Provided are: a coated sand having improved fluidity and being capable of improving a filling rate of a casting mold to be obtained; and a coated sand for advantageously manufacturing a casting mold having excellent strength, which coated sand provides a casting mold with good mold-releasability and collapsibility, gives cast products a favorable casting surface, and effectively improves sand adhesion on cast products. The coated sand is formed as a dry granular material having fluidity at room temperature, in which the surface of a refractory aggregate is coated with a solid layer of a water-soluble inorganic binder, and spherical particles of silicone resin having binder-repellency exist on the surface of the binder layer, or form a layer on the surface of the binder layer, a part of the spherical particles being not covered with the water-soluble inorganic binder and being exposed.

The present disclosure generally relates to partial integrated core-shell investment casting molds that can be assembled into complete molds. Each section of the partial mold may contain both a portion of a core and portion of a shell. Each section can then be assembled into a mold for casting of a metal part. The partial integrated core-shell investment casting molds and the complete molds may be provided with filament structures corresponding to cooling hole patterns on the surface of the turbine blade or the stator vane, which provides a leaching pathway for the core portion after metal casting. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.

The present disclosure generally relates to partial integrated core-shell investment casting molds that can be assembled into complete molds. Each section of the partial mold may contain both a portion of a core and portion of a shell. Each section can then be assembled into a mold for casting of a metal part. The partial integrated core-shell investment casting molds and the complete molds may be provided with filament structures corresponding to cooling hole patterns on the surface of the turbine blade or the stator vane, which provides a leaching pathway for the core portion after metal casting. The invention also relates to core filaments that can be used to supplement the leaching pathway, for example in a core tip portion of the mold.

A foundry mix includes a major amount of a foundry aggregate and an effective binding amount of a binder system. The binder system cures in the presence of sulfur dioxide and a free radical initiator. The binder system may include (1) 10 to 70 parts by weight of an epoxy novolac resin; (2) 0.5 to 10 parts by weight of resorcinol; (3) 20 to 70 parts by weight of a monomeric or polymeric acrylate; and (4) an effective amount of a free radical initiator. Notably, (1), (2), (3) and (4) are separate components or mixed with another of said components, provided (4) is not mixed with (3) until a foundry mix is to be created, where said parts by weight are based upon 100 parts of the binder system.

What is described are isocyanate compositions comprising β-dicarbonyl compounds and a binder system, especially for use in a process from the group consisting of polyurethane cold-box process and polyurethane no-bake process, with this isocyanate composition as polyisocyanate component.

A method for producing a sand mold includes mixing artificial sand with a furan resin composition including a furan resin precursor, preparing molding sand having the artificial sand and a surface-modified layer containing a resin cured product covering the artificial sand and including a curing agent attached to the surface-modified layer by mixing the curing agent including xylene sulfonic acid with the artificial sand with which the furan resin composition is mixed, and curing the furan resin composition, after mixing the artificial sand with the furan resin composition, and curing an added portion of the binder in the molding sand by adding the binder to the molding sand. In the step of curing the added portion of the binder, the curing agent for curing the furan resin composition is used also as a curing agent for curing the binder.

The subject matter of the invention are sizing compositions containing an aqueous carrier liquid, refractory base materials and CH-acidic compounds, as well as their use for casting molds, as well as casting molds coated with the sizing composition.

Curable compositions contain at least one polymerizable ionic species and, when cured (for example, by photocuring), provide cured compositions which are thermoplastic and yet fragmentable by a protic liquid medium such as water. The polymerizable ionic species corresponds to Formula (I) A+B− wherein A+ is a cationic species having a cationic functional group and a first polymerizable, ethylenically unsaturated functional group; and B″ is an anionic species having an anionic functional group and a second polymerizable, ethylenically unsaturated functional group which is the same as or different from the first polymerizable, ethylenically unsaturated functional group. The curable compositions are useful for forming sacrificial or temporary articles, for example by three-dimensional printing methods.

The present disclosure includes binder systems for making foundry articles. The binder systems may comprise a humic substance-containing component that comprise lignite, an isocyanate component, and a catalyst component. The binder systems may be mixed with an aggregate (e.g., sand) for making foundry articles such as molds and cores. Also disclosed herein are methods of making foundry articles using the binder systems.

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.