US3764509A - Electrolytic furnaces for the production of aluminium - Google Patents

Electrolytic furnaces for the production of aluminium Download PDF

Info

Publication number
US3764509A
US3764509A US00223068A US3764509DA US3764509A US 3764509 A US3764509 A US 3764509A US 00223068 A US00223068 A US 00223068A US 3764509D A US3764509D A US 3764509DA US 3764509 A US3764509 A US 3764509A
Authority
US
United States
Prior art keywords
blocks
cathode
carbon
cell
aluminium
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
Application number
US00223068A
Other languages
English (en)
Inventor
K Etzel
P Aeschbach
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.)
Alcan Holdings Switzerland AG
Original Assignee
Alusuisse Holdings AG
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 Alusuisse Holdings AG filed Critical Alusuisse Holdings AG
Application granted granted Critical
Publication of US3764509A publication Critical patent/US3764509A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

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 cells intended for use in the fusion electrolysis process for production of aluminium.
  • cathodes for use in the fusion electrolysis process for production of aluminium depends upon the resistance of the cathode material to electrolyte and metal melt as well as upon their electrical properties.
  • the cathodes generally used consist of a number of rows of parallelepipedic blocks comprising carbon or graphite, which are assembled together in an electrolysis tank to form a substantially flat base, the joints between the blocks being tamped or filled with cementing compositions.
  • the carbon, carbon bonded graphite (semi-graphite) or graphite blocks from which the cathode is generally formed and, in particular, the jointing composition together present an available pore volume of the order of 20 to 30% of the cathode volume, into which electrolyte and melt penetrate during operation of a cell comprising the cathode.
  • Constituents of the electrolyte and molten aluminium react'at the operating temperature with carbon or graphite, so that aluminium carbide and intermediate compounds, in particular, are formed.
  • the reaction products have a larger volume than the reactants, so that tensile stresses are set up in the cathode, and these are only partially taken up by the tank housing the cathode.
  • a set of blocks of carbon and/or carbonbonded graphite and/or graphite intended for assembly to form a cathode for use in a cell for the fusion electrolysis of an alumina-containing electrolyte to produce aluminium the blocks being shaped so as to abut closely one against the next over a common interface and each block having parallel end surfaces of different size so that, when assembled together, the smaller end surfaces together form one face of the cathode and the larger end surfaces together form an opposite face of the cathode, the blocks being grooved or slotted so that, when they are assembled to form a cathode, a conductor bar can pass through the grooves or slots in an assembled row of the blocks.
  • a tank in the bottom of which is arranged a cathode as a lining therefor the cathode being constituted by a set of blocks of carbon and/ or carbon-bonded graphite and/ or graphite according to the invention which has been assembled so that the blocks abut closely over a common interface with the smaller end surfaces together the top surface of the cathode and the larger end surfaces together forming the bottom surface of the cathode, the slots or grooves in the blocks being aligned with a conductor bar arranged therein.
  • the faces other than the aforesaid parallel faces will generally be of different slope.
  • the blocks will be of trapezoidal crosssection in at least one direction therethrough which is perpendicular to said parallel surfaces and parallel to an edge of a said opposed surface. This allows assembly of the blocks in line with the shorter edges of the trapezoidal faces being uppermost in the assembled cathode.
  • the blocks are of trapezoidal cross-section in two such directions, this will ensure improved cathode behaviour when blocks are assembled in a two dimensional layout.
  • the blocks will generally only be of trapezoidal cross-section in one direction; two opposed lateral sides will be vertical.
  • a layer capable of being compressed is arranged between the blocks from which the cathode is formed and the base or the lateral walls of the tank.
  • the compressible layer preferably consists of a porous material.
  • the compressible layer allows a certain degree of free expansion of the carbon block layer to occur. This floating arrangement further contributes to the suppression of mechanical stresses in the monolithic carbon block bed.
  • the effect of the compressible layer is enhanced if the base of the tank bottom is connected by expansion joints to the tank walls, the joints advantageously being provided with gas-impervious seals.
  • the compressible layers employed can be formed, for example, of porous refractory bricks which disintegrate under compressive stresses, of fillings of loose refractory material or thermoplastic plastics-bound carbon-containing compositions.
  • the cathode is preferably formed from a combination of types of blocks, blocks of graphite and/or carbon-bonded graphite being located in the centre of the cathode area and blocks of carbon being located at the cathode margins.
