Abstract: A process for making a filter suitable for filtering molten metal comprising (i) forming a slurry comprising (a) particles of a refractory material, (b) a binder and (c) a liquid carrier, (ii) coating a disposable former with a slurry, (iii) drying the coated former, (iv) optionally applying one or more additional coats of a refractory material and/or a binder, optionally with liquid carrier, and drying the one or more additional coats, and (v) firing the coated former to produce the filter, wherein the binder is a carbon rich source selected from one or more of the following classes of materials: pitches, tars and organic polymers that degrade to form carbon on pyrolysis.

Abstract: The present invention relates to a feeder element (10) for use in metal casting. The feeder element (10) (which serves the function of a breaker core) has a first end (16) for mounting on a mould plate (24), an opposite second end (18) for receiving a feeder sleeve (20) and a bore (14) between the first and second ends (16,18) defined by a sidewall (12). The feeder element (10) is compressible in use whereby to reduce the distance between said first and second ends (16,18). The invention also relates to a breaker core/feeder sleeve assembly (10,20).

Abstract: A seal, particularly for use with a ladle shroud in the casting of molten metal from a ladle, comprises an intumescent composition containing expandable graphite from which some, but not all, of interstitial water present therein has been removed. The interstitial water can be driven off from known expandable graphite by heating it to between approximately 230° C. and 280° C. for approximately 30 minutes. Once part of its interstitial water has been removed, the expandable graphite is used to produce the intumescent composition, which is then formed/shaped into the required seal.

Abstract: The present invention relates to an electrochemical sensor for determining the concentration of a group IA metal in a fluid such as molten metal. The sensor comprises a substantially pure quantity of the group 1A metal as a reference electrode (13) contained in a sensor housing (3), and a solid electrolyte constituting at least part of the sensor housing (3). The electrolyte is in electrical contact with the reference electrode (13) and the sensor is capable of operating at temperatures in excess of 973K. In a preferred arrangement, the sensor comprises a two part elongate conductor (15), a first part (17) of which extends from the reference electrode (13) into a refractory seal (11a), and a second part (19) of which extends from within the refractory seal (11a) externally of the sensor, the two parts (17, 19) being welded together.

Abstract: A filter for molten metal is an open-pored porous material comprising particles of refractory material embedded in and bonded together by a carbon matrix bonding material. The filter can be made by forming a porous article from refractory particles, e.g. refractory oxide, carbide or graphite, and a carbon-rich binder, e.g. tar, pitch or an organic (preferably aromatic) polymer that degrades to form carbon on pyrolysis, and then firing the porous article to generate the carbon matrix in which the refractory particles are embedded. The porous article is preferably made by coating a reticulated polyurethane foam with binder and refractory particles, and firing at preferably no higher than 800° C.

Abstract: A filter for molten metal is an open-pored porous material comprising particles of refractory material embedded in and bonded together by a carbon matrix bonding material. The filter can be made by forming a porous article from refractory particles, e.g. refractory oxide, carbide or graphite, and a carbon-rich binder, e.g. tar, pitch or an organic (preferably aromatic) polymer that degrades to form carbon on pyrolysis, and then firing the porous article to generate the carbon matrix in which the refractory particles are embedded. The porous article is preferably made by coating a reticulated polyurethane foam with binder and refractory particles, and firing at preferably no higher than 800° C.

Abstract: A filter for molten metal is an open-pored porous material comprising particles of refractory material embedded in and bonded together by a carbon matrix bonding material. The filter can be made by forming a porous article from refractory particles, e.g. refractory oxide, carbide or graphite, and a carbon-rich binder, e.g. tar, pitch or an organic (preferably aromatic) polymer that degrades to form carbon on pyrolysis, and then firing the porous article to generate the carbon matrix in which the refractory particles are embedded. The porous article is preferably made by coating a reticulated polyurethane foam with binder and refractory particles, and firing at preferably no higher than 800° C.

Abstract: Stopper rods for the continuous casting of molten metal have a stopper rod body, and a stopper rod tip at a lower end of the stopper rod body. The stopper rod tip defines a frustroconically shaped exterior surface which terminates in a recessed nose. The recessed nose is most preferably a curvilinear surface (e.g., a spherical segment), but non-curvilinear surfaces (e.g., prismatic, pyramidal, triangular, and quadrangular surfaces) may alternatively be employed. The frustroconically shaped exterior surface of the stopper rod tip most preferably forms an angle ? with respect to a horizontal plane which is sufficiently great so as to increase the velocity of the flowing molten metal to reduce the boundary layer thickness thereof adjacent the nozzle and stopper rod tip surfaces so as to minimize the deposition of inclusions thereon.

Abstract: A liner for a ladle is formed of a body of refractory material defining a hollow interior which is bounded by a continuous sidewall. Within the interior is a barrier of refractory material which faces the interior surface of part of the sidewall and is spaced inwardly therefrom in the hollow interior of the body to define with said facing part of said sidewall a spout for discharging molten metal, in use, from the ladle. The barrier has two longitudinal edge surfaces received at two facing inner portions of the sidewall respectively which are extended inwardly. By providing these inward extensions the barrier can be positioned within the interior of the liner thereby obviating the need for an outward extension from the liner body to define a spout. This enables the liner to be used with ladle shells without the shell requiring modification to accommodate such an outward extension.

