EP1623055A2 - Corps a base de carbone apte a etre mouille par l'aluminium - Google Patents

Corps a base de carbone apte a etre mouille par l'aluminium

Info

Publication number
EP1623055A2
EP1623055A2 EP04727661A EP04727661A EP1623055A2 EP 1623055 A2 EP1623055 A2 EP 1623055A2 EP 04727661 A EP04727661 A EP 04727661A EP 04727661 A EP04727661 A EP 04727661A EP 1623055 A2 EP1623055 A2 EP 1623055A2
Authority
EP
European Patent Office
Prior art keywords
metal
carbon
aluminium
particles
based particles
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP04727661A
Other languages
German (de)
English (en)
Inventor
Thinh T. Nguyen
Vittorio De Nora
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.)
Moltech Invent SA
Original Assignee
Moltech Invent SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Moltech Invent SA filed Critical Moltech Invent SA
Publication of EP1623055A2 publication Critical patent/EP1623055A2/fr
Withdrawn legal-status Critical Current

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
    • C25C3/12—Anodes
    • C25C3/125—Anodes based on carbon
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B35/00—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products
    • C04B35/515—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics
    • C04B35/52—Shaped ceramic products characterised by their composition; Ceramics compositions; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products based on non-oxide ceramics based on carbon, e.g. graphite
    • C04B35/522—Graphite
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/009—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone characterised by the material treated
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/45—Coating or impregnating, e.g. injection in masonry, partial coating of green or fired ceramics, organic coating compositions for adhering together two concrete elements
    • C04B41/52—Multiple coating or impregnating multiple coating or impregnating with the same composition or with compositions only differing in the concentration of the constituents, is classified as single coating or impregnation
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B41/00—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone
    • C04B41/80—After-treatment of mortars, concrete, artificial stone or ceramics; Treatment of natural stone of only ceramics
    • C04B41/81—Coating or impregnation
    • C04B41/89—Coating or impregnation for obtaining at least two superposed coatings having different compositions
    • C04B41/90—Coating or impregnation for obtaining at least two superposed coatings having different compositions at least one coating being a metal
    • 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
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00474—Uses not provided for elsewhere in C04B2111/00
    • C04B2111/0087—Uses not provided for elsewhere in C04B2111/00 for metallurgical applications
    • C04B2111/00879—Non-ferrous metallurgy
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3217—Aluminum oxide or oxide forming salts thereof, e.g. bauxite, alpha-alumina
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3262—Manganese oxides, manganates, rhenium oxides or oxide-forming salts thereof, e.g. MnO
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3272—Iron oxides or oxide forming salts thereof, e.g. hematite, magnetite
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3275—Cobalt oxides, cobaltates or cobaltites or oxide forming salts thereof, e.g. bismuth cobaltate, zinc cobaltite
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/327—Iron group oxides, their mixed metal oxides, or oxide-forming salts thereof
    • C04B2235/3279—Nickel oxides, nickalates, or oxide-forming salts thereof
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/32—Metal oxides, mixed metal oxides, or oxide-forming salts thereof, e.g. carbonates, nitrates, (oxy)hydroxides, chlorides
    • C04B2235/3281—Copper oxides, cuprates or oxide-forming salts thereof, e.g. CuO or Cu2O
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/40—Metallic constituents or additives not added as binding phase
    • C04B2235/402—Aluminium
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/40—Metallic constituents or additives not added as binding phase
    • C04B2235/404—Refractory metals
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/42—Non metallic elements added as constituents or additives, e.g. sulfur, phosphor, selenium or tellurium
    • C04B2235/422—Carbon
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/42—Non metallic elements added as constituents or additives, e.g. sulfur, phosphor, selenium or tellurium
    • C04B2235/422—Carbon
    • C04B2235/425—Graphite
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/02—Composition of constituents of the starting material or of secondary phases of the final product
    • C04B2235/30—Constituents and secondary phases not being of a fibrous nature
    • C04B2235/48—Organic compounds becoming part of a ceramic after heat treatment, e.g. carbonising phenol resins
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/74—Physical characteristics
    • C04B2235/75—Products with a concentration gradient
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/80—Phases present in the sintered or melt-cast ceramic products other than the main phase
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2235/00—Aspects relating to ceramic starting mixtures or sintered ceramic products
    • C04B2235/70—Aspects relating to sintered or melt-casted ceramic products
    • C04B2235/96—Properties of ceramic products, e.g. mechanical properties such as strength, toughness, wear resistance
    • C04B2235/9669—Resistance against chemicals, e.g. against molten glass or molten salts
    • C04B2235/9676—Resistance against chemicals, e.g. against molten glass or molten salts against molten metals such as steel or aluminium

