EP2598674A1 - Process for producing a cathode block for an aluminium electrolysis cell and a cathode block - Google Patents

Process for producing a cathode block for an aluminium electrolysis cell and a cathode block

Info

Publication number
EP2598674A1
EP2598674A1 EP11738711.8A EP11738711A EP2598674A1 EP 2598674 A1 EP2598674 A1 EP 2598674A1 EP 11738711 A EP11738711 A EP 11738711A EP 2598674 A1 EP2598674 A1 EP 2598674A1
Authority
EP
European Patent Office
Prior art keywords
cathode block
coke
layer
cathode
graphitization
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
EP11738711.8A
Other languages
German (de)
French (fr)
Other versions
EP2598674B1 (en
Inventor
Martin Kucher
Janusz Tomala
Frank Hiltmann
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.)
Sgl Cfl Ce GmbH
Original Assignee
SGL Carbon SE
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 SGL Carbon SE filed Critical SGL Carbon SE
Publication of EP2598674A1 publication Critical patent/EP2598674A1/en
Application granted granted Critical
Publication of EP2598674B1 publication Critical patent/EP2598674B1/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

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

  • the present invention relates to a method of manufacturing a cathode block for an aluminum electrolytic cell and a cathode block.
  • One known method of producing metallic aluminum is the Hall-Heroult process.
  • the bottom of an electro-lyse cell is formed by a cathode surface consisting of individual cathode blocks. From below, the cathodes are contacted via steel ingots, which are placed in corresponding elongated recesses in the bottom of the cathode blocks.
  • Cathode blocks are conventionally made by mixing coke with carbonaceous particles such as anthracite, carbon or graphite, compacting and carbonizing.
  • carbonaceous particles such as anthracite, carbon or graphite
  • a graphitization step follows at higher temperatures where the carbonaceous particles and coke are at least partially converted to graphite.
  • TiB 2 is introduced into an upper layer of a cathode block.
  • a top layer which is a TiB 2 graphite composite
  • TiB 2 and similar hard ceramic materials cause an improvement in the wettability of the cathode in the graphitized state and thus a better energy efficiency of the electrolysis process.
  • Ceramic hard materials can also increase the density and increase the hardness of cathodes, which results in better wear resistance, in particular compared with aluminum and cryolite melts. Hard materials are also referred to as RHM (refractory hard material).
  • the object of the present invention is therefore to provide a simple process for producing a TiB 2 graphite composite cathode, which is readily wettable to aluminum melts and has good wear properties, and a corresponding cathode block.
  • the object is achieved by a method according to claim 1.
  • a method for producing a cathode block according to the invention comprises the steps of providing starting materials comprising coke and a hard material powder such as TiB 2 , and optionally another carbonaceous material, mixing the starting materials, forming a cathode block, carbonizing and graphitizing, and cooling characterized in that the step of graphitizing at temperatures between 2300 and 3000 ° C, in particular between 2400 and 2900 ° C is performed.
  • the graphitization step is carried out at an average heating rate between 90 K / h and 200 K / h.
  • the graphitization step is carried out at an average heating rate between 90 K / h and 200 K / h.
  • the graphitization step is carried out at an average heating rate between 90 K / h and 200 K / h.
  • a duration of the temperature treatment may be 10 to 28 hours up to the time of commencement of the cooling.
  • graphitized carbon forms the entire cathode block. This has the advantage that a single green mass composition is necessary, and accordingly only a single mixing step.
  • the cathode block may have at least two layers, wherein the composite layer forms the second layer of the cathode block. This second layer is in direct contact with the melt of the electrolysis cell.
  • the cathode block preferably has at least one further layer (referred to below as the first layer) which has less hard material powder than the upper layer or no hard material powder. This can reduce the amount of expensive hard material powder used.
  • the first layer is not in direct contact with the aluminum melt and therefore does not have to have good wettability and wear resistance.
  • the second layer may have a height which is 10 to 50%, in particular 15 to 45%, of the total height of the cathode block.
  • a small height of the second layer such as about 20%, may be advantageous because a small amount of expensive hard material is needed.
  • a larger height of the second layer, such as 40% may be advantageous since a layer having a hard material has high wear resistance. The greater the height of this highly wear-resistant material relative to the overall height of the cathode block, the higher the wear resistance of the entire cathode block.
  • the coke comprises two types of coke, which have a different volume change behavior during carbonation and / or graphitization and / or cooling.
  • the carbon content of the cathode block preferably condenses to a bulk density of more than 1.68 g / cm 3 , in particular of more than 1.71 g / cm 3 , in particular up to 1.75 g / cm 3 .
  • a higher apparent density advantageously contributes to a longer service life. This may be due to the fact that more mass is present per unit volume of a cathode block, resulting in a given mass removal per unit time to a higher residual mass after a given removal period. On the other hand, it can be assumed that a higher bulk density with a corresponding corresponding lower porosity hampers an infiltration of electrolyte, which acts as a corrosive medium.
  • the second layer always has a high apparent density of, for example, more than 1.80 g / cm 3 , because of the addition of hard material after graphitization, it is advantageous if the first layer also has a high density after graphitization Bulk density of the invention over 1.68 g / cm 3 .
  • the small differences in thermal expansion behavior and bulk densities during the heat treatment steps reduce production times and reject rates of the cathode blocks. Furthermore, therefore, advantageously the resistance to thermal stresses and resulting damage in the application is also increased.
  • the two types of coke comprise a first type of coke and a second type of coke, the first type of coke having a greater shrinkage and / or expansion during the carbonizing and / or graphitizing and / or cooling than the second type of coke.
  • the increased shrinkage and / or expansion is an advantageous embodiment of a different volume change behavior, which is probably particularly well suited to lead to a greater compression than when mixed cokes that have the same shrinkage and / or expansion.
  • the stronger shrinkage and / or expansion refers to any temperature range.
  • a different volume change behavior may be present during cooling.
  • the shrinkage and / or expansion of the first type of coke during carbonation and / or graphitization and / or cooling based on the volume is at least 10% higher than that of the second coke variety, in particular at least 25% higher, in particular at least 50% higher.
  • the shrinkage and / or expansion of the first type of coke during carbonation and / or graphitization and / or cooling based on the volume at least 100% higher than that of the second coke, in particular at least 200% higher, in particular at least 300% higher.
  • the first type of coke undergoes shrinkage the second coke variety, however, an expansion in the same temperature interval, is detected by the inventive method.
  • a 300% higher shrinkage and / or expansion also includes the case that the second type of coke shrinks by 1, 0 vol .-%, the first Koksorte, however, by 2.0 vol .-% expands.
  • the second type of coke may have a greater shrinkage and / or expansion, as described above for the first coke variety.
  • At least one of the two types of coke is preferably a petroleum or coal-tar coke.
  • the weight percent of the second coke variety in the total amount of coke is between 50% and 90%.
  • the different volume change behavior of the first and second types of coke has a particularly good effect on compression during carbonization and / or graphitization and / or cooling.
  • Conceivable advantageous quantitative ranges of the second type of coke can be 50 to 60%, but also 60 to 80%, and 80 to 90%.
  • At least one carbonaceous material and / or pitch and / or additives are added to the coke. This can be advantageous both with regard to the processability of the coke and the subsequent properties of the cathode block produced.
  • the further carbonaceous material contains graphite-containing material;
  • the further carbonaceous material is graphite-containing material, such as graphite.
  • the graphite may be synthetic and / or natural be phit.
  • the carbonaceous material is advantageously 1 to 40% by weight, in particular from 5 to 30% by weight, based on the total amount of coke and carbonaceous material.
  • pitch in addition to the amount of coke and optionally carbonaceous material, which represents a total of 100 wt .-%, pitch in amounts of 5 to 40 wt .-%, in particular 15 to 30 wt .-% (based on 100 wt .-% the entire green mix). Pitch acts as a binder and serves to create a dimensionally stable body during carbonation.
  • Advantageous additives may be oil, such as press auxiliary oil, or stearic acid. These facilitate mixing of the coke and optionally the other components.
  • the coke comprises at least in one of the two layers, ie in the first and / or the second layer, two types of coke, which have a different volume change behavior during carbonation and / or graphitization and / or cooling.
  • This can presumably lead to a densification of the resulting graphite of more than 1.70 g / cm 3 , in particular more than 1.71 g / cm 3 .
  • both layers or one of them can be used
  • Layers are produced according to the invention with two different types of coke.
  • only the first layer can be produced according to the invention with two types of coke, while the second layer is produced with only one type of coke, but additionally contains TiB 2 as hard material.
  • the expansion behavior of the two layers are adjusted, which can advantageously increase the life of the layers.
  • the multilayer block has more than two layers.
  • one can any number of layers are produced according to the invention each with two types of coke different volume change behavior.
  • a first and a second coke are milled separately, separated into grain size fractions and mixed together with pitch together with, for example, 15 to 25 wt%, such as 20 wt% TiB 2 .
  • the weight fraction of the first coke may be, for example, 10 to 20% by weight or 40 to 45% by weight of the total amount of coke.
  • the mixture is filled into a mold that largely corresponds to the later shape of the cathode blocks and vibration-compressed or block-pressed.
  • the resulting green body is heated to a final temperature in a range of 2300 to 3000 ° C, such as 2600 or 2800 ° C, with a graphitization step, and then cooled.
  • the resulting cathode block has a bulk density of 1.68 g / cm 3 and a very high resistance to wear compared to liquid aluminum and cryolite. Due to the average degree of graphitization achieved, thermal and electrical conductivity are high. A loss of TiB 2 could not be determined by X-ray diffractometry. The wettability of the cathode block by liquid aluminum is very good.
  • a single coke variety is used.
  • the wetting behavior of the resulting cathode block is largely the same as in the first embodiment.
  • the thermal and electrical conductivity are similar to those in the first embodiment.
  • graphite powder or carbon particles are added to the coke mixture.

