عنوان مقاله [English]
The axial mixing in the flotation column leads to lower recovery of minerals. In the present work, the effects of height to diameter ratio and baffling on the axial mixing in flotation columns were investigated using two-phase computational fluid dynamics method. The computational domain is a column with a circular shape cross section having 3.2 m height and a 10 cm diameter. In order to reduce the calculations and simplify the problem, it was assumed that the column is firstly full of water, and then air enters from the side surface of a sparger of 15 cm length and 1 cm diameter. To validate the simulation results, a series of experiments were performed under the above condition in mineral processing laboratory of the University of Kashan. Twhree-dimensional simulation were performed using an Eulerian two-phase model for both the column without baffle and with a baffle located perpendicular to the cross section of the column with 2.8 m length and thickness of 0.4 cm. The predicted pressure values on the wall at heights of 0.2 and 2.6 meter of the column without baffle were in good agreement with experimentally measured values. The relative difference between simulated and measured values was less than 0.6%. Comparison of the computational results for the column without baffle and the one with baffle showed that baffling can reduce the axial velocity of water up to 17% which consequently reduces the axial mixing in the column.