Definitions

  • the invention relates a carbon-based body having an aluminium- wettable surface.
  • the body can be used as a component of an apparatus which during use contains molten aluminium that comes into contact with the component, for example an aluminium electrowinning cell or an apparatus for treating molten aluminium.
  • US Patents 5,378,327, 5,578,174 and 5,679,224 disclose increasing the resistance of carbon components used in aluminium electrowinning cells by impregnating the carbon with colloidal alumina, ceria, cerium acetate, lithia, silica, yttria, thoria, zirconia, magnesia or monoaluminium phosphate that contain species of sodium, lithium, potassium, aluminium, calcium or amonium; or with a solution, suspension or melt of lithium, sodium or potassium.
  • aluminium-wettability of RHM coatings has been significantly improved by the addition of aluminium-reactable metal oxides, such as iron, copper, cobalt, nickel, zinc and manganese oxides, as disclosed in WO01/42168 (de Nora/ Duruz), WO01/42531, (Nguyen/Duruz/ de Nora), WO02/096830 (Duruz/Nguyen/de Nora) and WO02/096831 (Nguyen/de Nora).
  • aluminium-reactable metal oxides such as iron, copper, cobalt, nickel, zinc and manganese oxides
  • Such RHM coated bodies have the following attributes: excellent wettability by molten aluminium, resistance to attack by molten aluminium and cryolite, low cost, environmentally safe, ability to absorb thermal and mechanical shocks, durability in the environment of an aluminium production cell, and ease of production and processing.
  • An object of the invention is to provide a carbon body that is easy to manufacture and that has an aluminium- wettable surface.
  • a main object of the invention is to provide a carbon body that has the desired mechanical, physical, chemical, and electrochemical characteristics so that it can be used in a molten aluminium environment, in particular in an aluminium electrowinning cell or in an apparatus for treating molten aluminium.
  • the invention relates to a carbon body having an aluminium-wettable outer part that is made of a carbon-rich mixture containing metal-based particles and carbon.
  • the metal-based particles are made of metal oxide particles and/or partly oxidised metal particles or a precursor thereof.
  • the metal of the metal-based particles are selected from iron, copper, cobalt, nickel, zinc and manganese and combinations thereof.
  • the metal oxide particles and/or partly oxidised metal particles are reactable with molten aluminium when exposed thereto to form a mixture of: aluminium oxide; the metal of said metal-based particles; and aluminium.
  • Carbon is an aluminium-repellent material.
  • carbon material is mixed with an aluminium-reactable metal oxide and/or partly oxidised metal
  • molten aluminium reacts therewith to form alumina and the metal derived from the metal oxide and/or partly oxidised metal by transfer of oxygen from the metal oxide and/or partly oxidised metal to the aluminium.
  • the metal derived from the metal oxide and/or partly oxidised metal may then be alloyed with unreacted molten aluminium.
  • the presence of the aluminium-reactable metal oxide and/or partly oxidised metal promotes infiltration of aluminium by reaction therewith into the carbon material.
  • alumina, aluminium and the metal derived from the metal oxide and/or partly oxidised metal form a mixture that remains within the carbon material, in particular at its surface, and maintains it wetted by aluminium after reaction.
  • the carbon body with the aluminium-wettable outer part according to the invention is less exposed to corrosion and erosion by molten aluminium compared to a non- wettable carbon body, despite penetration of aluminium into the body's outer part.
  • the reduced corrodability and erodability of the carbon body according to the invention has two causes.
  • the mixture of alumina, aluminium and the metal derived from the metal oxide and/or partly oxidised metal, formed at the body's outer part is less reactive than pure aluminium.
  • carbon reacts less with this mixture than it does with pure aluminium to form aluminium carbide.
