EP0009044B1 - Process for obtaining aluminium by electrolysis in a melted bath and electrolytic cell - Google Patents
Process for obtaining aluminium by electrolysis in a melted bath and electrolytic cell Download PDFInfo
- Publication number
- EP0009044B1 EP0009044B1 EP79900193A EP79900193A EP0009044B1 EP 0009044 B1 EP0009044 B1 EP 0009044B1 EP 79900193 A EP79900193 A EP 79900193A EP 79900193 A EP79900193 A EP 79900193A EP 0009044 B1 EP0009044 B1 EP 0009044B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- anode
- electrolysis
- aluminum
- electrolytic cell
- carbon
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25C—PROCESSES FOR THE ELECTROLYTIC PRODUCTION, RECOVERY OR REFINING OF METALS; APPARATUS THEREFOR
- C25C3/00—Electrolytic production, recovery or refining of metals by electrolysis of melts
- C25C3/06—Electrolytic production, recovery or refining of metals by electrolysis of melts of aluminium
Definitions
- the invention relates to a process for the production of aluminum by melt flow electrolysis in an alkali metal and / or alkaline earth metal halide electrolyte consisting predominantly of chlorides, a mixture containing aluminum oxide and carbon being used as the anode.
- the first method is based on the electrolysis of aluminum oxide, which is dissolved in molten cryolite at temperatures of 950-970 ° C. Apart from cryolite, no other salt has been found so far, whose dissolving power for aluminum oxide was sufficient to extract aluminum by electrolysis below 1000 ° C. In the technically operated electrolysis cells, the aluminum oxide content fluctuates between approx. 2 and 8 wt%. If the aluminum oxide content in the cryolite melt is too low, e.g. below 1-2%, the so-called anode effect occurs at the anode, which manifests itself in a multiple increase in cell voltage.
- the anode and cathode are made of carbon.
- the oxygen released from the aluminum oxide decomposition converts with the carbon of the anode to carbon dioxide and carbon monoxide. In the case of prebaked carbon anodes, about 0.43 to 0.50 kg of carbon are consumed per kg of aluminum produced.
- the second method concerns the melt flow electrolysis of aluminum chloride. Since the aluminum chloride sublimes at 183 ° C and is a poor ion conductor, it is usually dissolved in alkali chloride melts. In order to separate the aluminum liquid, one chooses electrolysis temperatures of approx. 700 ° C. Graphite is mainly used as the anode and cathode material. Gaseous chlorine is deposited on the graphite anode.
- Aluminum chloride electrolysis has a number of difficulties.
- the vapor pressure of the aluminum chloride dissolved in the molten salt is relatively high, so that aluminum chloride is also removed from the cell in appreciable amounts when the chlorine gas is extracted.
- With increasing aluminum chloride concentration in the melt the electrical conductivity drops.
- the supply of aluminum chloride, which is produced in gaseous form, into the molten salt is also difficult to accomplish.
- Experience has shown that the aluminum chloride and the molten salt must be free from oxidic impurities, because the decomposition of the oxides consumes carbon of the graphite anodes and thus the resistance is reduced.
- a particular disadvantage is that it has not yet been possible in a simple manner to extract from the aluminum ores, e.g. from bauxite, directly reducing aluminum chloride by reducing chlorination. It has therefore been proposed to first produce pure aluminum oxide by the known Bayer process and then to convert it with chlorine and carbon or phosgene to aluminum chloride and carbon dioxide.
- the process mentioned leads to pure aluminum, but includes an additional process step and is accordingly more complex.
- US Pat. No. 3,798,140 describes the refining electrolysis of an AISi alloy with the deposition of the pure aluminum on the cathode.
- the anode consists of a perforated graphite vessel (located below the cathode), with which the AISi alloy is immersed in the electrolyte and the remaining silicon residues are removed. This arrangement is not suitable for the extraction of aluminum from aluminum oxide, since aluminum cannot be deposited on the cathode due to the anode gases which are produced.
- the object of the present invention is to obtain aluminum from aluminum oxide by melt flow electrolysis using an electrolyte consisting predominantly of chlorides. Not only should the deficiencies described for aluminum chloride electrolysis and aluminum oxide electrolysis be avoided, but also the production of aluminum chloride as a starting material should be avoided.
- the electrolysis can be carried out particularly cheaply if the mixture of aluminum oxide and carbon in a weight ratio of 5-3: 1 is supplied as granules or in pieces during the electrolysis continuously through the anode and with an electrically conductive anode part made of graphite electrical contact.
- the wall of the anode container has a perforated shield towards the cathode.
- the surprising moment of the present invention is that the reducing chlorination of the aluminum oxide in the anode and the electrolytic decomposition of the aluminum chloride formed take place simultaneously in stoichiometric ratios. Despite the very low oxide content in the electrolyte melt, the above-mentioned phenomenon of the anode effect was not observed even when the anodic current density was raised above the normal level.
- the concentration of the intermediate aluminum chloride in the molten salt is at a very low level, so that neither its vapor pressure nor its unfavorable influence on the conductivity of the molten salts can be felt.
- alumina and carbon anode to be used as part of the invention posed several problems, the solution of which was an important task.
- the anode would have to consist of 85% aluminum oxide and 15% carbon if carbon dioxide is formed as the reaction gas in the electrochemical reduction.
- the deposition of carbon monoxide would require an anode with 74% Al 2 O 3 and 26% C.
- the formation of pure carbon monoxide is not possible due to the Boudouard equilibrium at temperatures around 750 ° C, but only a CO z -CO gas mixture with approx. 80% CO.
- the alumina-carbon ratio can be between the limits 5.66: 1 and 3.4: 1.
- the current yield deviating from 100% and a slight air burn-off of the anodes increase the carbon consumption. Under practical electrolysis conditions, a gas containing predominantly C0 2 develops at the anode.
- the weight ratio of A1 2 0 1 to C can fluctuate in the anode in a width of 5: 1 to 3: 1 without this having any noticeable disturbances in the electrolysis process.
- the self-adjusting CO 2 / CO ratio of the anode gas has a regulating effect.
- volume fraction of carbon in the Al 2 O 3 C anode is higher, however, because the true density of the carbon is approx. 2.00 g / cm 3 and that of the aluminum oxide is approx. 3.8 g / cm 3 . This gives a volume fraction of carbon of 32.2% for the stated weight ratio of 4: 1.
- An anode made of aluminum oxide and carbon can be produced, for example, by mixing finely divided aluminum oxide and / or aluminum hydroxide with electrode pitch, shaping it into a body and burning it in the absence of air at a slow heating rate up to about 1000 ° C.
- the fired aluminum oxide carbon anode has a specific electrical resistance of approximately 1000 ⁇ mm z / m.
