Abstract: A method of melting and casting metal comprising the steps of melting metal in a melting vessel, transferring metal from the melting vessel into a casting vessel by flow of metal under gravity and pumping metal against gravity from the casting vessel into a mold. The level of the top surface of the metal as the metal leaves the melting vessel is above the top surface of the metal in the casting vessel by not more than a maximum distance above which excessive turbulence occurs. The maximum distance lies in the range 50-200 mm.

Abstract: Method of and apparatus for making metal castings using a polystyrene pattern 10 embedded in unbonded sand 20 which is consolidated to form a mould M in which is defined a mould cavity C. Molten metal is fed into the cavity C and permitted to solidify to form a casting 11. The metal is aluminum or an aluminum alloy and at least part of the mould is formed of sand which comprises at least 50% zircon sand, or other particulate material suitable for making a mould and having a bulk density lying in the range 2-3 grams/cc. The mould M may have a moulding feature 9 having upper and lower surfaces for contact with the metal and which projects inwardly of the mould cavity C from the main wall thereof and the length of any one section of the molding feature 9 being at least twice the thickness of the thinnest part thereof by which the section is connected to the main wall of the mould cavity.

Abstract: A method of making a casting comprising the steps of, at a casting station, feeding molten metal from a primary source of molten metal into a mould cavity through an ingate below the top of the mould cavity, placing the cavity out of feeding relationship with the primary source by changing the orientation of the cavity relative to the direction of gravity to prevent flow of molten metal from the cavity towards the primary source and to permit of flow of metal from a secondary source to the cavity, the cavity being continuously connected to the primary source during said change of orientation, transferring the mould cavity to a cooling station spaced from the casting station and, at the cooling station, permitting molten metal to flow to the cavity from the secondary source while the metal in the cavity solidifies.

Abstract: A method of casting metal articles by feeding molten metal upwardly against the force of gravity from a source of molten metal into a mould cavity where the metal is permitted to solidify within the cavity after which the metal feed is interrupted and the casting is removed from the cavity. The mould cavity is made by embedding an in situ destroyable pattern in particulate moulding material to form a mould cavity. The pattern may be destroyable in situ by the heat of the metal as it is fed into the mould cavity or by applying heat prior to feeding the metal into the cavity. The source of metal may be a reservoir located at a level below the level of the cavity with a pump to pump metal upwardly into the cavity through a riser tube. The metal to be cast may be supplied to the reservoir in molten state or in solid state and melted in the reservoir.

Abstract: A method and apparatus for treating granular materials which require to be heated to drive off volatile constituents and which require to be cooled, for example foundry sand containing an organic binder. The method comprises the step of maintaining a mass of the material at a treatment temperature lying in the range 250.degree.-400.degree. C. for between four and thirty hours. The mass may be initially heated by virtue of a manufacturing process in which the mass has been previously used. Alternatively, the mass may be initially heated by a pre-heating step such as heating in a fluidized bed. Alternatively, the mass may be heated by being placed in heat transfer relationship with a second mass of the material which has been previously heated, for example, in a fluidized bed. Apparatus for performing the method is also disclosed.

Abstract: A chemically bondable foundry sand comprising a mixture of sand, binder and a plurality of fibres intimately mixed and dispersed throughout the mixture. Cores and moulds made from such sand have improved fracture resistance. The mixture may comprise from 0.01 to 1.0 wt. % of fibres, the length/diameter ratio of each fibre may be at least 10 and the fibres may have a length of from 1 to 20 mm. The fibres may be glass fibres, organic fibres or natural fibres. The binder may comprise a silicate binder or an organic binder such as a phenolic binder or a furane binder.

Abstract: A method and apparatus for treating granular materials which require to be heated to drive off volatile constituents and which require to be cooled, for example foundry sand containing an organic binder. The method comprises the step of maintaining a mass of the material at a treatment temperature lying in the range 240.degree. C.-400.degree. C. for between four and thirty hours. The mass may be initially heated by virtue of a manufacturing process in which the mass has been previously used. Alternatively, the mass may be initially heated by a preheating step such as heating in a fluidized bed. Alternatively, the mass may be heated by being placed in heat transfer relationship with a second mass of the material which has been previously heated, for example, in a fluidized bed. Apparatus for performing the method is also disclosed.