An intake hose on one sidewall of the machine communicates with a source of negative pressure to create a powerful suction air stream that draws particulate materials through the hose and propels them into a chamber where they separate from the air stream and charge by their own momentum directly into a discharge auger assembly on the opposite sidewall of the machine. The auger assembly joins with the sidewall of the machine at an upwardly and outwardly inclined attitude for elevating the materials into a suitable receiving truck or trailer alongside of the machine, and a lower longitudinal portion of the assembly which adjoins the sidewall is open along its length to facilitate the unimpeded reception and entry of particulate materials from the hose directly into the auger. The auger assembly includes a tubular housing surrounding an internal, longitudinally extending auger, and a pair of successive outlet ports in the housing adjacent the upper and outer end of the assembly are controlled by independently functioning, spring-biased, sealing doors that assist in providing an airlock in the assembly during operation to prevent the admittance of power-robbing ambient air to the separating chamber via the auger assembly.