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EP0324266A1 - Procédé de positionnement des électrodes dans des cellules d'électrolyse d'aluminium - Google Patents

Procédé de positionnement des électrodes dans des cellules d'électrolyse d'aluminium Download PDF

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Publication number
EP0324266A1
EP0324266A1 EP88312199A EP88312199A EP0324266A1 EP 0324266 A1 EP0324266 A1 EP 0324266A1 EP 88312199 A EP88312199 A EP 88312199A EP 88312199 A EP88312199 A EP 88312199A EP 0324266 A1 EP0324266 A1 EP 0324266A1
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EP
European Patent Office
Prior art keywords
anode
anodes
cells
setting
rule
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.)
Granted
Application number
EP88312199A
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German (de)
English (en)
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EP0324266B1 (fr
Inventor
Odd Skaar
Kurt Nilsson
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Norsk Hydro ASA
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Norsk Hydro ASA
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Publication date
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Application filed by Norsk Hydro ASA filed Critical Norsk Hydro ASA
Publication of EP0324266A1 publication Critical patent/EP0324266A1/fr
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    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25B—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR
    • C25B15/00—Operating or servicing cells
    • C25B15/04—Regulation of the inter-electrode distance
    • 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
    • C—CHEMISTRY; METALLURGY
    • C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C7/00—Constructional parts, or assemblies thereof, of cells; Servicing or operating of cells
    • C25C7/06—Operating or servicing

