蛇纹石溶解对颗粒间作用力的影响

Effect of Serpentine Dissolution on Interaction Forces between Particles

为深入探究矿物溶解引起的表面性质变化对矿物颗粒间相互作用的影响,通过溶解试验、沉降试验、扫描电子显微镜、Zeta电位分析、DLVO理论分析和AFM等多种手段,对蛇纹石表面溶解过程及颗粒间作用力的变化规律进行了系统研究。结果表明,蛇纹石溶解会引起表面阳离子组分大量进入溶液,表面荷电性质随之发生改变,这是导致颗粒间作用力变化的根本原因,直接影响着颗粒间的分散状态。当溶液pH值为4、7时,颗粒间相互吸引,引力大小分别为7.4 nN和17.5 nN;当pH值增大至11后,颗粒间作用力由引力变为斥力,大小为5.7 nN。总体而言,蛇纹石颗粒在碱性溶液中的分散效果最佳,在酸性溶液中分散效果次之,在纯水中的分散效果最差。

For further understanding of the effect of serpentine dissolution on interaction forces between particles,dissolution experiments,settling tests,SEM analysis,Zeta potential,DLVO theory analysis and AFM were used in this research.The surface dissolution property and the mechanical property between particles were systematically studied.Results showed that serpentine surface potential changed dramatically,then the particles interaction behavior in solution was changed.The attractive force between particles was 7.4 nN and 17.5 nN at pH of 4 and 7 respectively,so these particles exhibited a trend of aggregation.The attractive force turned to repulsive force(5.7 nN)when pH was adjusted to 11,which enhanced the particles dispersion,and settlement rate decreased at the same time.The change of potentials on serpentine surface caused by dissolution was considered as the basic reason that led to the change of interaction force.