| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a core recycling molding method for further increasing the strength of a core. <P>SOLUTION: There is provided the core recycling molding method in which a water-soluble core (core) is aerator-molded by using core sand in which aqueous solution of a binder comprising water-soluble inorganic salt (binder aqueous solution) is added to the cast sand, casting is performed by using the core, then sand-containing solution generated by the shaking-out of the core is recycled for a raw material of the core sand. The core sand has such a composition that: in a graph indicating relationship between a water content (X) and a fluidization ratio (Y) of the core sand, the water content of the core sand is lower than X at which Y indicates the minimum value, when performing the predetermined air fluidization experiment on the core sand; and the binder aqueous solution, to which fine inorganic powder of such an amount that the binder addition amount ensures the required strength is added, is added to the core sand. The fine inorganic powder is non-water absorbable, and has a melting point of ≥700°C, Mohs hardness of ≥5, and a grain size of 1/400-1/10 time the size of core sand. <P>COPYRIGHT: (C)2012,JPO&INPIT |