  • the aluminium layer that continuously wets the body's outer part during use inhibits exposure to the environment, e.g. cryolite, of the formed aluminium carbide and dissolution thereof into the environment.
  • the carbon body can be a fully manufactured body or a part-manufactured body that is subsequently, for example, subjected to a consolidation or conditioning treatment, e.g. a heat and/or aluminisation treatment.
  • a consolidation or conditioning treatment e.g. a heat and/or aluminisation treatment.
  • the carbon-rich mixture is made predominantly of carbon, i.e. carbon is the mixture's main constituent.
  • the body can comprise an inner part that is substantially free of metal-based particles, the body's outer part having a thickness of 5 to 50 mm, in particular from 10 to 25 mm.
  • the body comprises metal-based particles throughout.
  • the metal-based particles are impregnated into the carbon body.
  • the particles will be found in the body's pores, especially towards the body's surface.
  • the carbon and the metal-based particles in the outer part are present in a weight ratio metal-based particles/carbon from 1/100 to 1/20, in particular from 1/50 to 1/25.
  • the body's outer part is made of a heat treated mixture of the metal-based particles and particles of carbon.
  • the metal-based particles of the outer part are present in a weight ratio metal-based particles/carbon from 1/20 to 1/2, in particular from 1/8 to 1/4.
  • the outer part of the carbon body may comprise further particles of at least one additional metal compound.
  • the additional metal compound(s) can be selected from refractory borides, suicides, nitrides, carbides, phosphides, oxides, aluminise, metal alloys, mtermetallics, and mixtures thereof, of titanium, zirconium, hafnium, vanadium, silicon, niobium, tantalum and molybdenum.
  • the further particles and the metal-based particles of the outer part are present in a weight ratio further particles/metal-based particles from 1/10 to 1/2.
  • the metal-based particles can be present in the body's outer part in an organic carrier, in particular selected from pitch, polyurethane, ethylene glycol, polyethylene glycol, resins, esters or waxes, and/or an inorganic carrier, in particular selected from colloidal and/or polymeric metal compounds of metals selected from aluminium, silicon, yttrium, cerium, thorium, zirconium, tin, nickel, iron, chromium and magnesium which compounds form a metal oxide binder upon heat treatment.
  • an organic carrier in particular selected from pitch, polyurethane, ethylene glycol, polyethylene glycol, resins, esters or waxes
  • an inorganic carrier in particular selected from colloidal and/or polymeric metal compounds of metals selected from aluminium, silicon, yttrium, cerium, thorium, zirconium, tin, nickel, iron, chromium and magnesium which compounds form a metal oxide binder upon heat treatment.
  • the body can also be coated with an aluminium-wettable top coating which is free or substantially free of carbon.
  • top coatings in particular containing refractory borides and/or aluminium-reactable metal oxides, are disclosed in WO01/42168 (de Nora Duruz), WO01/42531, (Nguyen/Duruz/de Nora), WO02/096830 (Duruz/Nguyen/de Nora) and WO02/096831 (Nguyen/de Nora).
  • the invention also relates to a carbon body having an aluminium-wetted outer part producible by exposing the above described body to molten aluminium.
  • the outer part comprises a carbon-rich mixture containing: aluminium oxide; the metal of said metalbased particles; and aluminium.
  • the invention further relates to a method of manufacturing a carbon body.
  • the method comprises providing a mass of carbon and the above aluminium-reactable metal-based particles; adding the metal-based particles into the mass of carbon so as to form a carbon-rich mixture containing the metal-based particles; and consolidating by heat treatment the metal-based particles in the carbon mass to form an aluminium- wettable outer part of the carbon body which outer part is made of a carbon-rich mixture containing the metal-based particles.
