cell bottom that comprises: a cathode, in particular a series of carbon cathode blocks, having an aluminium-wettable upper surface; aluminium-wettable openly porous plates which are placed on the upper surface of the cathode and which during use, and preferably also prior to use, are filled with molten aluminium to form an aluminium-wetted drained active cathode surface above the upper surface of the cathode; and a recess which extends at a level below the upper surface of the cathode and which during use collects molten aluminium drained from the aluminium-wettable drained active cathode surface.
- openly porous plates on the upper surface of the cathode extend over at least part of the recess such that part of the aluminium-wetted drained active cathode surface is located over at least part of the recess.
- the openly porous aluminium-wettable plates are filled with aluminium and a bottom part of the plates is usually wetted by molten aluminium which also wets the aluminium-wettable surface of the cathode.
- the aluminium in the openly porous plates ensures optimal electrical conductivity from the cathode to the entire aluminium-wettable active cathode surface on the openly porous plates, even where the plates extend over the aluminium collection recess.
- the openly porous plates extending over at least part of the aluminium collection recess preferably cover a substantial part of the recess to maximise the surface area of the aluminium-wettable active cathode surface.
- the plates may leave only a small vertical opening above the recess sufficient to let product aluminium drain from the aluminium-wettable active cathode surface through the opening into the aluminium collection recess.
- the opening is a gap, typically located between one or more pairs of plates placed over and across the recess, preferably having a width of a couple or a few centimetres.
- an access to the aluminium collection recess is left for the tapping of molten aluminium.
- Such an access may be provided by placing openly porous plates which do not extend over the aluminium collection recess at the tapping location or by providing a hole of sufficient size, e.g. from about 20 to 40 cm diameter, in or between openly porous plates covering the aluminium collection recess at the tapping location.
- the aluminium-wettable openly porous plates are preferably made of ceramic-based materials which are resistant and inert to molten aluminium.
- the inert and resistant ceramic material may comprise at least one oxide selected from oxides of aluminium, zirconium, tantalum, titanium, silicon, niobium, magnesium and calcium and mixtures thereof, as a simple oxide and/or in a mixed oxide, for example an aluminate of zinc (ZnAlO 4 ) or titanium (TiAlO 5 ).
- suitable inert and resistant ceramic materials can be selected amongst nitrides, carbides and borides and oxycompounds thereof, such as aluminium nitride, AlON, SiAlON, boron nitride, silicon nitride, silicon carbide, aluminium borides, alkali earth metal zirconates and aluminiumates, and their mixtures.
- the aluminium-wettable openly porous plates contain an aluminium-wetting agent.
- Suitable wetting agents include metal oxides which are reactable with molten aluminium to form a surface layer containing alumina, aluminium and metal derived from the metal oxide and/or partly oxidised metal, such as manganese, iron, cobalt, nickel, copper, zinc, molybdenum, lanthanum or other rare earth metals or combinations thereof.
- the cathode can be made of carbon cathode blocks arranged in pairs across the cell bottom, spaced apart or end-to-end.
- the cathode can be made of carbon cathode blocks, each cathode block extending across substantially the entire cell bottom.
- the cathode can be made of graphite or another carbonaceous material.
- the cathode may be coated with a layer of aluminium-wettable material which forms the aluminium-wettable upper cathode surface.
- Suitable aluminium-wettable layers and carbonaceous materials for the cathode are disclosed in US Patent 5,651,874 (de Nora/Sekhar), and PCT applications WO98/17842 (Sekhar/Duruz/liu), WO01/42168 (de Nora/Duruz) and WO01/42536 (Nguyen/Duruz/de Nora).
- At least part of the aluminium collection recess is formed in a reservoir body that is juxtaposed to the cathode.
- This body may comprise anthracite or another carbonaceous material.
- the reservoir body is located between the blocks of at least one pair of carbon cathode blocks and spaces them apart across the cell bottom.
- the aluminium collection recess may be generally U-shaped.
- the cell may comprise a series of oxygen-evolving anodes facing the cathode.
