EP1392891B1 - Aluminium electrowinning cells having a drained cathode bottom and an aluminium collection reservoir - Google Patents
Aluminium electrowinning cells having a drained cathode bottom and an aluminium collection reservoir Download PDFInfo
- Publication number
- EP1392891B1 EP1392891B1 EP02726381A EP02726381A EP1392891B1 EP 1392891 B1 EP1392891 B1 EP 1392891B1 EP 02726381 A EP02726381 A EP 02726381A EP 02726381 A EP02726381 A EP 02726381A EP 1392891 B1 EP1392891 B1 EP 1392891B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- aluminium
- cell
- cathode
- anodes
- drained
- 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
- 229910052782 aluminium Inorganic materials 0.000 title claims abstract description 104
- 239000004411 aluminium Substances 0.000 title claims abstract description 104
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 title claims abstract description 104
- 238000005363 electrowinning Methods 0.000 title claims abstract description 12
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 10
- 229910002804 graphite Inorganic materials 0.000 claims abstract description 5
- 239000010439 graphite Substances 0.000 claims abstract description 5
- RHZUVFJBSILHOK-UHFFFAOYSA-N anthracen-1-ylmethanolate Chemical compound C1=CC=C2C=C3C(C[O-])=CC=CC3=CC2=C1 RHZUVFJBSILHOK-UHFFFAOYSA-N 0.000 claims abstract description 4
- 239000003830 anthracite Substances 0.000 claims abstract description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 22
- 239000003792 electrolyte Substances 0.000 claims description 22
- 238000000034 method Methods 0.000 claims description 11
- 239000000919 ceramic Substances 0.000 claims description 9
- 239000010410 layer Substances 0.000 claims description 9
- 229910052751 metal Inorganic materials 0.000 claims description 8
- 239000002184 metal Substances 0.000 claims description 8
- 150000001785 cerium compounds Chemical class 0.000 claims description 6
- 238000005868 electrolysis reaction Methods 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 6
- 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
- 239000007789 gas Substances 0.000 claims description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 4
- 229910052760 oxygen Inorganic materials 0.000 claims description 4
- 239000001301 oxygen Substances 0.000 claims description 4
- 229910052684 Cerium Inorganic materials 0.000 claims description 3
- GWXLDORMOJMVQZ-UHFFFAOYSA-N cerium Chemical compound [Ce] GWXLDORMOJMVQZ-UHFFFAOYSA-N 0.000 claims description 3
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 238000004090 dissolution Methods 0.000 description 4
- 239000003575 carbonaceous material Substances 0.000 description 3
- 229910017052 cobalt Inorganic materials 0.000 description 3
- 239000010941 cobalt Substances 0.000 description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 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
- 229910000640 Fe alloy Inorganic materials 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
- 229910010293 ceramic material Inorganic materials 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
- 239000000203 mixture Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 238000010079 rubber tapping Methods 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
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 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
- 238000000576 coating method Methods 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
- 238000004070 electrodeposition 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
- 238000011065 in-situ storage 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
- 239000011253 protective coating Substances 0.000 description 1
- 230000001681 protective effect Effects 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
- 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 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, 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.
- An object of the invention is to provide an aluminium electrowinning cell bottom and an aluminium electrowinning cell having an aluminium-wettable drained cathode which is made of conventional cell blocks which can be easily retrofitted in existing cells.
- 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.
- a major object of the invention is to provide a modular assembly of an aluminium collection reservoir and cathode blocks for an aluminium production cell.
- Yet another object of the invention is to provide a method to produce aluminium in an aluminium electrowinning cell provided with such a cell bottom.
- the invention provides a cell for the electrowinning of aluminium from alumina.
- This cell comprises a plurality of anodes, in particular oxygen-evolving anodes, facing a series of pairs of cathode blocks with aluminium-wettable drained cathode surfaces placed across the cell and a longitudinal aluminium collection recess which is located between the cathode blocks and which extends along the cell and is at a lower level than the drained cathode surfaces so that during use aluminium produced on the drained cathode surfaces drains into the aluminium collection recess.
