Method of reusing core sand

Abstract

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 is claimed is: 
     
         1 . A reuse treatment system for core sand comprising:
 a crushing apparatus configured to crush a core used for casting into granules, the core including water glass as a binder;   a heating apparatus configured to heat the granules at a temperature of 300° C. to 550° C.;   a detaching apparatus configured to detach the water glass from the core sand in the granules after heating the granules; and   a separating and collecting apparatus configured to separate and collect the core sand from a mixture of the water glass and the core sand, the water glass being detached from and the core sand.   
     
     
         2 . The reuse treatment system for core sand according to  claim 1 , wherein
 the water glass included in the granules includes water-soluble water glass and water-insoluble water glass,   the heating apparatus is configured to adjust an amount of water-soluble water glass such that the amount of water-soluble water glass is smaller than an amount of water- insoluble water glass by heating the granules.   
     
     
         3 . The reuse treatment system for core sand according to  claim 1 , wherein
 the water glass included in the granules includes water-soluble water glass and water-insoluble water glass,   the heating apparatus is configured such that a ratio of a mass of water-soluble water glass to a mass of the granules is adjusted to be 0.2% or lower by heating the granules.