Abstract: A process of pneumatic stirring of a bath of molten metal according to which a stirring fluid is injected through permeable refractory elements arranged at the bottom of a crucible containing the bath, in which the used stirring fluid is, at least temporarily, an organic liquid such as hydrocarbon.The process is advantageously used on a bath of molten pig iron during refining of the same by oxygen, and in which the organic liquid is replaced immediately after decarburization of the bath by an inert gas such as argon or nitrogen.The process thus permits an efficient stirring of the bath of molten metal without the risk of polluting the metal either by hydrogen or nitrogen.

Abstract: A device for blowing gas under pressure into a bath of liquid metal comprises a mass of refractory material which is porous at least at an inner portion thereof and placed into a metallic container constituted by an outer metallic envelope closed at one of the ends thereof by a bottom member through a central portion of which a conduit extends for feeding a gas under pressure to the porous inner portion of the mass. A deflector is provided fluid-tightly connected to the bottom inwardly of the envelope in which the wall of the deflector extends parallel to that of the envelope but short of the length of the latter. This permits, on the one hand, to avoid penetration of liquid metal between the envelope and the mass of refractory material to a point where it would block the gas feeding conduit and, on the other hand, to canalize the gas through the porous portion of the mass. The present invention relates likewise to a method of making the above device.

Abstract: The refractory piece permeable to gases according to the invention is designed to be incorporated in the inner refractory lining of a metallurgical container so that one of its surfaces will be in contact with the molten metal bath in said container, the opposite surface being equipped with means for introducing a gas under pressure.This piece, whose shape is generally hexahedral, consists essentially of a mass of nonporous refractory material that has a number of local discontinuities 8 extending throughout the piece along its height h between the surface in contact with the molten metal and the opposite surface. In an advantageous method of embodiment, the local discontinuities 8 are obtained by an assembly 1, in a metal casing, of nonporous refractory elements 2, in the form of plates and which are placed side by side along their large lateral surfaces, without any material gaskets or seals between them.The piece according to the invention is easy to make.

Abstract: An electric furnace for induction heating of metallic products comprises a planar inductor providing a sliding magnetic field, the inductor being incorporated in a pair of transversely spaced walls defining between themselves a space into which the product to be heated is inserted, a layer of refractory material at that side of each wall which borders the space and an independent cooling screen sandwiched between each wall and the respective layer of refractory material, in which the screen is constituted by a plurality of parallel, adjacent metal tubes out of mutual contact with each other to define between themselves electrically insulating spaces, preferably filled with electrically insulating material, and in which the tubes extend normal to the flow of the primary current through the inductor. Preferably at least one of the walls together with the respective refractory layer and screen is movable toward and away from the other wall to accommodate metal products of different widths in the space.

Abstract: Process and apparatus for hydrometallurgical treatment of metallurgical dust by acid leaching followed by a solid-liquid separation. The invention is characterized in that the leaching phase is effected by moderate acid attack (pH at the end of the reaction about 4 or 5) and in which a supplementary solid-solid separation stage is provided, before the solid-liquid separation or after. The invention is applicable to all dusts resulting from treatment of metals, notably ironworking dusts, and particularly those formed in blast furnaces so as to permit the separation and recovery of useful elements contained therein, such as iron, zinc and lead.

Abstract: An apparatus for the preparation of a sample for X-ray spectrometry comprises a crucible for fusible material, a vessel covering the crucible in a first position and serving to receive cast material from the crucible in a second position, an induction coil wherein the crucible is disposed for simultaneously heating the crucible until the material therein is fused and preheating the vessel covering the crucible, a mobile support mounted for rotation about a horizontal axis extending perpendicularly to the axis of the induction coil, the induction coil being affixed to the support and rotation of the support being capable of agitating the crucible during fusion of the material and for turning the crucible from an upright position wherein the material is fused to a casting position wherein the fused material is cast from the crucible, a casting table below the induction coil, and a sliding ramp connecting the casting table to the mobile support for slidingly guiding the vessel from the first to the second positi