- a carbon anode such as is used for Al 2 O 3 electrolysis in molten cryolite, has only a resistance of approx. 60 ⁇ mm z / m.
- the Al 2 O 3 -C anode is therefore not suitable for a long current path in the anode.
- the electrical resistance of the graphite electrodes is approx. 10 ⁇ mm z / m and is therefore six times smaller than that of a burned carbon anode.
- the graphite material can be loaded with current densities up to 10 A / cm 2 . If you want to achieve at least anodic current densities of 0.6 to 1.0 A / cm 2 , as are common in Al 2 O 3 electrolysis with carbon anode and cryolite melt, it is sufficient that a conductive cross section of about one is used for electrographite A fifth of the cross section of the Al 2 O 3 -C anode is provided.
- the composite anode made of the Al 2 O 3 -C body and the graphite material can then be similar to a prebaked carbon anode can be loaded without fear of overheating or unfavorable energy consumption.
- the highly conductive graphite material is mainly connected in parallel to the Al 2 O 3 -C body. This can be done, for example, in such a way that the graphite is in the form of a rod or plate in the core of the Al 2 O 3 -C body or comprises the Al 2 O 3 -C body on the outside.
- the auxiliary conductor made of electrographite is not consumed in the electrolysis cell in addition to the Al 2 O 3 -C mass.
- the electrographite can therefore be reused as a carrier material for the A ' 2 0 3- C mass.
- Figure 1 shows a vertical section through an electrolytic cell of simple design with only one vertically suspended cathode plate and two opposite anodes.
- the graphite cathode 1 with the metallic current conductor 2 is arranged in the center of the electrolysis cell.
- the anode consists of three basic elements.
- the first component of the anode is a graphite plate 4 with the threaded bolt 5, via which the electrolysis current is supplied.
- the A ' 2 0 3 -C mass 3 In front of the graphite plate 4 is the A ' 2 0 3 -C mass 3 in lump form.
- the A ' 2 0 3- C mass is charged as briquettes, pellets, tablets or other granules and held by a plate 6.
- it is made of graphite and has horizontal slots.
- the plate 6 embodies a type of diaphragm and has the task of ensuring that on the one hand no particles of the A ' 2 0 3- C mass reach the cathode 1 from the anode space and on the other hand a sufficiently free passage for the electrolyte melt 7 which separates the electrolysis space Fills cathode and anode, is present. Therefore, the plate 6 must either contain an open pore system or appropriate holes or channels.
- the aluminum is deposited in liquid form on the cathode 1. It drips from it and collects at the bottom of the electrolytic cell to bath 8.
- the anode from components 3,4 u. 6 and the rest of the electrolysis room are enclosed in a corrosion-resistant, electrically non-conductive masonry 9.
- the heat protection of the electrolysis cell is guaranteed by the fire-proof insulation 10.
- the batching of the lumpy Al 2 O 3 -C mass can be carried out batchwise or fully continuously using a funnel, adapted to the consumption of the electrolytic cell.
- the three-part anode according to claim 1 can of course be installed in multi-cell electrolysis units.
- FIG. 3 show an exemplary embodiment of a five-cell electrolysis battery. 2 shows a horizontal section at the height EF of FIG. 3 and FIG. 3 shows a vertical section through the CD of FIG. 2.
- 41 graphite cathode
- 42 cathodic current bolts made of metal
- 43 lumpy AI, 0, -C- Mass of the bipolar electrode
- 44 anode made of graphite
- 45 anodic current bolts made of metal
- 46 diaphragm plate of the bipolar electrode
- 47 graphite plate of the bipolar electrode
- 48 melt flow electrolyte
- 49 corrosion-resistant, electrically insulating lining material
- 50 ceramic heat insulation
- 51 steel container
- 52 fl u s-Siges aluminum
- 53 cover of the electrolytic cell
- 54 discharge holes for the exhaust gas.
- the cathode 41, the anode 44 and the bipolar electrodes 47/43/46 are, as can be seen from FIGS. 2 and 3, set loosely in the electrolysis room in the positions provided for this purpose.
- FIGS. 1 to 3 are to be regarded as examples and basic models which allow a variety of construction variants without changing the principle.
- the materials usually used for the cathode are carbon, electrographite, titanium boride, zirconium boride or mixtures thereof.
- FIG. 4 A process diagram for the production of the lumpy feed material from Al 2 O 3 and carbon is shown in FIG. 4.
- the individual process steps are to be considered as examples and can be replaced by similar process units.
- the chamber shaft furnace can be replaced by a tunnel furnace. If the flow diagram in FIG. 4 is compared with the preparation courses of the raw and auxiliary materials of the two known electrolysis processes mentioned at the outset, the process according to the invention has significant apparatus and energy-saving advantages.
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)
Abstract
Description
Die Erfindung betrifft ein Verfahren zur Gewinnung von Aluminium durch Schmelzflußelektrolyse in einem überwiegend aus Chloriden bestehenden Alkali- und/oder Erdalkalihalogenide-Elektrolyten, wobei als Anode ein Gemisch, enthaltend Aluminiumoxid und Kohlenstoff, verwendet wird.The invention relates to a process for the production of aluminum by melt flow electrolysis in an alkali metal and / or alkaline earth metal halide electrolyte consisting predominantly of chlorides, a mixture containing aluminum oxide and carbon being used as the anode.
Es sind im wesentlichen zwei Verfahren zur Schmelzflußelektrolytischen Gewinnung von Aluminium bekannt.There are essentially two methods known for the melt flow electrolytic extraction of aluminum.
Das erste Verfahren beruht auf der Elektrolyse von Aluminiumoxid, das in geschmolzenem Kryolith bei Temperaturen von 950-970°C gelöst wird. Außer Kryolith ist bislang kein anderes Salz gefunden worden, dessen Lösungsvermögen für Aluminiumoxid ausreichte, um damit unterhalb 1000°C Aluminium durch Elektrolyse zu gewinnen. In den technisch Betriebenen Elektrolysezellen schwankt der Aluminiumoxidgehalt zwischen rd. 2 und 8 Gew.-%. Bei zu niedrigen Aluminiumoxidgehalten in der Kryolithschmelze, z.B. unter 1-2%, tritt an der Anode der sogenannte Anodeneffekt auf, der sich in einer mehrfach erhöhten Zellenspannung äußert. Die Anode und Kathode bestehen aus Kohlenstoff. Der aus der Aluminiumoxidzersetzung freiwerdende Sauerstoff setzt sich mit dem Kohlenstoff der Anode zu Kohlendioxid und Kohlenmonoxid um. Dabei werden im Falle vorgebrannter Kohlenstoffanoden etwa 0,43 bis 0,50 kg Kohlenstoff pro kg erzeugtes Aluminium verbraucht.The first method is based on the electrolysis of aluminum oxide, which is dissolved in molten cryolite at temperatures of 950-970 ° C. Apart from cryolite, no other salt has been found so far, whose dissolving power for aluminum oxide was sufficient to extract aluminum by electrolysis below 1000 ° C. In the technically operated electrolysis cells, the aluminum oxide content fluctuates between approx. 2 and 8 wt%. If the aluminum oxide content in the cryolite melt is too low, e.g. below 1-2%, the so-called anode effect occurs at the anode, which manifests itself in a multiple increase in cell voltage. The anode and cathode are made of carbon. The oxygen released from the aluminum oxide decomposition converts with the carbon of the anode to carbon dioxide and carbon monoxide. In the case of prebaked carbon anodes, about 0.43 to 0.50 kg of carbon are consumed per kg of aluminum produced.
