EP0044794B1 - Procédé et appareillage pour réguler de façon précise la cadence d'introduction et la teneur en alumine d'une cuve d'électrolyse ignée, et application à la production d'aluminium - Google Patents

Procédé et appareillage pour réguler de façon précise la cadence d'introduction et la teneur en alumine d'une cuve d'électrolyse ignée, et application à la production d'aluminium Download PDF

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Publication number
EP0044794B1
EP0044794B1 EP81420104A EP81420104A EP0044794B1 EP 0044794 B1 EP0044794 B1 EP 0044794B1 EP 81420104 A EP81420104 A EP 81420104A EP 81420104 A EP81420104 A EP 81420104A EP 0044794 B1 EP0044794 B1 EP 0044794B1
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EP
European Patent Office
Prior art keywords
alumina
rate
internal resistance
tank
time
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
EP81420104A
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German (de)
English (en)
French (fr)
Other versions
EP0044794A1 (fr
Inventor
Paul Bonny
Jean-Louis Gerphagnon
Pierre Homsi
Maurice Keinborg
Gérard Laboure
Bernard Langon
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
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Filing date
Publication date
Application filed by Aluminium Pechiney SA filed Critical Aluminium Pechiney SA
Publication of EP0044794A1 publication Critical patent/EP0044794A1/fr
Application granted granted Critical
Publication of EP0044794B1 publication Critical patent/EP0044794B1/fr
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
    • 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
    • C25C3/14—Devices for feeding or crust breaking
    • 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
    • C25C3/20—Automatic control or regulation of cells