  • the metal-based particles can be impregnated into the outer part of the carbon body that forms the carbon mass.
  • the metal-based particles are then consolidated in the carbon body's outer part by heat treatment.
  • the metalbased particles are introduced into the body's outer part with the aid of a liquid carrier.
  • a solution, a dispersion or possibly a suspension will be used for the infiltration.
  • the liquid carrier may be organic or inorganic, in particular aqueous.
  • the metal-based particles in the carrier can be in ionic form (typical particle size below 5 nm), polymeric form (typical particle size form 5 to 10 nm) or colloidal form (typical particle size from 10 to 100 nm).
  • the metal-based particles may be present in the liquid carrier in the form of an oxide or oxidised metal, or a precursor thereof such as a metal, nitride, chloride, hydroxide or a metal organic compound such as an alkoxide, a formate or an acetates. This precursor will usually turn into an oxide or surface oxidised metal upon heat-treatment.
  • the size of the metal-based particles used for the impregnation is sufficiently small that the metal-based particles can infiltrate the porosity of the carbon body.
  • the metal- based particles can be dissolved in a solution, or can be in polymeric or colloidal form in a liquid carrier and have a typical size below about 100 nm as mentioned above.
  • the metal-based particles may be suspended or slurried in a liquid carrier and can have a larger size, typically up to 1, 10, 30, 50 or 100 micron depending on the size of the pores.
  • the metal-based particles are mixed with carbon particles that form the carbon mass, the mixed carbon particles and metal-based particles being then consolidated by heat treatment to form the outer part of the carbon body.
  • the metalbased particles may be in the form of an oxide or a surface oxidised metal, or a precursor thereof such as a metal, nitride, boride, carbide or metal organic compound. This precursor will usually turn into an oxide or surface oxidised metal upon heat-treatment.
  • a layer of the carbon particles and the metal-based particles can be consolidated on a substrate.
  • the substrate can be either baked, or non-baked or part- baked in which case the layer and the carbon substrate can be consolidated together by heat treatment.
  • the layer of the particle mixture can be formed by co- extrusion followed by heat treatment.
  • the carbon particles and the metal-based particles can be consolidated to form a self-sustaining body.
  • the heat treatment can be carried out at a temperature above 200°-450°C and usually below 3000°C. Typically, consolidation of the particle mixture takes place at a temperature from about 250° to 650°C. However, the heat treatment can also take place at temperatures up to around 2000° to 3000°C, especially when a carbon green, e.g. a substrate, is consolidated at the same time.
  • the metal-based particles When the metal-based particles are mixed with carbon particles and then consolidated, the metal-based particles may have any of the above sizes.
  • the aluminium-wettable outer part can be exposed before or during use to molten aluminium to react the outer part's metal-based particles with molten aluminium and wet the outer part by aluminium.
  • Another aspect of the invention relates to a carbon-rich particle mixture for forming upon heat treatment a self-sustaining body or a layer of carbon that contains the metal oxide and/or partly oxidised metal.
  • the particle mixture comprises carbon particles and the above described metal-based particles.
  • a further aspect of the invention relates to a component of an apparatus that during use contains molten aluminium.
  • the component comprises a body with an outer part containing the metal-based particles as described above.
  • Yet another aspect of the invention relates to an apparatus that during use contains molten aluminium and comprises the above component.
  • This apparatus can be a cell for the electrowinning of aluminium, the above- mentioned component being a cathodic component, a cell bottom component or a sidewall component.