Das zweite Verfahren betrifft die Schmelzflußelektrolyse von Aluminiumchlorid. Da das Aluminiumchlorid bei 183°C sublimiert und ein schlechter lonenleiter ist, wird es gewöhnlich in Alkalichloridschmelzen gelöst. Um das Aluminium flüssig abzuscheiden, wählt man Elektrolysetemperaturen von ca. 700°C. Als Anoden- und Kathodenmaterial wird hauptsächlich Grafit verwendet. An der Grafitanode wird gasförmiges Chlor abgeschieden.The second method concerns the melt flow electrolysis of aluminum chloride. Since the aluminum chloride sublimes at 183 ° C and is a poor ion conductor, it is usually dissolved in alkali chloride melts. In order to separate the aluminum liquid, one chooses electrolysis temperatures of approx. 700 ° C. Graphite is mainly used as the anode and cathode material. Gaseous chlorine is deposited on the graphite anode.
Die Aluminiumchloridelektrolyse ist mit einer Reihe von Schwierigkeiten behaftet. Zunächst bedeutet die Erfassung und Ableitung des an der Anode entwickelten gasförmigen Chlors bei ca. 700°C ein werkstofftechnisches Problem. Der Dampfdruck des in der Salzschmelze gelösten Aluminiumchlorids ist relativ hoch, so daß bei der Absaugung des Chlorgases auch Aluminiumchlorid in merklichen Mengen aus der Zelle entfernt wird. Mit zunehmender Aluminiumchloridkonzentration in der Schmelze fällt die elektrische Leitfähigkeit ab. Die Zufuhr von Aluminiumchlorid, das gasförmig anfällt, in die Salzschmelze ist ebenfalls schwierig zu bewerkstelligen. Das Aluminiumchlorid und die Salzschmelze müssen erfahrungsgemäß frei sein von oxidischen Verunreinigungen, denn infolge der Zersetzung der Oxide wird Kohlenstoff der Grafitanoden verbraucht und damit die Beständigkeit herabgesetzt. Ein besonderer Nachteil ist es jedoch, daß es bisher nicht in einfacher Weise gelungen ist, aus den Aluminiumerzen, z.B. aus Bauxit, durch reduzierende Chlorierung direkt reines Aluminiumchlorid herzustellen. Es ist deshalb vorgeschlagen worden, zunächst nach dem bekannten Bayer-Prozeß reines Aluminiumoxid zu erzeugen und dieses anschließend mit Chlor und Kohlenstoff bzw. Phosgen zu Aluminiumchlorid und Kohlendioxid umzusetzen.Aluminum chloride electrolysis has a number of difficulties. First of all, the detection and dissipation of the gaseous chlorine developed at the anode at approx. 700 ° C poses a technical problem. The vapor pressure of the aluminum chloride dissolved in the molten salt is relatively high, so that aluminum chloride is also removed from the cell in appreciable amounts when the chlorine gas is extracted. With increasing aluminum chloride concentration in the melt, the electrical conductivity drops. The supply of aluminum chloride, which is produced in gaseous form, into the molten salt is also difficult to accomplish. Experience has shown that the aluminum chloride and the molten salt must be free from oxidic impurities, because the decomposition of the oxides consumes carbon of the graphite anodes and thus the resistance is reduced. A particular disadvantage, however, is that it has not yet been possible in a simple manner to extract from the aluminum ores, e.g. from bauxite, directly reducing aluminum chloride by reducing chlorination. It has therefore been proposed to first produce pure aluminum oxide by the known Bayer process and then to convert it with chlorine and carbon or phosgene to aluminum chloride and carbon dioxide.
Der genannte Verfahrensweg führt zwar zu reinem Aluminium, beinhaltet aber eine zusätzliche Verfahrensstufe und ist dementsprechend aufwendiger.The process mentioned leads to pure aluminum, but includes an additional process step and is accordingly more complex.
Zur Durchführung der Aluminiumchloridelektrolyse sind mehrere Verfahrungsvorschläge gemacht worden.Several process proposals have been made for carrying out the aluminum chloride electrolysis.
Nach dem Handbuch der technischen Elektrochemie von Georg Eger, Leipzig 1955, Akad. Verlagsges. Band 3, 2. Auflage, Seiten 66 und 67 ist ein Verfahren zur Gewinnung von Aluminium durch Schmelzflußelektrolyse bekannt, wobei als Anode ein kompakter Körper, bestehend aus einer tonerdehaltigen Kohleelektrode, verwendet wird. Da von der tonerdehaltigen Elektrode bisweilen kleine Stücke abbröckeln, sollen die Elektroden mit einem porösen Behälter zum Auffangen dieser Stücke umgeben werden.According to the manual of technical electrochemistry by Georg Eger, Leipzig 1955, Akad. Verlagsges.
In der GB-PS 16,794 wird ein Elektrolyseverfahren beschrieben, bei dem als aluminiumenthaltender Rohstoff ein stückiges Gemisch aus All03 und Kohlenstoff durch die Anode zugeführt wird, wobei sich das Gemisch in unmittelbarer Nähe oder an er Kohlenstoffanode befindet.In GB-PS 16.794 an electrolysis method is described in which, and carbon is supplied through the anode and aluminum-containing raw material a lumpy mixture of Al l 0 3, wherein the mixture is in close proximity or on he carbon anode.
Bei diesem bekannten Verfahren wird durch Elektrolyse Chlor an der Anode ausgeschieden, das sich anschließend durch eine chemische Reaktion mit dem AI203/Kohlenstoffgemisch zu AICI3 umsetzt. Diese Verfahrensweise über die Herstellung von Zwischenprodukten bringt gewisse Nachteile mit sich, die mit der Chlorabscheidung zusammenhängen. Es muß nämlich eine absolut gasdichte Zelle entwickelt werden und eine Retorte oberhalb der Zelle zur Umsetzung des Chlors mit dem Oxid-Kohlenstoff-Gemisch installiert werden.In this known method, chlorine is excreted at the anode by electrolysis, which is then converted into AICI 3 by a chemical reaction with the Al 2 O 3 / carbon mixture. This procedure for the production of intermediates has certain disadvantages associated with chlorine separation. An absolutely gastight cell has to be developed and a retort has to be installed above the cell to react the chlorine with the oxide-carbon mixture.
