Raw material with 85% moisture are delivered into the screw dehydration machine (or belt dehydration machine) and dehydrated to 50% to 60% moisture content. Then the dehydrated product was delivered into the rotary dryer by screw conveyor for the drying process. High-temperature air heated by furnace could has full massl and heat exchange, taking away the moisture. The dry materials could pass through the drum quickly with the air force. Wet materials would be dropped gradually and get the fully dried. The eventual dry materials would be delivered out of the systems through screw conveyor.