  • cathode blocks having different thermal conductivities which are generally from 3 to 15 kcal./m.h. C. for carbon blocks, from 20 to 40 kcal./m.h. C. for carbon-bonded graphite blocks and from 60 to 160 kcal./m.h. C. for graphite blocks, the temperature distribution in the cathode is evened out. This contributes further to the suppression of mechanical sresses between the blocks.
  • the cathode By constructing the cathode in the aforesaid manner according to the invention, it is possible to substantially reduce, or eliminate bulging of the bed of blocks from which it is formed which would impair the operation of the furnace and cause the voltage drop to increase. Bulging of the cathode bed can be largely prevented even after operating for a relatively long time.
  • the cathodic current distribution is more likely to be constant than with known arrangements, so that a better current efficiency is obained.
  • the life of cells for production of aluminium by electrolysis with conventional cathodes is generally, on average, about 1200 days
  • cells using cathodes according to the invention are expected to have a life of at least 2500 days.
  • FIG. 1 is a cross-section through the pot of a cell for use in the production of aluminium by fusion electrolysis with thank and cathode, and
  • FIG. 2 is a perspective view of part of the cathode for the cell.
  • FIG. 1 of the drawing there is shown a steel tank 1 lined with fire-clay bricks 2.
  • a com pressible layer 3 consisting of coke and graphite powder and a thermoplastic binder, on which layer is formed an arrangement of blocks of carbonaceous material.
  • com pressible layer 3 consisting of coke and graphite powder and a thermoplastic binder, on which layer is formed an arrangement of blocks of carbonaceous material.
  • carbonbonded graphite blocks 4 are arranged in the marginal regions of the cell tank.
  • Each block has opposed surfaces of rectilinear dimensions, the top surfaces being smaller than the bottom surfaces and the angles between the vertical and the contact surfaces between two adjacent blocks becoming larger with increasing distance from the centre of the cell tank for any one row of blocks 4 and 5.
  • the blocks 4 and 5 comprise slots for accommodating a conductor bar 8.
  • the rows of blocks within the tank are supported against the lateral boundary of the tank by marginal blocks 6, which also consist of carbon and also contain slots in line with the slots in the blocks 4 and 5.
  • the distance between two blocks is about 0.8 mm. and the joints 7 therebetween are filled with a carbon-containing cementing composition. Because of the mutual wedging of the blocks which results from their being trapezoidal in section and the favourable anchoring of the rows of blocks with the marginal blocks, the bulging of the cathode formed from the blocks and a lifting of individual blocks in the event of a joint defect is sub- I stantially, if not completely, prevented.
  • FIG. 2 the shape and arrangement of the blocks 4 and 5 straddled on theconductor bar 8 can be seen more clearly. Since a small gap 9 exists between the bar 8 and the blocks 4 and 5 and the marginal blocks 6, this gap is filled with a cast metal or is tamped with a carbon-containing composition.
  • the blocks 4 and 5 shown in FIG. 2 havethepreferred shape according to the invention, that is, they have two lateral surfaces inclined relatively to the 'vertical at different angles, through which'surfaces the conductor bah-"extends, and two vertical, lateral boundary surfaces extending parallel to the conductor bar. The assembly of a ro'w'of the blocks is particularly facilitated by this arrangement.
  • cells for use on a commercial scale will generally be at least 5 to 6 metres long and about-4 metres wide. Since the blocks are generally about 50 to 80 cms. long in their various directions, this ,will mean that a number of rows of the blocks will generally'b'e used. In this case, all the lateral boundary surfaces-ofthe blocks can be inclined relatively to the vertical, each two "suc-' cessive lateral faces in "either direction being inclined at different angles relatively "to the vertical. This will'allow a cathode to be produced which is particularlvstable' against buckling.
  • the blocks for assembly to form a row are inverted and, assembled with their grooves in line.
  • a conductor bar is placed in the continuous groove,
  • the cathode material will generally extend some way: up the side walls of the tank.
  • the side walls will also generally be formed of carbon blocks and will preferably.
  • lateral has. shaped so that each lateral, surface will, abut closely against a lateral surface of. the adjacent block,; each block having parallel end surfaces of different size so that, 1
  • the smaller end-surfaces together form the upperface of the cathode and the larger end surfaces together form an underside of the cathode.
  • a cell according to nimi having a groove aligned with the"groove"s of the adjacentblocks receiving a conductor bar.
  • each block possessfour lateral surfaces, "at”least a"pair' of which lateral surfaces which" are opposed tofea'ch other being inclined at different angles to the vertical, said blocks being assembled into a plurality of parallel rows.
  • a cell according to claim 7 wherein the compressible material comprises loose refractory material.
  • a cell according to claim 7 wherein the compressible material comprises a thermoplastic plastics-bound carbon containing composition.
  • a cell as claimed in claim 4, wherein any carbon block present in the cathode has a thermal conductivity of from 3 to 15 kca1./m.h. C.
  • any carbonbonded graphite bloc-k present in the cathode has a thermal conductivity of from 20 to kcal./m.h. C.

