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EP0044794A1 - Verfahren und Vorrichtung zur genauen Regulierung der Zufuhrgeschwindigkeit und des Tonerdegehaltes in einer schmelzflüssigen Elektrolysezelle und Anwendung zur Aluminiumherstellung - Google Patents

Verfahren und Vorrichtung zur genauen Regulierung der Zufuhrgeschwindigkeit und des Tonerdegehaltes in einer schmelzflüssigen Elektrolysezelle und Anwendung zur Aluminiumherstellung Download PDF

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Publication number
EP0044794A1
EP0044794A1 EP81420104A EP81420104A EP0044794A1 EP 0044794 A1 EP0044794 A1 EP 0044794A1 EP 81420104 A EP81420104 A EP 81420104A EP 81420104 A EP81420104 A EP 81420104A EP 0044794 A1 EP0044794 A1 EP 0044794A1
Authority
EP
European Patent Office
Prior art keywords
alumina
rate
internal resistance
tank
introduction
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
EP81420104A
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English (en)
French (fr)
Other versions
EP0044794B1 (de
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
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 EP0044794A1 publication Critical patent/EP0044794A1/de
Application granted granted Critical
Publication of EP0044794B1 publication Critical patent/EP0044794B1/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
    • 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. .
  • alumina in the bath One of the essential factors, to ensure the regularity of operation of an aluminum production tank by electrolysis of alumina dissolved in the molten cryolite, is the rate of introduction: alumina in the bath.
  • An alumina defect 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 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 assumed to be 1.65 volts, U the voltage across the terminals of the tank and I the intensity passing through it.
  • the alumina concentration is fixed in the range of 2 to 8%.
  • the variation Aü as a function of time t, of the voltage at the terminals of each tank is measured, it is compared with a predetermined value and the rate of supply of alumina is modified to bring the ⁇ V / T to the standard value.
  • 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 A1 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 supplied for a predetermined time t with an amount of alumina greater than its theoretical consumption, until a predetermined alumina concentration is obtained (for example up to 7%), then the supply at a rate equal to the theoretical consumption for a time t 2 . predetermined, 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 interval chosen between 1 and 3.5% and which consists in introducing the alumina directly into the molten cryelite bath, in successive doses, of substantially constant weight and at variable time intervals, by at least one orifice maintained permanently open in the frozen crust and to modulate the rate of introduction of alumina according to variations in the pseudo-internal resistance of the tank in predetermined time intervals, alternating sentences of undernourishment and overeating alumina compared 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.
  • Another object of the same invention is the application of the above process and apparatus to the production of aluminum by the Hall-Héroult process, either with a normal or slightly acidic electrolyte based on cryolite which may also contain , from 5 to 13% AlF 3 , and operating at around 955 to 970 ° C, or with a very acidic electrolyte, which may contain 13 to 20% AlF 3 and operating at around 930 to 955 ° C , and may also contain Lithium, in the form of LiF, and operating at temperatures down to 910 ° C.
  • FIG. 1 represents the variation of the pseudo-internal resistance of an electrolytic cell as a function of its alumina content, with, as a parameter, the anode-cathode distance "DAM".
  • FIG. 2 represents the variation of the internal pseudo-resistance of an electrolysis cell as a function of time and of the rate of introduction of alumina according to the invention.
  • FIG. 3 shows the variation of the internal pseudo-resistance of an electrolysis tank as a function of time and the rate of introduction of alumina according to an alternative embodiment of the invention.
  • FIG. 4 represents the assembly of a metering device, of its feed hopper and of a device intended to keep open, permanently, the orifice for introducing alumina.
  • FIG. 5 represents the dispenser making it possible to deliver successive doses of alumina of substantially constant weight.
  • Figure 1 shows that the internal pseudo-resistance of a tank passes through a somewhat fuzzy minimum around 3.5-4% and increases rapidly on the side of low alumina contents and much more slowly on the side of high contents. To have a good sensitivity, it is therefore advantageous to be on the side of low alumina contents, without however falling below 1%, a value around which the internal pseudo-resistance increases very quickly when the alumina content decreases , which corresponds to the anode or packaging effect ".
  • Ri internal resistance designated by Ri to designate the pseudo-internal resistance.
  • 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%
  • Ri f [Al 2 O 3] that we can, from this fact, 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 any 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 dispenser essentially comprises a dispenser (5) and a dispenser (6) which introduces the alumina in 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 (20) 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 actuator (18) order go back up 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 actuator (18) order go back up 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-dispenser-biting assemblies, distributed for example between the two lines of anodes.
  • the measurement of the internal pseudo-resistance can be carried out by various means known to those skilled in the 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.
  • 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% of C1.
  • the bath contained 14% AlF 3 and 2% LiF, and the temperature was close to 935 ° C. An average Faraday yield of 95% was obtained.
  • the implementation of the invention provides, it is possible to indicate the elimination of accumulations of sludge on the bottom of the tanks, and the reduction of the average number of packaging, on each tank, to less than one per twenty. four hours.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Engineering & Computer Science (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)
  • Manufacture Of Electron Tubes, Discharge Lamp Vessels, Lead-In Wires, And The Like (AREA)
  • Ceramic Products (AREA)
  • Insulators (AREA)
  • Laying Of Electric Cables Or Lines Outside (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)
  • Liquid Crystal Substances (AREA)
  • Vessels, Lead-In Wires, Accessory Apparatuses For Cathode-Ray Tubes (AREA)
  • Chemical Treatment Of Metals (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
  • Rigid Pipes And Flexible Pipes (AREA)
  • Duct Arrangements (AREA)
  • Paper (AREA)
EP81420104A 1980-07-23 1981-07-15 Verfahren und Vorrichtung zur genauen Regulierung der Zufuhrgeschwindigkeit und des Tonerdegehaltes in einer schmelzflüssigen Elektrolysezelle und Anwendung zur Aluminiumherstellung Expired EP0044794B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
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
FR8016406 1980-07-23

