Abstract: The present invention concerns an electrolysis tank for the production of aluminum by means of the Hall-Heroult process, which operates at above 250,000 amperes, in particular from 270,000 to 320,000 amperes.The connection between each riser (7) and the anodic bus bar (5) is made by way of flexible electrical conductors (8); the central riser (7C) is disposed on the axis of the series, the two intermediate risers (7B, 7D) and the two equally spaced lateral risers (7A, 7E) through which substantially equal current strengths flow are connected to six upstream cathodic collectors (3), two central collectors (3A, 3B) two intermediate collectors (3C, 3D) and two lateral collectors (3E, 3F), and three downstream cathodic collectors (4), a central collector (4A) and two lateral collectors (4B, 4C).Equipotential connections provide for balancing of the current between the different sections of the upstream and downstream collectors.

Abstract: Device for assembly of profiles by a groove, tongue fitting, with locking by key, which avoids the risks of tongue and key sliding along groove. The device consists of making one of the male elements, tongue or key, longer than the other, in the direction of the generatrices of groove, and making one of the side surfaces of the longer element concave along the generatrices of groove. The invention allows realization of trellis constructions having oblique bars.

Abstract: The invention relates to a process for fractional crystallization of metals at the surface of a rotary drum.It is characterized in that the distance between the drum (1) and the bottom of the trough (4) containing the metal in the liquid state is regulated and said trough is divided, in the direction of rotation of the drum (3), into an upstream zone (6) and a downstream zone (7) between which the circulation of liquid is restricted, said distance being regulated in such a way as possibly to permit the crystals to be compressed in the upstream zone, and that the crystals are re-melted in the downstream zone, in order to collect the purified metal in the liquid state.The invention is used in the continuous purification of metals such as in particular aluminum.

Abstract: The present invention relates to a process and apparatus for the recovery of liquid aluminium by compression of hot dross.The process comprises placing the dross in a die up to a height which depends on the diameter of said die and which is lower at the center than at the periphery of the die, and then applying to the dross a punch which is moved downwardly at a speed which is lower in proportion to a lower level of concentration of liquid aluminium in the dross.The apparatus comprises a cylindrical die (10) provided with an insert member at each of its ends. The die rests on a base (3) which has an annular groove (4) on its upper face; the lower insert member (7) is of a diameter that is at least equal to the inside diameter of the groove and in any case less than the outside diameter and has a continuous upper face of conical shape; the space (16) between the wall surface of said insert member and the internal wall surface of the die is of a constant width and is disposed facing the groove.

Abstract: The present invention relates to a process and apparatus for the recovery of liquid aluminium by compression of hot dross.The process comprises placing the dross in a die up to a height which depends on the diameter of said die and which is lower at the center than at the periphery of the die, and then applying to the dross a punch which is moved downwardly at a speed which is lower in proportion to a lower level of concentration of liquid aluminium in the dross.The apparatus comprises a cylindrical die (10) provided with an insert member at each of its ends. The die rests on a base (3) which has an annular groove (4) on its upper face; the lower insert member (7) is of a diameter that is at least equal to the inside diameter of the groove and in any case less than the outside diameter and has a continuous upper face of conical shape; the space (16) between the wall surface of said insert member and the internal wall surface of the die is of a constant width and is disposed facing the groove.

Abstract: A selective chlorination method of a mixture of simple or complex metallic oxides, comprising at least one of the elements to be used, iron, aluminum, titanium and silicon, as well as the impurities accompanying said elements, said method consisting of a grinding, a calcination, a placing in suspension in a bath of melted salts of the mixture of said metallic oxides and of their impurities and of an introduction of chlorinating agents into said bath maintained at a temperature which assures the volatility of at least one of the metallic chlorides formed; characterized by the fact that, in order to selectively extract the metallic chlorides formed from the bath, specific chlorinating mixtures are introduced into this bath by successive steps, said mixtures having increasing chlorinating power, and the introduction is in a number at the most equal to the usuable elements to be chlorinated.

Abstract: Telomers and cotelomers with at least one sequence which can be cross-linked by light, and a method of preparing them.They are of the general formula ##STR1## wherein the taxogen links --(X.sub.i)-- belong to the group made up of 2-hydroxy ethyl acrylate and methacrylate, acrylic or methacrylic acid, vinyl alcohol and allyl alcohol; the ##STR2## links emanate from the same taxogen X.sub.i, esterified by means of a group with at least one photo-crosslinkable double bond in its molecule; and where 1<x+y.ltoreq.1000, Z being chosen from the group --H, --Cl, --Br; and where R may be a simple or macromolecular radical, in the latter case leading to the formation of dual sequence cotelomers.The manufacturing process comprises telomerisation by redox or radical catalysis, followed by grafting on the photo-cross-linkable group, the first phase of telomerisation being duplicated in the case of a cotelomer.The main application for the products is in coating metals.

Abstract: This invention relates to inserts for pistons of diesel engines of aluminum-silicon alloys obtained by powder metallurgy.These inserts are characterized in that they contain elements such as iron and zirconium.They find their application in the manufacture of pistons intended to work at high temperatures for long periods and exhibit a good friction capacity.

Abstract: This invention relates to a process for sintering aluminum alloy powders under pressure.It consists in placing the powder in a capsule, in coating the capsule with an easily melted, stable vitreous material with a viscosity between 10.sup.2 and 10.sup.5 poises at the sintering temperature and in pressing it in a unidirectional press.It applies, in powder metallurgy, to the obtaining of castings that exhibit homogeneous mechanical properties, these castings being able to be roughcasts or finished castings.

