金属离子对微细石英颗粒沉降特性的影响规律

Influence Mechanisms of Metal Ions on Settling Character of Fine Quartz

为掌握不同金属离子对微细石英颗粒沉降特性的影响规律,通过沉降试验研究了Ca^(2+)、Mg^(2+)、Al^(3+)、Fe^(3+)离子浓度和pH值对石英沉降特性及表面电位的影响。结果表明,Ca^(2+)、Mg^(2+)对石英沉降产率和表面电位影响较小;Al^(3+)、Fe^(3+)存在时,合理的离子浓度和溶液pH值能够提高石英沉降产率;随着Al^(3+)、Fe^(3+)浓度的增加,石英沉降产率不断增加,石英颗粒表面Zeta电位不断向正方向移动且变化比较明显;Al^(3+)在溶液pH值为5时有利于石英沉降,且Zeta电位绝对值最小;Fe^(3+)在溶液pH值为3~10时能够促进石英沉降;增加溶液pH值会使石英颗粒表面Zeta电位向负方向移动,pH值越高,石英颗粒表面Zeta电位向负方向移动趋势越明显。

In order to investigate the influence mechanisms of different metal ions on settling character of fine quartz,The effect of ion concentration and pH by Ca（2＋）,Mg（2＋）,Al（3＋） and Fe（3＋）on the settling character and Zeta potential of quartz were carried out through sedimentation experiments. The results show that Ca（2＋） and Mg（2＋） had little effect on sedimentation rate and Zeta potential of quartz. The proper concentration and pH by Al（3＋） and Fe（3＋） could increase the sedimentation rate of quartz. The sedimentation rate of quartz rose and Zeta potential of quartz moved in the forward direction obviously with the increase of ion concentration. The sedimentation rate of quartz was better and the absolute value of Zeta potential was minimal when the value of pH was 5 with Al（3＋） in the solution. The sedimentation rate of quartz was better under the value of pH between 3 and 10 with Fe（3＋） in the solution. Increasing the value of pH of the solution caused the Zeta potential of quartz particles to move in the negative direction. The higher the pH value was,the more obvious the trend of Zeta potential of quartz particles moving to the negative direction.