Turbulence in flotation cells

Abstract

It is known that turbulence plays an important part in the operation of a flotation cell. Rotational speed and thus intensity of turbulence has a strong influence on the recovery and grade of concentrate of single cells and cell banks. In this investigation an expression for the turbulent fluctuation of velocity is derived based on known equations of hydrodynamics. Substituting operational data of production size and smaller cells in the expression, it can be concluded that the expression is nearly constant regardless of cell size. It can be supposed that the turbulent fluctuation of velocity is constant and the small variation with cell size is due to the variation of some parameter held as constant. Another conclusion is that the ratio between the shaft power and the horizontal cross-sectional area of the cell is nearly independent of cell size and differs relatively little for cells of various types. The depth of the cell has no effect on the power needed for optimum flotation conditions. This explains the diminishing of specific power with increasing cell size because generally then also the cell depth increases.