Centrifugal slurry pump impeller

A centrifugal slurry pump impeller including a back shroud and a front shroud each with opposed inner and outer faces and an outer peripheral edge and a central axis, the front shroud including an impeller inlet and the back shroud including an impeller nose raised from the inner face of the back shroud facing the impeller inlet and in line with the central axis, a plurality of pumping vanes extending between the inner main faces of the back and front shroud, the pumping vanes being disposed in spaced apart relation, each pumping vane including opposed main side faces, a leading edge in the region of the central axis and a trailing edge in the region of the outer peripheral edges of the back and front shrouds with a passageway between adjacent pumping vanes, each passageway including a blended region between each of the main side faces of the pumping vanes and the inner faces of the front and back shrouds wherein a surface of the inner face of at least one of the front and back shrouds includes a raised portion located between the blended regions of adjacent pumping vanes and wherein the raised portion is separated from the impeller nose.