The present paper describes an experimental study using a multilayer paint technique to illustrate the wear patterns developed on an eight-bladed disc turbine in a gas/liquid/solids three-phase mixing tank. A distinctive wear pattern was found to develop on the low-pressure side of the blades. The patterns were found to be caused by the two intersecting vortices that developed along the blades. Several modifications were made to the impeller geometry to reduce wear. A new impeller design, which experienced a lower wear rate and showed an improved off bottom solids suspension performance, is recommended for operating in gas/liquid/solids reactors.