Definitions

  • the present invention relates to a method of setting elect­rodes in electrolysis cells, especially setting of carbon­aceous anodes in cells producing aluminium by electrolysis according to the Hall-Heroult process, as mentioned in the initial part of the present claim 1.
  • Aluminium is mostly produced by electolysis of aluminium oxide dissolved in a cryolite bath.
  • the electrolysis cells consist of a carbon cathode disposed in a steel shell which on the inside is isolated with refactory materials.
  • a carbon anode or a number of rechangeable carbon anodes which are partly submerged in the cryolite bath and which are gradually reduced by the oxygen originating from the decomposing of the aluminium oxide.
  • the carbon anodes are fixedly attached to so-called anode hangers which again are securely held to an anode bar for mechanical and electrical connection. As the carbon anodes are consumed and metal is charged from the cells (the metal represents the actual cathode), the anode bar is lowered to keep a constant distance between the cathode and the carbon anodes.
  • An electolysis cell of common size is usually provided with approximately 20 carbon anodes, and since the anodes are consumed gradually, each anode has to be replaced by a new one after 20-24 days. Thus, in each cell a used anode is replaced by a new one every day.
  • the new anodes are set or positioned so that the distance from the bottom side of these to the cathodes is the same as the distance for the old ones being exchanged.
  • the exchange of anodes is carried out in different ways. The most common way of doing it, is by providing the old (used) anode, or rather the anode hanger with a chalk mark referring to a reference point on the anode bar, usually the bottom side of the anode bar. The used anode is then placed alongside a new anode on the floor to transfer the measurement marked with the chalk mark on the old anode onto the new one, and the new anode is there­after inserted in the cell.
  • the here described manual method for setting the anodes is, however, liable to error, caused by the width of the chalk mark, errors of parallaxe during the tranference of the measurements from the old anode to the new anode, irregu­larities of the surface on which they are stood etc.
  • a mechanical device which is also based on the conventional method, is described in GB patent application No. 2.018.291.
  • the device comprises a crane which is employed to exchange old anodes with new ones.
  • the old anode is pulled out until, after passing through a certain travel, the surface facing the cathode has reached a predetermined horizontal plane.
  • the distance travelled through until then is stored.
  • the new anode is positioned with the surface facing the cathode in a second horizontal plane and is lowered towards the cathode in accordance with measurement of the stored level, the distance between the two horisontal planes and possibly with regard to different saggings of the crane caused by the different weights of the new and old anode.
  • the present invention it has been a main object to provide a method for setting (positioning) the anodes in electrolysis cells by which the above disadvantages are eliminated i.e. where: - a more even current absorption is achieved, whereby the anode slipping is reduced and repositioning of the anodes is avoided, - the control level is raised due to the fact that a sys­tematic source regarding variation in current absorption is eliminated, - there is achieved a greater chance to reveal problems connected to the anode-exchange routine, such as anode carbon remainders, mud etc.
  • the anode consumption is reduced as the anode endurance principally is governed by the "smallest" critical anode butts", - it is possible to increase the size of the electrolysis cells without having to use individual anode regulating means.
  • the invention is characterized by the features of the at­tached claim 1,
  • a Hall-­Herould electrolysis cell for producing aluminium principally consists of a cathode 2 and one or more above the cathode provided carbon anodes 3.
  • the cathode which contains the cryolite bath is made of carbon blocks 4 placed in an inter­nally isolated steel shell. The carbon blocks are connected to current leads by means of steel bars streching all the way through the cathode (not shown).
  • the carbon anodes are cast or in some other way fixedly connected to anode hangers 8, which in turn is releasably connected to an anode bar 7 by means of connectors (not shown). Electric current is supplied to the anode bar via flexibles 10, and the anode bar is lowered and lifted in a regulation zone 12 by means of jacks 11.
  • the electric current is lead, as will be appearant above, from the top to the bottom of the cells.
  • the aluminium oxide dissolved in the bath 13 is decomposed to aluminium metal and oxygen.
  • the aluminium is, due to the gravitational forces, deposited on the cat­hode, while the oxygen selectiveely reacts with the carbon of the anode to carbon dioxide.
  • the anodes are lowered. This is done by lowering the anode bar by means of said jacks 11.
  • the anode bar with the carbon anodes have reached the lower­most position, the anode bar has to be lifted - so called "cross lifting" - while the anode hangers are intermediately mechanically fixed to an assisting bar which are called raiser.
  • each anode has to be exchanged after approx. 20-24 days. In each cell there is thus about one anode exchange every day.
  • the main principle with the conventional setting method resides in that the new anodes should be positioned at the same level h above the cathode as the old anodes. In practice it is shown, however, that in connection with the anode exchange several errors occur which results in relatively large deviations in the setting height for the anodes. These setting deviations cause inreased anode consumption simul­taneously as they lead to operational disturbances due to the fact that the new anodes either draw too much or too little electric current.
  • the relations are as follows:
  • the anodes are positioned too low (short interpolare distance between the anode and the cathode) the current consumption is increased and accordingly the anode consump­tion increases. As opposed hereto, if the anodes are posi­tioned too high, the current and thus the anode consumption is reduced.
  • Fig. 2 a similar electrolysis cell as is shown in Fig. 1, but in which the anodes are positioned according to the present invention. The method will be described as follows:
  • the anode hangers When manufacturing new anodes, or rather when the anode hangers are assembled to the anode carbons, the anode hangers are provided with one or preferably two reference marks 16, 17.
  • the reference marks may be in the form of a readily removeable paint and is painted in a predetermined distance from the bottom side of the carbon anodes which is equal for all the anodes.
  • a fixed rule 18 is further made having mark­ings 19 in vertically, spaced apart relation. The distance between each reference point 19 defines the expected anode consumption pr. unit of time. This anode consumption is dependent upon several factors such as carbon quality and current density.
  • the rule 18 is thereafter fixedly positioned on the anode bar, one for each anode in the cells and in a distance from the metal plane 15 (the surface limit between the bath and metal) which is equal for each of the anodes.
  • the rule 18 may be drawn on paper which is glued onto the anode bar, or it can be painted or drawn directly on the anode bar.
  • the reference points 19 on the rule 18 are provided with num­bers 1,2,3 and so forth in rising order upwards (not shown).
  • the length of the rule is dependent upon the length of the regulation zone 12 for the anode bar and how large part of the anodes which can be consumed. Hence, the rules have to be longer than the sum of the length of the regulating zone for the anode bar and the length of the maximum anode consump­tion.
  • the lowermost reference mark 16 on the anode hanger will thus for the most part be employed when new anodes are positioned in the cell, while the uppermost reference mark 17 on the anode hanger for the most part will be employed when "cross­ing" of the anode bar takes place.
  • the rules 18 are positioned at a distance from the metal/bath surface limit which is equal for all of the anodes. If thus a line is drawn along the anode bar which toches the upper 21, or lower 22 end of the rules, it will have a shape which to a large extent corresponds to the curved metal plane.
  • the new anodes are positioned according to the expected setting height, i.e. the reference mark 16 or 17 on the anode rods 9 is placed in correspondance with the topical reference point (setting point) 19 on the rule 18 for the anode bar.
  • the calculation of the setting point is normally accomplished by means of a calculator which adds one reference point 19 (1,6 cm) for each day.
  • the calculator will decide to reduce the current consumption and give a signal indicating that the anode should be reposi­tioned at a higher level (one reference mark) above normal setting height.
  • the results are presented each day on a dayly set-list which the carbon exchange operators are using.
  • the metal plane As to the metal plane, this can be calculated by measure­ments or theoretically by means of magneto hydrodynamic models. In the following it will be further described how the metal plane preferably can be calculated by means of measurements.
  • the above-mentioned rules 18 are fixedly positioned on an anode bar in an electrolysis cell in the same horisontal plane, and the anodes are positioned according to the same reference mark, i.e. the bottom side of the anodes are posi­tioned in the same horisontal plane.
  • a statistic material is worked out in the form of measured current consumption I for anodes with an operational time of 24h. This is done for each anode position in the horisontal plane.
  • Fig. 3 shows schematically the horsisontal positions for n anodes in an elecrolysis cell.
  • ⁇ j can for instance represent the arithemtic average of m singular current con­sumption measurements, I, and which gives the equation: where E(I) is the expected value of the current consumption I and p(I) is the probability density distribution for the current I.

