... , industrial waste, and clay stone. They are widely used in building materials, metallurgy, and chemical industry.2. what the rotary dryer consist ... . Can I use the coal or gas as the heating source?Yea, you can use coal, gas, electricity, oil and ... sawdust industry, sawdust with flotation, drying mixed coal and other materials drying;Construction industry blast furnace slag, clay, limestone, sand, ...