DE3425058A1 - Process for preheating and firing preformed carbon anodes for the aluminium industry - Google Patents

Process for preheating and firing preformed carbon anodes for the aluminium industry

Info

Publication number
DE3425058A1
DE3425058A1 DE19843425058 DE3425058A DE3425058A1 DE 3425058 A1 DE3425058 A1 DE 3425058A1 DE 19843425058 DE19843425058 DE 19843425058 DE 3425058 A DE3425058 A DE 3425058A DE 3425058 A1 DE3425058 A1 DE 3425058A1
Authority
DE
Germany
Prior art keywords
preheating
support material
carbon anodes
aluminum
anodes
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.)
Withdrawn
Application number
DE19843425058
Other languages
German (de)
Inventor
Friedel 5064 Rösrath Isenhardt
Ernst Dr. 5300 Bonn Schultze-Rhonhof
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.)
Kloeckner Humboldt Deutz AG
Original Assignee
Kloeckner Humboldt Deutz 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 Kloeckner Humboldt Deutz AG filed Critical Kloeckner Humboldt Deutz AG
Priority to DE19843425058 priority Critical patent/DE3425058A1/en
Priority to NO852722A priority patent/NO852722L/en
Priority to FR8510292A priority patent/FR2567159A1/en
Publication of DE3425058A1 publication Critical patent/DE3425058A1/en
Withdrawn legal-status Critical Current

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Classifications

    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25CPROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
    • C25C3/00Electrolytic production, recovery or refining of metals by electrolysis of melts
    • C25C3/06Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
    • C25C3/08Cell construction, e.g. bottoms, walls, cathodes
    • C25C3/12Anodes
    • C25C3/125Anodes based on carbon
    • CCHEMISTRY; METALLURGY
    • C04CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04BLIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/52Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
    • C04B35/528Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite obtained from carbonaceous particles with or without other non-organic components
    • C04B35/532Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite obtained from carbonaceous particles with or without other non-organic components containing a carbonisable binder

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Ceramic Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Metallurgy (AREA)
  • Manufacturing & Machinery (AREA)
  • Structural Engineering (AREA)
  • Electrolytic Production Of Metals (AREA)
  • Manufacture And Refinement Of Metals (AREA)

Abstract

In a process for preheating and firing preformed, so-called green carbon anodes for the aluminium industry it is proposed that, instead of the coke breeze or sand backing materials previously used for maintaining the dimensional stability of the anode mouldings, either coarse-grained alumina or alumina mouldings or mouldings made of metallic aluminium or fluorides be used to ensure that, while the carbon anodes are transferred to a downstream induction kiln, any ignition or dust explosion of the backing material or entraining of contaminants having an adverse effect in the further use of the carbon anodes is avoided.

Description

H 84/31H 84/31

Anlage zum Patentgesuch derAnnex to the patent application by

Klöckner-Humboldt-DeutzKlöckner-Humboldt-Deutz

AktiengesellschaftCorporation

vom 03. GuIi 1984dated 3rd GuIi 1984

Verfahren zum Vorwärmen und Brennen von vorgeformten Kohleanoden für die AluminiumindustrieProcess for preheating and burning preformed carbon anodes for the aluminum industry

Die Erfindung betrifft ein Verfahren zum Vorwärmen und Brennen von vorgeformten, sogenannten grünen Kohleanoden für die Aluminiumindustrie.The invention relates to a method for preheating and firing preformed, so-called green carbon anodes for the aluminum industry.

Die grünen Kohlenanoden bestehen üblicherweise aus einer Preßmasse von Petrolkoks und Bindemittel, welche seine erwünschte Formbeständigkeit erst nach einer Erwärmung auf ca. 45O0C erhält. Folglich müssen die grünen Anoden während des Vorwarmungsprozesses mindestens bis zum Erreichen dieser Temperatur mitteis eines geeigneten wärmeoeständigen Materials in den Ofenkammern gestützt werden.The green carbon anodes are usually composed of a Press of petroleum coke and binder, which receives its desired dimensional stability after heating to about 45O 0 C. Consequently, the green anodes must be supported in the furnace chambers by means of a suitable heat-resistant material during the preheating process, at least until this temperature is reached.

Verfahren und Vorrichtungen zum Vorwärmen und Brennen von grünen Kohlenanoden unter Verwendung von Koksgruß oder Sand als Stützmaterial sind bekannt (Ullmanns Enzyklopädie der Technischen Chemie, 4. Auflage, Band 14, Seite 604).Methods and devices for preheating and burning green carbon anodes using coke breeze or sand as support material are known (Ullmanns Enzyklopadie der Technischen Chemie, 4th edition, volume 14, page 604).

