A sand screen or lower half deck 10 is arranged in the screen unit below the upper end portion of the deck 8 and is of fine rnesh to pass only small sand particles and divert all larger particles off its lower end itno the hopper. Sand aS passed by this screen 10 is diverted by un adjustable wing or gate II out from an end of the hopper 5 to a side delivery sand conveyor 12. Aggregate Production Line .The material rejected by the raw material receiving deck 8 is carried off the lower end thereof by an inclined chute 13 to a substantially centrally located primary jaw crusher 14 of conventional form, and the material is therefore reduced to smaller size by action of this crusher.
Such material then falls from the jaw crusher 14 to a conveyor 15 which carries it upwardly in a direction away from the hopper 5, to a point over the end of the frame A, Aggregate Recycling Plant the material being then dumped from the upper end of this conveyor down through a chute 16 to another conveyor 16a which returns it in the reverse direction upwardly over the screen unit and hopper.
Material thus crushed and returned to the screen unit is caused to fall through a chute IT upon the upper end of the uppermost, crushed material receiving deck.or screen 18 of the screen unit. This deck 18 has screens of two different sizes, the upper end section 19 having mesh openings, for example one-half inch square to pass material of the maximum size desired for chips, and the lower end section 20 having openings of substantially the same size as those in the deck 8 to pass material of the maximum size required in the aggregate.