Publications (2)

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

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EP81420104A Expired EP0044794B1 (de) 1980-07-23 1981-07-15 Verfahren und Vorrichtung zur genauen Regulierung der Zufuhrgeschwindigkeit und des Tonerdegehaltes in einer schmelzflüssigen Elektrolysezelle und Anwendung zur Aluminiumherstellung

Country Status (22)

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US (1) US4431491A (de)
EP (1) EP0044794B1 (de)
JP (1) JPS6037197B2 (de)
KR (1) KR850001767B1 (de)
AT (1) ATE10514T1 (de)
AU (1) AU549056B2 (de)
BR (1) BR8104735A (de)
CA (1) CA1157803A (de)
DE (1) DE3167452D1 (de)
ES (2) ES8302124A1 (de)
FR (1) FR2487386A1 (de)
GB (1) GB2080830B (de)
GR (1) GR74283B (de)
HU (1) HU187339B (de)
IN (1) IN154431B (de)
NO (1) NO157906C (de)
NZ (1) NZ197748A (de)
OA (1) OA06862A (de)
PL (1) PL134831B1 (de)
RO (1) RO82685B (de)
SK (1) SK545081A3 (de)
YU (1) YU44417B (de)

Cited By (6)

* 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
EP0195142A1 (de) * 1985-03-18 1986-09-24 Alcan International Limited Verfahren zur Steuerung der Zuführung von AlF3 zu einer Aluminiumreduktionszelle
EP0201438A1 (de) * 1985-05-07 1986-11-12 Aluminium Pechiney Verfahren zur genauen Regulierung einer geringen Tonerdegehalts in einer schmelzflüssigen Elektrolysezelle zur Aluminiumherstellung
EP0386899A2 (de) * 1989-02-24 1990-09-12 Comalco Aluminium, Ltd. Kontrollverfahren für Aluminium-Schmelzflussöfen
WO2018202959A1 (fr) 2017-05-03 2018-11-08 Laurent Michard Procédé de pilotage d'une cuve d'électrolyse de l'aluminium
EP3266904B1 (de) 2016-07-05 2021-03-24 TRIMET Aluminium SE Schmelzflusselektrolyseanlage und regelungsverfahren zu deren betrieb

Families Citing this family (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
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.
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
BR9106939A (pt) * 1990-10-05 1993-08-24 Portland Smelter Serv Pty Aparelho para suprimento controlado de alumina
ES2100543T3 (es) * 1992-07-14 1997-06-16 Portland Smelter Serv Pty Aparato para el suministro de alumina para un fundidor electrolitico.
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 (de) 2008-06-16 2009-12-23 Alcan International Limited Verfahren zur Herstellung von Aluminium in einer Elektrolysezelle
US8367953B2 (en) * 2008-06-17 2013-02-05 Mac Valves, Inc. Pneumatic system electrical contact device
US7915550B2 (en) * 2008-06-17 2011-03-29 Mac Valves, Inc. Pneumatic system electrical contact device
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
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
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