- Suitable oxygen-evolving metal-based anodes are disclosed in WO00/06802, WO00/06803 (both in the name of Duruz/de Nora/Crottaz), WO00/06804 (Crottaz/Duruz), WO01/42535 (Duruz/de Nora), WO01/42534 (de Nora/Duruz) and WO01/42536 (Duruz/Nguyen/de Nora).
- Oxygen-evolving anodes may be coated with a protective layer made of one or more cerium compounds, in particular cerium oxyfluoride, as disclosed in US Patents 4,614,569 (Duruz/Derivaz/Debely/Adorian), 4,680,094 (Duruz), 4,683,037 (Duruz) and 4,966,674 (Bannochie/Sheriff).
- a protective layer made of one or more cerium compounds, in particular cerium oxyfluoride, as disclosed in US Patents 4,614,569 (Duruz/Derivaz/Debely/Adorian), 4,680,094 (Duruz), 4,683,037 (Duruz) and 4,966,674 (Bannochie/Sheriff).
- Another aspect of the invention relates to a bottom of a cell for the electrowinning of aluminium from alumina.
- This cell bottom comprises a cathode, in particular a series of carbon cathode blocks, having an aluminium-wettable upper surface, aluminium-wettable openly porous plates which are placed on upper surface of the cathode, and a recess which extends at a level below the upper surface of the cathode.
- Openly porous plates covering the upper surface of the cathode extend over at least part of the aluminium collection recess.
- a further aspect of the invention relates to a cell for the electrowinning of aluminium comprising a bottom as described above.
- the aluminium-wettable openly porous plates are filled with molten aluminium to form an aluminium-wetted drained active cathode surface above the upper surface of the cathode.
- Yet a further aspect of the invention relates to a method of producing aluminium in a cell as described above.
- This method comprises passing an electrolysis current between anodes and the aluminium-wetted drained active cathode surface in an electrolyte comprising dissolved alumina to evolve gas at the anodes and produce aluminium on the drained active cathode surface.
- the produced aluminium drains into the aluminium collection recess from the drained active cathode surface over the openly porous plates which extend over at least part of the recess.
- the cell may evolve oxygen on the anodes.
- the anodes may be coated with a protective layer, such as a layer made of one or more cerium compounds, in particular cerium oxyfluoride, in which case the protective layer may be maintained by maintaining an amount of cerium species in the electrolyte, as disclosed in the above mentioned US Patents 4,614,569, 4,680,094, 4,683,037 and 4,966,674.
- the cell may be operated with an electrolyte at reduced temperature, e.g. 880° to 930° or even 940°C, to reduce dissolution of the metal-based anodes.
- Figure 1 illustrates one embodiment of a drained-cathode cell having an aluminium collection reservoir in accordance with the invention.
- the cell shown in Figure 1 comprises a plurality of oxygen evolving anodes 10 dipping in a molten electrolyte 5 and facing a cell bottom.
- the cell bottom comprises: a series of pairs of spaced apart carbon cathode blocks 25 placed across the cell and having an aluminium-wettable upper surface 22 formed by an aluminium-wettable layer.
- the upper surfaces 22 are covered with aluminium-wettable openly porous plates 21 which are filled with molten aluminium to form an aluminium-wetted drained active cathode surface 20 above the upper surfaces 22 of the carbon cathode blocks 25.
- the cathode blocks 25 are made of graphite and have a reduced height, e.g. 30 cm, and are coated with an aluminium-wettable layer which forms the upper surface 22 and which protects the graphite from erosion and wear. Suitable aluminium-wettable layers are disclosed in the above mentioned US Patent 5,651,874, WO98/17842, WO01/42168 and WO01/42531.
- the aluminium-wettable openly porous plates 21 covering the coated cathode blocks 25 can be made of the material disclosed in PCT/IB02/00668 (de Nora).
- the cell bottom further comprises a centrally-located recess 35 which extends at a level below the upper surfaces 22 of the carbon cathode blocks 25 and which during use collects molten aluminium 60 drained from the aluminium-wettable drained active cathode surface 20.
