... dry many kinds of materials which contain moisture, such as coal, coal slurry, slag, industrial waste, and clay stone. They are widely ... ring.3. Can I use the coal or gas as the heating source?Yea, you can use coal, gas, electricity, oil and wind power ... . 2. The fuel can be coal, fire, gas, and electricity and other fuel. 3. We can design the gas generator furnace, firebox, and euipped ...