• Using polyethylene as a coagulant for reducing turbidity from placer mining discharge

      Fan, Ray-Her (University of Alaska Mineral Industry Research Laboratory, 1987)
      Placer gold mining locations on Gilmore and Crooked Creeks in the Fairbanks and Central/Circle, Alaska areas, respectively, were chosen as study sites for evaluation of a unique water treatment process. The physical and chemical impacts on water quality by placer mining were investigated by measuring the pH value, turbidity, and solids content of the slurry samples. Sedimentation tests, zeta potential measurements, and particle size distribution analyses were conducted as well. Also analyzed were mineralogical and chemical composition of the suspended ultrafine particles. Flocculation tests using polyethylene oxide (PEO) with adjunct additives were conducted in the laboratory. Variable parameters such as mixing speed and time, reagent dosages, pH values, as well as synergistic factors were studied. Economic factors and chemical consumption were evaluated and a field treatment plant was designed and proposed.