- the aluminium collection recess 35 is formed in a reservoir body 30 which is placed between the blocks 25 of each pair of cathode blocks and spaces them apart across the cell. As shown in Figure 1, the recess 35 formed in the reservoir body 30 is generally U-shaped with rounded lower corners and an outwardly curved upper part.
- the reservoir body 30 is made of two generally L-shaped sections 31 assembled across the cell.
- the reservoir sections 31 are made of anthracite-based material.
- the aluminium-wettable layer forming the upper surfaces 22 extends in the recess 35 to protect the reservoir body 30 during use against wear and sodium intercalation.
- the reservoir body 30 extends below the cathode blocks 25 into the refractory and insulating material 26 of the cell bottom permitting a maximisation of the capacity of the aluminium collection recess 35.
- the reservoir body 30 has a solid base 32 which extends from above to below the bottom face of the cathode blocks 25 and provides sufficient mechanical resistance to keep the blocks 25 properly spaced apart across the cell when exposed to thermal expansion during start-up of the cell and normal operation.
- a solid base 32 which extends from above to below the bottom face of the cathode blocks 25 and provides sufficient mechanical resistance to keep the blocks 25 properly spaced apart across the cell when exposed to thermal expansion during start-up of the cell and normal operation.
- longitudinally spaced apart spacer bars 33 placed across the reservoir body 30 may provide additional mechanical strength to the reservoir body 30.
- Such spacer bars 33 can be made of carbon material coated with an aluminium-wettable protective layer.
- the openly porous plates 21 placed on the upper surfaces 22 of the carbon cathode blocks 25 and located in the central region of the cell bottom extend over part of the aluminium collection recess 35 so that during use the protruding part of the aluminium-wetted drained active cathode surface 20 is located over the recess 35.
- the openly porous plates 21 are spaced apart over the aluminium collection recess 35 to leave an access for the tapping of molten aluminium through a conventional tapping tube.
- the spacing between the openly porous plates 21 over the aluminium collection recess can be much smaller along the remaining parts of the recess 35, thereby maximising the surface area of the active cathode surface 20.
- the cell shown in Figure 1 comprises a series of corner pieces 41 made of the openly porous material of the plates 21 and filled with aluminium and placed at the periphery of the cell bottom against sidewalls 40.
- the sidewalls 40 and the surface of the electrolyte 5 are covered with a ledge and a small crust of frozen electrolyte 6.
- the cell is fitted with an insulating cover 45 above the electrolyte crust 6. Further details of suitable covers are disclosed in WO99/02763 (de Nora/Sekhar), WO01/31086 (de Nora/Duruz) and PCT/IB02/00669 (de Nora/Berclaz).
- the cell is also provided with exhaust pipes (not shown) that extend through the cover 45 for the removal of gases produced during electrolysis.
- the cell comprises alumina feeders 15 with feeding tubes 16 that extend through the insulating cover 45 between the anodes 10.
- the alumina feeders 15 are associated with a crust breaker (not shown) for breaking the crust 6 underlying the feeding tube 16 prior to feeding.
- the insulating material of the sidewalls 40 and cover 45 may be sufficient to prevent formation of any ledge and crust of frozen electrolyte.
- the sidewalls 40 are preferably completely shielded from the molten electrolyte 5 by a lining of the aforesaid openly porous material filled with aluminium.
- the anodes 10 are preferably made of electrolyte resistant inert metal-based material. Suitable metal-based anode materials inqlude iron alloys comprising nickel and/or cobalt which may be heat-treated in an oxidising atmosphere.
- the lifetime of the anode may be increased by a protective coating made of cerium compounds, in particular cerium oxyfluoride.
- a protective coating made of cerium compounds in particular cerium oxyfluoride.
- the cell may be operated with an electrolyte 5 at reduced temperature, typically from about 850° to 940°C, preferably from 880° to 930°C.
- an electrolyte 5 at reduced temperature typically from about 850° to 940°C, preferably from 880° to 930°C.
- Operating with an electrolyte at reduced temperature reduces the solubility of oxides, in particular of alumina. For this reason, it is advantageous to enhance alumina dissolution in the electrolyte 5.