- the aluminium collection recess is defined between the cathode blocks by a separate reservoir body which is placed between the blocks of each pair of cathode blocks spacing them apart across the cell and which extends along the cell.
- the cathode blocks can be made of graphite and/or have an aluminium-wettable upper part.
- the cathode blocks are coated with an aluminium-wettable layer.
- the cathode blocks are made of aluminium-wettable material.
- Suitable aluminium-wettable materials and carbon materials for cathode blocks 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).
- the cathode blocks may be covered with porous ceramic-based plates filled with molten aluminium whose surfaces serve as aluminium-wettable drained cathode surfaces on which aluminium is produced and from which aluminium drains into the collection reservoir.
- the ceramic-based plates are preferably made of 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 ceramic-based 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 aluminium-filled ceramic-based plates may extend from the cathode blocks over part of the aluminium collection recess, thereby the surface area of the aluminium-wettable drained cathode surface is increased.
- the reservoir body may be made of anthracite or other carbonaceous material.
- the reservoir body can be made of a plurality of sections assembled end-to-end longitudinally along the cell and/or side-by-side across the cell.
- the reservoir body has a generally U-shaped cross-section across the cell.
- the aluminium collection recess can have a triangular, rectangular or curved cross-section or a variation thereof which is suitable for the collection of aluminium.
- the aluminium collection recess is generally U-shaped with rounded lower corners and/or an outwardly curved upper part in cross-section
- the reservoir body has a rectangular cross-section with a planar upper surface which is at a level below the drained cathode surfaces and which constitutes the bottom surface of the aluminium collection recess.
- Upper parts of end faces of the cathode blocks may form the lateral surfaces of the aluminium collection recess.
- the bottom part of the aluminium collection recess may be horizontal or sloping longitudinally along the cell down towards one end of the cell or the centre of the cell.
- the anodes are oxygen-evolving anodes, such as metal-based anodes, in particular metal-based anodes having an oxide-based outer part.
- anodes can be made of an iron alloy comprising nickel and/or cobalt whose surface may be oxidised.
- Suitable 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 have an electrochemically active part coated with a slowly soluble protective layer, or 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), which can be continuously replenished by in-situ electrodeposition thereon of the cerium compound(s).
- a slowly soluble protective layer or 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), which can be continuously replenished by in-sit
- the invention also relates to a method of producing aluminium in a cell as described above.
- This method comprises passing an electrolysis current between the anodes and facing drained cathode surfaces in an electrolyte containing dissolved alumina to evolve gas, such as oxygen, at the anodes and produce aluminium on the drained cathode surfaces.
- gas such as oxygen
- the anodes may be oxygen-evolving and can be coated with a protective layer, such as a layer of one or more cerium compounds, in particular cerium oxyfluoride, in which case an amount of cerium species is preferably maintained in the electrolyte to maintain the protective cerium-based layer.
- a protective layer such as a layer of one or more cerium compounds, in particular cerium oxyfluoride, in which case an amount of cerium species is preferably maintained in the electrolyte to maintain the protective cerium-based layer.
- a further aspect of the invention relates to a bottom of a cell for the electrowinning of aluminium from alumina.
- This cell bottom comprises a series of pairs of cathode blocks with aluminium-wettable drained cathode surfaces placed thereacross and a longitudinal aluminium collection recess which is located between the cathode blocks and which extends along the cell bottom and is at a lower level than the drained cathode surfaces so that during use aluminium produced on the drained cathode surfaces drains into the aluminium collection recess.
- the aluminium collection recess is defined between the cathode blocks by a separate reservoir body which is placed between the cathode blocks spacing them apart across the cell bottom and which extends along the cell bottom.
- the cell bottom may comprise any of the above cell bottom-related features or any combination thereof.
- Another aspect of the invention relates to a method of producing aluminium in a cell comprising a cell bottom as described above.
- This method comprises passing an electrolysis current between anodes and the drained cathode surfaces of the cell bottom in an electrolyte containing dissolved alumina to evolve gas at the anodes and produce aluminium on the drained cathode surfaces.
- the produced aluminium drains from the drained cathode surfaces into the aluminium collection recess defined by the separate reservoir.