Ebenfalls ist ein Verfahren aus der DE-OS 32 23 573 bekannt, wobei grüne Kohleanoden, beispielsweise in Kammerring- oder Herdwagenöfen, auf eine Temperatur zwischen 300 und 500 0C vorgewärmt und anschließend durch induktive Heizung bei Temperaturen bis 1500 0C innerhalb elektrischen Induktionsspulen fertiggebrannt werden.Is also a method known from DE-OS 32 23 573 is known, said green carbon anodes, for example, preheated in Kammerring- or shuttle kilns, to a temperature between 300 and 500 0 C, followed by inductive heating at temperatures up to 1500 0 C in the electric induction coil completely burned will.

H 84/31H 84/31

Beim übergang zum induktiven Brennen der Kohleanoden ist es zweckmäßig, das Stützmaterial zu entfernen, um den Wirkungsgrad des Induktionsofens nicht zu beeinträchtigen. Das bisher verwendete Stützmaterial Koksgruß oder auch Sand sind für die nach der DE-OS 32 23 573 gelehrte Vorgehensweise nicht geeignet, da bei dem Entfernen von Koksgruß aus den Ofenkammern bei Eindringen von Außenluft die Gefahr einer Inbrandsetzung des Koksgrußes und/oder einer Staubexplosion entsteht, und, im Falle der Benutzung von Sand als Stützmaterial anhaftende Sandteilchen an den Anoden eine störende Verunreinigung für die zweckmäßige weitere Benutzung der Anoden, beispielsweise bei der elektrolytischen Gewinnung von Aluminium bilden.With the transition to inductive burning of the carbon anodes it is It is advisable to remove the support material in order not to impair the efficiency of the induction furnace. The previously used support material coke breeze or sand are taught according to DE-OS 32 23 573 The procedure is not suitable because coke burrs are removed from the furnace chambers when outside air penetrates there is a risk of the coke being set on fire and / or a dust explosion, and, in the event of use Sand particles adhering to the anodes by sand as a support material are a disruptive impurity for the expedient further use of the anodes, for example in the electrolytic extraction of aluminum.

Die Aufgabe der Erfindung besteht darin, die bisher bei dem Vorwärmen von grünen Kohleanoden als Stützmaterialien benutzte Stoffe durch solche zu ersetzen, die weder brennbar noch explosionsfähig sind, für die weiteren Prozeßstufen beziehungsweise Anwendungen der Kohleanoden keine nachteiligen Wirkungen haben und ferner nach dem Vorwärmen der Anoden leicht aus dem Vorwärmeofen entfernt werden können. Die Aufgabe wird dadurch gelöst, daß als Stützmaterial ein in dem Aluminiumprozeß ohnehin vorhandener Stoff verwendet wird. Solche Stoffe sind:The object of the invention is that so far in the Preheating of green carbon anodes to replace materials used as support materials with materials that do not are flammable or explosive, for the further process stages or applications of the carbon anodes have no adverse effects and are further easily removed from the preheating furnace after the anodes are preheated can be. The object is achieved in that a support material in the aluminum process anyway existing substance is used. Such substances are:

1. Tonerde, das heißt Oxide, Hydroxide und Oxihydrate des Aluminiums,1. Alumina, i.e. oxides, hydroxides and oxyhydrates of aluminum,

2. metallisches Aluminium, beispielsweise Aluminiumschrott;2. metallic aluminum, for example aluminum scrap;

3. Fluoride (Natriumfluorid, Aluminiumfluorid und ihre Mischungen, zum Beispiel Kryolith oder Chiolith).3. Fluorides (sodium fluoride, aluminum fluoride and their mixtures, for example cryolite or Chiolite).

H 84/31H 84/31

Diese Stoffe können vor dem übergang zum Induktionsofen durch Absaugen oder durch mit Klappen versehene Öffnungen aus dem Vorwärmeofen relativ problemlos entfernt werden.These substances can be used before the transition to the induction furnace can be removed relatively easily from the preheating furnace by suction or through openings provided with flaps.

Von den genannten Stoffen hat Tonerde den Vorteil, auch bei hohen Temperaturen beständig und unbrennbar zu sein. Ferner ist Tonerde nicht elektrisch leitend. Tonerde kann daher auch einen nachgeschalteten Induktionsofen passieren, ohne dessen Wirkungsgrad zu beeinträchtigen.Of the substances mentioned, alumina has the advantage of being resistant and non-flammable even at high temperatures. Further alumina is not electrically conductive. Alumina can therefore also pass through a downstream induction furnace without to impair its efficiency.

