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.

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.

An air wash abrasive particle separator apparatus which separates contaminants from previously-used abrasive particles contained in a contaminated abrasive particle mixture such that the abrasive particles may be re-used multiple times, the apparatus being in combination a contaminated abrasive particle mixture delivery device, an accumulator hopper assembly, a volume sensing device, an automatic flow control valve, a separator assembly and an air transfer device.

An air wash abrasive particle separator apparatus which separates contaminants from previously-used abrasive particles contained in a contaminated abrasive particle mixture such that the abrasive particles may be re-used multiple times, the apparatus being in combination a contaminated abrasive particle mixture delivery device, an accumulator hopper assembly, a volume sensing device, an automatic flow control valve, a separator assembly and an air transfer device.

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.

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.

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.

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.