- Figure 1 illustrates a drained-cathode cell having an aluminium collection reservoir in accordance with the invention.
- the cell shown in Figure 1 comprises a plurality of pairs of oxygen-evolving anodes 10 dipping in a molten electrolyte 5 and facing a series of pairs of cathode blocks 25 with aluminium-wettable drained cathode surfaces 20 spaced apart across the cell and a separate longitudinal reservoir body 30 which is located between the spaced apart blocks 25.
- the reservoir body 30 has an upper surface which defines a central aluminium collection recess 35. This recess 35 extends along and is at a lower level than the drained cathode surfaces 20 so that during use aluminium produced on the drained cathode surfaces 20 drains into the aluminium collection recess 35.
- 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 22 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 reservoir body 30 is generally U-shaped and the aluminium collection recess 35 has 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 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 cathode blocks 25 are covered with porous ceramic-based plates 21 which are filled with molten aluminium and which form the aluminium-wettable drained active cathode surfaces 20 on the cathode blocks 25.
- the aluminium-filled ceramic-based plates 21 extend from the cathode blocks 25 over part of the aluminium collection recess 35.
- projecting parts of the aluminium-wettable drained active cathode surfaces 20 are located above the aluminium collection 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 60 through a conventional tapping tube.
- the spacing between the openly porous plates 21 over the aluminium collection recess 35 can be much smaller along the remaining parts of the recess 35, thereby maximising the surface area of the active cathode surfaces 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 WO02/070784 (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 include 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 into the reservoir 30 from where it can be tapped.
Abstract
Description
Claims (20)
- A cell for the electrowinning of aluminium from alumina comprising a plurality of anodes, in particular oxygen-evolving anodes, facing a series of pairs of cathode blocks with aluminium-wettable drained cathode surfaces placed across the cell and an aluminium collection recess which is located between cathode blocks at a lower level than the drained cathode surfaces so that during use aluminium produced on the drained cathode surfaces drains into the aluminium collection recess,
characterised in that the aluminium collection recess is a longitudinal recess that extends along the cell and that is defined between the cathode blocks by a separate reservoir body which is placed between the cathode blocks spacing them apart across the cell and which extends along the cell. - The cell of any preceding claim, wherein the cathode blocks are made of graphite.
- The cell of any preceding claim, wherein the cathode blocks have an aluminium-wettable upper part.
- The cell of claim 3, wherein the cathode blocks are coated with an aluminium-wettable layer.
- The cell of claim 1, 2 or 3, wherein the cathode blocks are made of aluminium-wettable material.
- The cell of any preceding claim, which comprises porous ceramic-based plates placed on the cathode blocks and filled with molten aluminium.
- The cell of claim 6, which comprises aluminium-filled ceramic-based plates that extend from the cathode blocks over part of the aluminium collection reservoir.
- The cell of any preceding claim, wherein the reservoir body is made of anthracite.
- The cell of any preceding claim, wherein the reservoir body is made of a plurality of sections assembled end-to-end longitudinally along the cell.
- The cell of any preceding claim, wherein the reservoir body is made of at least two sections assembled side-by-side across the cell.
- The cell of any preceding claim, wherein the reservoir body has a generally U-shaped cross-section across the cell.
- The cell of claim 11, wherein the aluminium collection recess has rounded lower corners.
- The cell of claim 11 or 12, wherein the aluminium collection recess has an outwardly curved upper part.
- The cell of any preceding claim, wherein the anodes are oxygen-evolving anodes, such as metal-based anodes.
- The cell of claim 14, wherein the anodes are metal-based and have an electrochemically active outer oxide-based part.
- The cell of claim 14 or 15, wherein the oxygen-evolving anodes are coated with a protective layer, such as a layer made of one or more cerium compounds, in particular cerium oxyfluoride.
- A method of producing aluminium in a cell as defined in any preceding claim, said method comprising passing an electrolysis current between the anodes and facing drained cathode surfaces in an electrolyte containing dissolved alumina to evolve gas, in particular oxygen, at the anodes and produce aluminium on the drained cathode surfaces, the produced aluminium draining from the drained cathode surfaces into the aluminium collection recess defined by the separate reservoir body.
