This paper presents an analysis of the process of erosion wear of a down-pumping pitched blade impeller in a solid-liquid suspension. The time courses of the blending time of miscible liquids and the critical impeller speed for off-bottom suspension are investigated experimentally in dependence on the degree of wear of the impeller blades. On the basis of a description of the fluid flow of the agitated charge, we determine the relations between these process characteristics of the stirred system and the degree of wear of the impeller blades. It follows from the results of the experiments that all investigated characteristics of the tested pitched blade impeller (alpha = 45 degrees) depend on its erosion rate, with the exception of its energetic efficiency, which exhibits a constant value independent of the degree of erosion of the impeller blade. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.