Manufacturing of coating formed waste-molding sand and waste aggregate for reuse

摘要

PURPOSE: Provided is waste molding sand which is coated with a thin layer for inhibiting chemical properties of the waste molding sand so that the waste molding sand is reutilized as an equivalent of new molding sand and is used as cement aggregate. CONSTITUTION: The waste molding sand having a coating layer for recycle thereof is prepared by the method comprising the steps of: crushing a mold used for molding after being bound with sodium silicate; separating iron pieces contained in the waste molding sand by using a magnetic belt; screening waste molding sand having a particle size of 100 mesh or more; adsorbing a polymer emulsion that is stable to an alkaline environment on the surface of the screened molding sand particles in an amount of 1-25 wt%; and drying the adsorbed waste molding sand naturally or with hot air.