Abstract: An air stream separator for separating heavier and lighter fractions from a mixture, includes a first vibrating conveyor which conveys the mixture of materials into an upwardly directed air stream at the output end of the conveyor, and a second vibrating conveyor positioned at or below the level of the first conveyor; the second vibrating conveyor includes an input end defined by an upwardly inclined portion onto which a heavier fraction of mixture drops from the output of the first conveyor so that the heavier fraction is separated from the lighter fraction which is impelled by the air stream onto a main, horizontal portion of the second conveyor for conveyance thereon.