Abstract: An extrudable aluminum alloy billet includes an aluminum alloy composition including, in weight percent, between 0.90 and 1.30 manganese, between 0.05 and 0.25 iron, between 0.05 and 0.25 silicon, between 0.01 and 0.02 titanium, less than 0.01 copper, less than 0.01 nickel, and less than 0.05 magnesium, the aluminum alloy billet being homogenized at a temperature ranging between 550 and 600° C.

Abstract: A cell for the electrowinning of aluminium (50) from alumina dissolved in a molten electrolyte comprises a generally horizontal cell bottom (5), preferably aluminium-wettable, on which a pool of product aluminium (50) is collected from at least one electrically conductive cathodic element (10) having aluminium-wettable cathode surfaces (11). The cathodic element comprises an inclined cathodic wall (10) in the electrolyte (60) above the generally horizontal cell bottom (5). The cathodic wall (10) has an upwardly-oriented inclined face (11) that forms a sloping upper aluminium-wettable drained active cathode surface on which aluminium is produced and drains into the aluminium pool (50), and a downwardly-oriented inclined face (12) which is in contact with the molten electrolyte (60) and which overlies the aluminium pool (50). The aluminium pool (50) covers substantially the entire cell bottom (5) including underneath the cathodic wall (10).

Abstract: A metallic oxygen evolving anode for electrowinning aluminium by decomposition of alumina dissolved in a cryolite-based molten electrolyte, and operable at anode current densities of 1.1 to 1.3 A/cm2, comprises an alloy of nickel, iron, manganese, optionally copper, and silicon. Preferably, the alloy is composed of 64-66 w % Ni; Iron; 25-27 w % Fe; 7-9 w % Mn; 0-0.7 w % Cu; and 0.4-0.6 w % Si. The weight ratio Ni/Fe is in the range 2.1 to 2.89, preferably 2.3 to 2.6, the weight ratio Ni/(Ni+Cu) is greater than 0.98, the weight ratio Cu/Ni is less than 0.01, and the weight ratio Mn/Ni is from 0.09 to 0.15. The alloy surface can comprise nickel ferrite produced by pre-oxidation of the alloy. The alloy, optionally with a pre-oxidised surface, can be coated with an external coating comprising cobalt oxide CoO.

Abstract: The invention describes a process and apparatus producing a dense coke fraction from a first particulate coke fraction having a first average density and a first average particle size distribution, stratifying the coke fraction in a density separator into at least two fractions, the at least two fractions comprising a light coke fraction and the dense coke fraction. The dense fraction having an average density greater than the first average density and a particle size distribution substantially equivalent to the first average particle size distribution. The apparatus includes an inclined oscillating table comprising a gas-pervious deck, and a gas mover.

Abstract: Process for manufacturing alumina trihydrate by alkaline attack of bauxite, following the general steps of the Bayer process, and during which, after settling and before decomposition, the aluminate liquor undergoes a filtration, known as security filtration, so that at the end of the filtration it contains less than 10 mg/l of insoluble particles, characterized in that, during said security filtration, a filtration device is used that comprises a zone in which the liquor is subjected, after passing through said filtration media, to a pressure greater than 2 bar, preferably greater than 3 bar. Preferably, this device also comprises a zone in which the liquor is subjected, before passing through the filtration media, to a pressure greater than 5 bar, preferably greater than 6, typically in the vicinity of 7 bar. In this way, the aluminate liquor can be kept at a high temperature during the security filtration, typically greater than 130° C., preferably greater than 140° C.

Abstract: A process for shutting down an operating electrolytic cell for the production of aluminium is described. The process includes: lowering anodes until a lower portion of the anodes is immersed in an aluminium layer; allowing the aluminium layer and an electrolyte bath to cool down with the lower portion of the anodes immersed in the aluminium layer; determining if the electrolyte bath is solidified, and if the electrolyte bath is solidified, raising the anodes before solidification of the aluminium layer to create a space between the solidified electrolyte bath and the anodes and the aluminium layer.

Abstract: A siphoning operation is controlled to meet a target flow rate of liquid being siphoned into a container having a headspace to which a vacuum is induced with an ejector. The incremental mass of liquid siphoned into the container is monitored and the vacuum applied to the container is continuously adjusted. A vacuum regulator responsive to an electric current-to-pressure converter which is coupled to a control unit is provided to control the flow of pressurized fluid delivered to the ejector.

Abstract: A cell for the electrowinning of aluminum (50) from alumina, comprises an inclined plate-like or grid-like open anode structure (25) which has a generally v-shaped configuration in cross-section. The anode structure (25) has a downwardly-oriented sloping electrochemically active surface that is generally v-shaped in cross-section and spaced above an upwardly-oriented corresponding sloping cathode surface (11) by an anode-cathode gap (40) in which alumina dissolved in a circulating electrolyte (60) is electrolysed. The anode structure (25) has a plurality of anode through-passages (45) distributed thereover for an up-flow of alumina-depleted electrolyte (60) from the anode-cathode gap (40).

Abstract: An aluminium extrusion having a minimum section thickness and made from an aluminium alloy includes, in weight percent, between approximately 1.0 and 1.7 manganese, and between approximately 0.5 and 1.1 silicon, less than 0.3 iron with the balance being Al and inevitable impurities each less than 0.05 weight % and totaling less than 0.15 weight %, the extrusion being formed with an extrusion ratio less than 125 to retain a fibrous grain structure in which less than 40% of the minimum section thickness is recrystallized.

