STP623

    Turbidity and Zeta Potential Measurements of Clay Dispersibility

    Published: Jan 1977


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    Abstract

    The basic mechanisms identified with dispersive clays have been associated with swelling or repulsive forces. To evaluate clay dispersibility from the particle interaction point of view, suspensions of the soil material can be used where resultant turbidity of the suspension is assessed. In this study, the light transmittance technique for measurement of turbidity is used whereby appropriate calculation techniques can be applied to the measurements to obtain equilibrium clay concentration remaining in suspension in the supernatant.

    The adsorption/desorption measurements of the suspensions at various low salt concentrations indicate that desorption of the adsorbed ions from the clay surfaces contributes to clay dispersibility through increases in the double-layer thickness. The presence of amorphous silica and sesquioxides, as might be obtained from selective dissolution in the leaching process, reduces clay dispersibility, as indicated by increased zeta potential and refiltration rates.

    Keywords:

    clays, particle interaction, turbidity, transmittance, zeta potential, filtration, desorption, silicate minerals


    Author Information:

    Yong, RN
    William Scott professor of civil engineering and applied mechanics, and director, Soil Mechanics Research Laboratory; and research associate, Soil Mechanics Research Laboratory, McGill University, Montreal, P. Q.

    Sethi, AJ
    William Scott professor of civil engineering and applied mechanics, and director, Soil Mechanics Research Laboratory; and research associate, Soil Mechanics Research Laboratory, McGill University, Montreal, P. Q.


    Paper ID: STP27005S

    Committee/Subcommittee: D18.02

    DOI: 10.1520/STP27005S


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