PURPOSE: To quickly reduce smoke and malodorous gas generated from a mold just after burning by embedding the burnt mold adding thermosetting resin into heat resistant inorganic powder and bringing the burnt mold into contact with the inorganic powder for the necessary time.
CONSTITUTION: The mold 3 after burning is high temp. and at the time of leaving the mold as it is, reaction is progressed with residual heat and the malodorous gas of ammonia, etc., and the smoke are generated. Therefore, the burnt mold 3 is required to be immediately cooled to restrain the generation of the malodorous gas and smoke. The burnt mold 3 is quickly cooled with heat transfer by contacting with the fluidized inorganic powder 5 or with gas supplied in order to fluidize the inorganic powder 5. By this method, temp. of the burnt mold 5 is quickly lowered and the hardening reaction is completed to eliminate the generation of malodorous gas and smoke. Further, the inorganic powder 5 is used as adsorbent of the malodorous gas or in the case of containing the moisture in flowing gas and the inorganic powder 5, the cooling is efficiently executed with the vaporizing heat thereof.