- Enhanced alumina dissolution may be achieved by utilising an alumina feed device which sprays and distributes alumina particles over a large area of the surface of the molten electrolyte 5.
- Suitable alumina feed devices are disclosed in greater detail in WO00/63464 (de Nora/Berclaz).
- the cell may comprise means (not shown) to promote circulation of the electrolyte 5 from and to the anode-cathode gap to enhance alumina dissolution in the electrolyte 5 and to maintain in permanence a high concentration of dissolved alumina close to the active surfaces of anodes 10, for example as disclosed in WO00/40781 (de Nora).
- alumina dissolved in the electrolyte 5 is electrolysed to produce oxygen on the anodes 10 and aluminium 60 on the drained cathode surfaces 20.
- the product aluminium 60 drains from the cathode surfaces 20 over the openly porous plates 21 that extend over part of the reservoir 30 into the reservoir 30 from where it can be tapped.
- aluminium is produced on the drained active cathode surface 20 which covers not only the cathode blocks 25 but also part of the reservoir 30, thereby maximising the useful aluminium production area (i.e. the drained cathode surface 22) of the cell.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electrolytic Production Of Metals (AREA)
- Water Treatment By Electricity Or Magnetism (AREA)
- Secondary Cells (AREA)
Claims (17)
- Cuve pour l'électro-obtention d'aluminium à partir d'alumine ayant un fond de cuve qui comprend :une cathode, en particulier une série de blocs cathodiques en carbone, ayant une surface supérieure mouillable par l'aluminium ;des plaques ouvertement poreuses mouillables par l'aluminium qui sont placées sur la surface supérieure de la cathode et qui sont remplies d'aluminium en fusion pour former une surface cathodique active de drainage mouillée par l'aluminium au-dessus de la surface supérieure de la cathode ; etun évidement à un niveau au-dessous de la surface supérieure de la cathode et qui, pendant l'utilisation, recueille l'aluminium en fusion s'écoulant de la surface cathodique active de drainage mouillable par l'aluminium,
- Cuve selon la revendication 1, dans laquelle la cathode est réalisée en blocs cathodiques en carbone agencés par paires à travers le fond de la cuve.
- Cuve selon la revendication 1 ou 2 précédente, dans laquelle la cathode est réalisée en graphite.
- Cuve selon une quelconque revendication précédente, dans laquelle la cathode est revêtue d'une couche de matière mouillable par l'aluminium formant la surface cathodique supérieure mouillable par l'aluminium.
- Cuve selon une quelconque revendication, dans laquelle au moins une partie de l'évidement de collecte d'aluminium est formée dans un corps de réservoir qui est juxtaposé à la cathode.
- Cuve selon la revendication 5, dans laquelle le corps de réservoir comprend de l'anthracite.
- Cuve selon la revendication 5 ou 6 quand elle dépend de la revendication 2, dans laquelle le corps de réservoir est situé entre les blocs d'au moins une paire de blocs cathodiques en carbone et les espace en travers du fond de la cuve.
- Cuve selon une quelconque revendication précédente, dans laquelle l'évidement de collecte d'aluminium est généralement en forme de U.
- Cuve selon une quelconque revendication précédente, qui comprend une série d'anodes à dégagement d'oxygène faisant face aux plaques ouvertement poreuses mouillables par l'aluminium.
- Cuve selon la revendication 9, dans laquelle les anodes à dégagement d'oxygène sont revêtus d'une couche protectrice, telle qu'une couche réalisée en un ou plusieurs composés de cérium, en particulier de l'oxyfluorure de cérium.
- Procédé pour produire de l'aluminium dans une cuve telle que définie dans une quelconque revendication précédente, consistant à faire passer un courant d'électrolyse entre des anodes et la surface cathodique active de drainage mouillée par l'aluminium dans un électrolyte comprenant de l'alumine dissoute pour dégager du gaz au niveau des anodes et produire de l'aluminium sur la surface cathodique active de drainage, l'aluminium produit s'écoulant dans l'évidement de collecte d'aluminium à partir de la surface cathodique active de drainage sur les plaques ouvertement poreuses qui s'étendent jusqu'à une partie de l'évidement.
