EP0099840B1 - Elektrolysetrog für die Herstellung von Aluminium mit einem schwimmenden stromleitenden Schirm - Google Patents

Elektrolysetrog für die Herstellung von Aluminium mit einem schwimmenden stromleitenden Schirm Download PDF

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Publication number
EP0099840B1
EP0099840B1 EP83420109A EP83420109A EP0099840B1 EP 0099840 B1 EP0099840 B1 EP 0099840B1 EP 83420109 A EP83420109 A EP 83420109A EP 83420109 A EP83420109 A EP 83420109A EP 0099840 B1 EP0099840 B1 EP 0099840B1
Authority
EP
European Patent Office
Prior art keywords
electrolytic tank
tank according
screen
floating
floating screen
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
Application number
EP83420109A
Other languages
English (en)
French (fr)
Other versions
EP0099840A1 (de
Inventor
Michel Leroy
Maurice Keinborg
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Rio Tinto France SAS
Original Assignee
Aluminium Pechiney SA
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Aluminium Pechiney SA filed Critical Aluminium Pechiney SA
Publication of EP0099840A1 publication Critical patent/EP0099840A1/de
Application granted granted Critical
Publication of EP0099840B1 publication Critical patent/EP0099840B1/de
Expired legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
    • C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
    • C25C3/08—Cell construction, e.g. bottoms, walls, cathodes

Definitions

  • the present invention relates to a tank for the production of aluminum by electrolysis of alumina dissolved in the molten cryolite according to the Hall-Héroult process, comprising a floating conductive screen, between the anode and the cathode.
  • the electrical energy consumption is at least 13,000. KWh per tonne of metal, and often exceeds 14,000.
  • the voltage drop in the electrolyte represents about 1.5 volts, so it is responsible for more than a third of the total energy consumption.
  • cathodes based on electrically conductive refractories, such as titanium diboride TiB 2 , which is perfectly wet. by liquid aluminum and undergoes practically no attack by this metal at the temperature of electrolysis.
  • Such cathodes have been described, in particular, in English patents 784,695, 784,696, 784,697 to BRITISH ALUMINUM C °, and in the article by KE BILLEHAUG and HA OYE in "ALUMINUM", Oct. 1980, pages 642. -648 and Nov. 1980, pages 713 to 718.
  • the present invention constitutes another solution to the problem of reducing the interpolar distance without the risk of entraining the cathode aluminum towards the anode.
  • FIGS. 1 and 2 represent different modes of implementing the invention:
  • the floating conductive screen (1) consists of porous TiB 2 balls (2), but sealed on the surface, with an average density of 2.25.
  • These balls can be manufactured, for example, according to the technique described in the French brevent 1,579,540 in the name of ALUMINUM PECHINEY, which consists in sintering a mixture of TiB 2 and a substance which can be removed at the sintering temperature.
  • the diameter of these beads is between 5 and 50 mm and, preferably, between 10 and 40 mm.
  • the lower diameter limit is related to manufacturing costs and the upper limit is approximately twice the planned interpolar distance.
  • Such beads having a porosity of around 50% can be considered too fragile.
  • the sealing can be carried out in two stages: deposition of a medium dense bonding layer to the plasma, then of a thin sealing layer by chemical deposition or else by a chemical vapor deposition carried out in two stages, the the first being performed at lower pressure and temperature than the second.
  • the TiB 2 floating balls (2) form a substantially continuous layer at the interface (3) of the metal (4) and the electrolyte (5). It is this layer which forms the screen (1) between the anode (6) and the metal (4) and, at the same time, acts as cathode on which the liquid aluminum droplets produced by electrolysis are formed. These droplets wet the floating balls (2) and collect in the already formed layer (4). The risk of entrainment of the droplets towards the anode, where they would reoxidize, is therefore practically eliminated, which makes it possible to reduce the interpolar distance d to around 20 millimeters and to lower the voltage drop in the electrolyte to less than 1 volt.
  • the floating balls (2) have been drawn above the interface (3), but it is obvious that their exact position depends on their density ratio with the bath and the metal.
  • the floating screen is formed from beads based on TiB 2
  • this shape is not compulsory and any other shape may be suitable, for example cylindrical elements which, according to their length / diameter ratio, will float with the axis in vertical or horizontal position.
  • Flat discs for example, can be used.
  • the largest dimension of the elements used does not exceed 50 mm and, preferably, 40 mm, that is to say twice the target interpolar distance.
  • Figure 2 shows a solution in which the floating conductive screen is confined to the plumb of the anodes (6) by means of barriers (7) of dense refractory material. Openings (8) should preferably be made in these barriers to ensure the circulation of the liquid aluminum (4).
  • the implementation of the invention allows a significant reduction in the interpolar distance, up to around 20 mm, without loss of the electrolysis yield.
  • the potential difference at the terminals of the electrolysis cells thus modified is reduced from 4 volts to approximately 3.2 to 3.3 volts, with a proportional reduction in the energy consumption per tonne of aluminum produced.