Abstract: A process to continuously determine by an optical arrangement the profile of a charge fed into a blast furnace in which the surface of the charge is swept by a beam of light moving in a plane intersecting the surface so as to produce at the intersection of the plane with the surface a luminous trace, observing the luminous trace from a point outside the sweeping plane, and determining on the basis of the data defining the sweeping plane, the observation point and the direction of observation with respect to the plane the true position of the points constituting the luminous trace; and an apparatus for carrying out the process and including an illuminating system for illuminating the surface of the charge with a beam of light sweeping in a plane intersecting the surface to produce on the surface a luminous trace and a reception system cooperating with the illumination system for producing a picture of the actual profile of the luminous trace.

Abstract: An apparatus for cooling an elongated product during its movement through the apparatus comprises an elongated tube having a cooling fluid inlet at one end and a cooling fluid outlet at the other end so that the cooling fluid will flow from the one to the other end through the tube. The product to be cooled passes through the tube either in the same or in a direction opposite to the direction of flow of cooling fluid through the tube. At least one centralizing element is provided in the tube spaced from the opposite ends of the latter and having a central passage coaxial with the tube and a diameter smaller than that of the tube for the passage of the product therethrough, and a plurality of channels uniformly distributed about the central passage to facilitate flow of cooling water from one to the other end of the tube.

Abstract: A cooling jacket for an ingot mold for the continuous casting of metal comprises a tubular element and a grid of stiffening ribs projecting from the outer surface of the tubular element, in which the grid is provided at the intersection of the stiffening ribs with openings or bores which pass also through the tubular element for the passage of fastening elements in form of tie rods therethrough by which an inner tube for the passage of the metal to be cast can be fastened to the cooling jacket with radial clearance. The upright ingot mold in which the cooling jacket is used and which is especially employed for the casting of steel, includes, besides the cooling jacket and the inner tube, an outer shell surrounding the cooling jacket with considerable clearance. The outer shell is closed by plates at opposite ends to which opposite ends of the inner tube are respectively fastened and these plates are provided with openings aligned with the opposite open ends of the inner tube.

Abstract: An electrode, especially for use in metallurgical furnaces or the like containing a bath of molten material which extends through and outwardly beyond the furnace wall while its inner end is in contact with the bath of molten material. A cooling device, in form of a heat pipe, extends centrally through the electrode nearly up to the inner end of the latter and carrying at its outer end projecting beyond the outer end of the electrode a heat exchange device. The electrode includes at its inner end an arrangement for reducing heat convection from the molten material to the electrode.

Abstract: A method of continuous centrifugally casting of metal strands of non-circular, preferably substantially square cross-section, in which the metal continuously passing through an ingot mold of corresponding cross-section is rotated about the longitudinal axis of the mold by means of a rotating magnetic field which may be created by a stationary multi-phase inductor, and wherein the metal in the mold is continuously replenished by a jet of liquid metal impinging on the free surface of the metal in the mold at a point of impact in the neighborhood of one corner of the mold, preferably at a point located on the diagonal substantially midway between the mold wall and the center of the mold. This method causes any slack contained in the metal to concentrate at the center of the free upper metal surface in the mold, from where it can be easily removed.

Abstract: A metallurgical induction heating apparatus has an upwardly cupped induction coil having a housing formed with an upper rim and containing a heavy-duty coil. A crucible formed of a metallic base pan and a metallic holding collar interconnected by a plurality of upright tubular tierods so as to clamp a multiplicity of refractory bricks has an annular upper support body which extends outwardly beyond an upper mounting ring to which the upper ends of the tierods are connected and which rests on the rim of the induction heater. Means is provided for circulating a coolant fluid upwardly through the tierods and into an annular compartment formed inside the support body. A hood may be placed over this arrangement in gas-tight contact with the upper surface of the annular body so that the interior of the crucible can be evacuated or filled with an inert gas.

