To provide a treating method of recovered sand, with which the adjustment of moisture and the addition of binder for rebonding as molding sand are easily carried out and the defect of a casting is not generated even in the case of casting molten metal into a master mold with the rebonded molding sand.
The green sand master mold after casting is separated into a portion which is not subjected to the heat of molten metal, and a portion which is subjected to the heat of the molten metal. The moisture of the portion which is not subjected to the heat of the molten metal is adjusted by using this portion as facing sand in the molding of the master mold at the next time. Further, the addition of the binder and the adjustment of the moisture of the portion which is subjected to the heat of the molten metal are performed by using this portion as backing sand in the molding of the master mold at the next time.
MORI KUNIYASU
KANAYAMA RYOJI
HARADA HISASHI
TOKITA HIROAKI
SUGIMOTO KAZUO
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