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  • 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)
  • Conductive Materials (AREA)
  • Chemical Treatment Of Metals (AREA)

Claims (8)

1. Elektrolysetrog zur Erzeugung von Aluminium durch Elektrolyse von in einem Bad geschmolzenen Kryoliths gelöstem Aluminiumoxid nach dem Hall-Höroult-Verfahren zwischen wenigstens einer Kohlenstoffhaltigen Anode und einer ein kohlenstoffhaltiges kathodisches Substrat bedeckenden Aluminiumauflage,
dadurch gekennzeichnet,
daß er an der Grenzfläche (3) der Aluminiumauflage (4) und des Bades (5) geschmolzenen Kryoliths auf Höhe der Grenzfläche einen schwimmenden Schirm (1) aufweist, der aus der Nebeneinanderlage einer Mehrzahl von den elektrischen Stom leitenden Elementen besteht, die eine im wesentlichen zusammenhängende Schicht bilden und an der Oberfläche durch eine Abscheidung von Titandiborid einer Dicke von wenigstens gleich 20 um abgedichtet sind.
2. Elektrolysetrog nach Anspruch 1,
dadurch gekennzeichnet,
daß die den schwimmenden Schirm (1) bildenden, nebeneinanderliegenden Elemente aus porösem Titandiborid mit einer mittleren Dichte im Bereich von 2,15 bis 2,30 bei 960°C bestehen.
3. Elektrolysetrog nach Anspruch 1 oder 2,
dadurch gekennzeichnet,
daß die den schwimmenden Schirm (1) bildenden, nebeneinanderliegenden Elemente durch Sintern eines Gemisches von TiB2, einem zweiten, unter dem Bornitrid und dem Graphit gewählten Stoff und einem geeigneten Anteil eines in der Hitze entfernbaren Stoffes derart gebildet sind, um eine im wesentlichen 2,25 gleiche Enddichte bei 960° C zu erhalten.
4. Elektrolystrog nach Anspruch 1 oder 2,
dadurch gekennzeichnet,
daß die den Schirm (1) bildenden, nebeneinanderliegenden Elemente aus einem Graphitkern und einer TiB2> -Schale in einem 80 % Graphit und 20 9 TiB2 im wesentlichen gleichen Gewichtsverhältnis derart gebildet sind, um eine im wesentlichen 2,25 gleiche Enddichte zu erhalten.
5. Elektrolysetrog nach einem der Ansprüche 1 bis 4,
dadurch gekennzeichnet,
daß die ganze Grenzfläche (3) zwischen dem Metall (4) und dem Elektrolyt (5) vom schwimmenden Schirm (2) bedeckt ist.
6. Elektrolysetrog nach einem der Ansprüche 1 bis 4,
dadurch gekennzeichnet,
daß der schwimmende Schirm (2) auf die Vertikalprojektion der Anoden (6) mit Hilfe von Sperren (7) aus feuerfestem, dichtem Material begrenzt ist, die mit seitlichen Öffnungen (8) versehen sind.
7. Elektrolysetrog nach einem der Ansprüche 1 bis 6,
dadurch gekennzeichnet,
daß der Abstand zwischen jeder Anode und dem schwimmenden leitenden Schirm unter 40 mm und vorzugsweise gleich etwa 20 mm ist.
8. Elektrolysetrog nach einem der Ansprüche 1 bis 4,
dadurch gekennzeichnet,
daß der schwimmende Schirm aus Kugeln (2) mit einem Durchmesser im Bereich von 5 bis 50 mm und vorzugsweise von 10 bis 40 mm besteht.
EP83420109A 1982-06-30 1983-06-29 Elektrolysetrog für die Herstellung von Aluminium mit einem schwimmenden stromleitenden Schirm Expired EP0099840B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8211873 1982-06-30
FR8211873A FR2529580B1 (fr) 1982-06-30 1982-06-30 Cuve d'electrolyse pour la production d'aluminium, comportant un ecran conducteur flottant

Publications (2)

Publication Number Publication Date
EP0099840A1 EP0099840A1 (de) 1984-02-01
EP0099840B1 true EP0099840B1 (de) 1986-08-13

Family

ID=9275740

Family Applications (1)

Application Number Title Priority Date Filing Date
EP83420109A Expired EP0099840B1 (de) 1982-06-30 1983-06-29 Elektrolysetrog für die Herstellung von Aluminium mit einem schwimmenden stromleitenden Schirm

Country Status (17)

