Abstract: The invention relates to an exothermic molding material mixture for producing feeders for casting aluminum, comprising at least: - a fireproof base molding material; - a binder; - a proportion of an oxidizable metal of from 5 to 18% by weight relative to the molding material mixture; - an oxidizing agent at a proportion of 10 to 50% by weight relative to the quantity of oxidizing agent required for completely oxidizing the oxidizable metal; and - an igniter for oxidizing the oxidizable metal at a proportion of 15 to 50% by weight relative to the quantity of the oxidizable metal. A feeder made of the exothermic molding material mixture ignites reliably, even at low temperatures, and is characterized by low heat emission. It is therefore particularly suitable for casting aluminum.

Abstract: A process for producing a mold includes introducing a composition including a particulate, refractory material and a binder into a hollow model having an interior cavity which determines contours of all surfaces of the mold or a mold part, wherein the model includes at least two separate parts to permit removal of the mold, and applying a second composition containing at least one organosilicon component and at least one solvent to at least one of the separable parts before use.

Abstract: The invention relates to a moulding mixture for producing casting moulds for metalworking, a process for producing casting moulds, casting moulds obtained by the process and also their use. To produce the casting moulds, a refractory mould raw material and a binder based on water glass are used. A proportion of a particulate metal oxide selected from the group consisting of silicon dioxide, aluminium oxide, titanium oxide and zinc oxide is added to the binder. Particular preference is given to using synthetic amorphous silicon dioxide as metal oxide.

Abstract: The invention relates to a molding composition for producing insulating or exothermic feeders and other filling funnels and feeding elements for casting molds, which comprises at least: at least 10% by weight of a porous refractory material which has a continuous open pore structure; a binder for curing the molding mixture; if appropriate, a refractory filler; a proportion of a reactive aluminum oxide having a specific surface area of at least about 0.5 m2/g and an average particle diameter (D50) of from about 0.5 to 8 ?m. The invention further relates to a process for producing a feeder and other filling funnel or feeding elements for casting molds; feeders, filling funnels or feeding elements for casting molds which are obtained by the process and also their use for producing metal castings. The feeders and further shaped bodies for the foundry industry obtained from the molding composition of the invention have a particularly high gas permeability and a low density.

Abstract: The invention relates to a moulding mixture for producing casting moulds for metalworking, a process for producing casting moulds, casting moulds obtained by the process and also their use. To produce the casting moulds, a refractory mould raw material and a binder based on water glass are used. A proportion of a particulate metal oxide selected from the group consisting of silicon dioxide, aluminium oxide, titanium oxide and zinc oxide is added to the binder. Particular preference is given to using synthetic amorphous silicon dioxide as metal oxide.

Abstract: The present invention relates to a process for producing shaped bodies, in particular cores, molds and feeders in foundry technology, which comprises the following steps: a. Preparation of a composition comprising i. at least one phenolic resin in solid form, ii. at least one polyisocyanate, and iii. at least one refractory material, with the composition being prepared at a temperature which is below the melting point of the at least one phenolic resin; b. Molding of the composition to form a shaped body; c. Raising of the temperature of the composition to above the melting point of the at least one phenolic resin to cure the mixture. The invention also relates to shaped bodies, in particular cores, molds and feeders for foundry technology, which are obtainable by this process, and also a composition as is used in this process.