Abstract: An exothermic composition comprises a particulate readily oxidizable metal such as aluminum, magnesium or silicon and an organic fluorine-containing compound, and usually an oxidizing agent for the readily oxidizable metal. The preferred organic fluorine-containing compound is polytetrafluoroethylene. The composition may also contain a binder, a particulate refractory material, refractory fibres and/or organic fibres. The composition may be used in the casting of molten metal, either in particulate form or as a preformed shape such as a sleeve or board, to cover or surround molten metal in the feeder of a casting mould or in the head or head box of an ingot mould.

Abstract: A mould (61) for metal casting has a mould cavity (62) and a sprue (63) communicating directly with the mould cavity (62) and located in the sprue (63) a sleeve (64) of refractory material having a cellular ceramic filter (65) fixed therein. The mould, which has no running system apart from the sprue, may be a sand mould or a metal die for producing castings by gravity or low pressure diecasting. The cellular ceramic filter may be a honeycomb type of structure having cells which extend between two outer surfaces of the filter or a structure having interconnecting cells such as a ceramic foam.

Abstract: A mould (61) for metal casting has a mould cavity (62) and a sprue (63) communicating directly with the mould cavity (62) and located in the sprue (63) a sleeve (64) of refractory material having a cellular ceramic filter (65) fixed therein. The mould, which has no running system apart from the sprue, may be a sand mould or a metal die for producing castings by gravity or low pressure diecasting. The cellular ceramic filter may be a honeycomb type of structure having cells which extend between two outer surfaces of the filter or a structure having interconnecting cells such as a ceramic foam.

Abstract: An exothermic composition comprises a particulate readily oxidizable metal such as aluminium, magnesium or silicon and an organic fluorine-containing compound, and usually an oxidizing agent for the readily oxidizable metal. The preferred organic fluorine-containing compound is polytetrafluoroethylene. The composition may also contain a binder, a particulate refractory material, refractory fibres and/or organic fibres. The composition may be used in the casting of molten metal, either in particulate form or as a preformed shape such as a sleeve or board, to cover or surround molten metal in the feeder of a casting mould or in the head or head box of an ingot mould.

Abstract: A riser sleeve has at its end which is uppermost when the sleeve is located in the mould a holding member which can be engaged by a mechanical holding device so as to adapt the sleeve to automatic handling. The holding member may be for example a disc, ring or solid or hollow cylinder and may be formed integrally with the sleeve or formed separately and fixed to the sleeve. By adopting a standard shape and size for the holding member for a wide range of sleeve shapes and sizes the same holding device can be used to handle the whole range of sleeves.