Abstract: A rotary pump is disclosed for pumping liquid and solid materials carried in suspension therein. The rotary pump comprises an impeller and a housing. The housing forms a swirl chamber and an impeller chamber for receiving the impeller. The impeller is mounted rotationally within the impeller chamber for rotation in a given rotational direction. The impeller comprises a surface exposed to the swirl chamber and disposed substantially outside the swirl chamber, and a plurality of pockets recessed in the exposed surface. Each of the recessed pockets comprises a blade surface having a curved surface. The curved surface redirects the pumped liquid thereabout as the impeller is rotated, whereby the liquid and suspended solid materials are formed into a swirling vortex of increased rotational velocity to substantially prevent the solid materials from striking and damaging the impeller.