COATED SAND, MANUFACTURING METHOD FOR SAME, AND MANUFACTURING METHOD FOR MOLD

摘要

Purposes of the present invention are to provide a dry coated sand having a high degree of fluidity at the room temperature, a method of advantageously producing the coated sand, and a method of producing a casting mold having excellent properties, by using the coated sand. The dry coated sand is obtained by mixing an aqueous solution of a water glass used as a binder, with a heated refractory aggregate, whereby water in the aqueous solution is evaporated, and a coating layer of the binder is formed on surfaces of the refractory aggregate. A moisture percentage in the thus obtained dry coated sand is controlled so as to be not more than 0.5% by mass. The intended casting mold is obtained by filling a molding cavity of a forming mold, with the dry coated sand, and passing a steam through the coated sand, to solidify or cure the coated sand.

主权项

1. A coated sand which is in a dry state and which has fluidity at the room temperature, the coated sand being obtained by mixing an aqueous solution of a water glass used as a binder, with a heated refractory aggregate, to evaporate water in the aqueous solution of the water glass, for thereby forming a coating layer of the binder on surfaces of the refractory aggregate, the coated sand being characterized in that its moisture percentage is controlled so as to be not more than 0.5% by mass.