Definitions

  • the present invention relates to a method and an apparatus for precisely regulating the rate of introduction and the alumina content of an igneous electrolysis cell, and their application to the production of aluminum according to the Hall-Héroult process. .
  • a defect in alumina causes the appearance of "the anodic effect, or" packaging which results in a sudden increase in the voltage across the terminals of the tank, which can go from 4 to 30 or 40 volts, and which affects on the whole series.
  • This parameter is generally the variation of the internal resistance, or more exactly, of the internal pseudo-resistance which is equal to: e being an image of the counter-electromotive force of the tank, the value of which is generally accepted to be 1.65 volts, U the voltage across the terminals of the tank and I the intensity passing through it.
  • French patent 1,506,463 to V.A.W. is based on the measurement of the time that elapses between stopping the supply of alumina and the appearance of the anode effect;
  • American patent US-A-3400062 of ALCOA implements a "pilot anode to obtain an early detection of the tendency to runaway and regulate the rate of introduction of alumina, which is distributed from a hopper fitted with a frozen electrolyte crust piercing device.
  • US-A-3371 026 assigned to REYNOLDS describes a device making it possible to deliver doses of alumina of substantially constant weight, comprising means for keeping each loading orifice open.
  • the alumina concentration is fixed in the range of 2 to 8%.
  • the disadvantage of this process is that its sensitivity varies with the alumina content, which is precisely minimal in the interval used, from 3 to 5% of AI 2 0 3 (table page 84).
  • the alumina content is also fixed in the range of 2 to 8% and, preferably, 4 to 6%.
  • the tank is fed for a predetermined time t 1 , with an amount of alumina greater than its theoretical consumption, until a predetermined alumina concentration is obtained (for example up to 7%), then the l 'feeding at a rate equal to the theoretical consumption for a predetermined time t 2 , then the feeding is stopped until the appearance of the first symptoms of anode effect (“packaging”), and the feeding cycle is resumed at a rate higher than the theoretical consumption.
  • the alumina concentration varies, during the cycle, from 4.9 to 8% (example 1) or from 4.0 to 7% (example 2).
  • the object of the invention is a process for precise regulation of the rate of introduction and of the alumina content of a tank intended for the production of aluminum by electrolysis of alumina in a bath based on molten cryolite, the upper part of which forms a fixed crust, a process which maintains the alumina content in a narrow range chosen between 1 and 3.5% and which consists in introducing the alumina directly into the molten cryolite bath, in successive doses , of substantially constant weight and at variable time intervals, by at least one orifice kept open permanently in the frozen crust and to modulate the rate of introduction of alumina as a function of variations in the pseudo-internal resistance of the tank in predetermined time intervals, alternating sentences of undernourishment and supercharging of alumina with respect to the rate corresponding to the consumption of the tank.
  • Another object of the same invention is an apparatus for implementing the process for precise regulation of the alumina content, comprising means for delivering to each orifice successive doses of alumina of substantially constant weight, a means for measuring the the internal pseudo-resistance, a means of calculating the speed of variation of the internal resistance, means for varying the rate of introduction of the alumina doses as a function of variations in the internal resistance and means for varying the anode-cathode distance from the tank.
  • Ri f [A1 2 0 3] comprised between alumina contents of approximately 1 to 3.5%
  • Faraday efficiency significantly increased.
  • the process which is the subject of the invention, which consists in modulating the feed rate according to variations in the internal resistance, comprises the following successive stages (identical stages, in the different variants, will be designated by the same letters).
  • Ro for the internal resistance Ri which is, for example, 13.9 ⁇ for a modern 175,000 amp vessel with precooked anodes, and two upper and lower limit values between which the internal resistance will be allowed to vary, Ro + r and Ro - r, for example 13.9 ⁇ 0.1 ⁇ .
  • a regulation cycle is started when Ri is between 13.8 and 14.0 ⁇ .
  • the tank is supplied at a rate known as slow (which will be denoted CL) 15 to 50% lower than the normal consumption corresponding to the electrolysis process, which will be denoted CN (over a long period of time, CN is approximately around 100 kg / h for a 175,000 amp tank).
  • the tank will therefore gradually become depleted in alumina, the figurative point will go up in the direction of the arrow CL, FIG. 1, and Ri will grow (FIG. 2).
  • the successive values taken by the internal resistance are measured at equal time intervals t 1 , t 2 , t 3 , etc., for example every 3 to 6 minutes. In practice, a large number of measurements are taken, the average of which is taken so as to eliminate the risk of outliers.
  • the time T (fast rate feed) and the fast rate CR are adjusted so that the concentration of the electrolyte in alumina increases from 0.5 to 1% (in absolute value) and, preferably , from 0.5 to 0.6%.
  • One thus moved on a reduced portion of the curve Ri f [Al 2 O 3 ] which one can, therefore, and without appreciable error, to consider as linear in the interval.
  • This process therefore ensures a very high precision of the alumina content and, consequently, a very high regularity of operation of the tank.
  • the apparatus for implementing the invention comprises, first of all, a means for delivering, to each introduction orifice provided in the frozen electrolyte crust, successive doses of alumina of substantially constant weight, combined with an alumina storage means preferably located near the tank, which can be replenished periodically from a central storage.
  • Figures 4 and 5 show an alumina supply device according to the invention.
  • the alumina is stored in the hopper (1) placed in the tank superstructure. Its capacity can correspond, for example, to one or more days of walking, and it is itself replenished from a centralized storage, by all known means (pneumatic, fluidized transport, etc.).
  • the distributor (2) and the drilling tool (3) are placed inside the hopper and fixed on a plate (4) which forms the bottom.
  • the distributor essentially comprises a metering device (5) and a distributor (6) which introduces the alumina into the orifice (7) formed and maintained in the frozen crust (8) on the surface of the electrolyte (9).
  • the metering device comprises a tubular body (10) in which slides a rod (11) actuated by the jack (12).
  • This rod is provided with two conical plugs (13) (13 ') which cooperate with two conical bearings (14) (14') on which they can alternately come to bear in substantially sealed manner.
  • the tubular body (10) and the upper body (15) are joined coaxially by a plurality of ribs (16), leaving between them large spaces between which the alumina flows spontaneously by gravity when the shutter (13) is in the high position, so as to fill the tubular body whose capacity corresponds to a unit dose of alumina.
  • the central rod (11) brings the shutter (13) in the low position, on the bearing surface (14) while the shutter (13 ') leaves its bearing surface (14') and thus allows the alumina dose to flow through the distribution chute (6) directly into the orifice (7).
  • the drilling tool (3) is also arranged in a tubular body (17) placed inside the hopper. It comprises a jack (18), the rod (19) of which is provided, at its end, with an easily interchangeable chuck (20), with a scraping means (21) which makes it possible to eliminate, during the ascent of the stick, the crusts of electrolyte which could have adhered to it.
  • the controls of the jacks (12) and (18), not shown, are transferred to the outside of the hopper in a known manner.
  • the chisel (20) can be provided with a means for detecting the level of the electrolyte, such as an electrical contact, which gives the jack (18) the order to reassemble as soon as the crust has been broken and the end of the chisel has come into contact with the molten electrolyte.
  • a means for detecting the level of the electrolyte such as an electrical contact, which gives the jack (18) the order to reassemble as soon as the crust has been broken and the end of the chisel has come into contact with the molten electrolyte.
  • the capacity of the dispenser is set according to the power of the tank and the number of feed points.
  • a given tank may include one or more metering-distributing-picking assemblies, distributed for example between the two lines of anodes.
  • the measurement of internal pseudo-resistance can be carried out by various means known to man. art.
  • the simplest consists of measuring the intensity I, the voltage U at the terminals of the tank and performing the operation:
  • the information collected and processed is ultimately used to ensure the timing of successive doses of alumina.
  • CN normal rate CN
  • CL CN - 30% at a dose every 205 seconds.
  • magnesium halides at a concentration of up to 2% magnesium or alkali or alkaline earth chlorides at a concentration of up to the equivalent of 3% CI.
  • the bath contained 14% AIF 3 and 2% LiF, and the temperature was close to 935 ° C. An average Faraday yield of 95% was obtained.