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)
  • Ceramic Products (AREA)

Abstract

The invention relates to a process for producing a cathode block, comprising the following steps: providing starting materials, including coke and a hard material powder, such as TiB2, and also if appropriate a carbon-containing material, mixing the starting materials, forming a cathode block, carbonizing and graphitizing, and also cooling. According to the invention, the graphitizing step is carried out at temperatures of between 2300 and 3000°C, in particular between 2400 and 2900°C.

Description

Verfahren zum Herstellen eines Kathodenblocks für eine Aluminium-Elektrolysezelle und einen Kathodenblock  A method of manufacturing a cathode block for an aluminum electrolytic cell and a cathode block
Die vorliegende Erfindung betrifft ein Verfahren zum Herstellen eines Kathodenblocks für eine Aluminium-Elektrolysezelle und einen Kathodenblock. The present invention relates to a method of manufacturing a cathode block for an aluminum electrolytic cell and a cathode block.
Ein bekanntes Verfahren zur Herstellung von metallischem Aluminium ist der Hall- Heroult-Prozess. Bei diesem elektrolytischen Verfahren wird typischerweise der Boden einer Elektroysezelle von einer Kathodenfläche gebildet, die aus einzelnen Kathodenblöcken besteht. Von unten werden die Kathoden über Stahlbarren kontaktiert, die in entsprechenden länglichen Ausnehmungen in der Unterseite der Kathodenblöcke eingebracht sind. One known method of producing metallic aluminum is the Hall-Heroult process. In this electrolytic process, typically, the bottom of an electro-lyse cell is formed by a cathode surface consisting of individual cathode blocks. From below, the cathodes are contacted via steel ingots, which are placed in corresponding elongated recesses in the bottom of the cathode blocks.
Die Herstellung von Kathodenblöcken erfolgt herkömmlich durch Mischen von Koks mit kohlenstoffhaltigen Partikeln, wie Anthrazit, Kohlenstoff oder Graphit, Verdichten und Carbonisieren. Gegebenenfalls schließt sich ein Graphitierungsschritt bei höheren Temperaturen an, bei denen sich die kohlenstoffhaltigen Partikel und der Koks zumindest teilweise in Graphit umwandeln. Cathode blocks are conventionally made by mixing coke with carbonaceous particles such as anthracite, carbon or graphite, compacting and carbonizing. Optionally, a graphitization step follows at higher temperatures where the carbonaceous particles and coke are at least partially converted to graphite.
Durch die Graphitierung wird die thermische Leitfähigkeit des Kathodenmaterials stark erhöht und der spezifische elektrische Widerstand stark erniedrigt.  By graphitization, the thermal conductivity of the cathode material is greatly increased and the specific electrical resistance is greatly reduced.
Graphitierter Kohlenstoff und Graphit werden jedoch von flüssigem Aluminium schlecht bzw. gar nicht benetzt. Dadurch erhöht sich der Strombedarf und damit auch der Energiebedarf einer Elektrolysezelle. Graphitized carbon and graphite, however, are poorly or not wetted by liquid aluminum. This increases the power consumption and thus also the energy consumption of an electrolysis cell.
Um dieses Problem zu lösen, wird im Stand der Technik TiB2 in eine Oberschicht eines Kathodenblocks eingebracht. Dies ist beispielsweise in der DE 1 12006004078 beschrieben. Eine derartige Oberschicht, die einen TiB2-Graphit-Komposit darstellt, ist in direktem Kontakt mit der Aluminiumschmelze und damit ausschlaggebend für die Stromeinkopplung von der Kathode in die Aluminiumschmelze. TiB2 und ähnliche hartkeramische Materialien bewirken eine Verbesserung der Benetzbarkeit der Kathode im graphitierten Zustand und damit einen besseren Energieeffizienz des Elektrolyseprozesses. Keramische Hartstoffe können darüber hinaus die Rohdichte und die Härte von Kathoden erhöhen, was eine bessere Verschleißbeständigkeit insbesondere gegenüber Aluminium- und Kryolitschmelzen zur Folge hat. Hartmaterialien werden auch als RHM (refractory hard material) bezeichnet. In order to solve this problem, in the prior art TiB 2 is introduced into an upper layer of a cathode block. This is described for example in DE 1 12006004078. Such a top layer, which is a TiB 2 graphite composite, is in direct contact with the aluminum melt and thus crucial for the current injection from the cathode into the molten aluminum. TiB 2 and similar hard ceramic materials cause an improvement in the wettability of the cathode in the graphitized state and thus a better energy efficiency of the electrolysis process. Ceramic hard materials can also increase the density and increase the hardness of cathodes, which results in better wear resistance, in particular compared with aluminum and cryolite melts. Hard materials are also referred to as RHM (refractory hard material).
TiB2-Pulver und ähnliche Hartmaterialpulver verlieren jedoch während eines However, TiB 2 powders and similar hard material powders lose during one
Graphitierungsvorgangs teilweise ihre die Benetzbarkeit und die Verschleißbeständigkeit erhöhende Wirkung. Graphitierungsvorgangs partially their wettability and wear resistance increasing effect.
Aufgabe der vorliegenden Erfindung ist daher, ein einfaches Verfahren zur Herstellung einer TiB2-Graphit-Komposit-Kathode anzugeben, die gegenüber Aluminiumschmelzen gut benetzbar ist und gute Verschleißeigenschaften besitzt, sowie einen entsprechenden Kathodenblock. The object of the present invention is therefore to provide a simple process for producing a TiB 2 graphite composite cathode, which is readily wettable to aluminum melts and has good wear properties, and a corresponding cathode block.
Die Aufgabe wird durch ein Verfahren nach Anspruch 1 gelöst. The object is achieved by a method according to claim 1.
Ein erfindungsgemäßes Verfahren zur Herstellung eines Kathodenblocks weist die Schritte Bereitstellen von Ausgangsmaterialien, umfassend Koks und ein Hartmaterialpulver, wie etwa TiB2, sowie gegebenenfalls ein weiteres kohlenstoffhaltiges Material, Mischen der Ausgangsmaterialien, Formen eines Kathodenblocks, Carbonisie- ren und Graphitieren, sowie Abkühlen und ist dadurch gekennzeichnet, dass der Schritt des Graphitierens bei Temperaturen zwischen 2300 und 3000 °C, insbesondere zwischen 2400 und 2900 °C durchgeführt wird. A method for producing a cathode block according to the invention comprises the steps of providing starting materials comprising coke and a hard material powder such as TiB 2 , and optionally another carbonaceous material, mixing the starting materials, forming a cathode block, carbonizing and graphitizing, and cooling characterized in that the step of graphitizing at temperatures between 2300 and 3000 ° C, in particular between 2400 and 2900 ° C is performed.