Metallisches Aluminium hat den Vorteil, infolge seiner guten Wärmeleitfähigkeit den Wärmeaustausch zwischen Vorwärmeofen und Kohleanode nicht zu behindern. Allerdings muß metallisches Aluminium, wegen seiner elektrischen Leitfähigkeit und verhältnismäßig niedrigem Schmelzpunkt nach dem Vorwärmen aer Anoden entfernt una vom Induktionsofen ferngehalten werden. Ferner darf als Stützmaterial nur ein grobkörniges oder aus Formkörpern wie Kugeln, Granalien, rohr- oder stangenförmige Teilchen bestehender Aluminiumschrott verwendet werden, um die Gefahr einer Aluminium-Staubexplosion zu vermeiden.Metallic aluminum has the advantage, due to its good thermal conductivity, the heat exchange between Not to obstruct the preheating furnace and carbon anode. However, metallic aluminum, because of its electrical properties Conductivity and relatively low melting point after preheating the anodes away from the Induction furnace are kept away. Furthermore, only a coarse-grained or molded body such as Balls, granules, tubular or rod-shaped particles of existing aluminum scrap are used to make the Avoid the risk of an aluminum dust explosion.

Fluoride sind ebenfalls als Stützmaterial für das Vorwärmen von Kohleanoden geeignet, mit der zusätzlichem Maßnahme, daß mögliche Fluoridemissionen durch geeignete Abscheidevorrichtungen entgegengewirkt wird.Fluorides are also suitable as support material for preheating carbon anodes, with the additional measure that possible fluoride emissions are counteracted by suitable separation devices.

Im Falle einer Entfernung des Stützmaterials aus dem Vorwärmeofen, welcher jedoch nur bei Verwendung von metallischem Aluminium und Fluoriden zwingend erforderlich ist, kann dieses Stützmaterial für den nächsten Vorwärmevorgang wiederbenutzt werden.In the case of removal of the support material from the preheating furnace, which, however, only occurs when using metallic aluminum and fluoride is imperative, this support material can be used for the next Preheating process can be used again.

Die Erfinaung wira im foigenaen annana von arei Ausführungsbeispielen näher erläutert:The discovery is in the foigenaen annana of arei Exemplary embodiments explained in more detail:

H 84/31H 84/31

Ausführungsbeispiel 1:Embodiment 1:

Eine grüne Kohleanode mit den Abmessungen 1,20 m χ 0,80 m χ 0,60 mA green carbon anode measuring 1.20 m by 0.80 m by 0.60 m

wird senkrecht stehend in den Vorwärmeofen eingesetzt.is placed vertically in the preheating furnace.

Der Zwischenraum zwischen der Kohleanode und der Ofenwand wird mit Formkörpern aus Tonerde, vorzugsweise Kugeln mit einem Durchmesser zwischen 5 und 50 mm, aufgefüllt. Anschließend wird die Anode erwärmt wie in der DE-OS 32 23 573 beschrieben.The space between the carbon anode and the furnace wall is filled with shaped bodies made of alumina, preferably spheres with a diameter between 5 and 50 mm. The anode is then heated as described in DE-OS 32 23 573.

Ausführungsbeispiel 2:Embodiment 2:

Es wird gearbeitet wie in Ausführungsbeispiel 1. Anstelle der Formkörper aus Tonerde wird eine grobkörnige Tonerde mit einer Körnung zwischen 0,1 und 10 mm eingefüllt.The procedure is as in embodiment 1. Instead the molded body made of alumina is filled with a coarse-grained alumina with a grain size between 0.1 and 10 mm.

Ausführungsbeispiel 3:Embodiment 3:

Es wird gearbeitet wie in Ausführungsbeispiel 1. Anstelle der Formkörper aus Tonerde werden Formkörper aus Aluminium, vorzugsweise Kugeln, Granalien oder rohr- beziehungsweise stangenförmige Teilchen, eingefüllt. Sobald die Kohleanode die Temperatur von ca. 350 bis 5000C erreicht hat, Dei der nach DE-OS 32 23 573 zu induktiver Heizung übergegangen wird, werden die Formkörper aus Aluminium durch eine geeignete Vorrichtung aus dem Ofen entfernt, zum Beispiel durch mit Klappen versehene Öffnungen am Boden des Ofens oder durch Absaugen.The procedure is as in embodiment 1. Instead of the shaped bodies made of alumina, shaped bodies made of aluminum, preferably spheres, granules or tubular or rod-shaped particles, are filled. As soon as the carbon anode has reached the temperature of approx. 350 to 500 0 C, Dei which is switched to inductive heating according to DE-OS 32 23 573, the aluminum moldings are removed from the furnace by a suitable device, for example with flaps provided openings at the bottom of the furnace or by suction.

