Abstract: A chopped mixture derived from municipal solid waste, free of ferrous metal is fed into the open upper end of a vertical rotor chamber for contact sequentially by an upper and lower high-speed rotor, with the rotor blades of the rotors further chopping the mixture and imparting centrifugal force to the mixture particles. Selectifier screens concentrically surround the rotor blades at the upper and lower rotor positions and have mesh openings which effect ballistic separation and elimination of glass, grit, sand, dust and fiber elements at these levels dependent upon the screen size openings. The two rotors are separated to form an intermediate treatment zone permitting liquid or solid spray of the mixture particles passing vertically downward from the upper rotor zone to the lower rotor zone.