This product is mainly used for cast iron, cast stee(wet), surface dry type, dry type and high pressure modeling as a sand binder, product compared with other similar products in our country, with a high montmorillonite content, excellent wet tensile strength and high compressive strength and thermal swelling and good thermal stability etc., using the product can enhance the reusability of molding sand, reduce the addition amount of bentonite, Reduce the sand system moisture, increase the strength and toughness of molding sand, improve air permeability, obviously improve the quality of casting, solve the problems of sand inclusion, scar, block falling, porosity, sand punching and sand collapse, reduce the rejection rate, so as to reduce the production cost and storage and transportation costs of casting enterprises.