- The method of claim 17, wherein the anodes are coated with an oxygen-evolving protective layer, such as a layer made of one or more cerium compounds, in particular cerium oxyfluoride, that can be maintained by maintaining an amount of cerium species in the electrolyte.
- A bottom of a cell for the electrowinning of aluminium from alumina comprising a series of pairs of cathode blocks with aluminium-wettable drained cathode surfaces placed thereacross and a aluminium collection recess which is located between cathode blocks at a lower level than the drained cathode surfaces so that during use aluminium produced on the drained cathode surfaces drains into the aluminium collection recess,
characterised in that the aluminium collection recess is a longitudinal recess that extends along the cell bottom and that is defined between the cathode blocks by a separated reservoir body which is placed between the cathode blocks spacing them apart across the cell bottom and which extends along the cell bottom. - A method of producing aluminium in a cell comprising a cell bottom as defined in claim 19, said method comprising passing an electrolysis current between anodes and the drained cathode surfaces of the cell bottom in an electrolyte containing dissolved alumina to evolve gas at the anodes and produce aluminium on the drained cathode surfaces, the produced aluminium draining from the drained cathode surfaces into the aluminium collection recess defined by the separate reservoir.
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
WOPCT/IB01/00956 | 2001-05-30 | ||
IB0100956 | 2001-05-30 | ||
PCT/IB2002/001883 WO2002097168A1 (en) | 2001-05-30 | 2002-05-28 | Aluminium electrowinning cells having a drained cathode bottom and an aluminium collection reservoir |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1392891A1 EP1392891A1 (en) | 2004-03-03 |
EP1392891B1 true EP1392891B1 (en) | 2004-10-06 |
Family
ID=11004114
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP02726381A Expired - Lifetime EP1392891B1 (en) | 2001-05-30 | 2002-05-28 | Aluminium electrowinning cells having a drained cathode bottom and an aluminium collection reservoir |
Country Status (8)
Country | Link |
---|---|
EP (1) | EP1392891B1 (en) |
AT (1) | ATE278822T1 (en) |
CA (1) | CA2448311A1 (en) |
DE (1) | DE60201534T2 (en) |
ES (1) | ES2225783T3 (en) |
NO (1) | NO20035303L (en) |
NZ (1) | NZ529849A (en) |
WO (1) | WO2002097168A1 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101368282B (en) * | 2007-08-14 | 2012-07-11 | 北京有色金属研究总院 | Lower cathode rare earth metal electrolytic tank and electrolysis technique adopting the same |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
AU2007226245B2 (en) * | 2006-03-10 | 2011-05-12 | Rio Tinto Alcan International Limited | Aluminium electrowinning cell with enhanced crust |
RU2482224C2 (en) * | 2011-04-18 | 2013-05-20 | Общество с ограниченной ответственностью "Объединенная Компания РУСАЛ Инженерно-технологический центр" | Cathode device for aluminium electrolytic cell with embossed hearth |
WO2014077720A1 (en) * | 2012-11-13 | 2014-05-22 | Общество с ограниченной ответственностью "Объединенная Компания РУСАЛ Инженерно-технологический центр" | Lining for an aluminium electrolyzer having inert anodes |
RU2509830C1 (en) * | 2012-12-18 | 2014-03-20 | Общество с ограниченной ответственностью "Легкие металлы" | Electrolytic cell for production of aluminium |
RU2518029C1 (en) * | 2013-03-11 | 2014-06-10 | Общество с ограниченной ответственностью "Легкие металлы" | Electrolyser for aluminium production |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1251962B (en) * | 1963-11-21 | 1967-10-12 | The British Aluminium Company Limited, London | Cathode for an electrolytic cell for the production of aluminum and process for the production of the same |
US4602990A (en) * | 1983-02-17 | 1986-07-29 | Commonwealth Aluminum Corporation | Low energy aluminum reduction cell with induced bath flow |
DE69526264T2 (en) * | 1994-09-08 | 2002-10-24 | Moltech Invent Sa | Aluminum electrolytic cell with drainable cathode |
DE60003683T2 (en) * | 1999-04-16 | 2004-06-03 | Moltech Invent S.A. | ALUMINUM ELECTRIC RECOVERY CELL WITH V-SHAPED CATHODE BOTTOM |
-
2002
- 2002-05-28 WO PCT/IB2002/001883 patent/WO2002097168A1/en not_active Application Discontinuation
- 2002-05-28 CA CA002448311A patent/CA2448311A1/en not_active Abandoned
- 2002-05-28 NZ NZ529849A patent/NZ529849A/en unknown
- 2002-05-28 AT AT02726381T patent/ATE278822T1/en not_active IP Right Cessation
- 2002-05-28 EP EP02726381A patent/EP1392891B1/en not_active Expired - Lifetime