Abstract: The subject of the invention is a cast part with high static mechanical strength, and for fatigue and hot creep, made of aluminum alloy of composition: Si: 3-11%, preferably 5.0-9.0% Fe <0.50%, preferably <0.30%, preferably still <0.19% or even 0.12% Cu: 2.0-5.0%, preferably 2.5-4.2%, preferably still 3.0-4.0% Mn: 0.05-0.50%, preferably 0.08-0.20% Mg: 0.10-0.25%, preferably 0.10-0.20% Zn: <0.30%, preferably <0.10% Ni: <0.30%, preferably <0.10% V: 0.05-0.19%, preferably 0.08-0.19%, preferably still 0.10-0.19% Zr: 0.05-0.25%, preferably 0.08-0.20% Ti: 0.01-0.25%, preferably 0.05-0.20% other elements <0.05% each and 0.15% in total, the rest aluminum. It more particularly relates to cylinder heads for supercharged diesel or petrol internal combustion engines.

Abstract: A brazing sheet made up of a core sheet made of aluminum alloy covered on at least one side with a layer of cladding forming a sacrificial anode. The layer of cladding is formed of an aluminum alloy of chemical composition, in % by weight: Si: >2.0-7.0; Fe<0.5; Cu<1.0; Mn: 1.0-2.0; Mg<0.5; Zn: 1.0-3.0; Cr<0.25; Ni<1.5; Ti<0.25; Co<1.5; V, In, Sn, Zr, Sc<0.25 each; other elements <0.05 each and 0.15 in total. A heat exchanger tube may be produced by folding and brazing from the brazing sheet, where the layer of cladding forms a sacrificial anode constituting the lining of the tube or “inner-liner.

Abstract: A slurry comprises suspended aluminum particles in a colloid having dispersed colloidal particles of a metal oxide such as a hydroxide. The metal oxide is reducible by metallic aluminum. The slurry has such a basic pH that dissolution of the aluminum particles in the slurry is inhibited so that when the slurry is subjected to a heat treatment, the undissolved aluminum particles are reactable with the colloidal particles to form an aluminum-based mixture resistant to chemical attack made of aluminum oxide, metal aluminum and the metal of the colloidal particles. The slurry can be used to form an aluminum-based protective coating on a component, in particular of an aluminum electrowinning cell or an apparatus for treating molten aluminum.

Abstract: The invention relates to a method of producing aluminium in an electrolysis cell, which includes setting up a succession of control periods of duration T, identifying perturbative tending operations on the cell that can introduce superfluous alumina in the electrolytic bath, noting the performance of the perturbative tending operations, determining a regulation feed rate B(k?) for each control period k? and setting a specified feed rate SR(k?) equal to M(k?)×B(k?), where M(k?) is a predetermined modulation factor that modulates the regulation feed rate B(k?) so as to take into account a reduction of the needs of the cell induced by the superfluous alumina. The method of the invention makes it possible to significantly reduce the rate of occurrence of anode effects.

Abstract: The invention relates to a metal boride precursor mixture comprising a metal oxide and a boric oxide combined in such a manner so as to produce intimately linked clusters wherein the boric oxide is found within the metal oxide. Furthermore, the invention discloses a carbon composite material made with the metal boride precursor mixture and a carbonaceous component. Finally, the invention also teaches the process for preparing the metal boride precursor mixture comprising steps of providing a metal oxide and a boron oxide, mechanically mixing the metal oxide and the boron oxide at a temperature that liquefies the boron oxide and may impregnate the metal oxide to produce an intimately linked cluster of metal oxide and boric oxide.

Abstract: A multi-layer cathode block (30) for an electrolytic cell (10) has at least a surface layer (32) with a surface expansion index and a second layer (34) with a second expansion index. The surface layer (32) includes a surface wetting agent in a first total amount. The second layer (34) includes a wetting agent in a second total amount. The surface layer (32) is directly superposed to the second layer (34). The second wetting agent in the second layer (34) includes metal boride precursors that react together to generate a metal boride component in situ when the cathode block (30) is exposed to start-up and operation conditions of the electrolytic cell (10). The second total amount is lower than the first total amount and is selected so as to minimize the difference between the expansion indexes of the surface layer (32) and the second layer (34).

Abstract: A cell for electrowinning a metal, in particular aluminium, from a compound thereof dissolved in an electrolyte (30) comprises an anode (40) and a cathode (10,11) that contact the electrolyte (30), the cathode (10,11) being during use at a cathodic potential for reducing thereon species of the metal to be produced from the dissolved compound. The electrolyte (30) further contains species of at least one element that is liable to contaminate the product metal (20) and that has a cathodic reduction potential which is less negative than the cathodic potential of the metal to be produced. The cell further comprises a collector (50) for removing species of such element (s) from the electrolyte (30).

Abstract: An anode for electrowinning of aluminium from alumina comprises a cobalt-containing metallic outer part that is covered with an integral oxide layer containing predominantly cobalt oxide CoO. The integral oxide layer can be formed by surface oxidation of cobalt from the metallic outer part before use.

Abstract: The invention relates to a device (50) and a method for short-circuiting a specified electrolysis in a row of electrolysis cells intended for the production of aluminium. This device includes a bridging member (60) including at least two opposite contact arms and at least one bridging conductor electrically that electrically connects the contact arms. The contact arms are shaped like a wedge. The device further includes a clasping member (70) including a frame and a least two opposite thrust members. The clasping member (70) is fit to embrace the bridging member (60) so that each thrust member bears on each contact arm and so that, upon moving the contact arms with respect to the clasping member, each thrust member urges the corresponding contact arm towards the conductors (201, 202) inserted between the contact arms, so as to create and secure a short-circuit. The invention makes it possible to short-circuit electrolysis cells with increased amperages.