RECONDITIONING METHOD OF MOLDING SAND

摘要

PURPOSE:To remove the binder on the surface of old sand for a casting mold used for casting by friction between the old sand and fresh sand and reconditioning the old sand to molding sand at a low cost by mixing said old sand with the fresh sand and rotating the same at a high speed. CONSTITUTION:Old sand and fresh sand are put respectively into an old sand tank 11 and a fresh sand tank 12. The electrically driven gate 14 of the tank 12 is opened to charge a prescribed amt. of the fresh sand into a reconditioning device 15 so that a self-lining layer by the fresh sand is formed on the inside surface of the rotary drum in the device 15. The electrically driven gate 13 of the tank 11 is then opened to charge the old sand into the device 15. The fresh sand and the old sand are mixed in the rotary drum so that the satisfactory reconditioning effect of the old sand is obtd. and the grain shape of the fresh sand is improved by the friction or polishing force by the fresh sand having sharp angles with the old sand. The old sand is thus reconditioned to the molding sand at a low cost.