In der US-PS 3,798,140 ist die Raffinationselektrolyse einer AISi-Legierung unter Abscheidung des reinen Aluminiums an der Kathode beschrieben. Die Anode besteht aus einem (unterhalb der Kathode angeordneten) perforierten Grafitgefäß, mit dem die AISi-Legierung in den Elektrolyten eingetaucht und die zurückbleibenden Siliziumreste herausgenommen werden. Zur Gewinnung von Aluminium aus Aluminiumoxid ist diese Anordnung nicht geeignet, da wegen der entstehenden Anodengase Aluminium an der Kathode nicht abgeschieden werden kann.US Pat. No. 3,798,140 describes the refining electrolysis of an AISi alloy with the deposition of the pure aluminum on the cathode. The anode consists of a perforated graphite vessel (located below the cathode), with which the AISi alloy is immersed in the electrolyte and the remaining silicon residues are removed. This arrangement is not suitable for the extraction of aluminum from aluminum oxide, since aluminum cannot be deposited on the cathode due to the anode gases which are produced.
Aufgabe der vorliegenden Erfindung ist es, Aluminium aus Aluminiumoxid durch Schmelzflußelektrolyse unter Verwendung eines überweigend aus Chloriden bestehenden Elektrolyten zu gewinnen. Dabei sollen nicht nur die für die Aluminiumchloridelektrolyse und Aluminiumoxidelektrolyse beschriebenen Mängel vermieden, sondern außerdem noch auf die Herstellung von aluminiumchlorid als Ausgangsmaterial verzichtet werden.The object of the present invention is to obtain aluminum from aluminum oxide by melt flow electrolysis using an electrolyte consisting predominantly of chlorides. Not only should the deficiencies described for aluminum chloride electrolysis and aluminum oxide electrolysis be avoided, but also the production of aluminum chloride as a starting material should be avoided.
Es wurde gefunden, daß die Elektrolyse sich dann besonders günstig durchführen läßt, wenn das Gemisch aus Aluminiumoxid und Kohlenstoff im Gewichtsverhältnis 5-3:1 als Granulat oder stückig während der Elektrolyse kontinuierlich durch die Anode zugeführt wird und mit einem elektrisch leitenden Anodenteil aus Grafit in elektrischem Kontakt steht. Zur Durchführung des Verfahrens ist es vorteilhaft, wenn die Wand des Anodenbehälters zur Kathode hin eine perforierte Abschirmung aufweist.It has been found that the electrolysis can be carried out particularly cheaply if the mixture of aluminum oxide and carbon in a weight ratio of 5-3: 1 is supplied as granules or in pieces during the electrolysis continuously through the anode and with an electrically conductive anode part made of graphite electrical contact. To carry out the method, it is advantageous if the wall of the anode container has a perforated shield towards the cathode.
Das überraschende Moment der vorliegenden Erfindung ist, daß die reduzierende Chlorierung des Aluminiumoxids in der Anode und die elektrolytische Zerlegung des gebildeten Aluminiumchlorids gleichzeitig in stöchiometrischen Verhältnissen ablaufen. Trotz recht geringen Oxidgehalts in der Elektrolytschmelze wurde auch bei einer über das Normalmaß angehobenen anodischen Stromdichte das eingangs erwähnte Phänomen des Anodeneffekts nicht beobachtet.The surprising moment of the present invention is that the reducing chlorination of the aluminum oxide in the anode and the electrolytic decomposition of the aluminum chloride formed take place simultaneously in stoichiometric ratios. Despite the very low oxide content in the electrolyte melt, the above-mentioned phenomenon of the anode effect was not observed even when the anodic current density was raised above the normal level.
Im Vergleich zu den beiden bekannten Elektrolyseverfahren, der AlCl3-Elektrolyse und der Al2O3-Elektrolyse in Kryolith, lassen sich für das erfindungsgemäße Verfahren folgende Vorteile aufzeigen: Die Handhabung und der Transport von Chlor und Aluminiumchlorid entfallen. Der Aufwand für die Apparate und Einrichtungen ist deshalb beachtlich kleiner. Chlor ist ein sehr korrosives Gas, insbesondere wenn es bei ca. 700°C in der AICl3-Eletrolysezelle aufgefangen werden muß. Aluminiumchlorid ist hygroskopisch, wird durch Luftfeuchtigkeit hydrolytisch in Hydroxid und Salzsäure gespalten und beansprucht als Sublimat viel Raum. Der Umgang mit Aluminiumchlorid und Chlor erfordert geschlossene, korrosionsbeständige Apparaturen. Daraus resultieren größere Investitions-, Betriebs- und Reparaturkosten.In comparison to the two known electrolysis processes, AlCl 3 electrolysis and Al 2 O 3 electrolysis in cryolite, the following advantages can be demonstrated for the process according to the invention: The handling and transportation of chlorine and aluminum chloride are eliminated. The outlay for the apparatus and equipment is therefore considerably less. Chlorine is a very corrosive gas, especially if it has to be collected in the AICl 3 electrolytic cell at approx. 700 ° C. Aluminum chloride is hygroscopic, is hydrolytically split into hydroxide and hydrochloric acid by air humidity and, as a sublimate, takes up a lot of space. Handling aluminum chloride and chlorine requires closed, corrosion-resistant equipment. This results in higher investment, operating and repair costs.
Ferner befindet sich die Konzentration des als Zwischenprodukt auftretenden Aluminiumchlorids in der Salzschmelze auf einem sehr niedrigen Niveau, so daß weder sein Dampfdruck noch seine ungünstige Beeinflussung der Leitfähigkeit der geschmolzenen Salze spürbar werden.Furthermore, the concentration of the intermediate aluminum chloride in the molten salt is at a very low level, so that neither its vapor pressure nor its unfavorable influence on the conductivity of the molten salts can be felt.
Die als Teil der Erfindung zu verwendene Anode aus Aluminiumoxid und Kohlenstoff warf einige Probleme auf, deren Lösung eine wichtige Aufgabe war.The alumina and carbon anode to be used as part of the invention posed several problems, the solution of which was an important task.