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1457746A (fr) * 1964-09-29 1966-01-24 Reynolds Metals Co Perfectionnements apportés aux moyens de commande pour cuves de réduction
US3371026A (en) * 1964-02-04 1968-02-27 Reynolds Metals Co Electrolytic reduction cell with crustbreaking and ore feeding means
DE1925201A1 (de) * 1968-05-20 1969-11-27 Reynolds Metals Co Verfahren zum Betreiben eines Elektrolyseofens fuer die Reduktion von Aluminiumoxyd
US3616316A (en) * 1968-01-19 1971-10-26 Reynolds Metals Co Reduction cell control system
US3660256A (en) * 1967-12-07 1972-05-02 Gen Electric Method and apparatus for aluminum potline control
FR2179099A1 (de) * 1972-04-06 1973-11-16 Aluminum Co Of America

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3622475A (en) * 1968-08-21 1971-11-23 Reynolds Metals Co Reduction cell control system
JPS548109A (en) * 1977-06-22 1979-01-22 Mitsubishi Keikinzoku Kogyo Controlling method of feeding alumina into aluminum electrolytic bath

Patent Citations (6)

* 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
DE1925201A1 (de) * 1968-05-20 1969-11-27 Reynolds Metals Co Verfahren zum Betreiben eines Elektrolyseofens fuer die Reduktion von Aluminiumoxyd
FR2179099A1 (de) * 1972-04-06 1973-11-16 Aluminum Co Of America

Cited By (9)

* 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
EP0195142A1 (de) * 1985-03-18 1986-09-24 Alcan International Limited Verfahren zur Steuerung der Zuführung von AlF3 zu einer Aluminiumreduktionszelle
EP0201438A1 (de) * 1985-05-07 1986-11-12 Aluminium Pechiney Verfahren zur genauen Regulierung einer geringen Tonerdegehalts in einer schmelzflüssigen Elektrolysezelle zur Aluminiumherstellung
FR2581660A1 (fr) * 1985-05-07 1986-11-14 Pechiney Aluminium Procede de regulation precise d'une faible teneur en alumine dans une cuve d'electrolyse ignee pour la production d'aluminium
EP0386899A2 (de) * 1989-02-24 1990-09-12 Comalco Aluminium, Ltd. Kontrollverfahren für Aluminium-Schmelzflussöfen
EP0386899A3 (de) * 1989-02-24 1991-02-06 Comalco Aluminium, Ltd. Kontrollverfahren für Aluminium-Schmelzflussöfen
US5089093A (en) * 1989-02-24 1992-02-18 Comalco Aluminum Ltd. Process for controlling aluminum smelting cells
EP3266904B1 (de) 2016-07-05 2021-03-24 TRIMET Aluminium SE Schmelzflusselektrolyseanlage und regelungsverfahren zu deren betrieb
WO2018202959A1 (fr) 2017-05-03 2018-11-08 Laurent Michard Procédé de pilotage d'une cuve d'électrolyse de l'aluminium

Also Published As

Publication number Publication date
YU174581A (en) 1984-02-29
HU187339B (en) 1985-12-28
US4431491A (en) 1984-02-14
ES504180A0 (es) 1982-12-16
ES8302124A1 (es) 1982-12-16
NO157906B (no) 1988-02-29
ATE10514T1 (de) 1984-12-15
OA06862A (fr) 1983-02-28
SK278294B6 (en) 1996-09-04
FR2487386A1 (fr) 1982-01-29
FR2487386B1 (de) 1984-09-14
SK545081A3 (en) 1996-09-04
RO82685B (ro) 1984-06-30
NO157906C (no) 1988-06-08
AU7319881A (en) 1982-01-28
EP0044794B1 (de) 1984-11-28
BR8104735A (pt) 1982-04-13
JPS5751278A (en) 1982-03-26
KR830006476A (ko) 1983-09-24
ES8306192A1 (es) 1983-05-01
JPS6037197B2 (ja) 1985-08-24
KR850001767B1 (ko) 1985-12-09
CA1157803A (fr) 1983-11-29
AU549056B2 (en) 1986-01-09
GB2080830B (en) 1983-10-05
RO82685A (ro) 1984-05-12
PL232287A1 (de) 1982-03-01
DE3167452D1 (en) 1985-01-10
IN154431B (de) 1984-10-27
ES514946A0 (es) 1983-05-01
NZ197748A (en) 1985-07-31
YU44417B (en) 1990-08-31
GB2080830A (en) 1982-02-10
GR74283B (de) 1984-06-21
PL134831B1 (en) 1985-09-30
NO812512L (no) 1982-01-25

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