Abstract: Device for transporting powder comprising a conveyer, which includes a lower channel in which a gas circulates, and an upper channel, designed for the circulation of powder and said gas, said lower channel and said upper channel being separated by a porous wall that said gas can pass through, the lower channel being supplied with gas at a pressure allowing the potential fluidization of said powder in said upper channel, said upper channel being provided in its upper part with transverse walls placed so that they delimit with the upper wall of said upper channel at least one upper zone in which a gas bubble under pressure is formed as a result of putting said air chute under potential fluidization pressure. At the level of at least one bubble so formed, the wall of the upper channel includes a means of removal for fluidization gas provided with a means of creating pressure drop, which creates a substantially constant pressure drop.

Abstract: A trough for cooling and delivering molten metal to a casting station. The trough comprises a refractory portion for holding the molten metal and heat transfer means associated to external walls of the refractory portion for extracting heat from the molten metal. The heat transfer means may comprise a fluidized bed compartment for holding and fluidizing a fluidization material. Also, the heat transfer means may comprise a cooling jacket, an inner wall of the cooling jacket and the external walls of the refractory portion defining the fluidized bed compartment.

Abstract: This preheating connector for electrically connecting an anode stern to an anode frame of an electrolytic cell during the warm-up phase of the electrolytic cell, includes means of fixing to the anode frame, and bearing means designed to exert pressure on the anode stem in order to keep it pressed up against the anode frame, the fixing means and bearing means being configured and arranged so as to add on the preheating connector onto a so-called permanent connector for electrical and mechanical connection of the anode stem to the anode frame during the continuous operating mode of the cell.

Abstract: The invention relates to a method of producing aluminum 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 electrical connection device connecting the cells in series comprises: a first conductor (16) connected to the cathode assembly of cell (N?1) and to the anode frame of cell (N), having a portion (19) located between said pots (N?1) and (N) in which the current (I) flows in the direction of the alignment axis (x) of the pots; a second conductor (24) connected to the cathode assembly of cell (N) and to the anode frame of cell (N+1), having a portion (23) located between said pots (N?1) and (N) in which the current flows away from the axis. short-circuiting wedges (20, 21) housed between said portions (19, 23) of said conductors (16, 24); a third conductor (27) to balance the current flowing through the wedges.

Abstract: The invention relates to a method for distributing powder by means of a main conveyor (3) between a feed zone (1) and a plurality of receiver units (R1, R2, R3, R4, R5) arranged along said main conveyor, said method including: (a) filling the conveyor as far as a downstream receiver unit, (b) isolating the feed zone, and (c) conveying the powder from at least one portion of the main conveyor to at least one receiver unit. The invention also concerns a device for implementing the distribution method and an installation for the production of aluminum by igneous electrolysis including said means for feeding a series of cell feed hoppers in said installation.

Abstract: The process involves pouring a smothering powder onto a spent anode placed on a support to cover it, with the aim of limiting fluorinated gas emission by the anode. The support may include a temporary tank, pre-filled with powder and provided with an opening for discharging the powder towards the anode on the support.

Abstract: An aluminum smelter comprising: (i) a series of electrolytic cells, designed for the production of aluminum, forming one or more rows, (ii) a supply station designed to supply the series of electrolytic cells with an electrolysis current, the said electricity supply station comprising two poles, (iii) a main electrical circuit through which the electrolysis current flows, having two extremities each connected to one of the poles of the supply station, (iv) at least one electrical conductor made of superconducting material, characterized in that the electrical conductor made of superconducting material is placed wholly or partly within an enclosure forming a magnetic shield.

Abstract: Aluminum smelter comprising: (i) a series of electrolytic cells, comprising an anode, a cathode and a pot shell equipped with a side wall and a bottom, each cathode including at least one cathode output, (ii) a main electric circuit through which an electrolysis current passes, including an electrical conductor connected to each cathode output of a cell N, and to the anode of a cell N+1, and (iii) a means to stabilize the electrolytic cells. At least one of the cathode outputs of the cathode of N passes through the bottom of the pot shell, and during the operation of N and N+1, the electrolysis current passes, in an upstream-downstream direction only, through each electrical conductor extending from each cathode output of N in the direction of N+1.