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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)
  • Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
  • Crystals, And After-Treatments Of Crystals (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)
  • Compositions Of Oxide Ceramics (AREA)
  • Automatic Analysis And Handling Materials Therefor (AREA)
  • Rigid Pipes And Flexible Pipes (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
  • Duct Arrangements (AREA)
  • Paper (AREA)
  • Insulators (AREA)
  • Laying Of Electric Cables Or Lines Outside (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
  • Chemical Treatment Of Metals (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
  • Liquid Crystal Substances (AREA)
  • Ceramic Products (AREA)
EP81420104A 1980-07-23 1981-07-15 Procédé et appareillage pour réguler de façon précise la cadence d'introduction et la teneur en alumine d'une cuve d'électrolyse ignée, et application à la production d'aluminium Expired EP0044794B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR8016406 1980-07-23
FR8016406A FR2487386A1 (fr) 1980-07-23 1980-07-23 Procede et appareillage pour reguler de facon precise la cadence d'introduction et la teneur en alumine d'une cuve d'electrolyse ignee, et application a la production d'aluminium

Publications (2)

Publication Number Publication Date
EP0044794A1 EP0044794A1 (fr) 1982-01-27
EP0044794B1 true EP0044794B1 (fr) 1984-11-28

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EP81420104A Expired EP0044794B1 (fr) 1980-07-23 1981-07-15 Procédé et appareillage pour réguler de façon précise la cadence d'introduction et la teneur en alumine d'une cuve d'électrolyse ignée, et application à la production d'aluminium

Country Status (22)

Country Link
US (1) US4431491A (ja)
EP (1) EP0044794B1 (ja)
JP (1) JPS6037197B2 (ja)
KR (1) KR850001767B1 (ja)
AT (1) ATE10514T1 (ja)
AU (1) AU549056B2 (ja)
BR (1) BR8104735A (ja)
CA (1) CA1157803A (ja)
DE (1) DE3167452D1 (ja)
ES (2) ES504180A0 (ja)
FR (1) FR2487386A1 (ja)
GB (1) GB2080830B (ja)
GR (1) GR74283B (ja)
HU (1) HU187339B (ja)
IN (1) IN154431B (ja)
NO (1) NO157906C (ja)
NZ (1) NZ197748A (ja)
OA (1) OA06862A (ja)
PL (1) PL134831B1 (ja)
RO (1) RO82685B (ja)
SK (1) SK278294B6 (ja)
YU (1) YU44417B (ja)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101643920B (zh) * 2009-09-10 2011-02-09 中国铝业股份有限公司 铝电解槽氧化铝浓度的控制方法

