Sealing Sand With Waterborne Bentonite

A model, designed to resemble field conditions as nearly as possible, was used to study the sealing of sands with waterborne bentonite. Four sizes of sand were sealed with a Wyoming bentonite using suspensions having 0.1% to 6% concentration. Time of sealing varied directly with the sand particle size. Drying damaged the original seal but a second sealing treatment proved very effective. Waterborne bentonite formed a lasting seal in sands that were nearly free of silt and clay. This was accomplished with a combination of adequate bentonite penetration and a repeated bentonite treatment. Estimated cost figures showed this method of sealing to be feasible if proper bentonite concentrations are used and if the bentonite source is within an economical shipping distance of the sealing site.