Abstract: The invention relates to an electrolysis tank for production of aluminum by electrolysis of alumina dissolved in a molten cryolite bath, by the Hall-Heroult process, between at least a carbon anode and an aluminum sheet covering a carbon cathode substrate. At the interface of the aluminum sheet and molten cryolite bath it comprises a floating screen, which is conductive of electric current, not connected to the carbon cathode substrate and free to move at least in the vertical direction.The floating conductive screen can extend over the entire interface or be limited to being perpendicular to each anode.The distance between each anode and the floating conductive screen can be reduced to about 20 mm.

Abstract: The invention concerns floating cathode elements which are intended for the electrolytic production of aluminum using the Hall-Heroult process in an electrolysis tank comprising a molten cryolite-base bath, between a carbon anode, and a cathodic layer of molten aluminum, said elements comprising at least one active cathode element (30) formed of electrically conductive refractory material such as titanium diboride and supported by an intermediate support (31) which is inert with respect to the liquid aluminum and the electrolyte, the mean relative density of the assembly of the acitve cathode element and the inert intermediate support being lower than the relative density of the liquid aluminum under the normal conditions of operation of the electrolysis tank.

Abstract: The present invention relates to a process for the electromagnetic casting of metals. The process is characterized by simultaneously using a stationary field and a variable field at a suitable frequency for producing both radial vibrations within the metal which is not yet in a solidified condition and limiting agitation of the metal. The invention can be used in any circumstance where both the structure and the surface condition of the cast products are to be improved.

Abstract: The present invention concerns a process for vertical continuous casting at speeds which are close to a meter per minute. The process is characterized in that the use of a top feeder head and an electromagnetic field are combined and that, by controlling the position in respect of height of the top feeder head and the cooling system relative to the field generating means, the distances between certain parameters such as the solidification front and the base plane of the top feeder head are maintained constant in the course of the casting operation. This process makes it possible to cast aluminium and alloys thereof in the form of billets or plates, the smallest dimension of which does not exceed 150 mm and which have a surface that does not require any scalping treatment.

Abstract: A process for casting metals comprising simultaneously applying a stationary magnetic field and a variable magnetic field to the molten metal in the course of solidification. The magnetic fields act in the same direction and generate radial vibrations in the metal, causing the cast metal to have an improved homogeneous structure and surface condition.

Abstract: Telomers and cotelomers with at least one sequence which can be cross-linked by light, and a method of preparing them.They are of the general formula ##STR1## wherein the taxogen links --(X.sub.i)-- belong to the group made up of 2-hydroxy ethyl acrylate and methacrylate, acrylic or methacrylic acid, vinyl alcohol and allyl alcohol; the ##STR2## links emanate from the same taxogen X.sub.i, esterified by means of a group with at least one photo-crosslinkable double bond in its molecule; and where 1<x+y.ltoreq.1000, Z being chosen form the group --H, --Cl, --Br; and where R may be a simple or macromolecular radical, in the latter case leading to the formation of dual sequence cotelomers.The manufacturing process comprises telomerization by redox or radical catalysis, followed by grafting on the photo-crosslinkable group, the first phase of telomerization being duplicated in the case of a cotelomer.The main application for the products is in coating metals.

Abstract: A method and apparatus is described for forming non-ferrous, constant section, stackable auto-clamping blocks. The method advantageously utilizes a movable carriage having in addition to cutter means, a pair of jaws which are each generally shaped like a combined prism-trihedron to form mating surfaces in the formed blocks which allows stacking.

Abstract: The invention relates to an apparatus for carrying out a process for separating electrolysis bath residues on used anode units removed from electrolysis cells for the production of aluminum by the Hall-Heroult process, said units comprising a cabon residue 5 or "butt", in which are sealed discs 3 interconnected by flanges 2 welded to a suspension rod 13, the axes of the discs 3 being parallel to the axis of the suspension rod 13, said process comprising passing at least one rotary milling cutter 9, of which the axis of rotation 10 in the working position is substantially parallel to the axis of the rod 13, through the space situated between the discs and around the discs 3 and defined by the upper face of the carbon butt 5 on the one hand and the flanges 2 on the other hand.

Abstract: The invention concerns a process for improving the characteristics in respect of fatigue strength and toughness of worked Al alloys in the treated state, by means of a thermo-mechanical treatment which is carried out on the cast and possibly homogenized product.It comprises the following steps:(a) casting an initial product along an axis XX' by a known method(b) optional homogenization(c) upsetting in the hot state, preferably by means of a press, along the axis XX', with an upsetting ratio (initial length/final length along axis XX')>1.4(d) drawing in the hot state in the direction of the axis XX', with a rate of working (initial cross section/final cross section, considered perpendicularly to the axis XX')>1.

Abstract: The heating apparatus according to the invention concerns open circulatory-firing baking furnaces comprising an assembly of chambers which are heated by gases which circulate in hollow partitions (7, 19, 25) which divide the chambers into compartments. The hot gases are produced by fuel injection means (13, 17) which are placed in the upper part of the partitions.In accordance with the invention, instead of the fuel injectors (13, 17) being placed in the same direction as the flow of combustion-supporting gas, the injectors (26, 29) are placed countercurrent, which permits the temperature distribution and the accuracy of the control action to be substantially enhanced.The apparatus is applied in particular to baking carbon anodes which are used in aluminum electrolysis cells.

Abstract: The present invention relates to a method of controlling and regulating operational parameters of a machine for continuously casting bands between cylinders, allowing adhesion to be avoided. This method comprises considering as parameters the torque exerted on one or other of the cylinders for moving the band on and comprises permanently comparing the frequency of the variations in the torque measurement with a reference frequency. When the variation frequency is greater than the reference frequency, the casting speed of the machine is reduced and/or the lubricant flow rate is increased until the variation frequency is again lower than the reference frequency. The speed of the casting machine is then increased as long as the variation frequency remains below the reference frequency.