In order to obtain dry sand that meets the production requirements, the raw wet sand must be dried and the moisture content should be less than 0.5%. The main production equipment used in the drying process is a three-pass dryer, which is newly developed for the drying of sand Dryer, high thermal efficiency, novel structure, compact, stable and efficient. After the sand is dried, it is sent to a classification screen by a belt conveyor. The dry sand is divided into several grains according to the process requirements and stored in the discharge bin.