Apparatus for grinding material which enters the grinder in a wet condition and is subject to drying heat at the grinder to leave moisture in the ground material directed for independently material separation so the propelling initially hot gases looses its temperature level before returning to the grinder. A portion of the returning gases carrying ground fine with moisture therein is directed into a bag house to recover the fines and a portion of the drying heat is directed into the bag house to independently maintain a temperature level above the dew point temperature level in the bag house to prevent moisture from plugging the bag house. The apparatus provides two circulation loops, each with its independent moisture control, and a common transport for collecting product from each loop.