Aluminum Pechiney

Aluminium Pechiney

Claude Vanvoren

Jean-Luc Basquin

Benoit Coste

Oliver Bonnardel

Francois Keime

Christian Dreyer

Airy-Pierre Lamaze

Jean-Claude Thomas

Delphine Bonnafous

Laurent Fiot

Bernard Eygulnent

Jean Biarez

Denis Jouaffre

Guillaume Girault

Elisabeth Couzinie

This invention relates to a cathode element for use in a pot of an electrolytic cell intended for production of aluminum. The cathode element comprises a cathode block and a steel connection bar. The connection bar includes at least one metal insert, whose electrical conductivity is greater than the electrical conductivity of the said steel. The presence of an insert according to the invention can simultaneously result in a very large drop in the global cathode voltage and a very strong reduction in the current density at the head of the block.

Cathode element for use in an electrolytic cell intended for production of aluminum

The invention relates to a cooling method of a igneous electrolytic cell for aluminium production wherein heat transfer fluid droplets (or 'divided heat transfer fluid') are produced, preferentially in a confined volume in contact with a specified surface of at least one wall of the shell of the pot of the electrolytic cell, so as to induce the evaporation of all or part of said droplets by contact with said surface and remove the heat from said surface. The invention also relates to a cooling system capable of implementing the cooling method. The invention makes it possible to obtain a high cooling efficiency due to the latent heat of vaporisation of the heat transfer fluid.

Method and system for cooling an electrolytic cell for aluminum production

The present invention relates to a method of pre-heating a pot provided with anodes and cathodes for the production of aluminium by electrolysis, said method including a first step, prior to the pot being supplied with current, during which a layer of a granular conductive material is deposited then crushed between the anodes and the cathodes, characterized in that the granular conductive material is graphite-based and in that the layer of granular conductive material only extends, after crushing, over a part of a lower surface of each anode and takes the form of contact blocks.

Method of pre-heating a stack for aluminium electrolysis production

The invention relates to a regulation method for an electrolytic cell for the production of aluminium by means of reduction of alumina dissolved in a molten cryolite bath, wherein a solidified bath ridge is formed on the internal walls of the pot, a quantity B, referred to as the 'ridge variation indicator', which is sensitive to the variation of said solidified bath ridge, is determined and at least one of the setting means of the pot (such as the anode-metal distance) and/or at least one control operation (such as the addition of AlF) is modified as a function of the value obtained for said indicator. The indicator may be determined from electrical measurements on the pot and/or from measurements of the liquid metal surface area. The method according to the invention makes it possible to regulate an electrolytic cell effectively at currents of up to 500 kA with an electrolyte bath with an AlFcontent greater than 11% and reduce the number of AlFcontent measurements in the bath considerably.

Method for regulating an electrolytic cell

The invention relates to a regulation method for an electrolytic cell for the production of aluminium by means of reduction of alumina dissolved in a molten cryolite bath and comprises the addition, in the electrolyte bath, during pre-determined time intervals p referred to as 'periods', of a determined quantity Q(p) of aluminium trifluoride (AlF) determined by the following equation: Q(p)=Qint(p)&#x2212;Qc1(p)+Qt(p), where Qint(p) is an integral (or 'self-adaptive') term which represents the total actual AlFrequirements of the cell and which is calculated from a mean Qm(p) of the actual AlFsupplies made during the last N periods, Qc1 is a compensating term corresponding to the so-called &#x201c;equivalent&#x201d; quantity of AlFcontained in the alumina added to the cell during the period p, and Qt(p) is a corrective term which is a typically increasing function of the difference between the measured bath temperature T(p) and the set-point temperature To. The method according to the invention makes it possible to regulate effectively the acidity of an electrolytic cell at intensities of up to 500 kA with an electrolyte bath having an AlFcontent greater than 11%.

Method for regulating an electrolysis cell

The invention concerns a process for shaping, by compacting, carbonaceous blocks formed by a carbonaceous paste based on a carbonaceous aggregate such as coke, anthracite or graphite, and an organic cokable binder such as tar and optional additives. The carbonaceous paste is introduced into a mould in which some of the walls are displaceable with respect to their initial position and there are successively applied to said paste at least one stress .sigma..sub.n along an axis A.sub.n, then at least one stress .sigma..sub.n+1 along an axis A.sub.n+1 which is not coincident with the axis A.sub.n, then at least one stress .sigma..sub.n+2 along an axis A.sub.n+2 which is not coincident with the axis A.sub.n+1, and so forth, repetitively, each stress .sigma..sub.(i) being applied after at least partial suppression of the stress .sigma..sub.(i-1). Use of the process substantially enhances compactness of the carbonaceous blocks.

Process of shaping carbonaceous blocks by multiaxial compacting

An apparatus for shaping, by compacting, carbonaceous blocks formed by a carbonaceous paste based on a carbonaceous aggregate such as coke, anthracite or graphite, and an organic cokable binder such as tar and optional additives. The carbonaceous paste is introduced into a mould in which some of the walls are displaceable with respect to their initial position and there are successively applied to said paste at least one stress .sigma.n along an axis An, then at least one stress .sigma.n+1 along an axis An+1 which is not coincident with the axis An, then at least one stress .sigma.n+2 along an axis An+2 which is not coincident with the axis An+1, and so forth, repetitively, each stress .sigma.(i) being applied after at least partial suppression of the stress .sigma.(i-1). Use of the apparatus substantially enhances compactness of the carbonaceous blocks.

Apparatus for shaping carbonaceous blocks by multiaxial compacting

Apparatus and process for optimizing combustion in chamber-type furnaces

The invention relates to an apparatus of the vibrocompactor type for compacting carbonaceous blocks, and which comprises a vibrating table on which a carbonaceous paste is to be disposed, a heavy mass located below the table, and damper means located between the table and the mass for suspending the table above the mass. According to the invention, the damper means comprises inflatable pneumatic cushions. These cushions may be connected in parallel permanently to a source of fluid under a controllable pressure, or alternatively may be connected in parallel during the inflation of the cushions, and then isolated individually or in groups from the source of fluid. The apparatus may also include a means for measuring the pressure in each cushion or in a group of cushions, and a means for signalling the drop in pressure in each cushion or group.

Pneumatic suspension for vibrocompactors which are used in particular

The invention relates to a method of regulating the tar content of precooked anodes intended for the production of aluminum by electrolysis, to an optimum level Bm corresponding to the maximum dry density of the anodes, which utilizes measurements on crude anodes emerging from compaction and without awaiting the results of the cooking process. The method comprises the following repeatedly carrying out of the following sequence of steps:

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La Murette, France

Claude Vanvoren