Claims (6)

03. Juli 1984 KHD RWS/Gn H 84/31 PatentansprücheJuly 03, 1984 KHD RWS / Gn H 84/31 patent claims 1. Verfahren zum Vorwärmen und Brennen von vorgeformten
Kohleanoden für die Aluminiumindustrie, dadurch gekennzeichnet, daß zur Erhaltung der Formstabilität der
Anodenformlinge wenigstens während der Vorwärmphase der
Anoden ein inerter, unbrennbarer, leicht entfernbarer und
in der Herstellung von Aluminium vorkommender Stoff als
Stützmaterial verwendet wird.
1. Procedure for preheating and firing preformed
Carbon anodes for the aluminum industry, characterized in that to maintain the dimensional stability of the
Anode preforms at least during the preheating phase
Anodes an inert, incombustible, easily removable and
Substance found in the manufacture of aluminum as
Support material is used.
2. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß als Stützmaterial grobkörnige Tonerde verwendet wird.2. The method according to claim 1, characterized in that coarse-grained alumina is used as the support material. 3. Verfahren nach Anspruch 1, daaurch gekennzeichnet, daß als Stützmaterial Formkörper, vorzugsweise Kugeln, aus
Tonerde verwendet werden.
3. The method according to claim 1, characterized in that molded bodies, preferably spheres, are made as the support material
Clay can be used.
4. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß als Stützmaterial metallstaubfreie Formkörper aus Aluminium verwendet werden.4. The method according to claim 1, characterized in that metal dust-free molded bodies made of aluminum are used as the support material be used. 5. Verfahren nach Anspruch 1, dadurch gekennzeichnet, daß als Stützmaterial metallische Flußsäuresalze verwendet
werden.
5. The method according to claim 1, characterized in that metallic hydrofluoric acid salts are used as the support material
will.
6. Verfahren nach einem oder mehreren der Ansprüche 1 bis 5, dadurch gekennzeichnet, daß die Anodenformlinge mit dem Stützmaterial umschüttet werden.6. The method according to one or more of claims 1 to 5, characterized in that the anode blanks are poured with the support material.
DE19843425058 1984-07-07 1984-07-07 Process for preheating and firing preformed carbon anodes for the aluminium industry Withdrawn DE3425058A1 (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
DE19843425058 DE3425058A1 (en) 1984-07-07 1984-07-07 Process for preheating and firing preformed carbon anodes for the aluminium industry
NO852722A NO852722L (en) 1984-07-07 1985-07-05 PROCEDURE FOR HEATING AND BURNING ALREADY FORMED COAL ANODES FOR THE ALUMINUM INDUSTRY
FR8510292A FR2567159A1 (en) 1984-07-07 1985-07-05 Baking carbon anodes for aluminium industry

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19843425058 DE3425058A1 (en) 1984-07-07 1984-07-07 Process for preheating and firing preformed carbon anodes for the aluminium industry

Publications (1)

Publication Number Publication Date
DE3425058A1 true DE3425058A1 (en) 1986-02-06

Family

ID=6240072

Family Applications (1)

Application Number Title Priority Date Filing Date
DE19843425058 Withdrawn DE3425058A1 (en) 1984-07-07 1984-07-07 Process for preheating and firing preformed carbon anodes for the aluminium industry

Country Status (3)

Country Link
DE (1) DE3425058A1 (en)
FR (1) FR2567159A1 (en)
NO (1) NO852722L (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT391885B (en) * 1988-02-19 1990-12-10 Neuper Christel USE OF ESPECIALLY CLOSED WASTE
DE10300443A1 (en) * 2003-01-07 2004-07-22 Corus Aluminium Voerde Gmbh Process for production of granular packing material for annealing of anodes for electrolytic production of aluminum involves comminuting anode residue material so that a mean grain size fraction is precipitated

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1771738C3 (en) * 1966-08-09 1973-11-15 Elettrocarbonium S.P.A., Mailand (Italien) Process for the production of graphite and shaped charcoal bodies, precipitated from 1571455
NO135630C (en) * 1972-03-23 1977-05-04 Sumitomo Chemical Co

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT391885B (en) * 1988-02-19 1990-12-10 Neuper Christel USE OF ESPECIALLY CLOSED WASTE
US5028370A (en) * 1988-02-19 1991-07-02 Christel Neuper Electrode manufacture and support material
DE10300443A1 (en) * 2003-01-07 2004-07-22 Corus Aluminium Voerde Gmbh Process for production of granular packing material for annealing of anodes for electrolytic production of aluminum involves comminuting anode residue material so that a mean grain size fraction is precipitated
DE10300443B4 (en) * 2003-01-07 2006-07-06 Corus Aluminium Voerde Gmbh Process for producing granular packing material for use in burning anodes

Also Published As

Publication number Publication date
FR2567159A1 (en) 1986-01-10
NO852722L (en) 1986-01-08

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