Abstract: A pump impeller is adapted for rotatably mounting within a volute of a centrifugal slurry pump. The pump impeller has an intake opening that is formed coaxially with an axis of rotation of the impeller. The impeller also has an outlet opening that extends about the periphery of the impeller and blades that extend generally radially between the intake opening and the outlet opening. The region between adjacent blades defines a respective blade passage through which slurry flows upon rotation of the impeller. The impeller is dimensioned relative to the volute so that the ratio of the blade passage width at the entry of the blade passage to the blade width passage at the periphery of the impeller is in a range of 1.5 to 1.7, and the ratio of the diameter of the impeller to the blade passage width is in a range of 9.3 to 10.2 and that the ratio of the impeller diameter to the width of the volute is in a range of 3.8 to 4.2. This dimensioning enables the pump to operate in a specific speed range of 22 to 30.