A METHOD FOR MAKING SAND COVERED WITH BENTONITE THE SAND AND A METHOD FOR RECYCLING MOLDING SAND FOR A MOLD USING THE SAND COVERED BY BENTONITE

摘要

PURPOSE: A method for making sand covered by bentonite by mixing discarded sand, reproduced sand or new sand or some or all of them with bentonite, the sand, and a method for recycling molding sand for a mold using the sand are provided. CONSTITUTION: In a method for making bentonite-covered sand by mixing reproduced sand and new sand, or one of them with bentonite so as to be used as sand supplement to collected sand, the method comprises the steps of mixing reproduced sand and new sand or one of them, floury bentonite, and water having a weight the same as or greater than that of the bentonite to make a mixture, and drying the mixture. The bentonite-covered sand is made by mixing reproduced sand and new sand or one of them, floury bentonite, and water having a weight the same as or greater than that of the bentonite to make a mixture, so that the reproduced sand and new sand or one of them is covered by the bentonite. The method for recycling molding sand comprises the steps of collecting discarded sand that is discharged from a sand processing line for a molding, reproducing the discarded sand that is collected and mixing the discarded sand with at least bentonite, so that bentonite-covered sand is made, and supplying the bentonite-covered sand to sand collected from a green sand processing line as supplementary sand. The method for recycling molding sand comprises the steps of collecting discarded sand that is discharged from a sand processing line for a molding, mixing the discarded sand with at least bentonite, so that bentonite-covered sand is made, and supplying the bentonite-covered sand to sand collected from a green sand processing line as supplementary sand.