A double layer cooler for particulate material has a conveyor to which separate streams of such material are delivered at spaced intervals to form lower and upper layers of material on the conveyor. As the layers move toward the discharge end of the conveyor a coolant passes upwardly through the layers. At the discharge end of the conveyor the material of the lower layer is discharged, whereas the material of the upper layer passes over a stationary quantity of material to a crusher in which the upper layer material is crushed. From the crusher material is returned to that stream which forms the lower layer on the conveyor. The lower layer of material thus is precooled and comminuted.