Country Link
US (1) US4533452A (de)
EP (1) EP0099840B1 (de)
JP (1) JPS5920484A (de)
KR (1) KR840006510A (de)
AU (1) AU562447B2 (de)
BR (1) BR8303459A (de)
CA (1) CA1190892A (de)
DE (1) DE3365289D1 (de)
ES (1) ES8403984A1 (de)
FR (1) FR2529580B1 (de)
GR (1) GR77515B (de)
IN (1) IN159794B (de)
NO (1) NO832365L (de)
OA (1) OA07473A (de)
SU (1) SU1356967A3 (de)
YU (1) YU140683A (de)
ZA (1) ZA834761B (de)

Families Citing this family (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3469043D1 (en) * 1983-11-29 1988-03-03 Alcan Int Ltd Aluminium reduction cells
US4631121A (en) * 1986-02-06 1986-12-23 Reynolds Metals Company Alumina reduction cell
US4919782A (en) * 1989-02-21 1990-04-24 Reynolds Metals Company Alumina reduction cell
US5129998A (en) * 1991-05-20 1992-07-14 Reynolds Metals Company Refractory hard metal shapes for aluminum production
EP0572896B1 (de) * 1992-05-25 1998-01-07 Canon Kabushiki Kaisha Magnetischer Entwickler und Verfahren zur Erkennung von Zeichen aus magnetischer Tinte
US5486278A (en) * 1993-06-02 1996-01-23 Moltech Invent S.A. Treating prebaked carbon components for aluminum production, the treated components thereof, and the components use in an electrolytic cell
US5472578A (en) * 1994-09-16 1995-12-05 Moltech Invent S.A. Aluminium production cell and assembly
US5753382A (en) * 1996-01-10 1998-05-19 Moltech Invent S.A. Carbon bodies resistant to deterioration by oxidizing gases
WO2018092103A1 (en) * 2016-11-19 2018-05-24 Jan Petrus Human Electrodes for use in the electro-extraction of metals

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE433408A (de) * 1938-04-08
US3287247A (en) * 1962-07-24 1966-11-22 Reynolds Metals Co Electrolytic cell for the production of aluminum
GB1169012A (en) * 1965-10-21 1969-10-29 Montedison Spa Furnace and Process for Producing, in Fused Bath, Metals from their Oxides, and Electrolytic Furnaces having Multiple Cells formed by Horizontal Bipolar Carbon Electrodes
US4338177A (en) * 1978-09-22 1982-07-06 Metallurgical, Inc. Electrolytic cell for the production of aluminum
US4177128A (en) * 1978-12-20 1979-12-04 Ppg Industries, Inc. Cathode element for use in aluminum reduction cell
US4224128A (en) * 1979-08-17 1980-09-23 Ppg Industries, Inc. Cathode assembly for electrolytic aluminum reduction cell
GB2069530B (en) * 1980-01-28 1984-05-16 Diamond Shamrock Corp Packed cathode bed for electrowinning metals from fused salts
CH644406A5 (de) * 1980-04-03 1984-07-31 Alusuisse Schmelzflusselektrolysezelle zur herstellung von aluminium.
US4349427A (en) * 1980-06-23 1982-09-14 Kaiser Aluminum & Chemical Corporation Aluminum reduction cell electrode
ZA824255B (en) * 1981-06-25 1983-05-25 Alcan Int Ltd Electrolytic reduction cells
CH648870A5 (de) * 1981-10-23 1985-04-15 Alusuisse Kathode fuer eine schmelzflusselektrolysezelle zur herstellung von aluminium.
FR2518124A1 (fr) * 1981-12-11 1983-06-17 Pechiney Aluminium Elements cathodiques flottants, a base de refractaire electroconducteur, pour la production d'aluminium par electrolyse
US4436598A (en) * 1983-09-28 1984-03-13 Reynolds Metals Company Alumina reduction cell

Also Published As

Publication number Publication date
IN159794B (de) 1987-06-06
AU562447B2 (en) 1987-06-11
JPS5920484A (ja) 1984-02-02
AU1646083A (en) 1984-01-05
ZA834761B (en) 1984-03-28
GR77515B (de) 1984-09-24
KR840006510A (ko) 1984-11-30
ES523678A0 (es) 1984-04-01
NO832365L (no) 1984-01-02
EP0099840A1 (de) 1984-02-01
BR8303459A (pt) 1984-02-07
FR2529580B1 (fr) 1986-03-21
YU140683A (en) 1985-12-31
SU1356967A3 (ru) 1987-11-30
ES8403984A1 (es) 1984-04-01
OA07473A (fr) 1984-12-31
DE3365289D1 (en) 1986-09-18
FR2529580A1 (fr) 1984-01-06
US4533452A (en) 1985-08-06
JPS6141997B2 (de) 1986-09-18
CA1190892A (fr) 1985-07-23

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