Temperaturen unter 2900 °C haben sich als besonders vorteilhaft erwiesen, da herkömmliches TiB2 unter 2900 °C nicht aufschmilzt. Ein Aufschmelzen hat zwar vermutlich keine chemische Veränderung des TiB2 zur Folge, denn auch nach einem Aufschmelzen und einem anschließenden Abkühlen wird röntgendiffraktometrisch TiB2 in einem Kathodenblock nachgewiesen. Durch ein Aufschmelzen können jedoch fein verteilte TiB2-Partikel zu größeren Partikeln agglomerieren. Auch besteht eine gewisse Gefahr, dass sich flüssiges TiB2 unkontrolliert durch offene Porosität bewegt. Im erfindungsgemäßen Temperaturbereich ist der Graphitierungsprozess so weit fortgeschritten, dass eine hohe thermische und elektrische Leitfähigkeit des kohlenstoffhaltigen Materials gegeben ist. Temperatures below 2900 ° C have proven to be particularly advantageous since conventional TiB 2 does not melt below 2900 ° C. Although melting does not presumably result in a chemical change of the TiB 2 , because even after melting and subsequent cooling, X-ray diffractometry detects TiB 2 in a cathode block. By melting, however, finely divided TiB 2 particles can agglomerate into larger particles. There is also a certain risk that liquid TiB 2 moves uncontrollably through open porosity. In the temperature range according to the invention the graphitization process has progressed so far that a high thermal and electrical conductivity of the carbonaceous material is given.
Vorzugsweise wird der Graphitierungsschritt mit einer durchschnittlichen Aufheizrate zwischen 90 K/h und 200 K/h durchgeführt. Alternativ oder zusätzlich wird die Preferably, the graphitization step is carried out at an average heating rate between 90 K / h and 200 K / h. Alternatively or additionally, the
Graphitierungstemperatur für eine Dauer zwischen 0 und 1 h gehalten. Bei diesen Aufheizraten bzw. dieser Haltedauer werden hinsichtlich Graphitierung und Erhaltung des Hartmaterials besonders gute Ergebnisse erzielt. Graphitierungstemperatur held for a period between 0 and 1 h. At these heating rates or holding periods, particularly good results are achieved with regard to graphitization and preservation of the hard material.
Vorteilhaft kann eine Dauer der Temperaturbehandlung bis zu dem Zeitpunkt eines Beginns der Abkühlung 10 bis 28 Stunden betragen. Advantageously, a duration of the temperature treatment may be 10 to 28 hours up to the time of commencement of the cooling.
Es kann vorteilhaft sein, dass der Komposit mit Hartmaterial und Graphit bzw. It may be advantageous that the composite with hard material and graphite or
graphitiertem Kohlenstoff den gesamten Kathodenblock bildet. Dies hat den Vorteil, dass eine einzige Grünmassenzusammensetzung notwendig ist und entsprechend nur ein einziger Mischschritt. graphitized carbon forms the entire cathode block. This has the advantage that a single green mass composition is necessary, and accordingly only a single mixing step.
Alternativ kann es vorteilhaft sein, dass der Kathodenblock zumindest zwei Schichten aufweist, wobei die Kompositschicht die zweite Schicht des Kathodenblocks bildet. Diese zweite Schicht ist in direktem Kontakt zur Schmelze der Elektrolysezelle. Alternatively, it may be advantageous for the cathode block to have at least two layers, wherein the composite layer forms the second layer of the cathode block. This second layer is in direct contact with the melt of the electrolysis cell.
Bevorzugt besitzt der Kathodenblock zumindest eine weitere Schicht (im folgenden erste Schicht genannt), die weniger Hartmaterialpulver aufweist als die Oberschicht oder kein Hartmaterialpulver aufweist. Dies kann die Menge an eingesetztem preisintensivem Hartmaterialpulver verringern. Die erste Schicht ist bei Einsatz der Kathode in einer Aluminiumelektrolysezelle nicht in direktem Kontakt zur Aluminiumschmelze und muss daher keine gute Benetzbarkeit und Verschleißbeständigkeit aufweisen. The cathode block preferably has at least one further layer (referred to below as the first layer) which has less hard material powder than the upper layer or no hard material powder. This can reduce the amount of expensive hard material powder used. When the cathode is used in an aluminum electrolysis cell, the first layer is not in direct contact with the aluminum melt and therefore does not have to have good wettability and wear resistance.
Vorteilhaft kann die zweite Schicht eine Höhe besitzen, die 10 bis 50 %, insbesondere 15 bis 45 %, der Gesamthöhe des Kathodenblocks beträgt. Eine geringe Höhe der zweiten Schicht, wie etwa 20 %, kann vorteilhaft sein, da eine geringe Menge an kostenintensivem Hartmaterial nötig ist. Alternativ kann eine größere Höhe der zweiten Schicht, wie etwa 40 %, vorteilhaft sein, da eine Schicht, die ein Hartmaterial besitzt, eine hohe Verschleißbeständigkeit besitzt. Je größer die Höhe dieses hoch verschleißfesten Materials in Bezug auf die Gesamthöhe des Kathodenblocks, desto höher die Verschleißfestigkeit des gesamten Kathodenblocks. Advantageously, the second layer may have a height which is 10 to 50%, in particular 15 to 45%, of the total height of the cathode block. A small height of the second layer, such as about 20%, may be advantageous because a small amount of expensive hard material is needed. Alternatively, a larger height of the second layer, such as 40%, may be advantageous since a layer having a hard material has high wear resistance. The greater the height of this highly wear-resistant material relative to the overall height of the cathode block, the higher the wear resistance of the entire cathode block.
Bevorzugt umfasst der Koks zwei Kokssorten, die ein unterschiedliches Volumenänderungsverhalten während des Carbonisierens und/oder Graphitierens und/oder Abkühlens besitzen. Preferably, the coke comprises two types of coke, which have a different volume change behavior during carbonation and / or graphitization and / or cooling.
