A pump for transferring particulate material from a source to a remote location, including a particulate chamber having open ends, check valves at the open ends, a vacuum source connected to the chamber adjacent one end, a gas source at the opposed end of the chamber and a control which alternatively connects the vacuum to the chamber to draw particulate material from the source to the chamber and connecting the gas under pressure to drive the particulate material to the remote location. In a preferred embodiment, the chamber has a cylindrical inner diameter and the source of vacuum is a venturi pump connected to a pinch valve permitting overflow of particulate material through the pinch valve and venturi pump, which is returned to the source. In one embodiment, the pinch valve surrounds an open end of the chamber permitting overflow while avoiding agglomeration of the particulate material.