  • aluminium electrowinning cells are for example disclosed in US Patents 5,683,559, 5,888,360, 6,093,304 (all de Nora), 6,358,393 and 6,436,273 (both de Nora/Duruz).
  • the apparatus may be an apparatus for treating molten aluminium, the above component being exposed during use to molten aluminium.
  • Examples of such apparatus are disclosed in the abovementioned WO00/63630, WO01/42168, WO01/42531 and WO02/096831 .
  • Yet a further aspect of the invention relates to a method of operating the above apparatus.
  • the component is exposed to molten aluminium.
  • the method comprises electrowinning aluminium which comes into contact with the component.
  • the apparatus is an apparatus for treating molten aluminium, the method comprises treating molten aluminium which comes into contact with the component.
  • a graphitized carbon block was made aluminium-wettable by impregnation with an iron compound and then the block was aluminised as follows.
  • the block was impregnated over a depth of about 2.5 to 3 cm.
  • the impregnated part of the carbon block contained about 1.5 weight% Fe 2 O 3 .
  • the impregnated carbon block was then dipped into a bath of molten aluminium at a temperature of 940°C. After 12 hours the carbon block was extracted form the molten aluminium. The block was wetted by an adherent thin layer of molten aluminium. Aluminium had impregnated the block's entire surface over a depth of at least 0.2 mm and locally up to about 20 mm and had partly alloyed with iron upon reaction of aluminium and the block's iron oxide (forming alumina and iron metal that will usually alloy with aluminium).
  • the aluminised block was then tested in a laboratory aluminium electrowinning cell containing an electrolyte made of 11 wt% aluminium fluoride (A1F 3 ), 9.6 wt alumina (A1203), 5 wt% potassium fluoride (KF), 4 wt% CaF, the balance being cryolite (Na 3 A1F 6 ).
  • An electrolysis current was passed through the block at a cathode current density of about 0.5 A/cm 2 .
  • the block was still perfectly wetted by a film of molten aluminium.
  • the penetration of the block by molten aluminium did not significantly change during operation in the cell.
  • a mixture of iron oxide and carbon was prepared by mixing 18 g of graphite powder (with a particle size below about 100 to 200 micron), 3 g iron oxide powder (with a particle size below about 45 micron) and 12 g pitch.
  • the carbon-based block was dipped into a bath of molten aluminium at a temperature of 940°C. After 12 hours the carbon block was extracted form the molten aluminium. The block was wetted by an adherent thin layer of molten aluminium and impregnated to a depth of about 0.2 mm by aluminium that had reacted and alloyed with iron upon reaction of aluminium and the block's iron oxide.
  • Example 3 An aluminised carbon-based body manufactured as in Example 3 was used as a cathode in a laboratory cell as in Example 2 and behaved similarly.
  • a graphitized porous carbon block was made aluminium-wettable by impregnation with an iron compound and then the block was aluminised as follows.
  • the carbon block was covered with a layer of colloidal Fe 2 O 3 particles as well as impregnated over a depth of 3-4 cm from the block's surface.
  • the impregnated part of the carbon block contained about 3 to 4 weight% Fe 2 O 3 .
  • This colloidal impregnation was about 1 cm deeper than the Fe(NO 3 ) 3
  • Example 1 (dissolved) impregnation of Example 1 due to the low viscosity of the colloidal solution compared to the nitrate solution used in Example 1.
  • the impregnated carbon block was aluminised as in Example 1.
  • Example 1 An aluminised graphitized carbon cathode block was prepared as in Example 1 and tested in a cell under the conditions described in Example 2. [71] After 300 hours, the test was interrupted and the cathode block examined. No measurable wear or corrosion was observed on the cathode. [72] In comparison, an untreated carbon block, i.e. non-impregnated and non- aluminised, used in a cell under the same conditions has wear rate of 1 mm per 100 hours.

