A Laser Technique to Quantify the Size, Porosity, and Density of Clay Clusters During Sedimentation

    Volume 24, Issue 1 (March 2001)

    ISSN: 0149-6115

    CODEN: GTJOAD

    Page Count: 9


    Likos, WJ
    Graduate research assistant, Colorado School of Mines, Engineering Division, Golden, CO

    Lu, N
    Assistant professor, Colorado School of Mines, Engineering Division, Golden, CO

    (Received 11 October 1999; accepted 26 September 2000)

    Abstract

    A technique is developed for measuring the size, porosity, and density of clay clusters (flocs) and the distributions of these fundamental quantities during sedimentation. A laser-particle counter is used to detect cluster size and size distribution. Cluster velocities are computed by taking measurements at successive time intervals. By comparing the initial cluster size distribution with the measured distribution as sedimentation proceeds, a unique relationship between cluster size and settling velocity can be established. By applying a settling model for porous spheres, a unique relationship between cluster diameter and porosity is then established. Cluster density is calculated using fundamental mass-volume relationships. The technique and its working principles are illustrated via two sets of experiments, one for kaolinite clusters in distilled water and another for kaolinite clusters in 0.5 M NaCl. Consistent with double-layer theory, the results show that the porosity of clusters in distilled water is higher than the porosity of clusters in NaCl solution. The results also show that power-law relationships, which state that cluster porosity increases with cluster size, may not be valid for clusters very close to the primary particle size.


    Paper ID: GTJ11284J

    DOI: 10.1520/GTJ11284J

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    Author
    Title A Laser Technique to Quantify the Size, Porosity, and Density of Clay Clusters During Sedimentation
    Symposium , 0000-00-00
    Committee D18