Abstract: A molten metal is poured into the upper end of a vertically tubular continuous-casting mold and is withdrawn as a hardened casting from the lower end of the mold. An electromagnetic field is displaced upwardly counter-current to the descending metal so as to mix the molten part of the metal and displace non-magnetic inclusions away from the hardening skin of the metal. The mold is operated in accordance with the following formula:B.sup.2 .times.L=(1/.gamma.v)(16d.sup.2 +120d)wherein B equals effective strength of magnetic field in tesla, L equals overall vertical length of field in meters, .gamma. equals electrical conductivity of metal being cast in ohms.sup.-1 .times.meter.sup.-1, v equals vertical travel speed of field in meters/second, and d equals desired surface depth of non-metallic inclusions in millimeters i.e., the distance from the outer surface of the casting in a direction normal to this surface.

Abstract: A method of continuous centrifugal casting of metal products in which molten metal is rotated during the passage through an elongated cooled ingot mold about the axis of the latter and in which the still liquid core of the partly solidified casting as it leaves the ingot mold is subjected to forces counteracting the rotation of the still liquid core of the casting.

Abstract: Stainless steel is produced in a converter with a tuyere defining a central conduit and a peripheral conduit concentrically surrounding the central conduit, by blowing an oxidizing refining gas through the central conduit into a molten metal bath, the refining gas initially consisting of pure oxygen and being subsequently diluted by gaseous argon, and injecting liquid argon into the converter through the peripheral conduit, to refine the molten metal bath until it has attained a desired level of carbon.

Abstract: An electromagnetic apparatus comprising two inductors generating a gliding magnetic field. Each inductor has a plane active face and the faces of the two inductors define a parallelepiped space therebetween to receive an armature. A plurality of pairs of rectilinear electrical conductors at each active face are associated to form two-phase imbricated windings connected in series within each inductor. The input conductor of each inductor is connected to the output conductor to form a single closed winding connected as a Wheatstone bridge. A two-phase generator feeds electric energy to the input conductors, one phase of the generator being connected between the points of junction of the two-phase windings of one inductor and the other generator phase is connected between the points of junction of the two inductors.

Abstract: A composition for forming a protective layer or slag at the surface of molten steel in the mold during a continuous casting process. The composition is constituted by a mixture of a natural silicate of low melting point and an elevated contents of alkaline oxides, a basic compound, a flux and pulverulent carbon. The natural silicate is a feldspar, a nepheline or nepheline-syenite. The composition is intended for use in continuous steel casting processes.

Abstract: A crucible for an induction heating apparatus has a base pan and a collar between which lies a refractory lining. Respective lower and upper mounting rings secured to the base pan and the collar are vertically interconnected by an annular array of non-round-section tierods that are tubular so a coolant can be passed through them. These tierods further have angularly juxtaposed sides which define spaces of outwardly decreasing angular width. Wedge-shaped blocks of refractory and electrically insulating material tightly fit between the sides of the rods and are of outwardly decreasing angular width. Inside these blocks the crucible is lined with further layers of refractory material.

Abstract: In the production of steel from pig iron melted and refined in a vessel, the pig iron is preheated in two phases. In the first preheating phase, the cold pig iron and hot gases recovered from the melting and refining vessel are moved simultaneously through a first and higher rotary tubular furnace whose lower open end is in communication with an upper open end of a second and lower rotary tubular furnace constituting a second preheating phase. The second furnace is heated from the outside to regulate the temperature of the pig iron to a desired value before it is introduced into the vessel from the second furnace.

Abstract: In a method of operating an installation for the agglomeration of a particulate charge of a mineral and combustible material mixture supported on an elongate grid, moving through a treatment path, the position of the point of firing of the charge is determined, this position corresponding to the contact of the local combustion zone of the mixture with the grid and the velocity of displacement of the moving grid being modified to maintain this point of firing at a predetermined position in respect of the path. The installation comprises sampling means for determining the instant at which the temperature of the gas passed through the charge rises, calculating means generating a signal representative of the position of the point of firing, and a comparator unit generating a correction signal for modifying the velocity by comparing the correction signal with a reference signal. This improves the regularity of the firing of minerals to be agglomerated.