搅拌流场中微细粒赤铁矿絮凝动力学研究

Study on Flocculation Kinetics of Fine Hematite in Stirring Flow Field

主要研究了搅拌转速与搅拌桨距槽底轴向距离对絮凝动力学的影响。研究结果表明:提高搅拌转速有利于提高絮凝体初始生长速率,但超过一定转速絮凝体初始生长速率常数K值变化不明显。当搅拌转速由900 r/min上升至1 000 r/min、1 100 r/min时,絮凝体初始生长速率常数K由0.008 5上升至0.012 3和0.012 5,分别升高了0.003 8和0.004 0;搅拌桨距槽底轴向距离对絮凝体初始速率的影响存在一定限制,当轴向距离由15 mm升至20 mm、25 mm时,絮凝体生长速率常数K值由0.009 7上升至0.012 1、0.010 9,分别增加0.002 4和0.001 2。通过修正絮凝动力学公式得出能够描述较大时间跨度下的絮凝过程的动力学公式。

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 from900r/min to1000r/min and1100r/min,the initial growth rate of floc increased from0.0085to0.0123and0.0125,respectively.The axial distance of stirring paddle from the bottom showed some effects on the initial rate of floc.When it increased from15mm to20mm and25mm,the initial growth rate constant K of floc also increased from0.0097to0.0121and0.0109,respectively.Through the amendment,the flocculation kinetic equations could describe the flocculation process in a large time span.