Journal of the Korean Society of Mineral and Energy Resources Engineers ISSN:2288-0291(Print) 2288-2790(Online) 한국자원공학회지

Fine particles are deposited in port area, and the sediments are dredged regularly. The dredged sediments contaminated with heavy metals must be treated properly. The heavy metal contaminants were separated from the sediments by gravity separation processes such as Knelson concentrator, and the results were compared with those by dense medium separation. The recovery of Pb, Cu, Zn decreases and the contents in the overflow product increases with increasing centrifugal acceleration speed of Knelson concentrator. In the dense medium separation test, the contents of heavy metals in sunk product are higher than those in floated product. Because the heavy metal contaminants were contained in fibrous materials, the components were separated into overflow product in Knelson separation by waterstream working, whereas they precipitated in the dense medium test due to high density. The contents of Pb, Cu, Zn in trapped-product of Knelson separation were 91.1 mg/kg, 238 mg/kg, 89.3 mg/kg, respectively, which indicated that the heavy metals were removed successfully by Knelson separation process.