Experimental and computational analysis of the impeller angle in a flotation cell by PIV and CFD.

Rotor–stator mechanisms, which are the key components in flotation cells, serve to mix the slurry and the air bubbles. The optimization of rotor–stator mechanisms improves the metallurgical performance and decreases the energy consumption of a flotation cell. The angle of the impeller blades, which is an important aspect of the design of rotor–stator mechanisms, significantly impacts the pumping and power consumption of a flotation cell. The flow pattern of a flotation cell with different impellers was investigated by combining PIV measurements and CFD simulation. PIV and CFD also revealed the flow field characteristics of the test cross-section under the impeller. The PIV measurement results agree with the CFD prediction results, and the backward impeller, radial impeller and forward impeller all produce similar flow patterns with upper and lower circulations. The velocity-area method, which integrates the axial velocity in the area of the selected section using CFD simulation, can be used to calculate the impeller circulation volume. The circulation volumes of the backward impeller and radial impeller are almost identical and are approximately 7% larger than that of the forward impeller. Thus, the backward impeller and radial impeller are better choices when large-volume circulation is needed. Based on the CFD simulation, the power consumption of the backward impeller is 13% less than that of the radial impeller and 19% less than that of the forward impeller. The backward impeller was shown to save more energy than the other two impellers, and it can decrease the operation cost for concentrators. This study aids the structural design of impellers for KYF flotation cells. [ABSTRACT FROM AUTHOR]