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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)
  • Immobilizing And Processing Of Enzymes And Microorganisms (AREA)
EP19880312199 1987-12-30 1988-12-22 Procédé de positionnement des électrodes dans des cellules d'électrolyse d'aluminium Expired EP0324266B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
NO875479A NO162975C (no) 1987-12-30 1987-12-30 Fremgangsmaate for setting av elektroder i elektrolyseceller.
NO875479 1987-12-30

Publications (2)

Publication Number Publication Date
EP0324266A1 true EP0324266A1 (fr) 1989-07-19
EP0324266B1 EP0324266B1 (fr) 1992-09-30

Family

ID=19890508

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19880312199 Expired EP0324266B1 (fr) 1987-12-30 1988-12-22 Procédé de positionnement des électrodes dans des cellules d'électrolyse d'aluminium

Country Status (6)

Country Link
EP (1) EP0324266B1 (fr)
AU (1) AU615975B2 (fr)
BR (1) BR8806985A (fr)
CA (1) CA1336701C (fr)
DE (1) DE3875099T2 (fr)
NO (1) NO162975C (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2874934A1 (fr) * 2004-09-08 2006-03-10 Ecl Soc Par Actions Simplifiee Procede de changement d'anode dans une cellule de production d'aluminium par electrolyse incluant un ajustement de la position de l'anode et dispositif pour le mettre en oeuvre
WO2006030092A3 (fr) * 2004-09-08 2006-12-07 Ecl Procédé de changement d'anode dans une cellule de production d'aluminium par électrolyse incluant un ajustement de la position de l'anode et dispositif pour le mettre en oeuvre
WO2013132464A1 (fr) * 2012-03-09 2013-09-12 Jan Petrus Human Gain électrique et raffinage électrique
US8607853B2 (en) 2005-01-06 2013-12-17 Modular Heat Exchangers Limited Modular heat exchanger connectable in multiple different configurations
JP2014501331A (ja) * 2010-12-23 2014-01-20 ジーイー−ヒタチ・ニュークリア・エナジー・アメリカズ・エルエルシー モジュラーアノードアッセンブリおよび電気化学的還元のためにそれを使用する方法
US8636836B2 (en) 2009-02-04 2014-01-28 Purdue Research Foundation Finned heat exchangers for metal hydride storage systems
US8778063B2 (en) 2009-02-04 2014-07-15 Purdue Research Foundation Coiled and microchannel heat exchangers for metal hydride storage systems
WO2016097968A1 (fr) * 2014-12-15 2016-06-23 Dubai Aluminium Pjsc Système de suivi de tiges d'anode pour des installations d'électrolyse
WO2017145066A1 (fr) * 2016-02-26 2017-08-31 Jan Petrus Human Extraction électrolytique
US9920443B2 (en) 2010-12-23 2018-03-20 Ge-Hitachi Nuclear Energy Americas Llc Modular cathode assemblies and methods of using the same for electrochemical reduction

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NO307110B1 (no) * 1998-07-01 2000-02-07 Elkem Materials Fremgangsmåte for estimering av elektrodespissposisjon

