Dosing interval of coagulant and flocculant influences settling behavior of coal slime

Using the high-speed motion acquisition system, we studied the settling process of the coal flocs under different addition interval time. The gray value and zeta potential of supernatant generally increased as the interval time increased, proving the effect of interval time on coal slime sedimentation. Furthermore, the interval time 25 s presented the smallest floc amount. The floc size and zeta potential were measured via the inverted fluorescence microscope and the micro electrophoresis, respectively. The interval time 25 s presented the fastest settling velocity. The floc amount in supernatant roughly decreased as the zeta potential increased. The settling velocity decreased with the settling time. The results can provide valuable insight into the development of technology for coal slime sedimentation.