Die Anode müßte theoretisch aus 85% Aluminiumoxid und 15% Kohlenstoff bestehen, wenn bei der elektrochemischen Reduktion als Reaktionsgas Kohlendioxid gebildet wird. Die Abscheidung von Kohlenmonoxid würde eine Anode mit 74% Al2O3 und 26% C voraussetzen. Die Entstehung von reinem Kohlenmonoxid ist jedoch aufgrund des Boudouard-Gleichgewichtes bei Temperaturen um 750°C nicht möglich, sondern nur ein COz-CO-Gasgemisch mit rd. 80% CO. Theoretisch kann also das Aluminiumoxid-Kohlenstoff-Verhältnis zwischen den Grenzen 5,66:1 und 3,4:1 liegen. Die von 100% abweichende Stromausbeute und ein geringfügiger Luftabbrand der Anoden erhöhen den Kohlenstoffverbrauch. Unter praktischen Elektrolysebedingungen entwickelt sich an der Anode ein überwiegend C02 enthaltendes Gas. Das Gewichtsverhältnis von A1201 zu C kann in der Anode in einer Breite von 5:1 bis 3:1 schwanken, ohne daß sich dadurch gravierende Störungen des Elektrolyseablaufs bemerkbar machen. Das sich selbst einstellende CO2/CO-Verhältnis des Anodengases hat einen regulierenden Effekt. In den durchgeführten Versuchen wurde eine brauchbare Zusammensetzung der Anode aus 80 Gew.-% Al2O3 und 20 Gew.-% C, d.h. ein Gewichtsverhältnis von 4:1 angestrebt.Theoretically, the anode would have to consist of 85% aluminum oxide and 15% carbon if carbon dioxide is formed as the reaction gas in the electrochemical reduction. The deposition of carbon monoxide would require an anode with 74% Al 2 O 3 and 26% C. The formation of pure carbon monoxide is not possible due to the Boudouard equilibrium at temperatures around 750 ° C, but only a CO z -CO gas mixture with approx. 80% CO. Theoretically, the alumina-carbon ratio can be between the limits 5.66: 1 and 3.4: 1. The current yield deviating from 100% and a slight air burn-off of the anodes increase the carbon consumption. Under practical electrolysis conditions, a gas containing predominantly C0 2 develops at the anode. The weight ratio of A1 2 0 1 to C can fluctuate in the anode in a width of 5: 1 to 3: 1 without this having any noticeable disturbances in the electrolysis process. The self-adjusting CO 2 / CO ratio of the anode gas has a regulating effect. In the tests carried out, a usable composition of the anode of 80% by weight Al 2 O 3 and 20% by weight C, ie a weight ratio of 4: 1, was aimed for.
Der Volumenanteil des Kohlenstoffs in der Al2O3-C-Anode ist allerdings höher, weil die wahre Dichte des Kohlenstoffs ca. 2,00 g/cm3 und die des Aluminiumoxids ca. 3,8 g/cm3 betragt. Daraus errechnet sich für das angegebere Gewichtsverhältnis von 4:1 ein Volumenanteil des Kohlenstoffs von 32,2%.The volume fraction of carbon in the Al 2 O 3 C anode is higher, however, because the true density of the carbon is approx. 2.00 g / cm 3 and that of the aluminum oxide is approx. 3.8 g / cm 3 . This gives a volume fraction of carbon of 32.2% for the stated weight ratio of 4: 1.
Eine Anode aus Aluminiumoxid und Kohlenstoff läßt sich zum Beispiel in der Weise herstellen, daß man feinteiliges Aluminiumoxid und/oder Aluminiumhydroxid mit Elektrodenpech mischt, zu einem Körper formt und unter Luftabschluß mit langsamer Aufheizgeschwindigkeit bis etwa 1000°C brennt. Die gebrannte Aluminiumoxid - Kohlenstoff - Anode weist einen spezifischen elektrischen Widerstand von etwa 1000 Ω mmz/m auf.An anode made of aluminum oxide and carbon can be produced, for example, by mixing finely divided aluminum oxide and / or aluminum hydroxide with electrode pitch, shaping it into a body and burning it in the absence of air at a slow heating rate up to about 1000 ° C. The fired aluminum oxide carbon anode has a specific electrical resistance of approximately 1000 Ω mm z / m.
Eine Kohlenstoffanode, wie sie für die Al2O3-Elektrolyse in geschmolzenem Kryolith verwendet wird, hat nur einen Widerstand von ca. 60 Ω mmz/m. Die Al2O3-C-Anode ist deshalb für einen langen Stromweg in der Anode nicht geeignet. Um den Spannungsabfall in der Al2O3-C-Anode möglichst niedrig zu halten, ist es für das erfindungsgemäße Verfahren zweckdienlich, die A1201-C-Anode mit einem Hilfsleiter aus Elektrografit zu kombinieren. Der elektrische Widerstand der Grafitelektroden liegt bei rd. 10 Ω mmz/m und ist somit sechsmal kleiner als der einer gebrannten Kohlenstoffanode. Das Grafitmaterial kann mit Stromdichten bis zu 10 A/cm2 beaufschlagt werden. Will man zumindest anodische Stromdichten von 0,6 bis 1,0 A/cm2 erzielen, wie sie in der Al2O3-Elektrolyse mit Kohlenstoffanode und Kryolithschmelze üblich sind, so genügt es, daß für den Elektrografit ein leitender Querschnitt von etwa einem Fünftel des Querschnitts der Al2O3-C-Anode vorgesehen wird. Die Verbundanode aus dem Al2O3-C-Körper und dem Grafitmaterial kann dann ähnlich wie eine vorgebrannte Kohlenstoffanode belastet werden, ohne eine Überhitzung oder einen ungünstigen Energieverbrauch befürchten zu müssen. Der gut leitende Grafitwerkstoff wird dem Al2O3-C-Körper hauptsächlich parallel geschaltet. Das kann z.B. in der Art geschehen, daß sich der Grafit in Stab- oder Plattenform im Kern des Al2O3-C-Körpers befindet oder den Al2O3-C-Körper außen umfaßt.A carbon anode, such as is used for Al 2 O 3 electrolysis in molten cryolite, has only a resistance of approx. 60 Ω mm z / m. The Al 2 O 3 -C anode is therefore not suitable for a long current path in the anode. In order to keep the voltage drop in the Al 2 O 3 C anode as low as possible, it is expedient for the method according to the invention to combine the A1 2 0 1 C anode with an auxiliary conductor made of electrographite. The electrical resistance of the graphite electrodes is approx. 10 Ω mm z / m and is therefore six times smaller than that of a burned carbon anode. The graphite material can be loaded with current densities up to 10 A / cm 2 . If you want to achieve at least anodic current densities of 0.6 to 1.0 A / cm 2 , as are common in Al 2 O 3 electrolysis with carbon anode and cryolite melt, it is sufficient that a conductive cross section of about one is used for electrographite A fifth of the cross section of the Al 2 O 3 -C anode is provided. The composite anode made of the Al 2 O 3 -C body and the graphite material can then be similar to a prebaked carbon anode can be loaded without fear of overheating or unfavorable energy consumption. The highly conductive graphite material is mainly connected in parallel to the Al 2 O 3 -C body. This can be done, for example, in such a way that the graphite is in the form of a rod or plate in the core of the Al 2 O 3 -C body or comprises the Al 2 O 3 -C body on the outside.
