Evaluation of Phosphatic Clay Disposal and Reclamation Methods. Volume 7. Engineering Properties of Flocculated Phosphatic Clays

摘要

The index properties, settling and consolidation behavior, and shear strength characteristics of three phosphatic clays flocced with a commercially available flocculant are presented and compared with properties of unflocced clays. The specific Agrico-Saddle Creek, USSAC-Rockland and CF Mining-Hardee phosphatic clays sampled during the Phase I study were selected for the investigation. These three clays were previously found to be characteristic of high, average and relatively low plasticity phosphatic clays, respectively, with differing mineralogy, and settling and consolidation properties which bracketed the range of behavioral characteristics reported for unflocced phosphatic clays. The flocculated phosphatic clays were prepared using NALCO 7877 flocculant. The NALCO 7877 flocculant is an acrylamide polymer emulsion containing 29% polymer solids by dry weight. The flocculant is reportedly used with phosphatic clays at loading rates of 0.3 to 1.2 pounds of polymer per ton of clay. For this investigation, the flocculant was added to clay suspensions in one increment as a 0.1% solution by volume.