Abstract: A solid waste comminuting apparatus (10) for reducing solid waste material (12). The apparatus (10) has rolls (42, 44) for severing material that is fed into the entrance (32). After the material is severed, it is carried by an airstream to a fan (112). The subdivided pieces are directed to a separator screen (131) mounted within the centrifugal housing. The airstream carries the small pieces (14e) through the separator screen (131) into an outer volute chamber (135) for discharge from the apparatus. The large pieces (14a-14d) which do not pass through the separator screen (131) are recycled through a recycle outlet (143) and a recycle conduit (150) back to the rolls (42, 44) for further size reduction.