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.

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.

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.

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.

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.

An apparatus and a method for cleaning sand used at a foundry, wherein sand to be cleaned is screened by a screening apparatus. The screened sand and at least one liquid mixture is fed into an abrasive apparatus. After that, the screened sand is rubbed by the abrasive apparatus. The rubbed sand and at least one liquid mixture is added to a water separation screen for separating a water blend from the rubbed sand. Finally, the separated sand is transferred into an oven and cleaned thermally by rotating the separated sand in the heated oven.

An apparatus and a method for cleaning sand used at a foundry, wherein sand to be cleaned is screened by a screening apparatus. The screened sand and at least one liquid mixture is fed into an abrasive apparatus. After that, the screened sand is rubbed by the abrasive apparatus. The rubbed sand and at least one liquid mixture is added to a water separation screen for separating a water blend from the rubbed sand. Finally, the separated sand is transferred into an oven and cleaned thermally by rotating the separated sand in the heated oven.

In a casting sand reclamation system and a casting sand reclamation method, an appropriate reclamation process is performed according to the properties of casting sand to improve the reclamation accuracy and the reclamation yield. Capacitance measuring devices 70 and 71 that measure the capacitance of casting sand 1 (recovered sand 1a or reclamation sand 1b) are arranged on an upstream side and a downstream side of a batch-type polishing device 7, and feedback control is performed based on the measurement results of the capacitances by these capacitance measuring devices 70 and 71. A sorting device 10 sorts the recovered sand 1a polished by the polishing device 7 into a sand grain component (reclamation sand) and a fine grain component (containing a binder), and has a capacity N times that of the polishing device 7. A control device 80 performs feedback control based on capacitance RU of the recovered sand 1a measured for each polishing process on an upstream side of the polishing device 7, and an average value of N capacitances RD of the reclamation sand 1b measured for each polishing process on a downstream side of the sorting device 10.

In a casting sand reclamation system and a casting sand reclamation method, an appropriate reclamation process is performed according to the properties of casting sand to improve the reclamation accuracy and the reclamation yield. Capacitance measuring devices 70 and 71 that measure the capacitance of casting sand 1 (recovered sand 1a or reclamation sand 1b) are arranged on an upstream side and a downstream side of a batch-type polishing device 7, and feedback control is performed based on the measurement results of the capacitances by these capacitance measuring devices 70 and 71. A sorting device 10 sorts the recovered sand 1a polished by the polishing device 7 into a sand grain component (reclamation sand) and a fine grain component (containing a binder), and has a capacity N times that of the polishing device 7. A control device 80 performs feedback control based on capacitance RU of the recovered sand 1a measured for each polishing process on an upstream side of the polishing device 7, and an average value of N capacitances RD of the reclamation sand 1b measured for each polishing process on a downstream side of the sorting device 10.