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1525011A (fr) * 1966-05-12 1968-05-17 Pechiney Prod Chimiques Sa Dispositif pour le réglage en hauteur d'une électrode verticale et procédé pour la mise en oeuvre de ce dispositif
US3491002A (en) * 1964-09-21 1970-01-20 Reynolds Metals Co Adjusting anode blocks in an electrolytic cell
DE1558759A1 (de) * 1967-09-30 1970-04-23 Siemens Ag Verfahren zur Ermittlung des Abstandes zwischen Anode und Kathode eines Aluminium-Elektrolyseofens
US4540474A (en) * 1984-06-04 1985-09-10 Aluminum Company Of America Light level electrode setting gauge and method of use

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3705842A (en) * 1970-11-16 1972-12-12 Patricia J Barbato Float measuring device for mercury cells

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3491002A (en) * 1964-09-21 1970-01-20 Reynolds Metals Co Adjusting anode blocks in an electrolytic cell
FR1525011A (fr) * 1966-05-12 1968-05-17 Pechiney Prod Chimiques Sa Dispositif pour le réglage en hauteur d'une électrode verticale et procédé pour la mise en oeuvre de ce dispositif
DE1558759A1 (de) * 1967-09-30 1970-04-23 Siemens Ag Verfahren zur Ermittlung des Abstandes zwischen Anode und Kathode eines Aluminium-Elektrolyseofens
US4540474A (en) * 1984-06-04 1985-09-10 Aluminum Company Of America Light level electrode setting gauge and method of use

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2874934A1 (fr) * 2004-09-08 2006-03-10 Ecl Soc Par Actions Simplifiee Procede de changement d'anode dans une cellule de production d'aluminium par electrolyse incluant un ajustement de la position de l'anode et dispositif pour le mettre en oeuvre
WO2006030092A3 (fr) * 2004-09-08 2006-12-07 Ecl Procédé de changement d'anode dans une cellule de production d'aluminium par électrolyse incluant un ajustement de la position de l'anode et dispositif pour le mettre en oeuvre
US7422675B2 (en) 2004-09-08 2008-09-09 E.C.L. Process for changing anodes in an electrolytic aluminum production cell including adjustment of the position of the anode and device for implementing the process
AU2005284068B2 (en) * 2004-09-08 2010-07-29 E.C.L. Method of changing an anode of a cell for the production of aluminium by means of electrolysis, including an adjustment of the position of the anode, and device for performing same
US8607853B2 (en) 2005-01-06 2013-12-17 Modular Heat Exchangers Limited Modular heat exchanger connectable in multiple different configurations
US8636836B2 (en) 2009-02-04 2014-01-28 Purdue Research Foundation Finned heat exchangers for metal hydride storage systems
US8778063B2 (en) 2009-02-04 2014-07-15 Purdue Research Foundation Coiled and microchannel heat exchangers for metal hydride storage systems
JP2014501331A (ja) * 2010-12-23 2014-01-20 ジーイー−ヒタチ・ニュークリア・エナジー・アメリカズ・エルエルシー モジュラーアノードアッセンブリおよび電気化学的還元のためにそれを使用する方法
US9920443B2 (en) 2010-12-23 2018-03-20 Ge-Hitachi Nuclear Energy Americas Llc Modular cathode assemblies and methods of using the same for electrochemical reduction
WO2013132464A1 (fr) * 2012-03-09 2013-09-12 Jan Petrus Human Gain électrique et raffinage électrique
WO2016097968A1 (fr) * 2014-12-15 2016-06-23 Dubai Aluminium Pjsc Système de suivi de tiges d'anode pour des installations d'électrolyse
WO2017145066A1 (fr) * 2016-02-26 2017-08-31 Jan Petrus Human Extraction électrolytique

Also Published As

Publication number Publication date
NO875479L (no) 1989-07-03
DE3875099T2 (de) 1993-02-18
CA1336701C (fr) 1995-08-15
NO875479D0 (no) 1987-12-30
NO162975B (no) 1989-12-04
EP0324266B1 (fr) 1992-09-30
DE3875099D1 (de) 1992-11-05
AU2760688A (en) 1989-07-06
AU615975B2 (en) 1991-10-17
NO162975C (no) 1990-03-14
BR8806985A (pt) 1989-09-05

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