Landscapes

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

Abstract

Corps en carbone comportant une partie extérieure apte à être mouillée par l'aluminium et constituée d'un mélange enrichi en carbone renfermant du carbone et des particules à base de métal aptes à réagir avec l'aluminium. Les particules à base de métal sont composées de particules d'oxyde métallique et de particules d'oxyde métallique partiellement oxydées. Le métal des particules à base de métal est choisi parmi le fer, le cuivre, le cobalt, le nickel, le zinc et le manganèse. Le corps en carbone est utilisable, par exemple comme cathode, dans une cellule d'extraction électrolytique d'aluminium, ou dans un appareil de traitement de l'aluminium en fusion, et lors de sa mise en oeuvre il est mouillé par l'aluminium en fusion.
EP04727661A 2003-04-17 2004-04-15 Corps a base de carbone apte a etre mouille par l'aluminium Withdrawn EP1623055A2 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
IB0301472 2003-04-17
IB0304043 2003-09-09
PCT/IB2004/050457 WO2004092449A2 (fr) 2003-04-17 2004-04-15 Corps a base de carbone apte a etre mouille par l'aluminium

Publications (1)

Publication Number Publication Date
EP1623055A2 true EP1623055A2 (fr) 2006-02-08

Family

ID=35612575

Family Applications (1)

Application Number Title Priority Date Filing Date
EP04727661A Withdrawn EP1623055A2 (fr) 2003-04-17 2004-04-15 Corps a base de carbone apte a etre mouille par l'aluminium

Country Status (5)

Country Link
US (1) US20060289300A1 (fr)
EP (1) EP1623055A2 (fr)
CA (1) CA2522839A1 (fr)
NO (1) NO20055432L (fr)
WO (1) WO2004092449A2 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111364061A (zh) * 2018-12-25 2020-07-03 中南大学 一种铝电解用可润湿性炭素阴极及其制备方法和应用

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2565964A1 (fr) * 1984-06-13 1985-12-20 Lafarge Refractaires Nouveaux refractaires a haute teneur en alumine et leur procede d'obtention
US4699763A (en) * 1986-06-25 1987-10-13 Westinghouse Electric Corp. Circuit breaker contact containing silver and graphite fibers
DE69735585T2 (de) * 1996-10-18 2006-11-02 Moltech Invent S.A. Start-up von elektrozellen zur gewinnung von aluminium
DE69809202T2 (de) * 1997-05-23 2003-05-28 Moltech Invent S.A., Luxemburg/Luxembourg Aluminium-herstellungszelle und kathode
ES2194719T3 (es) * 1999-04-16 2003-12-01 Moltech Invent Sa Revestimiento de proteccion de componentes expuestos a desgaste utilizados en el refino de metales fundidos.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2004092449A3 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111364061A (zh) * 2018-12-25 2020-07-03 中南大学 一种铝电解用可润湿性炭素阴极及其制备方法和应用
CN111364061B (zh) * 2018-12-25 2021-03-16 中南大学 一种铝电解用可润湿性炭素阴极及其制备方法和应用

Also Published As

Publication number Publication date
WO2004092449A3 (fr) 2005-05-06
US20060289300A1 (en) 2006-12-28
CA2522839A1 (fr) 2004-10-28
NO20055432L (no) 2005-11-16
WO2004092449A2 (fr) 2004-10-28

Similar Documents

Publication Publication Date Title
AU2005205239A1 (en) Ceramic material for use at elevated temperature
WO2004025751A2 (fr) Anodes non carbonees destinees a l'electroextraction d'aluminium et autres composants resistant a l'oxydation munis de revetements de l'oxyde de fer
EP1240118B1 (fr) Revetement de protection d'aluminium mouillable pour composants de carbone utilises dans des processus metallurgiques
AU778640B2 (en) Aluminium-wettable protective coatings for carbon components used in metallurgical processes
AU2001233530A1 (en) A method for providing a protective coating for carbonaceous components of an electrolysis cell
WO2001061076A1 (fr) Procede pour munir des constituants carbones d'une cellule d'electrolyse d'un revetement protecteur
AU682855B2 (en) Conditioning of cell components for aluminium production
EP1366214B1 (fr) Materiau ceramique poreux mouillable par l'aluminium
US20060289300A1 (en) Aluminium-wettable carbon-based body
US5728466A (en) Hard and abrasion resistant surfaces protecting cathode blocks of aluminium electrowinning cells
US7935241B2 (en) Slurries for producing aluminium-based coatings
US5746895A (en) Composite refractory/carbon components of aluminium production cells
EP1693486B1 (fr) Procédé pour munir des constituants carbonés d'une cellule d'électrolyse d'un revêtement protecteur
EP0786020A1 (fr) Composants cathodiques traites, a base de carbone ou en carbone pour des cellules de production d'aluminium
CA2160469C (fr) Elements obtenus par la micropyrotechnique pour l'electrolyse de l'aluminium
AU2002236143A1 (en) Aluminium-wettable porous ceramic material

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: 20051115

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR

DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20081101