EP0072043A1
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Electrolytic production of aluminum
Assignee: Moltech Invent SA
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Filing: 1982-06-29
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Granted: —
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Expires: 2002-06-29
Abstract
Abstract In the electrolytic production of aluminum by electrowinning or electrorefining processes, cell components such as cathode current feeders which in use are normally covered with molten aluminum are made of a composite material of aluminum or an aluminum alloy or Intermetallic compound with an aluminum oxycompound, usually alumina, and possibly containing minor amounts of additives such as borides carbides, nitrides or oxides. The composite material, which remains mechanically stable and electrically conductive at 1000°C, may be prepared by hot pressing powders at 1000-1700°C possibly after surface treating the alumina to improve wettability by molten AI. The components are optionally coated, e.g. with TiB 2 . The composite materials are also useful as non-current carrying components, including separator walls, weirs, packing elements and baffles.
Inventors
- 👤 Vittorio De Nora
- 👤 Jurgen Friedrich Gauger
- 👤 Jean-Marie Fresnel
- 👤 Iudita Lea Adorian
- 👤 Jean-Jacques René Duruz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 23:38
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/5053; C04B41/5062; C04B41/507; C04B41/80; C04B41/81; C04B41/85; C04B41/87; C25; C25C; C25C3/00; C25C3/06; C25C3/08; C25C3/16; C25C3/24
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
34 words
A component of an aluminum production cell which in use is normally covered with molten aluminum, characterized in that it has a surface and/or an inner part made of a composite aluminum-aluminum oxycompound material.
Claim 2
Dependent Claim
34 words
A component of an aluminum production cell which in use is normally covered with molten aluminum, characterized in that it has a surface and/or an inner part made of a composite aluminum-aluminum oxycompound material.
Claim 3
Dependent Claim
21 words
The aluminum-production cell component of claim 1, in which the composite material is an electrically conductive part of a current-carrying component.
Claim 4
Dependent Claim
16 words
The aluminum-production cell component of Claim 2 , which is a cathode or cathode current feeder.
Claim 5
Dependent Claim
18 words
The aluminum-production cell component of Claim 2, which is an anode current feeder of an aluminum electrorefining cell.
Claim 6
Dependent Claim
16 words
The aluminum-production cell component of Claim 2, which is a current-carrying part of a cell lining.
Claim 7
Dependent Claim
17 words
The aluminum-production cell component of Claim 1, which is a separator wall, weir, packing element or baffle.
Claim 8
Dependent Claim
18 words
The aluminum-production cell component of Claim 1, in which the aluminum oxycompound of the composite material is alumina.
Claim 9
Dependent Claim
19 words
The aluminum-production cell component of Claim 1, in which the aluminum of the composite material is essentially pure aluminum.
Claim 10
Dependent Claim
26 words
The aluminum-production cell component of Claim 1, in which the composite material contains an alloy or intermetallic compound of aluminum with at least one other metal.
Claim 11
Dependent Claim
48 words
The aluminum-production cell component of Claim 1, in which the composite material comprises at least 1 % by weight of aluminum in the metallic state, at least 10 % by weight of the aluminum oxycompound and further comprises at least one nitride, boride, carbide and/or a different oxide.
Claim 12
Dependent Claim
23 words
The aluminum-production cell component of Claim 1, in which the composite material contains 1-50 % by weight of aluminum in the metallic state.
Claim 13
Dependent Claim
24 words
The aluminum-production cell component of Claim 1, in which the composite material further comprises an agent assisting retention of the aluminum at elevated temperatures.
Claim 14
Dependent Claim
44 words
The aluminum-production cell component of Claim 11, in which the composite material comprises as said agent up to 5 % by weight of lithium, magnesium, calcium, titanium, chromium, iron, cobalt, nickel, zirconium, hafnium, and/or one or more diborides of titanium, zirconium, hafnium and niobium.
Claim 15
Dependent Claim
18 words
The aluminum-production cell component of any preceding claim, in which the composite material is obtained by hot-pressing particles.
Claim 16
Dependent Claim
28 words
The aluminum-production cell component of Claim 14, in which the composite material is formed by hot-pressing the particles at a temperature of from about 1000°C to about 1600°C..
Claim 17
Dependent Claim
23 words
The aluminum-production cell component of any one of Claims 1-13, in which the composite material is pre-formed into a body by cold-pressing particles.
