Both a hydraulic (wet) separation process and a dry separation process are used in combination to recover sand, bentonite clay and organics from foundry waste created during operation of a green sand foundry. These recovered ingredients are then recycled for reuse in making additional green sand molds.

A composition for making a core for use in a moulding or casting process, a core comprising said composition, and a mould for producing an article by high pressure die casting or semi-solid casting. The composition comprises a particulate refractory material, a binder composition comprising at least one hydrophilic polymer, comprising at least one polysaccharide or polysaccharide derivative; and at least one pozzolanic additive. The mould comprises a core for defining an internal cavity of the article and the core comprises a solidified core composition. The solidified core composition comprises a particulate refractory material and a binder composition, degrades in water such that a cylinder of the solidified core composition having a maximum height of 80 mm and a maximum diameter of 50 mm disintegrates in no more than 10 minutes when immersed in water at a temperature of 20° C. and stirred at a speed of 60 rpm, and has a flexural strength of at least 300 N/cm.sup.2. The invention also resides in a method for producing an article by high pressure die casting or semi-solid casting.

A composition for making a core for use in a moulding or casting process, a core comprising said composition, and a mould for producing an article by high pressure die casting or semi-solid casting. The composition comprises a particulate refractory material, a binder composition comprising at least one hydrophilic polymer, comprising at least one polysaccharide or polysaccharide derivative; and at least one pozzolanic additive. The mould comprises a core for defining an internal cavity of the article and the core comprises a solidified core composition. The solidified core composition comprises a particulate refractory material and a binder composition, degrades in water such that a cylinder of the solidified core composition having a maximum height of 80 mm and a maximum diameter of 50 mm disintegrates in no more than 10 minutes when immersed in water at a temperature of 20° C. and stirred at a speed of 60 rpm, and has a flexural strength of at least 300 N/cm.sup.2. The invention also resides in a method for producing an article by high pressure die casting or semi-solid casting.

Investment casting shell composition binders comprising hydrophilic fibrils having an average diameter between about 1 nm and about less than 1 μm can be used for the preparation of investment casting shell compositions or slurries. The investment casting shell binders and compositions can be used in an investment casting process to produce investment casting shells with improved shell build thickness and strength.

A sand additive for use in a “no bake” foundry mix composition having a polyurethane-based binder system reduces the amount of smoke emitted when molds and cores formed from the composition are exposed to molten metal, as compared to when the sand additive is not used. The sand additive comprises yellow iron oxide having the chemical formula Fe(OH).sub.3. It can also comprise at least one of red iron oxide, black iron oxide and wüstite. In such cases, the yellow iron oxide accounts for about 10 to about 40 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wüstite, and preferably, about 20 to about 30 weight percent of the combined weight of the yellow iron oxide, red iron oxide, black iron oxide and wüstite.

A powder binder product for use in making a slurry for investment casting molds comprising Nano-sized powders; and an organic polymer powder, wherein it does not require aqueous colloidal silica to produce slurries used to build investment casting molds. The Nano-sized powders comprise fumed alumina, boehmite, fumed silica, or fumed titanium oxide or combinations thereof. The coarse refractory powder, combined with the powder binder for mold manufacture, comprises milled zircon, tabular alumina or fused alumina, fused silica, alumino-silicate, zirconia, and yttria or combinations thereof. The organic polymer in a powder binder comprises a cellulose-based material. A powder investment casting binder, that once fired, consists of up to 96 weight percent aluminum oxide.

What is described is the use of a composition containing one or more formaldehyde scavengers for production of a coating on a main body of a mold or core for metal casting that emits formaldehyde when heated, wherein the coating forms a surface of the mold or core that comes into contact with a metal melt in the casting operation.

Provided are a binder in the producing of a casting sand mold according to an ink jet type lamination shaping method in which a binder is printed with respect to sand, a method for producing the binder, and a method for producing a casting sand mold using the binder. Specifically, provided are a binder useful for a casting sand mold of an ink jet type, containing: a resol-type phenolic resin that is obtained by reacting aldehydes (A1), phenols (P1), and a compound (N) having two or more phenolic hydroxyl groups in one molecule or by reacting the aldehydes (A1) and a novolac-type phenolic resin (N1), in the presence of an alkali catalyst, and has a dispersion degree (Mw/Mn) of 1.0 to 3.5 and a phenolic monomer residue of 5% or less, a method for producing the binder, and a method for producing a casting sand mold.

The present invention relates to a method of disintegrating a foundry mold comprising sand and a polyurethane binder. The present invention further relates to a method of disintegrating a foundry mold by contacting it with a composition comprising at least one carboxylic acid amide and at least one tyalkanolamine.

A process (i) for producing a metal casting or (ii) for producing a cured shaped part for use in the casting of metallic castings is described. Furthermore, the use of an aliphatic polymer which comprises structural units containing hydroxy groups and has been crosslinked by etherification as binder of a shaped part for use in the casting of metallic castings is described. A shaped part for use in the casting of metallic castings, comprising at least one base mould material and a cured binder comprising or consisting of an aliphatic polymer which comprises structural units containing hydroxy groups and has been crosslinked by etherification, is likewise described. In addition, a cured shaped part which is producible by a process according to the invention and also a mould material mixture for use in the process of the invention are described.