Es hat sich nun überraschenderweise herausgestellt, daß der Hilfsleiter aus Elektrografit neben der Al2O3-C-Masse in der Elektrolysezelle nicht verbraucht wird. Der Elektrografit kann deshalb als Trägermaterial für die A'203-C-Masse wiederverwendet werden.It has now surprisingly been found that the auxiliary conductor made of electrographite is not consumed in the electrolysis cell in addition to the Al 2 O 3 -C mass. The electrographite can therefore be reused as a carrier material for the A ' 2 0 3- C mass.
Nachem die Grundzüge des erfindungsgemäßen Verfahrens dargestellt wurden, sollen drei nach diesem Prinzip arbeitende Elektrolyseeinheiten beschrieben werden.After the basic features of the method according to the invention have been presented, three electrolysis units operating on this principle will be described.
Figur 1 zeigt einen Vertikalschnitt durch eine Elektrolysezelle einfacher Ausführung mit nur einer senkrecht eingehängten Kathodenplatte und zwei gegenüberliegenden Anoden. In der Mitte der Elektrolysezelle ist die Kathode 1 aus Grafit mit dem metallischen Stromleiter 2 angeordnet. Die Anode setzt sich aus drei Grundelementen zusammen. Der erste Bestandteil der Anode ist eine Grafitplatte 4 mit dem Gewindebolzen 5, über den der Elektrolysestrom zugeführt wird. Vor der Grafitplatte 4 befindet sich die A'203-C-Masse 3 in stückiger Form. Die A'203-C-Masse wird als Briketts, Pellets, Tabletten oder als sonstiges Granulat chargiert und von einer Platte 6 gehalten. Sie besteht in diesem Beispiel aus Grafit und ist mit Horizontalschlitzen versehen. Aber auch andere Werkstoffe, insbesondere Sinterkorund, Zirkoniumoxid und Sintermagnesia sind für die Fertigung der Platte 6 geeignet. Die Platte 6 verkörpert eine Art Diaphragm und hat die Aufgabe zu erfüllen, daß einerseits keine Teilchen der A'203-C-Masse aus dem Anodenraum zur Kathode 1 gelangen und andererseits ein ausreichend freier Durchgang für die Elektrolytschmelze 7, die den Elektrolyseraum zwischen Kathode und Anode ausfüllt, vorhanden ist. Deshalb muß die Platte 6 entweder ein offenes Porensystem oder zweckentsprechende Löcher oder Kanäle enthalten. An der Kathode 1 wird das Aluminium flüssig abgeschieden. Es tropft von ihr ab und sammelt sich am Boden der Elektrolysezelle zu dem Bad 8.Figure 1 shows a vertical section through an electrolytic cell of simple design with only one vertically suspended cathode plate and two opposite anodes. The
Die Anode aus den Bestandteilen 3,4 u. 6 sowie der übrige Elektrolyseraum sind eingefaßt in ein korrosionsbeständiges, elektrisch nicht leitendes Mauerwerk 9. Der Wärmeschutz der Elektrolysezelle wird durch die feuerfeste Isolierung 10 gewährliestet.The anode from
Die Chargierung der stückigen Al2O3-C-Masse kann, dem Verbrauch der Elektrolysezelle angepaßt, satzweise oder vollkontinuierlich über einen Trichter erfolgen.The batching of the lumpy Al 2 O 3 -C mass can be carried out batchwise or fully continuously using a funnel, adapted to the consumption of the electrolytic cell.
Die dreiteilige Anode nach Anspruch 1 läßt sich selbstverständlich in mehrzellige Elektrolyseaggregate einbauen.The three-part anode according to
Das erfindungsgemäße Verfahren gestattet es auch, Elektrolysebatterien mit Bipolarelektroden zu betreiben. Figur 2 u. 3 zeigen ein Ausführungsbeispiel für eine fünfzellige Elektrolysebatterie. Dabei stellt Figur 2 einen Horizontalschnitt in Höhe EF der Figur 3 und Figur 3 einen Vertikalschnitt durch CD der Figur 2 dar. Es bezeichnen im einzelnen: 41=Grafitkathode, 42=kathodische Strombolzen aus Metall, 43=stückige AI,0,-C-Masse der Bipolarelektrode, 44=Anode aus Grafit, 45=anodische Strombolzen aus Metall, 46=diaphragmaplatte der Bipolarelektrode, 47=Grafitplatte der Bipolarelektrode, 48=Schmelzflußelektrolyt, 49=korrosionsbeständiges, elektrisch isolierendes Auskleidungsmaterial, 50=keramische Wärmeisolation, 51=Stahlbehälter, 52=flüs-siges Aluminium, 53=Abdeckung der Elektrolysezelle, 54=Austrittslöcher für Abgas.The method according to the invention also allows electrolysis batteries to be operated with bipolar electrodes. Figure 2 u. 3 show an exemplary embodiment of a five-cell electrolysis battery. 2 shows a horizontal section at the height EF of FIG. 3 and FIG. 3 shows a vertical section through the CD of FIG. 2. Specifically: 41 = graphite cathode, 42 = cathodic current bolts made of metal, 43 = lumpy AI, 0, -C- Mass of the bipolar electrode, 44 = anode made of graphite, 45 = anodic current bolts made of metal, 46 = diaphragm plate of the bipolar electrode, 47 = graphite plate of the bipolar electrode, 48 = melt flow electrolyte, 49 = corrosion-resistant, electrically insulating lining material, 50 = ceramic heat insulation, 51 = steel container, 52 = fl u s-Siges aluminum, 53 = cover of the electrolytic cell, 54 = discharge holes for the exhaust gas.
Die Kathode 41, die Anode 44 und die Bipolarelektroden 47/43/46 werden, wie aus Figur 2 und 3 erkennbar ist, lose in den Elektrolyseraum in die dafür vorgesehenen Positionen eingestellt.The
Die in den Figuren 1 bis 3 beschriebenen Elektrolysezellen sind als Beispiele und Basismodelle zu betrachten, die ohne Änderung des Prinzips mannigfaltige Konstruktionsvarianten erlauben.The electrolysis cells described in FIGS. 1 to 3 are to be regarded as examples and basic models which allow a variety of construction variants without changing the principle.