- Procédé selon la revendication 11, consistant à faire dégager de l'oxygène sur les anodes.
- Procédé selon la revendication 12, dans lequel les anodes ont un revêtement protecteur, tel qu'un revêtement réalisé en un ou plusieurs composés de cérium, en particulier de l'oxyfluorure de cérium, ledit procédé consistant à maintenir une quantité d'espèce de cérium dans l'électrolyte pour conserver la couche protectrice.
- Procédé selon une quelconque des revendications 11 à 13, dans lequel l'électrolyte est à une température dans la plage de 850°C à 940°C.
- Fond d'une cuve pour l'électro-obtention d'aluminium à partir d'alumine, comprenant une cathode, en particulier une série de blocs cathodiques en carbone, ayant une surface supérieure mouillable par l'aluminium, des plaques ouvertement poreuses mouillables par l'aluminium qui sont placées sur la surface supérieure de la cathode, et un évidement de collecte d'aluminium qui se trouve à un niveau au-dessous de la surface supérieure de la cathode, dans lequel des plaques ouvertement poreuses recouvrant la surface supérieure de la cathode s'étendent jusqu'à une partie de l'évidement de collecte d'aluminium.
- Cuve pour l'électro-obtention d'aluminium comprenant un fond tel que défini dans la revendication 15, dans laquelle les plaques ouvertement poreuses mouillables par l'aluminium sont remplies d'aluminium en fusion pour former une surface cathodique active de drainage mouillée par l'aluminium au-dessus de la surface supérieure de la cathode.
- Procédé pour produire de l'aluminium dans une cuve telle que définie dans la revendication 16, consistant à faire passer un courant d'électrolyse entre des anodes et la surface cathodique active de drainage mouillée par l'aluminium dans un électrolyte comprenant de l'alumine dissoute pour dégager du gaz au niveau des anodes et produire de l'aluminium sur la surface cathodique active de drainage, l'aluminium produit s'écoulant dans l'évidement de collecte d'aluminium à partir de la surface cathodique active de drainage sur les plaques ouvertement poreuses qui s'étendent jusqu'à une partie de l'évidement.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
IB0100953 | 2001-05-30 | ||
WOPCT/IB01/00953 | 2001-05-30 | ||
PCT/IB2002/001884 WO2002097169A1 (fr) | 2001-05-30 | 2002-05-28 | Enceintes d'electro-extraction d'aluminium comprenant un fond de cathode draine et un reservoir de collecte d'aluminium |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1392892A1 EP1392892A1 (fr) | 2004-03-03 |
EP1392892B1 true EP1392892B1 (fr) | 2005-01-19 |
Family
ID=11004112
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP02730626A Expired - Lifetime EP1392892B1 (fr) | 2001-05-30 | 2002-05-28 | Enceintes d'electro-extraction d'aluminium comprenant un fond de cathode draine et un reservoir de collecte d'aluminium |
Country Status (8)
Country | Link |
---|---|
EP (1) | EP1392892B1 (fr) |
AT (1) | ATE287463T1 (fr) |
CA (1) | CA2448313A1 (fr) |
DE (1) | DE60202676T2 (fr) |
ES (1) | ES2231696T3 (fr) |
NO (1) | NO20035306L (fr) |
NZ (1) | NZ529852A (fr) |
WO (1) | WO2002097169A1 (fr) |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3369162D1 (en) * | 1982-05-10 | 1987-02-19 | Eltech Systems Corp | Dimensionally stable drained aluminum electrowinning cathode method and apparatus |
-
2002
- 2002-05-28 NZ NZ529852A patent/NZ529852A/en unknown
- 2002-05-28 CA CA002448313A patent/CA2448313A1/fr not_active Abandoned
- 2002-05-28 AT AT02730626T patent/ATE287463T1/de not_active IP Right Cessation
- 2002-05-28 WO PCT/IB2002/001884 patent/WO2002097169A1/fr not_active Application Discontinuation
- 2002-05-28 ES ES02730626T patent/ES2231696T3/es not_active Expired - Lifetime
- 2002-05-28 EP EP02730626A patent/EP1392892B1/fr not_active Expired - Lifetime
- 2002-05-28 DE DE60202676T patent/DE60202676T2/de not_active Expired - Fee Related
-
2003
- 2003-11-28 NO NO20035306A patent/NO20035306L/no not_active Application Discontinuation
Also Published As
Publication number | Publication date |
---|---|
CA2448313A1 (fr) | 2002-12-05 |
NZ529852A (en) | 2005-11-25 |
NO20035306D0 (no) | 2003-11-28 |
NO20035306L (no) | 2003-11-28 |
WO2002097169A1 (fr) | 2002-12-05 |
DE60202676T2 (de) | 2005-06-16 |
DE60202676D1 (de) | 2005-02-24 |
EP1392892A1 (fr) | 2004-03-03 |
ATE287463T1 (de) | 2005-02-15 |
ES2231696T3 (es) | 2005-05-16 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1554416B1 (fr) | Cellules d'extraction electrolytique de l'aluminium avec anodes a base de metal | |
