Abstract: A mixing and conditioning machine for turning dust and very fine particles into pellets comprising an elongated, generally horizontal trough formed of flexible rubber-like material having a downwardly concave arcuate bottom wall and vertical side walls. A rotor assembly comprises an elongated, generally horizontal shaft extending lengthwise within a trough with paddles distributed along the length of the shaft. The shaft is rotated to cause the paddles to mix and pelletize material introduced into the trough at the inlet end and move the material to the outlet end for discharge. The side walls of the trough are attached to the machine frame at points located a substantial distance above the bottom wall so that the trough is suspended from the points of attachment and enabled to flex as the shaft rotates, preventing build-up of material in the trough.