Drum dryer is used for drying materials with humidity or granularity in the industries of mineral dressing, building material, metallurgy and chemical. Rotary drying machine can be used for drying many kinds of materials with convenient and reliable operation; therefore, drying machine has been widely used in those industries. China is one of the major countries manufacturing dryer and is also the best producer in the world. Henan Hongji Mining Machinery Co., Ltd. is one of the best sellers in those companies manufacturing dryer in China. The customer can choose different kinds of drying machines according to different moisture requirement in various industry. The water content of finished product can be able to below 1-0.5%