Claim 18
Dependent Claim
26 words
The aluminum-production cell component of Claim 16, in which the pre-formed cold-pressed body is subjected to heat treatment prior to fitting the component in a cell.
Claim 19
Dependent Claim
25 words
The aluminum-production cell component of any preceding claim, in which an exposed surface of the component is at least partly coated with another aluminum-wettable material.
Claim 20
Independent Claim
27 words
A method of manufacturing an aluminum-production cell component according to any preceding claim, characterized by submitting particles of aluminum and of the aluminum oxycompound to heat treatment.
Claim 21
Independent Claim
44 words
A method of manufacturing an aluminum-production cell component according to any one of claims 1-18, characterized by reacting aluminum with one or more suitable oxides to produce alumina in situ with an excess of unreacted aluminum and a reduced form of the starting oxide(s).
Claim 22
Dependent Claim
26 words
The method of Claim 19 or 20, in which a mixture of the particles is hot-pressed at a temperature of from about 1000°C to about 1600°C.
Claim 23
Dependent Claim
23 words
The method of Claim 19, 20 or 21, in which the particles are mixed and cold-pressed prior to hot-pressing or other heat treatment.
Claim 24
Dependent Claim
16 words
The method of Claim 19 or 20, in which the particles are plasma-sprayed onto a support.
Claim 25
Dependent Claim
27 words
The method of Claim 19, in which prior to or during the heat treatment the aluminum oxycompound is subjected to a treatment to assist retention of aluminum.
Claim 26
Dependent Claim
42 words
The method of Claim 24, in which said treatment comprises contacting the aluminum oxycompound with an aluminum retaining agent chosen from lithium, magnesium, calcium, titanium, chromium, iron, cobalt, nickel, zirconium, hafnium, and/or one or more diborides of titanium, zirconium, niobium and hafnium.
Claim 27
Dependent Claim
23 words
The method of Claim 20, in which the aluminum and said oxides are mixed with pre-formed alumina prior to carrying out the reaction.
Claim 28
Independent Claim
65 words
A method of pre-forming an aluminum-production cell component according to any one of claims 1-17, comprising forming a self-sustaining body by cold-pressing particles of aluminum and an aluminum oxycompound and/or an oxide capable of forming an aluminum oxycompound by reaction with the aluminum in which case the aluminum is present in a quantity to leave an excess of unreacted aluminum after completion of the reaction.
Claim 29
Dependent Claim
43 words
An aluminum production electrolysis cell comprising one or more components with a surface and/or inner part made of a composite aluminum-aluminum oxycompound material as claimed in any one of Claims 1-18 or as manufactured by the method of any one of Claims 19-27.
Claim 30
Independent Claim
61 words
A method of producing aluminum by electrolysis in an electrowinning or an electrorefining cell, characterized by using a cell component with a surface and/or inner part made of a composite aluminum-aluminum oxycompound material as claimed in any one of Claims 1-18 or as manufactured by the method of any one of Claims 19-27, the component being normally covered with molten aluminum.
Claim 31
Dependent Claim
35 words
The method of producing aluminum of Claim 29, in which the cell component is a cathode or cathode current feeder with a substantially horizontal surface which is drained to maintain a thin film of aluminum.
Claim 32
Dependent Claim
38 words
The method of producing aluminum of Claim 29, in which the cell component is a cathode or cathode current feeder with a perpendicular or inclined surface facing an anode and down which a thin film of aluminum flows.
Claim 33
Independent Claim
54 words
A method of electrorefining aluminum comprising cathodically forming purified molten aluminum in an electrorefining cell, characterized in that at least a part of the cell in contact with the purified aluminum is made of a composite alumina-aluminum material composed of alumina and aluminum of pure grades, possibly containing other oxides resistant to molten aluminum.
Claim 34
Independent Claim
54 words
A method of electrorefining aluminum comprising cathodically forming purified molten aluminum in an electrorefining cell, characterized in that at least a part of the cell in contact with the purified aluminum is made of a composite alumina-aluminum material composed of alumina and aluminum of pure grades, possibly containing other oxides resistant to molten aluminum.
Claim 35
Dependent Claim
20 words
The method of electrorefining aluminum of Claim 32, in which said part of the cell is a cathode current feeder.
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