Die üblicherweise für die Kathode verwendeten Werkstoffe sind Kohlenstoff, Elektrografit, Titanborid, Zirkoniumborid oder Gemische derselben.The materials usually used for the cathode are carbon, electrographite, titanium boride, zirconium boride or mixtures thereof.
Ein Verfahrensschema zur Herstellung des stückigen Aufgabegutes aus Al2O3 und Kohlenstoff ist in Figur 4 dargestellt. Die einzelnen Verfahrensschritte sind als Beispiele zu betrachten und durch ähnliche Verfahrenseinheiten ersetzbar. So kann beispielsweise der Kammerschachtofen durch einen Tunnelofen ersetzt werden. Vergleicht man das Fließbild in Figur 4 mit den Vorbereitungsgängen der Roh- und Hilfsstoffe der beiden eingangs erwähnten bekannten Elektrolyseprozesse, so weist das erfindungsgemäße Verfahren bedeutende apparative und energiesparende Vorteile auf.A process diagram for the production of the lumpy feed material from Al 2 O 3 and carbon is shown in FIG. 4. The individual process steps are to be considered as examples and can be replaced by similar process units. For example, the chamber shaft furnace can be replaced by a tunnel furnace. If the flow diagram in FIG. 4 is compared with the preparation courses of the raw and auxiliary materials of the two known electrolysis processes mentioned at the outset, the process according to the invention has significant apparatus and energy-saving advantages.
Claims (4)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE2805374A DE2805374C2 (en) | 1978-02-09 | 1978-02-09 | Process for the production of aluminum by molten electrolysis |
DE2805374 | 1978-02-09 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0009044A1 EP0009044A1 (en) | 1980-04-02 |
EP0009044B1 true EP0009044B1 (en) | 1983-03-09 |
Family
ID=6031475
Family Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP79100362A Expired EP0003598B1 (en) | 1978-02-09 | 1979-02-08 | Process for the production of aluminium by electrolysis of fused salts |
EP79900193A Expired EP0009044B1 (en) | 1978-02-09 | 1979-08-13 | Process for obtaining aluminium by electrolysis in a melted bath and electrolytic cell |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP79100362A Expired EP0003598B1 (en) | 1978-02-09 | 1979-02-08 | Process for the production of aluminium by electrolysis of fused salts |
Country Status (12)
Country | Link |
---|---|
US (1) | US4919771A (en) |
EP (2) | EP0003598B1 (en) |
JP (1) | JPS55500203A (en) |
AT (1) | AT375409B (en) |
AU (1) | AU523266B2 (en) |
CA (1) | CA1151099A (en) |
DD (1) | DD142061A5 (en) |
DE (1) | DE2805374C2 (en) |
ES (2) | ES477525A1 (en) |
GR (1) | GR64827B (en) |
NO (1) | NO790412L (en) |
WO (1) | WO1979000606A1 (en) |
Families Citing this family (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4342637A (en) * | 1979-07-30 | 1982-08-03 | Metallurgical, Inc. | Composite anode for the electrolytic deposition of aluminum |
NZ193092A (en) * | 1979-06-27 | 1983-09-30 | Pora Inc | Electrode for the deposition of aluminium from a molten electrolyte |
US4409083A (en) * | 1980-02-06 | 1983-10-11 | Metallurgical, Inc. | Cell with composite anode for electrolytic production of magnesium |
US4354918A (en) * | 1981-01-14 | 1982-10-19 | Martin Marietta Corporation | Anode stud coatings for electrolytic cells |
JPS57120682A (en) * | 1981-01-16 | 1982-07-27 | Mitsui Alum Kogyo Kk | Production of aluminum |
WO1983000171A1 (en) * | 1981-07-01 | 1983-01-20 | De Nora, Vittorio | Electrolytic production of aluminum |
US4595466A (en) * | 1985-03-07 | 1986-06-17 | Atlantic Richfield Company | Metal electrolysis using a low temperature bath |
DE4118304A1 (en) * | 1991-06-04 | 1992-12-24 | Vaw Ver Aluminium Werke Ag | ELECTROLYSIS CELL FOR ALUMINUM EFFICIENCY |
US5651874A (en) | 1993-05-28 | 1997-07-29 | Moltech Invent S.A. | Method for production of aluminum utilizing protected carbon-containing components |
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 |
US5310476A (en) | 1992-04-01 | 1994-05-10 | Moltech Invent S.A. | Application of refractory protective coatings, particularly on the surface of electrolytic cell components |
US5413689A (en) * | 1992-06-12 | 1995-05-09 | Moltech Invent S.A. | Carbon containing body or mass useful as cell component |
CA2122364A1 (en) * | 1992-08-04 | 1994-02-17 | Alexei A. Marakushev | Method of producing aluminum from aluminous raw material |
US5397450A (en) * | 1993-03-22 | 1995-03-14 | Moltech Invent S.A. | Carbon-based bodies in particular for use in aluminium production cells |
US5679224A (en) * | 1993-11-23 | 1997-10-21 | Moltech Invent S.A. | Treated carbon or carbon-based cathodic components of aluminum production cells |
EP1146146B1 (en) | 1994-09-08 | 2003-10-29 | MOLTECH Invent S.A. | Horizontal drained cathode surface with recessed grooves for aluminium electrowinning |
US5753163A (en) | 1995-08-28 | 1998-05-19 | Moltech. Invent S.A. | Production of bodies of refractory borides |
US9903035B2 (en) | 2012-12-03 | 2018-02-27 | The Regents Of The University Of California | Devices, systems and methods for coating surfaces |
FR3016894B1 (en) * | 2014-01-27 | 2017-09-01 | Rio Tinto Alcan Int Ltd | ELECTROLYSIS TANK HAVING AN ANODIC ASSEMBLY CONTAINED IN A CONFINEMENT ENCLOSURE |
JP7333223B2 (en) * | 2019-07-30 | 2023-08-24 | 東邦チタニウム株式会社 | Molten salt electrolytic cell, method for forming molten salt solidified layer, method for manufacturing metal |
Family Cites Families (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US503929A (en) * | 1893-08-22 | Method of producing aluminum | ||
GB309605A (en) * | 1928-04-14 | 1930-07-14 | Ig Farbenindustrie Ag | Process and apparatus for the electrolysis of molten substances |
GB483068A (en) * | 1935-09-27 | 1938-04-07 | Magall Ag | Improvements in or relating to the production of magnesium and other alkali earth metals by electrolysis of fused electrolytes |
GB511076A (en) * | 1937-03-16 | 1939-08-14 | Verwertung Chemisch Tech Verfa | Improvements in or relating to processes for the manufacture of anodes for use in the production of aluminium, beryllium, magnesium, or alkali earth metals by electrolysis of fused starting materials |