Überraschenderweise hat sich gezeigt, dass die Lebensdauer der mit einem solchen Verfahren hergestellten Kathodenblöcke deutlich höher ist als bei den mit herkömmlichen Verfahren hergestellten Kathodenblöcken. Surprisingly, it has been shown that the lifetime of the cathode blocks produced by such a method is significantly higher than in the case of the cathode blocks produced by conventional methods.
Bevorzugt verdichtet sich der Kohlenstoffanteil des Kathodenblocks zu einer Rohdichte von über 1 ,68 g/cm3, insbesondere von über 1 ,71 g/cm3, insbesondere bis zu 1 ,75 g/cm3. The carbon content of the cathode block preferably condenses to a bulk density of more than 1.68 g / cm 3 , in particular of more than 1.71 g / cm 3 , in particular up to 1.75 g / cm 3 .
Vermutlich trägt eine höhere Rohdichte vorteilhaft zu einer längeren Lebensdauer bei. Dies kann zum einen darin begründet liegen, dass pro Volumeneinheit eines Kathodenblocks mehr Masse vorhanden ist, was bei einem gegebenen Masseabtrag pro Zeiteinheit zu einer höheren Restmasse nach einer gegebenen Abtragsdauer führt. Zum anderen lässt sich vermuten, dass eine höhere Rohdichte mit einer entsprechenden korrespondierenden niedrigeren Porosität eine Infiltration von Elektrolyt, das als korrosives Medium wirkt, behindert. Presumably, a higher apparent density advantageously contributes to a longer service life. This may be due to the fact that more mass is present per unit volume of a cathode block, resulting in a given mass removal per unit time to a higher residual mass after a given removal period. On the other hand, it can be assumed that a higher bulk density with a corresponding corresponding lower porosity hampers an infiltration of electrolyte, which acts as a corrosive medium.
Mit dieser Variante werden die Vorteile der erfindungsgemäßen Graphitierungstem- peratur in einem Bereich zwischen 2300 und 3000 °C mit der Erhöhung der Rohdichte des Kathodenblocks kombiniert. Dadurch wird vorteilhaft eine Folge der unvollständigen Graphitierung zumindest teilweise kompensiert. With this variant, the advantages of the graphitization temperature according to the invention in a range between 2300 and 3000 ° C combined with the increase in bulk density of the cathode block. As a result, a consequence of the incomplete graphitization is advantageously at least partially compensated.
Da die zweite Schicht wegen des Zusatzes an Hartmaterial nach einem Graphitieren immer eine hohe Rohdichte von beispielsweise über 1 ,80 g/cm3 aufweist, ist es vorteilhaft, wenn die erste Schicht nach einem Graphitieren ebenfalls eine hohe Rohdichte von erfindungsgemäß über 1 ,68 g/cm3 aufweist. Die geringen Unterschiede im thermischen Ausdehnungsverhalten und Rohdichten während der Wärmebehandlungsschritte verringern Produktionszeiten und Ausschussraten der Kathodenblöcke. Des Weiteren ist daher vorteilhafterweise die Beständigkeit gegenüber thermischen Spannungen und daraus resultierenden Schädigungen in der Anwendung ebenfalls noch erhöht. Since the second layer always has a high apparent density of, for example, more than 1.80 g / cm 3 , because of the addition of hard material after graphitization, it is advantageous if the first layer also has a high density after graphitization Bulk density of the invention over 1.68 g / cm 3 . The small differences in thermal expansion behavior and bulk densities during the heat treatment steps reduce production times and reject rates of the cathode blocks. Furthermore, therefore, advantageously the resistance to thermal stresses and resulting damage in the application is also increased.
Vorteilhaft umfassen die zwei Kokssorten eine erste Kokssorte und eine zweite Kokssorte, wobei die erste Kokssorte während des Carbonisierens und/oder Graphi- tierens und/oder Abkühlens eine stärkere Schwindung und/oder Ausdehnung aufweist als die zweite Kokssorte. Hierbei ist die stärkere Schwindung und/oder Ausdehnung eine vorteilhafte Ausbildung eines unterschiedlichen Volumenänderungsverhaltens, die vermutlich besonders gut geeignet ist, zu einer stärkeren Verdichtung zu führen, als wenn Kokssorten gemischt werden, die eine gleiche Schwindung und/oder Ausdehnung besitzen. Dabei bezieht sich die stärkere Schwindung und/oder Ausdehnung auf einen beliebigen Temperaturbereich. Somit kann beispielsweise lediglich eine stärkere Schwindung des ersten Koks beim Carbonisieren vorliegen. Andererseits kann beispielsweise zusätzlich oder stattdessen eine stärkere Ausdehnung in einem Übergangsbereich zwischen Carbonisieren und Graphitieren vorliegen. Stattdessen oder zusätzlich kann sich beim Abkühlen ein unterschiedliches Volumenänderungsverhalten vorliegen. Advantageously, the two types of coke comprise a first type of coke and a second type of coke, the first type of coke having a greater shrinkage and / or expansion during the carbonizing and / or graphitizing and / or cooling than the second type of coke. Here, the increased shrinkage and / or expansion is an advantageous embodiment of a different volume change behavior, which is probably particularly well suited to lead to a greater compression than when mixed cokes that have the same shrinkage and / or expansion. The stronger shrinkage and / or expansion refers to any temperature range. Thus, for example, only a stronger shrinkage of the first coke during carbonization can be present. On the other hand, for example, in addition or instead, there may be a greater extent in a transition region between carbonization and graphitization. Instead or in addition, a different volume change behavior may be present during cooling.
Bevorzugt ist die Schwindung und/oder Ausdehnung der ersten Kokssorte während des Carbonisierens und/oder Graphitierens und/oder Abkühlens bezogen auf das Volumen zumindest 10 % höher als die der zweiten Kokssorte, insbesondere zumindest 25 % höher, insbesondere zumindest 50 % höher. Somit ist beispielsweise im Fall einer 10 % höheren Schwindung der ersten Kokssorte die Schwindung von Raumtemperatur bis 2000 °C bei der zweiten Kokssorte 1 ,0 Vol.-%, bei der ersten Kokssorte hingegen 1 , 1 Vol.-%. Preferably, the shrinkage and / or expansion of the first type of coke during carbonation and / or graphitization and / or cooling based on the volume is at least 10% higher than that of the second coke variety, in particular at least 25% higher, in particular at least 50% higher. Thus, for example, in the case of a 10% higher shrinkage of the first coke variety, the shrinkage from room temperature to 2000 ° C for the second type of coke 1, 0 vol .-%, in the first coke variety, however, 1, 1 vol .-%.