Families Citing this family (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2527647A1 (fr) * 1982-05-27 1983-12-02 Pechiney Aluminium Dispositif amovible d'alimentation ponctuelle en alumine d'une cuve d'electrolyse pour la production d'aluminium
DE3305236C2 (de) * 1983-02-10 1985-11-21 Schweizerische Aluminium Ag, Chippis Vorrichtung zur Steuerung einer Einschlagvorrichtung einer Schmelzflußelektrolysezelle und Verfahren zum Betreiben der Vorrichtung
NO166821C (no) * 1985-02-21 1991-09-04 Aardal & Sunndal Verk As Fremgangsmaate for styring av aluminiumoksyd-tilfoerselen til elektrolyseovner for fremstilling av aluminium.
EP0195142B1 (en) * 1985-03-18 1988-09-07 Alcan International Limited Controlling alf 3 addition to al reduction cell electrolyte
FR2581660B1 (fr) * 1985-05-07 1987-06-05 Pechiney Aluminium Procede de regulation precise d'une faible teneur en alumine dans une cuve d'electrolyse ignee pour la production d'aluminium
US4654130A (en) * 1986-05-15 1987-03-31 Reynolds Metals Company Method for improved alumina control in aluminum electrolytic cells employing point feeders
FR2605410B1 (fr) * 1986-10-17 1988-11-25 Pechiney Aluminium Procede et dispositif de mesure electrochimique de la concentration en ions oxyde dans un bain a base d'halogenures fondus
US4752362A (en) * 1987-01-27 1988-06-21 Aluminum Company Of America Detecting and estimating shorting phenomena in hall cells and control of cell anodes in response thereto
NZ232580A (en) * 1989-02-24 1992-12-23 Comalco Alu Aluminium smelting process control
US5324408A (en) * 1990-10-05 1994-06-28 Portland Smelter Services Pty. Ltd. Apparatus for controlled supply of alumina
CA2126181A1 (en) * 1992-07-14 1994-01-20 James P. Kissane Alumina supply apparatus for electrolytic smelter
DE4443225C2 (de) * 1994-12-05 2000-08-24 Hamburger Aluminium Werk Gmbh Verfahren zum Regeln der Al¶2¶O¶3¶-Konzentration bei der Erzeugung von Aluminium
FR2749858B1 (fr) * 1996-06-17 1998-07-24 Pechiney Aluminium Procede de regulation de la teneur en alumine du bain des cuves d'electrolyse pour la production d'aluminium
CA2230882C (en) 1997-03-14 2004-08-17 Dubai Aluminium Company Limited Intelligent control of aluminium reduction cells using predictive and pattern recognition techniques
NO311623B1 (no) * 1998-03-23 2001-12-17 Norsk Hydro As Fremgangsmåte for styring av aluminiumoksidtilförsel til elektrolyseceller for fremstilling av aluminium
RU2189403C2 (ru) * 2000-12-05 2002-09-20 Закрытое акционерное общество "ТоксСофт" Способ управления электролизерами для получения алюминия и устройство для его осуществления
FR2821364B1 (fr) * 2001-02-28 2004-04-09 Pechiney Aluminium Procede de regulation d'une cellule d'electrolyse
AUPR443901A0 (en) * 2001-04-10 2001-05-17 Bhp Innovation Pty Ltd Method for reduction of metal oxides to pure metals
US6837982B2 (en) 2002-01-25 2005-01-04 Northwest Aluminum Technologies Maintaining molten salt electrolyte concentration in aluminum-producing electrolytic cell
RU2255149C1 (ru) * 2004-05-05 2005-06-27 Общество с ограниченной ответственностью "Инженерно-технологический центр" Способ управления алюминиевым электролизером при изменении скорости растворения глинозема
EP2135975A1 (en) 2008-06-16 2009-12-23 Alcan International Limited Method of producing aluminium in an electrolysis cell
US7915550B2 (en) * 2008-06-17 2011-03-29 Mac Valves, Inc. Pneumatic system electrical contact device
US8367953B2 (en) * 2008-06-17 2013-02-05 Mac Valves, Inc. Pneumatic system electrical contact device
US9719180B2 (en) * 2013-12-17 2017-08-01 Control Automation, Llc Dose meter for crust punch and alumina dispenser
CN106460210B (zh) * 2014-06-19 2019-01-11 俄铝工程技术中心有限责任公司 用于控制向用于生产铝的电解池进料铝的方法
EP3266904B1 (de) 2016-07-05 2021-03-24 TRIMET Aluminium SE Schmelzflusselektrolyseanlage und regelungsverfahren zu deren betrieb
FR3065969B1 (fr) 2017-05-03 2019-07-19 Laurent Michard Procede de pilotage d'une cuve d'electrolyse de l'aluminium
CN109554728B (zh) * 2018-12-27 2021-04-27 中国神华能源股份有限公司 氧化铝电解控制方法、存储介质及电子设备