- 2002-05-28 ES ES02726381T patent/ES2225783T3/en not_active Expired - Lifetime
- 2002-05-28 DE DE60201534T patent/DE60201534T2/en not_active Expired - Fee Related
-
2003
- 2003-11-28 NO NO20035303A patent/NO20035303L/en not_active Application Discontinuation
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101368282B (en) * | 2007-08-14 | 2012-07-11 | 北京有色金属研究总院 | Lower cathode rare earth metal electrolytic tank and electrolysis technique adopting the same |
Also Published As
Publication number | Publication date |
---|---|
WO2002097168A1 (en) | 2002-12-05 |
CA2448311A1 (en) | 2002-12-05 |
NZ529849A (en) | 2005-01-28 |
ATE278822T1 (en) | 2004-10-15 |
EP1392891A1 (en) | 2004-03-03 |
DE60201534D1 (en) | 2004-11-11 |
NO20035303D0 (en) | 2003-11-28 |
ES2225783T3 (en) | 2005-03-16 |
NO20035303L (en) | 2003-11-28 |
DE60201534T2 (en) | 2005-10-20 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP1554416B1 (en) | Aluminium electrowinning cells with metal-based anodes | |
EP1392891B1 (en) | Aluminium electrowinning cells having a drained cathode bottom and an aluminium collection reservoir | |
EP1185724B1 (en) | Aluminium electrowinning cells having a v-shaped cathode bottom | |
WO2007105124A2 (en) | Aluminium electrowinning cell with reduced heat loss | |
EP1392892B1 (en) | Aluminium electrowinning cells having a drained cathode bottom and an aluminium collection reservoir | |
CA2505285C (en) | Aluminium electrowinning cells with metal-based anodes | |
AU2002256854A1 (en) | Aluminium electrowinning cells having a drained cathode bottom and an aluminium collection reservoir | |
US8097144B2 (en) | Aluminium electrowinning cell with enhanced crust | |
EP1366216B1 (en) | Cell for the electrowinning of aluminium operating with metal-based anodes | |
AU2002302918A1 (en) | Aluminium electrowinning cells having a drained cathode bottom and an aluminium collection reservoir | |
CA2450097A1 (en) | Electrolytic cell with improved powder feed device | |
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 |
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: 20041006 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: 20041006 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: 20041006 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: 20041006 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: 20041006 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: 20041006 |
|
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: 60201534 Country of ref document: DE Date of ref document: 20041111 Kind code of ref document: P |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
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: 20050106 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: 20050106 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: 20050106 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2225783 Country of ref document: ES Kind code of ref document: T3 |
|
LTIE | Lt: invalidation of european patent or patent extension |
Effective date: 20041006 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
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 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
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 Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES 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 |
|
ET | Fr: translation filed | ||
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 |
|
26N | No opposition filed |
Effective date: 20050707 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: MM4A |
|
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: NL Payment date: 20070425 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20070426 Year of fee payment: 6 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FD2A Effective date: 20060529 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: GB Payment date: 20070427 Year of fee payment: 6 |
|
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: 20050306 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: IT Payment date: 20070523 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 20070529 Year of fee payment: 6 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20080528 |
|
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: 20081201 |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST Effective date: 20090119 |
|
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: 20081202 Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20080602 |
|
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: 20080528 |
|
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: 20080528 |