Vorteilhafterweise ist die Schwindung und/oder Ausdehnung der ersten Kokssorte während des Carbonisierens und/oder Graphitierens und/oder Abkühlens bezogen auf das Volumen zumindest 100 % höher als die der zweiten Kokssorte, insbesondere zumindest 200 % höher, insbesondere zumindest 300 % höher. Somit ist bei- spielsweise im Fall einer 300 % höheren Ausdehnung der ersten Kokssorte die Ausdehnung von Raumtemperatur bis 1000 °C bei der zweiten Kokssorte 1 ,0 Vol.-%, bei der ersten Kokssorte hingegen 4,0 Vol.-%. Advantageously, the shrinkage and / or expansion of the first type of coke during carbonation and / or graphitization and / or cooling based on the volume at least 100% higher than that of the second coke, in particular at least 200% higher, in particular at least 300% higher. Thus, For example, in the case of a 300% higher expansion of the first coke variety, the expansion from room temperature to 1000 ° C for the second coke variety 1, 0 vol .-%, in the first coke variety, however, 4.0 vol .-%.
Auch der Fall, dass die erste Kokssorte eine Schwindung erfährt, die zweite Kokssorte hingegen im gleichen Temperaturintervall eine Ausdehnung, wird durch das erfindungsgemäße Verfahren erfasst. Eine um 300 % höhere Schwindung und/oder Ausdehnung umfasst somit beispielsweise auch den Fall, dass die zweite Kokssorte um 1 ,0 Vol.-% schwindet, die erste Kokssorte sich dagegen um 2,0 Vol.-% ausdehnt. The case that the first type of coke undergoes shrinkage, the second coke variety, however, an expansion in the same temperature interval, is detected by the inventive method. For example, a 300% higher shrinkage and / or expansion also includes the case that the second type of coke shrinks by 1, 0 vol .-%, the first Koksorte, however, by 2.0 vol .-% expands.
Alternativ kann in zumindest einem beliebigen Temperaturintervall des erfindungsgemäßen Verfahrens statt der ersten Kokssorte die zweite Kokssorte eine stärkere Schwindung und/oder Ausdehnung aufweisen, wie oben für die erste Kokssorte beschrieben. Alternatively, in at least one arbitrary temperature interval of the method according to the invention, instead of the first type of coke, the second type of coke may have a greater shrinkage and / or expansion, as described above for the first coke variety.
Bevorzugt ist zumindest eine der beiden Kokssorten ein Petrol- oder Steinkohlen- teerpechkoks. At least one of the two types of coke is preferably a petroleum or coal-tar coke.
Bevorzugt beträgt der Mengenanteil in Gewichtsprozent der zweiten Kokssorte an der Gesamtmenge an Koks zwischen 50 % und 90 %. In diesen Mengenbereichen wirkt sich das unterschiedliche Volumenänderungsverhalten der ersten und zweiten Kokssorte besonders gut auf eine Verdichtung während des Carbonisierens und/oder Graphitierens und/oder Abkühlens aus. Denkbare vorteilhafte Mengenbereiche der zweiten Kokssorte können 50 bis 60 % sein, aber auch 60 bis 80 %, sowie 80 bis 90 %. Preferably, the weight percent of the second coke variety in the total amount of coke is between 50% and 90%. In these quantitative ranges, the different volume change behavior of the first and second types of coke has a particularly good effect on compression during carbonization and / or graphitization and / or cooling. Conceivable advantageous quantitative ranges of the second type of coke can be 50 to 60%, but also 60 to 80%, and 80 to 90%.
Vorteilhaft werden dem Koks zumindest ein kohlenstoffhaltiges Material und/oder Pech und/oder Additive zugegeben. Dies kann sowohl hinsichtlich der Verarbeitbar- keit des Koks als auch der späteren Eigenschaften des hergestellten Kathodenblocks vorteilhaft sein. Advantageously, at least one carbonaceous material and / or pitch and / or additives are added to the coke. This can be advantageous both with regard to the processability of the coke and the subsequent properties of the cathode block produced.
Bevorzugt enthält das weitere kohlenstoffhaltige Material graphithaltiges Material; insbesondere besteht das weitere kohlenstoffhaltige Material aus graphithaltigem Material, wie etwa Graphit. Der Graphit kann synthetischer und/oder natürlicher Gra- phit sein. Durch derartiges weiteres kohlenstoffhaltiges Material wird erreicht, dass die notwendige Schwindung der Kathodenmasse, die durch den Koks dominiert wird, verringert wird. Preferably, the further carbonaceous material contains graphite-containing material; In particular, the further carbonaceous material is graphite-containing material, such as graphite. The graphite may be synthetic and / or natural be phit. By such further carbonaceous material is achieved that the necessary shrinkage of the cathode mass, which is dominated by the coke, is reduced.
Vorteilhaft liegt das kohlenstoffhaltige Material bezogen auf die Gesamtmenge aus Koks und kohlenstoffhaltigem Material zu 1 bis 40 Gew-.%, insbesondere zu 5 bis 30 Gew.-% vor. The carbonaceous material is advantageously 1 to 40% by weight, in particular from 5 to 30% by weight, based on the total amount of coke and carbonaceous material.
Bevorzugt kann zusätzlich zu der Menge an Koks und gegebenenfalls kohlenstoffhaltigem Material, die insgesamt 100 Gew.-% darstellt, Pech in Mengen von 5 bis 40 Gew.-%, insbesondere 15 bis 30 Gew.-% (bezogen auf 100 Gew.-% der gesamten Grünmischung) zugegeben werden. Pech wirkt als Bindemittel und dient dazu, während des Carbonisierens einen formstabilen Körper zu erzeugen. Preferably, in addition to the amount of coke and optionally carbonaceous material, which represents a total of 100 wt .-%, pitch in amounts of 5 to 40 wt .-%, in particular 15 to 30 wt .-% (based on 100 wt .-% the entire green mix). Pitch acts as a binder and serves to create a dimensionally stable body during carbonation.
Vorteilhafte Additive können Öl, wie Presshilfsöl, oder Stearinsäure sein. Diese erleichtern ein Mischen des Kokses und gegebenenfalls der weiteren Komponenten. Advantageous additives may be oil, such as press auxiliary oil, or stearic acid. These facilitate mixing of the coke and optionally the other components.