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)
US00223068A 1971-02-04 1972-02-03 Electrolytic furnaces for the production of aluminium Expired - Lifetime US3764509A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2105247A DE2105247C3 (de) 1971-02-04 1971-02-04 Ofen für die Schmelzflußelektrolyse von Aluminium

Publications (1)

Publication Number Publication Date
US3764509A true US3764509A (en) 1973-10-09

Family

ID=5797801

Family Applications (1)

Application Number Title Priority Date Filing Date
US00223068A Expired - Lifetime US3764509A (en) 1971-02-04 1972-02-03 Electrolytic furnaces for the production of aluminium

Country Status (11)

Country Link
US (1) US3764509A (enrdf_load_stackoverflow)
JP (1) JPS5526195B1 (enrdf_load_stackoverflow)
AT (1) AT316887B (enrdf_load_stackoverflow)
CA (1) CA968745A (enrdf_load_stackoverflow)
CH (1) CH561784A5 (enrdf_load_stackoverflow)
DE (1) DE2105247C3 (enrdf_load_stackoverflow)
FR (1) FR2124516B1 (enrdf_load_stackoverflow)
GB (1) GB1362933A (enrdf_load_stackoverflow)
IT (1) IT947222B (enrdf_load_stackoverflow)
NL (1) NL7201310A (enrdf_load_stackoverflow)
NO (1) NO128828B (enrdf_load_stackoverflow)

