Described is a method of preparing a particulate refractory composition for use in the manufacture of foundry moulds and cores from spent foundry moulds or cores formed of refractory material and a binder containing water glass, the method comprising the following steps: providing broken material from spent foundry moulds or cores or preparing broken material from spent foundry moulds or cores, wherein the broken material comprises particles and/or aggregates of particles of refractory material having hardened water glass binder on their surface, mixing the broken material with particulate amorphous oxide comprising silicon dioxide in an amount of 85% by weight or more, based on the total amount of the particulate amorphous oxide, to give a mixture and subjecting the mixture to a heat treatment at a temperature of 400° C. or higher. Also described are a corresponding use, a reclamation mixture, and a method of making a foundry mould or core.

A water supply and kneading system for green sand, including: a weighing hopper that stores green sand that has been weighed; a kneading machine that kneads the green sand and water; a sand loading means for releasing the green sand in the weighing hopper into the kneading machine, or shutting off the release; a water supply device that supplies water to the green sand in the kneading machine; a moisture sensor that includes a pair of electrodes and measures the moisture content of the green sand stored in the weighing hopper by measuring an electric potential difference between the electrodes; and a kneading control device that controls the amount of water supplied by the water supply device and controls the sand loading means on the basis of the output of the moisture sensor.

According to one embodiment a solid component mixing apparatus is provided that includes a mixing device, a first dosing device for supplying sand and a second dosing device for supplying a solid additive that are communicated with the mixing device. The mixing device includes a vertical mixing chamber with a rectangular cross-section, the contour of the chamber being formed by four side walls, such that two side walls opposite one another are wider than the other two walls. The chamber includes a first inlet communicated with the first dosing device and a second inlet communicated with the second dosing device, the second inlet being at a lower height than the first inlet, and the second inlet being arranged in one of the wider side walls of the chamber. Associated mixing methods are also provided.

Described is a method of preparing a particulate refractory composition for use in the manufacture of foundry moulds and cores from spent foundry moulds or cores formed of refractory material and a binder containing water glass, the method comprising the following steps: providing broken material from spent foundry moulds or cores or preparing broken material from spent foundry moulds or cores, wherein the broken material comprises particles and/or aggregates of particles of refractory material having hardened water glass binder on their surface, mixing the broken material with particulate amorphous oxide comprising silicon dioxide in an amount of 85% by weight or more, based on the total amount of the particulate amorphous oxide, to give a mixture and subjecting the mixture to a heat treatment at a temperature of 400° C. or higher. Also described are a corresponding use, a reclamation mixture, and a method of making a foundry mould or core.

Described is a method of preparing a particulate refractory composition for use in the manufacture of foundry moulds and cores from spent foundry moulds or cores formed of refractory material and a binder containing water glass, the method comprising the following steps: providing broken material from spent foundry moulds or cores or preparing broken material from spent foundry moulds or cores, wherein the broken material comprises particles and/or aggregates of particles of refractory material having hardened water glass binder on their surface, mixing the broken material with particulate amorphous oxide comprising silicon dioxide in an amount of 85% by weight or more, based on the total amount of the particulate amorphous oxide, to give a mixture and subjecting the mixture to a heat treatment at a temperature of 400° C. or higher. Also described are a corresponding use, a reclamation mixture, and a method of making a foundry mould or core.

A chemical regeneration method of water glass used sand, which belongs to the field of resource recycling in the casting industry. The present invention adopts a two-component reagent composed of calcium oxide and tap water, an emulsion composed of sucrose and calcium oxide, and a calcium chloride aqueous solution to process the regeneration of the used sand, and prepares the sample of the reclaimed sand obtained after the reagent mixed with the used sand is sealed and placed for 0 to 24 hours respectively, and tests the properties of the sample including: initial strength, final strength and collapsibility, and sodium carbonate content, and compares the properties of raw sand and used sand after the tests. Among several regeneration methods, each property index of the reclaimed sand obtained by using calcium oxide and tap water to regenerate for 12 hours is the best.

The invention provides a method for the cost-effective, resource-saving and highly productive recovery of moulding sand (F) from a foundry sand mixture (G), which comprises at least one proportion (FAB) of moulding material fragments or loose moulding material grains, which accumulates when a cast part is demoulded from a casting mould as a result of the destruction of casting cores or moulded parts representing the cast part which have been formed from the moulding sand (F) and an inorganic binder and optionally one or a plurality of additives to set the properties of the moulding material, wherein the method comprises the work steps a) mixing the foundry sand mixture (G) with cleaning water (RW) to form a slurry (S) in order to dissolve the inorganic binder residues (AB) contained in the foundry sand mixture (G) and optionally present additives from the moulding sand (F) and to rinse them out of the foundry sand mixture (G),
and b) separating the cleaning water (RWK) contaminated with the inorganic binder residues (AB) from the moulding sand (F) contained in the slurry (S),
and wherein the process temperature of the slurry (S) formed from the cleaning water and the foundry sand mixture (G) (work step a)) is 50 to 200° C.

A casting mold making apparatus and a method employing a tank with a pour hole formed at a bottom wall of the tank and an opening section open toward the opposite side to a bottom wall side. A first process of the method includes stirring component materials inside the tank with a stirring impeller so as to make a foam mixture while an opening section side of the tank is closed and the pour hole is closed. The second process is performed after the first process and includes opening the pour hole, pressing the tank against a mold such that a fill hole formed so as to pass into the mold is disposed adjacent to the pour hole, and supplying compressed air into the tank while stirring the foam mixture inside the tank with the stirring impeller so as to fill the foam mixture into a cavity of the mold.

A casting method is provided that includes a mold, a mixer, and first and second materials. A first pour and a second pour are dispensed from the mixer. The first pour has different proportions of the first and second materials as compared to the second pour. The first pour forms a first layer of a molded part, and the second pour forms a second layer of the molded part.

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.