Abstract: A tundish impact pad formed from refractory material comprising a base having an impact surface which, in use, faces upwardly against a stream of molten metal entering a tundish, a wall extending upwardly from the base around at least a part of the periphery of the impact surface, one or more portions of the upper part of the wall supporting one or more overhangs which project inwardly over the periphery of the base. At least one of said overhangs has at least a part whose under-surface curves or slopes, the curvature or slope lying in a direction along the length of the wall. Preferably the pad has rectangular base and a pair of opposite walls is provided with an overhang that arches upwardly towards the centre of the wall. An overhang on the second pair of walls can be, for example, planar and parallel to the base. The width of the curved or sloping overhangs increases in both directions away from its centre/top.

Abstract: A liner for a ladle is formed of a body of refractory material defining a hollow interior which is bounded by a continuous sidewall. Within the interior is a barrier of refractory material which faces the interior surface of part of the sidewall and is spaced inwardly therefrom in the hollow interior of the body to define with said facing part of said sidewall a spout for discharging molten metal, in use, from the ladle. The barrier has two longitudinal edge surfaces received at two facing inner portions of the sidewall respectively which are extended inwardly. By providing these inward extensions the barrier can be positioned within the interior of the liner thereby obviating the need for an outward extension from the liner body to define a spout. This enables the liner to be used with ladle shells without the shell requiring modification to accommodate such an outward extension.

Abstract: A process for forming a mould or a core for casting molten metal by machining (e.g. cutting or drilling) to the desired shape a bonded particulate refractory material wherein the shear strength of the refractory particles is less than the shear strength of the bonds between the particles. The preferred particulate is aluminosilicate microspherers (e.g. “flyash floaters”) and the binder is preferably based on silica (e.g. fumed silica/sodium hydroxide). The bonded particulate material is easily machined to form accurately dimensioned moulds or parts thereof.

Abstract: A tundish impact pad formed from refractory material, the impact pad (1) comprising a base (3) having an impact surface (5) which in use faces upwardly to receive molten metal poured onto the impact pad, and a wall (7) extending upwardly from the base around at least part of the periphery of the impact surface, the wall including an overhang (9) projecting over a peripheral region (11) of the impact surface (5), the overhang (9) including a plurality of protrusions (13) which project further over the impact surface (5) than the remainder of the overhang (5).

Abstract: A method and apparatus for adding a metal, for example sodium, to a melt of a material, for example aluminum, in a vessel, in which a molten compound of the metal or a solution of a compound of the metal is provided in a container (12), the container being positioned outside the vessel, the compound is electrolytically decomposed and ions of the metal are caused to pass through a wall of a solid-state electrolyte (14) which is a conductor therefor, from a first side of the wall to an opposite second side thereof, and to combine with electrons at the second side of the wall and then to flow as molten metal from the container into the melt in the vessel.

Abstract: A tundish of improved flow characteristics for molten metal has an outlet in its base. The outlet is spaced longitudinally of the tundish from a pour zone. The pour zone is positioned to receive a stream of molten steel from a ladle. An impact pad is provided on the floor of the tundish in the pour zone, the impact pad comprising a base having an impact surface, an upwardly extending side wall along the periphery of the base, the side wall having an inner surface with an undercut portion to face the incoming steel stream, and the undercut portion having a surface shape to receive and reverse the direction of flow of the incoming stream. A dam is positioned between the impact pad and the outlet. The dam has one or more holes to allow through-passage of a proportion of the steel, and the dam extends upwardly from the tundish floor about 40-60% of the height of the uppermost level of steel in the tundish.

Abstract: A molten metal handling vessel, comprising a base and one or more sidewalls surrounding the base and extending upwardly therefrom, the interior surfaces of the base and sidewall(s) each comprising a lining formed from refractory material, the sidewall lining including a ledge spaced a distance from the base lining, the ledge projecting inwardly into the interior of the vessel and extending around at least a quarter of the periphery of the base, and all parts of the sidewall lining below the ledge projecting at least as far into the vessel as does the ledge.

Abstract: A nozzle for guiding molten metal flowing from a vessel into a mould, the nozzle comprising a conduit which is elongate along an axis which is oriented substantially vertically during use, the nozzle having at least one upper inlet, at least two lower outlets which are inclined to the axis, and at least one lower outlet located generally axially between the inclined outlets, the minimum combined cross-sectional area of the inclined outlets being at least twice as great as the minimum combined cross-sectional area of the one or more generally axially located outlets.

Abstract: A filter assembly for filtering molten metal poured into a mold includes a filter formed from refractory material, the filter having first and second porous surfaces through which molten metal may flow, and a peripheral surface and a locator attachable to at least one of the first, second and peripheral surfaces of the filter and arranged to extend from the at least one of the first, second and peripheral surfaces of the filter to another of the first, second and peripheral surfaces or to another part of those surface(s), during use. The locator locates the filter in a mold into which molten metal is poured.

Abstract: A bonded particulate material and a method for forming an bonded particulate material are defined. The material includes a particulate metal oxide that is capable of forming a metalate in the presence of an alkali. The metal oxide particles are typically dissolved in a solution of the alkali and then dried, such that an undissolved metal oxide core remains, surrounded by a metalate which is in turn bonded to metalate of adjacent particle and/or to a fill material.

Abstract: Ceramic compositions which are of particular value in the handling or casting of steel, for example as lining materials or for producing nozzles or shrouds used in continuous casting, comprise a mixture of particles of boron nitride, zirconium diboride and at least one other refractory material, bonded together by carbon produced by the decomposition of an organic binder such as a resin or pitch. The other refractory material may be for example a refractory metal, an oxide, a carbide, a boride or a nitride. Zirconium oxide containing compositions comprising 5-70% by weight boron nitride, 5-60% by weight zirconium diboride and 5-80% by weight of zirconium oxide are particularly suitable for forming at least that part of a nozzle which in use is at the slag line in a molten steel vessel.