US3009863A (en) * | 1957-04-24 | 1961-11-21 | Aluminum Co Of America | Methods for thermally processing carbon articles |
AU427351B1 (en) * | 1966-05-23 | 1972-08-23 | Comalco Aluminium Chell Bay) Limited And Universityof Tasmania | Anodes forthe electrolytic production of aluminium and aluminium alloys |
US3798140A (en) * | 1973-02-01 | 1974-03-19 | Us Interior | Process for producing aluminum and silicon from aluminum silicon alloys |
CH615463A5 (en) * | 1975-05-30 | 1980-01-31 | Alusuisse | |
AU506485B2 (en) * | 1976-06-09 | 1980-01-03 | National Research Development Corp. | Packed, bed electrorefining |
US4115215A (en) * | 1976-09-22 | 1978-09-19 | Aluminum Company Of America | Aluminum purification |
DE2721038C3 (en) * | 1977-05-10 | 1980-03-13 | Nippon Light Metal Co. Ltd., Tokio | Process for the electrolytic production of aluminum |
-
1978
- 1978-02-09 DE DE2805374A patent/DE2805374C2/en not_active Expired
-
1979
- 1979-01-17 GR GR58118A patent/GR64827B/en unknown
- 1979-01-19 AT AT0039079A patent/AT375409B/en not_active IP Right Cessation
- 1979-01-24 JP JP50041079A patent/JPS55500203A/ja active Pending
- 1979-01-24 WO PCT/DE1979/000007 patent/WO1979000606A1/en unknown
- 1979-01-24 US US06/143,139 patent/US4919771A/en not_active Expired - Lifetime
- 1979-02-07 ES ES477525A patent/ES477525A1/en not_active Expired
- 1979-02-07 ES ES477521A patent/ES477521A1/en not_active Expired
- 1979-02-07 DD DD79210877A patent/DD142061A5/en unknown
- 1979-02-08 EP EP79100362A patent/EP0003598B1/en not_active Expired
- 1979-02-08 AU AU44087/79A patent/AU523266B2/en not_active Ceased
- 1979-02-08 NO NO790412A patent/NO790412L/en unknown
- 1979-02-09 CA CA000321165A patent/CA1151099A/en not_active Expired
- 1979-08-13 EP EP79900193A patent/EP0009044B1/en not_active Expired
Non-Patent Citations (1)
Title |
---|
Handbuch der technischen Elektrochemie, Georg Eger, Leipzig 1955, Akademische Verlagsgesellschaft, Bd. 3, 2. Aufl. * |
Also Published As
Publication number | Publication date |
---|---|
ATA39079A (en) | 1983-12-15 |
GR64827B (en) | 1980-06-03 |
NO790412L (en) | 1979-08-10 |
EP0009044A1 (en) | 1980-04-02 |
WO1979000606A1 (en) | 1979-08-23 |
US4919771A (en) | 1990-04-24 |
EP0003598B1 (en) | 1984-06-06 |
AU523266B2 (en) | 1982-07-22 |
JPS55500203A (en) | 1980-04-10 |
AT375409B (en) | 1984-08-10 |
DE2805374A1 (en) | 1979-08-16 |
DD142061A5 (en) | 1980-06-04 |
ES477521A1 (en) | 1979-06-16 |
EP0003598A1 (en) | 1979-08-22 |
ES477525A1 (en) | 1979-07-16 |
AU4408779A (en) | 1979-08-16 |
DE2805374C2 (en) | 1982-07-15 |
CA1151099A (en) | 1983-08-02 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
EP0009044B1 (en) | Process for obtaining aluminium by electrolysis in a melted bath and electrolytic cell | |
US4988417A (en) | Production of lithium by direct electrolysis of lithium carbonate | |
DE1101773B (en) | Process for the continuous extraction of pure ductile, coarsely crystalline titanium by fused-salt electrolysis | |
DE2251262A1 (en) | CHEMICAL PROCESS | |
US2975111A (en) | Production of titanium | |
US4214956A (en) | Electrolytic purification of metals | |
US4409073A (en) | Process for the electrolytic reduction of metals and an improved particulate carbon electrode for the same | |
WO2014016247A1 (en) | Method for producing an alkali metal | |
DE2451840A1 (en) | METHOD AND APPARATUS FOR THE PRODUCTION OF ANHYDROUS METAL CHLORIDES | |
DE3000210A1 (en) | ELECTROLYTIC CLEANING OF METALS | |
US3696008A (en) | Electrolytic production of aluminum | |
DE3012694A1 (en) | DEVICE AND METHOD FOR GALVANICALLY DEPOSITING ALUMINUM BY ELECTROLYSIS | |
AT282210B (en) | Process and device for the production of aluminum and aluminum alloys | |
CA1075195A (en) | Arsenic removal from electrolytes | |
DE1210426C2 (en) | Process for the electrolytic production of phosphine | |
US2817630A (en) | Methods of producing titanium and zirconium | |
CA1120423A (en) | Electrowinning of metals | |
US4547272A (en) | Method and apparatus for production of a metal from metallic oxide ore using a composite anode | |
US2952591A (en) | Electrolytic preparation of calcium carbide | |
DE1558760C3 (en) | Method and device for the electrolysis of oxides | |
Hertzberg et al. | The Flammability of Coal Dust-Air Mixtures: Lean Limits, Flame Temperatures, Ignition Energies, and Particle Size Effects | |
CA1172600A (en) | Electrolytically deposited aluminum | |
AT275173B (en) | Method and device for the electrolysis of oxides | |
US2951795A (en) | Production of polyvalent metals | |
CN115637465A (en) | Method for separating and purifying metal vanadium in vanadium-aluminum alloy |
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 |
|
AK | Designated contracting states |
Designated state(s): CH FR GB LU SE |
|
17P | Request for examination filed |
Effective date: 19790926 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
AK | Designated contracting states |
Designated state(s): CH FR GB LU SE |
|
ET | Fr: translation filed | ||
RAP2 | Party data changed (patent owner data changed or rights of a patent transferred) |
Owner name: VEREINIGTE ALUMINIUMWERKE AKTIENGESELLSCHAFT |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FR Payment date: 19831130 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: SE Payment date: 19831231 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: CH Payment date: 19840109 Year of fee payment: 6 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: LU Payment date: 19840111 Year of fee payment: 6 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19840131 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SE Effective date: 19870125 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: CH Effective date: 19870131 |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee | ||
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 19870930 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
REG | Reference to a national code |
Ref country code: FR Ref legal event code: ST |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: GB Effective date: 19881118 |
|
EUG | Se: european patent has lapsed |
Ref document number: 79900193.8 Effective date: 19870923 |
|
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 |