Effect of height of flotation column on flow field.

Cyclonic‐static microbubble flotation column (FCSMC) is a sorting equipment for micro fine‐grained minerals. The column height is an important factor affecting the flotation efficiency, which will directly affect the flow field and separation performance. In this study, particle image velocimetry measurement on single phase of lab‐scale FCSMC with diameter D of 0.1 m was tested to verify the accuracy of the turbulent model used in computational fluid dynamics simulation. Then the FCSMC with different upper column and lower column height were simulated and analyzed. Results show that the axial velocity and tangential velocity play a major role in FCSMC. With the increasing of the upper column height, both tangential velocity and centrifugal intensity decrease, which help to get a static environment for column flotation unit. But too high upper column height will affect the separation of the cyclone flotation unit due to small centrifugal intensity. When the lower column height‐to‐diameter ratio H2/D increases from 1 to 4, it has no obvious effect on column flotation unit, but does effect on the flow field of the cyclone flotation unit. As the lower column height increases, the upward overflow is more prominent and the region becomes larger. Peculiarly, tangential velocity is large under too small lower column height, like H2/D = 1, but is bad for the separation of large size tailings due to low distance and great suction. Within the scope of this study, the lower column height range is more suitable for H2/D = 2–3. [ABSTRACT FROM AUTHOR]