Bevorzugt umfasst der Koks zumindest in einer der beiden Schichten, also in der ersten und/oder der zweiten Schicht, zwei Kokssorten, die ein unterschiedliches Volumenänderungsverhalten während des Carbonisierens und/oder Graphitierens und/oder Abkühlens besitzen. Dies kann vermutlich zu einer Verdichtung des entstehenden Graphits von über 1 ,70 g/cm3, insbesondere über 1 ,71 g/cm3 führen. Je nach Wunsch und/oder Bedarf können somit beide Schichten oder eine der beiden Preferably, the coke comprises at least in one of the two layers, ie in the first and / or the second layer, two types of coke, which have a different volume change behavior during carbonation and / or graphitization and / or cooling. This can presumably lead to a densification of the resulting graphite of more than 1.70 g / cm 3 , in particular more than 1.71 g / cm 3 . Depending on desire and / or need, both layers or one of them can be used
Schichten erfindungsgemäß mit zwei unterschiedlichen Kokssorten hergestellt werden. Somit ergibt sich die Möglichkeit, Rohdichten und Rohdichteverhältnisse wie nötig oder gewünscht einzustellen. Beispielsweise kann ausschließlich die erste Schicht erfindungsgemäß mit zwei Kokssorten hergestellt werden, während die zweite Schicht mit lediglich einer Kokssorte hergestellt wird, aber zusätzlich TiB2 als Hartmaterial enthält. Dadurch werden die Ausdehnungsverhalten der beiden Schichten angeglichen, was vorteilhafterweise die Lebensdauer der Schichten erhöhen kann. Layers are produced according to the invention with two different types of coke. Thus, there is the possibility to adjust bulk densities and raw density ratios as necessary or desired. For example, only the first layer can be produced according to the invention with two types of coke, while the second layer is produced with only one type of coke, but additionally contains TiB 2 as hard material. As a result, the expansion behavior of the two layers are adjusted, which can advantageously increase the life of the layers.
Gegebenenfalls kann es vorteilhaft sein, dass der Mehrfachschichtblock mehr als zwei Schichten aufweist. In diesem Fall kann von den mehr als zwei Schichten eine beliebige Anzahl der Schichten erfindungsgemäß jeweils mit zwei Kokssorten unterschiedlichen Volumenänderungsverhaltens hergestellt werden. Optionally, it may be advantageous that the multilayer block has more than two layers. In this case, of the more than two layers one can any number of layers are produced according to the invention each with two types of coke different volume change behavior.
Weitere vorteilhafte Aus- und Weiterbildungen der Erfindung werden im Folgenden anhand eines bevorzugten Ausführungsbeispiels erläutert. Further advantageous embodiments and developments of the invention will be explained below with reference to a preferred embodiment.
Zur Herstellung eines erfindungsgemäßen Kathodenblocks werden ein erster und ein zweiter Koks getrennt voneinander gemahlen, in Korngrößenfraktionen getrennt und miteinander mit Pech zusammen mit beispielsweise 15 bis 25 Gew.-%, wie etwa 20 Gew.-% TiB2, gemischt. Der Gewichtsanteil des ersten Koks kann beispielsweise 10 bis 20 Gew.-% oder 40 bis 45 Gew.-% an der Gesamtmenge Koks betragen. Die Mischung wird in eine Form, die weitgehend der späteren Form der Kathodenblöcke entspricht, eingefüllt und vibrationsverdichtet oder blockgepresst werden. Der entstehende Grünkörper wird bis auf eine Endtemperatur in einem Bereich von 2300 bis 3000 °C, wie etwa 2600 oder 2800 °C aufgeheizt, wobei ein Graphitierungsschritt erfolgt, und anschließend abgekühlt. Der entstehende Kathodenblock besitzt eine Rohdichte von 1 ,68 g/cm3 und eine sehr hohe Verschleißbeständigkeit gegenüber flüssigem Aluminium und Kryolith. Durch den erhaltenen mittleren Graphitie- rungsgrad sind thermische und elektrische Leitfähigkeit hoch. Ein Verlust an TiB2 konnte röntgendiffraktometrisch nicht festgestellt werden. Die Benetzbarkeit des Kathodenblocks durch flüssiges Aluminium ist sehr gut. To produce a cathode block according to the invention, a first and a second coke are milled separately, separated into grain size fractions and mixed together with pitch together with, for example, 15 to 25 wt%, such as 20 wt% TiB 2 . The weight fraction of the first coke may be, for example, 10 to 20% by weight or 40 to 45% by weight of the total amount of coke. The mixture is filled into a mold that largely corresponds to the later shape of the cathode blocks and vibration-compressed or block-pressed. The resulting green body is heated to a final temperature in a range of 2300 to 3000 ° C, such as 2600 or 2800 ° C, with a graphitization step, and then cooled. The resulting cathode block has a bulk density of 1.68 g / cm 3 and a very high resistance to wear compared to liquid aluminum and cryolite. Due to the average degree of graphitization achieved, thermal and electrical conductivity are high. A loss of TiB 2 could not be determined by X-ray diffractometry. The wettability of the cathode block by liquid aluminum is very good.
Alternativ wird eine einzige Kokssorte eingesetzt. Das Benetzungsverhalten des sich ergebenden Kathodenblocks ist weitgehend gleich gut wie im ersten Ausführungsbeispiel. Die thermische sowie elektrische Leitfähigkeit liegen in ähnlichen Bereichen wie im ersten Ausführungsbeispiel. Alternatively, a single coke variety is used. The wetting behavior of the resulting cathode block is largely the same as in the first embodiment. The thermal and electrical conductivity are similar to those in the first embodiment.
In einer weiteren Variante des Ausführungsbeispiels wird der Koksmischung Graphitpulver oder Kohlenstoffpartikel zugegeben. In a further variant of the exemplary embodiment, graphite powder or carbon particles are added to the coke mixture.
Alle in der Beschreibung, den Beispielen und Ansprüchen genannten Merkmale können in beliebiger Kombination zu der Erfindung beitragen. Die Erfindung beschränkt sich jedoch nicht auf die angegebenen Beispiele, sondern kann auch in Abwandlungen ausgeführt werden, die hier nicht konkret beschrieben sind. All features mentioned in the description, examples and claims may contribute to the invention in any combination. However, the invention is not limited to the examples given, but may also be carried out in modifications which are not specifically described here.

