Abstract: For improving flotation performance, the material mixing process in mixing tank is simulated with iodine fading process. The characteristics of pulp mixing with axial and radial flow impellers under the effect of different stirring mechanisms are summarized. A novel pulp mixing mechanism working with a combination of 2 impellers, which incorporates the advantages of the above mentioned 2 types of impellers is proposed. The characteristics of the pulp mixing mechanism under different impeller combinations, such as power consumption, mixing time, shearing performance and mixing efficiency, are investigated. Result of study shows that pulp mixing using a combination of 2 impellers can lead to effective coupling of flow field. Finally, an appropriate combination of impellers is selected as a model for further study.