... which contain moisture, not to say ordinary materials such as coal, coal slurry, slag, industrial waste, and clay stone. It could ... manure, cow manure, poultry dung, etc. Indirect heat transfer Rotary dryer: It is used for drying materials with humidity or granularity ... of mineral dressing, building material, metallurgy and chemical. Rotating dryer can be used for drying many kinds of materials and ...