EP1392891B1 (fr) | Enceintes d'electro-extraction d'aluminium comprenant un fond de cathode draine et un reservoir de collecte d'aluminium | |
EP1366214B1 (fr) | Materiau ceramique poreux mouillable par l'aluminium | |
EP1392892B1 (fr) | Enceintes d'electro-extraction d'aluminium comprenant un fond de cathode draine et un reservoir de collecte d'aluminium | |
WO2007105124A2 (fr) | Cellule d'extraction electrolytique d'aluminium avec pertes de chaleur réduites | |
CA2505285C (fr) | Cellules d'extraction electrolytique de l'aluminium a anodes a base de metal | |
AU2002302918A1 (en) | Aluminium electrowinning cells having a drained cathode bottom and an aluminium collection reservoir | |
EP1366216B1 (fr) | Cellule pour l'electro-obtention d'aluminium fonctionnant avec des anodes a base metallique | |
US8097144B2 (en) | Aluminium electrowinning cell with enhanced crust | |
AU2002256854A1 (en) | Aluminium electrowinning cells having a drained cathode bottom and an aluminium collection reservoir | |
CA2450097A1 (fr) | Cellule electrolytique dote d'un dispositif d'alimentation en poudre ameliore | |
AU2002236145B2 (en) | Cell for the electrowinning of aluminium operating with metal-based anodes | |
AU2004213650B2 (en) | Aluminium electrowinning cells with metal-based anodes | |
AU2002236145A1 (en) | Cell for the electrowinning of aluminium operating with metal-based anodes | |
AU2002236143A1 (en) | Aluminium-wettable porous ceramic material |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20031204 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
|
AX | Request for extension of the european patent |
Extension state: AL LT LV MK RO SI |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20050119 Ref country code: LI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20050119 Ref country code: FI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20050119 Ref country code: CH Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20050119 Ref country code: BE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20050119 Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20050119 |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
REF | Corresponds to: |
Ref document number: 60202676 Country of ref document: DE Date of ref document: 20050224 Kind code of ref document: P |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20050419 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20050419 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20050419 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: ES Payment date: 20050510 Year of fee payment: 4 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2231696 Country of ref document: ES Kind code of ref document: T3 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20050528 Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20050528 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20050530 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MC Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20050531 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
ET | Fr: translation filed | ||
26N | No opposition filed |
Effective date: 20051020 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: MM4A |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20060505 Year of fee payment: 5 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20060528 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: ES Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20060529 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: IT Payment date: 20060531 Year of fee payment: 5 Ref country code: FR Payment date: 20060531 Year of fee payment: 5 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: NL Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20061201 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20060528 |
|
NLV4 | Nl: lapsed or anulled due to non-payment of the annual fee |
Effective date: 20061201 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FD2A Effective date: 20060529 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: PT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20050619 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20080131 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: DE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20071201 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20070531 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20070528 |