Claims

Patentansprüche claims
1 . Verfahren zur Herstellung eines Kathodenblocks, aufweisend die Schritte Bereitstellen von Ausgangsmaterialien, umfassend Koks und ein Hartmaterialpulver, wie etwa TiB2, sowie gegebenenfalls ein kohlenstoffhaltiges Material, Mischen der Ausgangsmaterialien, Formen eines Kathodenblocks, Carbonisieren und Graphitieren, sowie Abkühlen, dadurch gekennzeichnet, dass der Schritt des Graphitierens bei Temperaturen zwischen 2300 und 3000 °C, insbesondere zwischen 2400 und 2900 °C durchgeführt wird. 1 . A method of making a cathode block, comprising the steps of providing starting materials comprising coke and a hard material powder such as TiB 2 , and optionally a carbonaceous material, mixing the starting materials, forming a cathode block, carbonizing and graphitizing, and cooling, characterized in that the Step of graphitizing at temperatures between 2300 and 3000 ° C, in particular between 2400 and 2900 ° C is performed.
2. Verfahren nach Anspruch 1 , dadurch gekennzeichnet, dass der Graphitie- rungsschritt mit einer Aufheizrate zwischen 90 und 200 K/h durchgeführt wird und/oder bei der Graphitierungstemperatur zwischen 2300 und 2900 °C durchgeführt wird. 2. The method according to claim 1, characterized in that the graphitization step is carried out at a heating rate between 90 and 200 K / h and / or is carried out at the graphitization temperature between 2300 and 2900 ° C.
3. Verfahren nach Anspruch 1 oder 2, dadurch gekennzeichnet, dass der Koks zwei Kokssorten umfasst, die während des Carbonisierens und/oder Graphitierens und/oder Abkühlens ein unterschiedliches Volumenänderungsverhalten besitzen. 3. The method according to claim 1 or 2, characterized in that the coke comprises two types of coke, which have a different volume change behavior during carbonization and / or graphitization and / or cooling.
4. Verfahren nach Anspruch 3, dadurch gekennzeichnet, dass der Kathodenblock mit einer Rohdichte von über 1 ,68 g/cm3, insbesondere von über 1 ,71 g/cm3 erhalten wird. 4. The method according to claim 3, characterized in that the cathode block with a bulk density of about 1, 68 g / cm 3 , in particular of about 1, 71 g / cm 3 is obtained.
5. Verfahren nach einem oder mehreren der Ansprüche 1 bis 4, dadurch 5. The method according to one or more of claims 1 to 4, characterized
gekennzeichnet, dass der ganze Kathodenblock als Komposit mit Graphit und Hartmaterial hergestellt wird. in that the entire cathode block is produced as a composite with graphite and hard material.
6. Verfahren nach einem oder mehreren der Ansprüche 1 bis 5, dadurch 6. The method according to one or more of claims 1 to 5, characterized
gekennzeichnet, dass der Kathodenblock als Mehrfachschichtblock hergestellt wird, wobei eine erste Schicht als Ausgangsmaterial Koks enthält und eine zweite Schicht als Ausgangsmaterial Koks und ein Hartmaterial, insbesondere TiB2, enthält. in that the cathode block is produced as a multilayer block, wherein a first layer contains coke as starting material and a second layer contains coke as starting material and a hard material, in particular TiB 2 .
7. Verfahren nach Anspruch 6, dadurch gekennzeichnet, dass der Kathodenblock als die erste und/oder zweite Schicht als Ausgangsmaterial zumindest ein weiteres kohlenstoffhaltiges Material enthält. 7. The method according to claim 6, characterized in that the cathode block contains as the first and / or second layer as a starting material at least one further carbonaceous material.
8. Verfahren nach Anspruch 6 oder 7, dadurch gekennzeichnet, dass die zweite Schicht mit einer Dicke hergestellt wird, die 10 bis 50 %, insbesondere 15 bis 45 %, der Gesamtdicke des Kathodenblocks beträgt. 8. The method according to claim 6 or 7, characterized in that the second layer is produced with a thickness which is 10 to 50%, in particular 15 to 45%, of the total thickness of the cathode block.
9. Verfahren nach einem oder mehreren der Ansprüche 1 bis 8, dadurch 9. The method according to one or more of claims 1 to 8, characterized
gekennzeichnet, dass ein Anteil an Graphit und/oder graphitiertem Kohlenstoff bezogen auf den gesamten Kohlenstoffgehalt in zumindest einer Schicht des Kathodenblocks zumindest 60 % beträgt. characterized in that a proportion of graphite and / or graphitized carbon based on the total carbon content in at least one layer of the cathode block is at least 60%.
10. Verfahren nach Anspruch 9, dadurch gekennzeichnet, dass der Anteil an Graphit und/oder graphitiertem Kohlenstoff zumindest 80 % beträgt. 10. The method according to claim 9, characterized in that the proportion of graphite and / or graphitized carbon is at least 80%.
EP11738711.8A 2010-07-29 2011-07-29 Process for producing a cathode block for an aluminium electrolysis cell Active EP2598674B1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE102010038665A DE102010038665A1 (en) 2010-07-29 2010-07-29 A method of manufacturing a cathode block for an aluminum electrolytic cell and a cathode block
PCT/EP2011/063077 WO2012013769A1 (en) 2010-07-29 2011-07-29 Process for producing a cathode block for an aluminium electrolysis cell and a cathode block

Publications (2)

Publication Number Publication Date
EP2598674A1 true EP2598674A1 (en) 2013-06-05
EP2598674B1 EP2598674B1 (en) 2018-02-14

Family

ID=44546387

Family Applications (1)

Application Number Title Priority Date Filing Date
EP11738711.8A Active EP2598674B1 (en) 2010-07-29 2011-07-29 Process for producing a cathode block for an aluminium electrolysis cell

Country Status (9)

Country Link
EP (1) EP2598674B1 (en)
JP (1) JP5631492B2 (en)
CN (1) CN103069053A (en)
CA (1) CA2805562C (en)
DE (1) DE102010038665A1 (en)
NO (1) NO2598674T3 (en)
RU (1) RU2556192C2 (en)
UA (1) UA109020C2 (en)
WO (1) WO2012013769A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102012201468A1 (en) * 2012-02-01 2013-08-01 Sgl Carbon Se A method of making a cathode block for an aluminum electrolytic cell and a cathode block
DE102013202437A1 (en) * 2013-02-14 2014-08-14 Sgl Carbon Se Cathode block with a wettable and abrasion resistant surface

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4308114A (en) * 1980-07-21 1981-12-29 Aluminum Company Of America Electrolytic production of aluminum using a composite cathode
US4308115A (en) * 1980-08-15 1981-12-29 Aluminum Company Of America Method of producing aluminum using graphite cathode coated with refractory hard metal
US4376029A (en) * 1980-09-11 1983-03-08 Great Lakes Carbon Corporation Titanium diboride-graphite composits
CN85205776U (en) * 1985-12-31 1986-10-22 东北工学院 Tib2 composite layers-type cathode for ai electrolysis
US6001236A (en) * 1992-04-01 1999-12-14 Moltech Invent S.A. Application of refractory borides to protect carbon-containing components of aluminium production cells
DE19714433C2 (en) * 1997-04-08 2002-08-01 Celanese Ventures Gmbh Process for producing a coating with a titanium boride content of at least 80% by weight
FR2789093B1 (en) * 1999-02-02 2001-03-09 Carbone Savoie GRAPHITE CATHODE FOR ALUMINUM ELECTROLYSIS
FR2878520B1 (en) * 2004-11-29 2015-09-18 Saint Gobain Ct Recherches FRICTION REFRACTOR BLOCK BASED ON SILICON CARBIDE WITH SILICON NITRIDE BOND
CN100491600C (en) 2006-10-18 2009-05-27 中国铝业股份有限公司 Method for preparing carbon block of cathode capable of being humidified
CN101158048A (en) * 2007-08-03 2008-04-09 中国铝业股份有限公司 Graphitized wetable cathode carbon block for aluminium electrolysis bath and production method thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2012013769A1 *