Abstract: An aluminum smelter comprising: (i) a series of electrolytic cells, designed for the production of aluminum, forming one or more rows, (ii) a supply station designed to supply the series of electrolytic cells with an electrolysis current, the said electricity supply station comprising two poles, (iii) a main electrical circuit through which the electrolysis current flows, having two extremities each connected to one of the poles of the supply station, (iv) at least one secondary electrical circuit comprising an electrical conductor made of superconducting material through which a current flows, running along the row or rows of electrolytic cells, characterized in that the electrical conductor made of superconducting material in the secondary electrical circuit runs along the row or rows of electrolytic cells at least twice in such a way as to make several turns in series.

Abstract: The invention relates to a ring furnace (1) having a longitudinal axis and comprising elongated bays (10), a plurality of hollow partitions (3, 3?) arranged within the casing of each bay so as to be parallel to the longitudinal axis, a first end transverse wall (41) located at a first end of each bay (10), a second end transverse wall (42) located at a second end of each bay (10) and possibly one or more intermediate transverse walls (43) located between the first and second ends. The hollow partitions and transverse walls define baking pits (2) within the bays (10) for stacking carbonaceous articles therein. The baking pits have a length Lp and a width Wp, said length Lp being at least 15 times greater than said width Wp.

Abstract: An aluminum alloy composition includes, in weight percent: 0.7-1.10 manganese; 0.05-0.25 iron; 0.21-0.30 silicon; 0.005-0.020 nickel; 0.10-0.20 titanium; 0.014 max copper; and 0.05 max zinc, with the balance being aluminum and unavoidable impurities. The alloy may tolerate higher nickel contents than existing alloys, while providing increased corrosion resistance, as well as similar extrudability, strength, and performance. Billets of the alloy may be homogenized at 590-640° C. and controlled cooled at less than 250° C. per hour. The homogenized billet may be extruded into a product, such as an aluminum alloy heat exchanger tube.

Abstract: A method for starting up an electrolytic cell (20) for aluminum production having a cathode block (26) with an upper surface (32), the method comprising: disposing contact resistance material (46) over the upper surface (32) of the cathode block (26); lowering a plurality of anodes (28) to abut the contact resistance material (46); filling the electrolytic cell (20) and covering the anodes (28) with solid electrolyte material (72) comprising crushed electrolytic bath material, cryolite, or mixtures thereof; delivering electrical current to the anodes (28) to at least partially melt the solid electrolyte material (72) and raising the anodes (28) when a predetermined depth of molten electrolyte material has been reached.

Abstract: The subject of the invention is an anode block (13, 13a-13e) made of carbon for a pre-baked anode (4) for use in a metal electrolysis cell (1) comprising a higher face (24), a lower face (23), designed to be laid out opposite a higher face of a cathode (9), and four side faces (21,22,34), and including at least one first groove (31a-31e) leading onto at least one of the side faces, in which the first groove has a maximum length Lmax in a plane parallel to the lower face, and characterized in that the first groove does not lead onto said lower or higher faces, or leads onto said lower or higher faces over a length L0 less than half the maximum length Lmax.

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: An apparatus for refining a process liquor that includes solids, which apparatus includes a vessel having a base and a side wall that define an internal volume for containing the process liquor and for allowing gravity settling of the solids in the liquor, whereby to produce a refined liquor toward a top of the internal volume and a slurry toward a bottom of the internal volume, the apparatus further includes solids displacement elements disposed within the internal volume for directing settled solids and/or settling solids in the vicinity of the side wall or of the base toward a flow path of the slurry being extracted from the slurry outlet. A processing plant including the above refining apparatus and a method for refining a process liquor.

Abstract: An electrolytic cell is suitable for production of aluminium, and includes at least one collector bar made of first metal and at least one complementary bar made of a second metal having an electrical conductivity greater than the first metal and arranged adjacent to one of the side faces of the collector bar so that the external end of the complementary bar is at a specified distance from a specified end face of the block. The second end terminates so as to limit heat losses from said cell. The cell makes it possible to obtain significantly lower voltage drops while avoiding excessive heat losses through the collector bars.

Abstract: The invention concerns a method for separating solid and liquor components of a process slurry comprising solid material entrained in a liquor, said method comprising: (a) a pre-treatment step of adding a flocculent to the process slurry and mixing the flocculent and the slurry by selecting a higher extent of mixing in an early stage of said step than in a later stage of said step, and (b) a solid/liquor separation step of allowing separation of solid material, including aggregates of solid material, and liquor of said process slurry to produce process outputs of a clarified liquor and solid material with some entrained liquor. The invention also concernes a method and an apparatus for adding a flocculent to a process slurry.