Rotary dryer is widely used for drying materials in the industries of cement, mine, construction, chemical, food, compound fertilizer, etc. Feeding and discharging unit is installed with thermocouple to control drier temperature. The temperature change of drier's feeding end can be indicated by the thermometer to control the inner drier temperature ( generally 250-350o) There are many kinds of dryer machines in mining industry. The commonly used equipment is roller dryer. This machine has many advantages. The rotary dryer is mainly composed by the revolving body, lifting plate, driving device, supporting device, sealing ring and other components. So it has the advantages of reasonable structure, perfect workmanship, high yield, low energy consumption and convenient operation.