Study on Flocculation Kinetics of Fine Hematite in Stirring Flow Field

The influence of stirring speed and stirring axial distance from the bottom on the coagulation kinetics was investigated in this paper. The result showed that increasing the stirring speed could improve the initial growth rate of floc, but once exceeding a certain speed, the initial growth rate constant K of floc barely changed. When the stirring speed increased from 900 r/min to 1 000 r/min and 1 100 r/min, the initial growth rate of floc increased from 0.008 5 to 0.012 3 and 0.012 5, respectively. The axial distance of stirring paddle from the bottom showed some effects on the initial rate of floc. When it increased from 15 mm to 20 mm and 25 mm, the initial growth rate constant K of floc also increased from 0.009 7 to 0.012 1 and 0.010 9, respectively. Through the amendment, the flocculation kinetic equations could describe the flocculation process in a large time span.