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3371026A (en) * 1964-02-04 1968-02-27 Reynolds Metals Co Electrolytic reduction cell with crustbreaking and ore feeding means
FR1457746A (fr) * 1964-09-29 1966-01-24 Reynolds Metals Co Perfectionnements apportés aux moyens de commande pour cuves de réduction
US3660256A (en) * 1967-12-07 1972-05-02 Gen Electric Method and apparatus for aluminum potline control
US3616316A (en) * 1968-01-19 1971-10-26 Reynolds Metals Co Reduction cell control system
US3712857A (en) * 1968-05-20 1973-01-23 Reynolds Metals Co Method for controlling a reduction cell
US3622475A (en) * 1968-08-21 1971-11-23 Reynolds Metals Co Reduction cell control system
US3847761A (en) * 1972-04-06 1974-11-12 Aluminum Co Of America Bath control
JPS548109A (en) * 1977-06-22 1979-01-22 Mitsubishi Keikinzoku Kogyo Controlling method of feeding alumina into aluminum electrolytic bath

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101643920B (zh) * 2009-09-10 2011-02-09 中国铝业股份有限公司 铝电解槽氧化铝浓度的控制方法

Also Published As

Publication number Publication date
GB2080830A (en) 1982-02-10
ES8302124A1 (es) 1982-12-16
PL134831B1 (en) 1985-09-30
GB2080830B (en) 1983-10-05
ES8306192A1 (es) 1983-05-01
AU549056B2 (en) 1986-01-09
HU187339B (en) 1985-12-28
BR8104735A (pt) 1982-04-13
AU7319881A (en) 1982-01-28
YU174581A (en) 1984-02-29
FR2487386B1 (ja) 1984-09-14
ES504180A0 (es) 1982-12-16
CA1157803A (fr) 1983-11-29
RO82685A (ro) 1984-05-12
JPS6037197B2 (ja) 1985-08-24
GR74283B (ja) 1984-06-21
YU44417B (en) 1990-08-31
PL232287A1 (ja) 1982-03-01
ATE10514T1 (de) 1984-12-15
NO812512L (no) 1982-01-25
SK545081A3 (en) 1996-09-04
EP0044794A1 (fr) 1982-01-27
NO157906C (no) 1988-06-08
NO157906B (no) 1988-02-29
US4431491A (en) 1984-02-14
IN154431B (ja) 1984-10-27
ES514946A0 (es) 1983-05-01
DE3167452D1 (en) 1985-01-10
RO82685B (ro) 1984-06-30
SK278294B6 (en) 1996-09-04
KR830006476A (ko) 1983-09-24
FR2487386A1 (fr) 1982-01-29
KR850001767B1 (ko) 1985-12-09
JPS5751278A (en) 1982-03-26
NZ197748A (en) 1985-07-31
OA06862A (fr) 1983-02-28

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