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
USB430385I5 (enrdf_load_stackoverflow) * 1974-01-03 1975-01-28
US3871986A (en) * 1973-10-31 1975-03-18 Reynolds Metals Co Joint ramming cement for electrolytic reduction cell cathodes
US4052288A (en) * 1976-01-13 1977-10-04 Aluminium Pechiney Process for brasquing fused electrolysis cells
FR2355093A1 (fr) * 1976-06-16 1978-01-13 Alusuisse Cellule d'electrolyse pour la fabrication d'aluminium
US4076610A (en) * 1975-07-10 1978-02-28 Elettrocarbonium S.P.A. Cathode in cells for producing aluminium by electrolysis of smelted salts thereof
US4290874A (en) * 1980-06-25 1981-09-22 Aluminum Company Of America Gasket for sealing joints in carbonaceous elements in electrolysis cell
US4402808A (en) * 1982-07-30 1983-09-06 Aluminum Company Of America Gasket for sealing joints between electrodes and adjacent cell lining and for improving bath circulation in electrolysis cells
US4430187A (en) 1981-04-22 1984-02-07 Swiss Aluminium Ltd. Reduction cell pot
US4536273A (en) * 1982-03-05 1985-08-20 Sintef Diffusion barrier for aluminium electrolysis furnaces
US4561958A (en) * 1984-11-30 1985-12-31 Reynolds Metals Company Alumina reduction cell
US4589967A (en) * 1983-07-28 1986-05-20 Sigri Gmbh Lining for an electrolysis cell for the production of aluminum
US4605481A (en) * 1984-06-13 1986-08-12 Aluminium Pechiney Modular cathodic block and cathode having a low voltage drop for Hall-Heroult electrolysis tanks
US4683046A (en) * 1985-03-22 1987-07-28 Swiss Aluminium Ltd. Reduction pot for the production of aluminum
US5108572A (en) * 1987-07-29 1992-04-28 Yan Lathion Electrolytic furnace
US6627062B1 (en) 1999-02-02 2003-09-30 Carbone Savoie Graphite cathode for the electrolysis of aluminium
EP2650404A1 (en) * 2012-04-12 2013-10-16 SGL Carbon SE Electrolysis cell, in particular for the production of aluminium

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CH657383A5 (de) * 1981-08-31 1986-08-29 Alusuisse Elektrolysewanne zur herstellung von aluminium mittels schmelzflusselektrolyse und verfahren zum einsetzen der eisenbarren.
DE4336024A1 (de) * 1993-10-22 1995-04-27 Didier Werke Ag Bodenauskleidung eines Aluminiumelektrolyseofens
WO2014060422A2 (de) * 2012-10-17 2014-04-24 Sgl Carbon Se Kathodenblock mit trapezförmigem querschnitt
DE102012218958A1 (de) * 2012-10-17 2014-04-30 Sgl Carbon Se Kathodenblock mit trapezförmigem Querschnitt
DE102012218959A1 (de) * 2012-10-17 2014-04-30 Sgl Carbon Se Kathodenblock mit trapezförmigem Querschnitt

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3871986A (en) * 1973-10-31 1975-03-18 Reynolds Metals Co Joint ramming cement for electrolytic reduction cell cathodes
US4001104A (en) * 1974-01-03 1977-01-04 Union Carbide Corporation Cemented collector bar assemblies for aluminum cell carbon bottom block
USB430385I5 (enrdf_load_stackoverflow) * 1974-01-03 1975-01-28
US4076610A (en) * 1975-07-10 1978-02-28 Elettrocarbonium S.P.A. Cathode in cells for producing aluminium by electrolysis of smelted salts thereof
US4052288A (en) * 1976-01-13 1977-10-04 Aluminium Pechiney Process for brasquing fused electrolysis cells
FR2355093A1 (fr) * 1976-06-16 1978-01-13 Alusuisse Cellule d'electrolyse pour la fabrication d'aluminium
US4124476A (en) * 1976-06-16 1978-11-07 Egon Rapolthy Electrolytic cell for the production of aluminium
US4290874A (en) * 1980-06-25 1981-09-22 Aluminum Company Of America Gasket for sealing joints in carbonaceous elements in electrolysis cell
US4430187A (en) 1981-04-22 1984-02-07 Swiss Aluminium Ltd. Reduction cell pot
US4536273A (en) * 1982-03-05 1985-08-20 Sintef Diffusion barrier for aluminium electrolysis furnaces
US4402808A (en) * 1982-07-30 1983-09-06 Aluminum Company Of America Gasket for sealing joints between electrodes and adjacent cell lining and for improving bath circulation in electrolysis cells
US4589967A (en) * 1983-07-28 1986-05-20 Sigri Gmbh Lining for an electrolysis cell for the production of aluminum
US4605481A (en) * 1984-06-13 1986-08-12 Aluminium Pechiney Modular cathodic block and cathode having a low voltage drop for Hall-Heroult electrolysis tanks
US4561958A (en) * 1984-11-30 1985-12-31 Reynolds Metals Company Alumina reduction cell
US4683046A (en) * 1985-03-22 1987-07-28 Swiss Aluminium Ltd. Reduction pot for the production of aluminum
US5108572A (en) * 1987-07-29 1992-04-28 Yan Lathion Electrolytic furnace
US6627062B1 (en) 1999-02-02 2003-09-30 Carbone Savoie Graphite cathode for the electrolysis of aluminium
EP2650404A1 (en) * 2012-04-12 2013-10-16 SGL Carbon SE Electrolysis cell, in particular for the production of aluminium
WO2013153053A1 (en) * 2012-04-12 2013-10-17 Sgl Carbon Se Electrolysis cell, in particular for the production of aluminum
CN104428451A (zh) * 2012-04-12 2015-03-18 西格里碳素欧洲公司 电解槽、特别是用于生产铝的电解槽
RU2630114C2 (ru) * 2012-04-12 2017-09-05 Сгл Карбон Се Электролизер, в частности, для получения алюминия
US10801118B2 (en) 2012-04-12 2020-10-13 Tokai Cobex Gmbh Electrolysis cell, in particular for the production of aluminum

