A casting slurry for the manufacture of shell molds, including powder particles and a binder, further including a surfactant. Use of such a casting slurry for the manufacture of a shell mold.

Inorganic coated sand in a dry state having refractory aggregate; and an inorganic binder layer formed on a surface of the refractory aggregate, in which the inorganic binder layer contains a metasilicate hydrate.

The present invention relates to investment casting moulds comprising a furnace dust, wherein said furnace dust comprises ZrO.sub.2 and/or Al.sub.2O.sub.3. The present invention also relates to investment casting moulds comprising a metal oxide dust comprising ZrO.sub.2 and one or more materials selected from alumina, silica and aluminosilicate, and wherein said metal oxide dust has a d.sub.50 of 10 μm or less. The invention also relates to compositions for the production of investment casting moulds, the use of dusts in the formation of investment casting moulds, and the use of investment casting moulds of the invention.

The present invention relates to investment casting moulds comprising a furnace dust, wherein said furnace dust comprises ZrO.sub.2 and/or Al.sub.2O.sub.3. The present invention also relates to investment casting moulds comprising a metal oxide dust comprising ZrO.sub.2 and one or more materials selected from alumina, silica and aluminosilicate, and wherein said metal oxide dust has a d.sub.50 of 10 μm or less. The invention also relates to compositions for the production of investment casting moulds, the use of dusts in the formation of investment casting moulds, and the use of investment casting moulds of the invention.

What are described is a process for producing casting molds, cores and mold base materials regenerated therefrom, a mixture for combination with a solution or dispersion comprising waterglass for production of casting molds and/or cores, a molding material mixture, a mold base material mixture, and a casting mold or a core. What is also described is the corresponding use of an amount of particulate sheet silicates having a d.sub.90 of less than 45 μm or a corresponding mixture as additive for production of a molding material mixture comprising waterglass and particulate amorphous silicon dioxide, which is cured by chemical reaction of constituents of the molding material mixture with one another, in the production of a casting mold or a core, to facilitate the breakdown and/or to increase the regeneratability of the casting mold or core.

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.

An expandable aggregate mixture for a mold, which contains an aggregate, a water-soluble binder, a water-soluble foaming agent, water, and spherical metal oxide particles.

A method for inorganic binder casting, comprising: selecting a Shape-Forming Material based on pre-determined manufacturing and shape characteristics, selecting a casting shape based on pre-determined design characteristics, and forming the Shape-Forming Material into a mold. The mold is coated with an inorganic binder solution at a pre-defined weight ratio and is dehydrated the Shape-Forming Material. The method further comprises pouring a hot liquid metal into the mold and allowing said hot liquid metal to cool to form a molded part. The Shape-Forming Material may be washed from said molded part with a solvent, the inorganic material and Shape-Forming Material reclaimed, reused, and the Shape-Forming Material reformed to a mold. The method further comprises recreating a liquid inorganic binder solution using the reclaimed inorganic material and recoating the Shape-Forming Material with the reclaimed inorganic binder solution.

A method of reusing core sand includes crushing a core used for casting into granules, the core includes water glass as a binder, and the water glass includes water-soluble water glass and water-insoluble water glass; heating the core; detaching the water glass from the core sand; and separating and collecting the core sand from a mixture of the water glass and the core sand.

What are described is a process for producing casting molds, cores and mold base materials regenerated therefrom, a mixture for combination with a solution or dispersion comprising waterglass for production of casting molds and/or cores, a molding material mixture, a mold base material mixture, and a casting mold or a core. What is also described is the corresponding use of an amount of particulate sheet silicates having a d.sub.90 of less than 45 μm or a corresponding mixture as additive for production of a molding material mixture comprising waterglass and particulate amorphous silicon dioxide, which is cured by chemical reaction of constituents of the molding material mixture with one another, in the production of a casting mold or a core, to facilitate the breakdown and/or to increase the regeneratability of the casting mold or core.