Also Published As

Publication number Publication date
JP2013532772A (en) 2013-08-19
DE102010038665A1 (en) 2012-02-02
CA2805562C (en) 2015-06-16
CA2805562A1 (en) 2012-02-02
EP2598674B1 (en) 2018-02-14
NO2598674T3 (en) 2018-07-14
WO2012013769A1 (en) 2012-02-02
RU2556192C2 (en) 2015-07-10
CN103069053A (en) 2013-04-24
JP5631492B2 (en) 2014-11-26
UA109020C2 (en) 2015-07-10
RU2013108752A (en) 2014-09-10

Similar Documents

Publication Publication Date Title
DE1251962B (en) Cathode for an electrolytic cell for the production of aluminum and process for the production of the same
EP2576870B1 (en) Carbon body, method for producing a carbon body and use thereof
DE102015222439B4 (en) Process for the production of graphite bodies
DD295878B5 (en) Process for producing a Soederberg electrode
EP2598675B1 (en) Cathode block for an aluminium electrolysis cell and a process for the production thereof
DE3034359A1 (en) Process for producing high-density,high-strength carbon and graphite material
WO2012107400A2 (en) Graphitized cathode block having an abrasion-proof surface
EP2598674B1 (en) Process for producing a cathode block for an aluminium electrolysis cell
DE1092215B (en) Cathode and cell for the production of aluminum from aluminum oxide by fused-salt electrolysis
EP2809833B1 (en) Method for producing a cathode block for an aluminum electrolytic cell
EP2598673B1 (en) Process for producing a cathode block for an aluminium electrolysis cell
EP2673401A2 (en) Surface-profiled graphite cathode block having an abrasion-proof surface
EP2956573A1 (en) Cathode block having an abrasion-resistant surface that can be wetted
EP0068518B1 (en) Process for the manufacture of carbon bodies from coke without auxiliary binder
AT208606B (en) Solid conductor and process for its manufacture
EP3272187B1 (en) Electrode composition
DE2112287B2 (en) Carbon block as cathode for an electrolytic aluminum cell and process for its production
DE1180141B (en) Anode for use in the direct electrolytic reduction of uranium oxides to uranium and process for the production of this anode
DE102016226122A1 (en) Novel cathode block
DE102011001834A1 (en) Novel combined graphitized heterotyped cathode for the recovery of aluminum and its graphitized cathode barrier block
AT210865B (en) Method of making a shaped carbon body
WO2013026674A1 (en) Titanium diboride granules as erosion protection for cathodes
DE202011109452U1 (en) graphite electrode

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20130228

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

DAX Request for extension of the european patent (deleted)
GRAP Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOSNIGR1

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: SGL CFL CE GMBH

INTG Intention to grant announced

Effective date: 20170822

GRAS Grant fee paid

Free format text: ORIGINAL CODE: EPIDOSNIGR3

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

REG Reference to a national code

Ref country code: GB

Ref legal event code: FG4D

Free format text: NOT ENGLISH

REG Reference to a national code

Ref country code: CH

Ref legal event code: EP

REG Reference to a national code

Ref country code: IE

Ref legal event code: FG4D

Free format text: LANGUAGE OF EP DOCUMENT: GERMAN

REG Reference to a national code

Ref country code: DE

Ref legal event code: R096

Ref document number: 502011013724

Country of ref document: DE

Ref country code: AT

Ref legal event code: REF

Ref document number: 969887

Country of ref document: AT

Kind code of ref document: T

Effective date: 20180315

REG Reference to a national code

Ref country code: NL

Ref legal event code: MP

Effective date: 20180214

REG Reference to a national code

Ref country code: NO

Ref legal event code: T2

Effective date: 20180214

REG Reference to a national code

Ref country code: FR

Ref legal event code: PLFP

Year of fee payment: 8

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: NL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: LT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: ES

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: HR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: FI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: CY

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: LV

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: SE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: RS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: GR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180515

Ref country code: BG

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180514

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: IT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: PL

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: EE

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: RO

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

REG Reference to a national code

Ref country code: DE

Ref legal event code: R097

Ref document number: 502011013724

Country of ref document: DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SM

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: SK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: CZ

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: DK

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20181115

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 502011013724

Country of ref document: DE

Owner name: COBEX GMBH, DE

Free format text: FORMER OWNER: SGL CFL CE GMBH, 86405 MEITINGEN, DE

Ref country code: DE

Ref legal event code: R081

Ref document number: 502011013724

Country of ref document: DE

Owner name: TOKAI COBEX GMBH, DE

Free format text: FORMER OWNER: SGL CFL CE GMBH, 86405 MEITINGEN, DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: SI

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

REG Reference to a national code

Ref country code: CH

Ref legal event code: PL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MC

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

Ref country code: LU

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180729

REG Reference to a national code

Ref country code: BE

Ref legal event code: MM

Effective date: 20180731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: CH

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180731

Ref country code: LI

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180731

REG Reference to a national code

Ref country code: IE

Ref legal event code: MM4A

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: BE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180731

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180729

REG Reference to a national code

Ref country code: GB

Ref legal event code: 732E

Free format text: REGISTERED BETWEEN 20190801 AND 20190807

REG Reference to a national code

Ref country code: AT

Ref legal event code: MM01

Ref document number: 969887

Country of ref document: AT

Kind code of ref document: T

Effective date: 20180729

REG Reference to a national code

Ref country code: NO

Ref legal event code: CHAD

Owner name: COBEX GMBH, DE

Ref country code: NO

Ref legal event code: CREP

REG Reference to a national code

Ref country code: NO

Ref legal event code: CREP

Representative=s name: PLOUGMANN VINGTOFT, POSTBOKS 1003 SENTRUM, 0104

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: AT

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180729

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: TR

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: HU

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT; INVALID AB INITIO

Effective date: 20110729

Ref country code: PT

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180214

REG Reference to a national code

Ref country code: DE

Ref legal event code: R081

Ref document number: 502011013724

Country of ref document: DE

Owner name: TOKAI COBEX GMBH, DE

Free format text: FORMER OWNER: COBEX GMBH, 65189 WIESBADEN, DE

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: MK

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20180214

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: IS

Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

Effective date: 20180614

REG Reference to a national code

Ref country code: NO

Ref legal event code: CHAD

Owner name: TOKAI COBEX GMBH, DE

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NO

Payment date: 20230721

Year of fee payment: 13

Ref country code: GB

Payment date: 20230720

Year of fee payment: 13

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20230725

Year of fee payment: 13

Ref country code: DE

Payment date: 20230711

Year of fee payment: 13