Also Published As

Publication number Publication date
CA968745A (en) 1975-06-03
NL7201310A (enrdf_load_stackoverflow) 1972-08-08
DE2105247B2 (de) 1979-10-04
DE2105247C3 (de) 1980-06-12
DE2105247A1 (de) 1972-08-17
IT947222B (it) 1973-05-21
CH561784A5 (enrdf_load_stackoverflow) 1975-05-15
JPS5526195B1 (enrdf_load_stackoverflow) 1980-07-11
NO128828B (enrdf_load_stackoverflow) 1974-01-14
FR2124516B1 (enrdf_load_stackoverflow) 1974-12-13
FR2124516A1 (enrdf_load_stackoverflow) 1972-09-22
GB1362933A (en) 1974-08-07
AT316887B (de) 1974-07-25

Similar Documents

Publication Publication Date Title
US3764509A (en) Electrolytic furnaces for the production of aluminium
EP1845174B1 (en) Cathodes for aluminium electrolysis cell with non-planar slot design
AU2006328947B2 (en) Cathodes for aluminium electrolysis cell with expanded graphite lining
US4093524A (en) Bonding of refractory hard metal
US20060151333A1 (en) Cathode systems for electrolytically obtaining aluminum
US4795540A (en) Slotted cathode collector bar for electrolyte reduction cell
US3607685A (en) Aluminum reduction cell and system for energy conservation therein
US4349427A (en) Aluminum reduction cell electrode
CA2619085A1 (en) Methods for in-situ formation of slots in a soderberg anode
US3256173A (en) Electrolytic furnace with lined cathode pots for the production of aluminum
US5135621A (en) Composite cell bottom for aluminum electrowinning
RU2245395C2 (ru) Графитовый катод для электролиза алюминия
US2758964A (en) Continuous electrode and method of making the same
US3029194A (en) Furnace and process for the electrolysis of aluminum
US4683046A (en) Reduction pot for the production of aluminum
CN201305634Y (zh) 一种具有纵向和横向减波功能的新型阴极结构铝电解槽
US2938843A (en) Process for the production of aluminum by fused bath alumina electrolysis and three-layer anode for carrying out said process
US4290874A (en) Gasket for sealing joints in carbonaceous elements in electrolysis cell
RU2149925C1 (ru) Катодное устройство алюминиевого электролизера
CN120380203A (zh) 用于铝电解槽的阴极集流体组件
CA2470757A1 (en) Process for the graphitization of cathode blocks
KR860000043B1 (ko) 알루미늄 제조용 전해조의 라이닝 방법
WO2025171488A1 (en) Electrolytic cells containing fused cast refractories and lining components
NZ540976A (en) Cathode systems for electrolytically obtaining aluminium