Removal of Heavy Metals (Cu, Pb, and Zn) from Contaminated Sediment Using a Flotation Technique

This paper investigates the effectiveness of froth flotation to remove copper and other heavy metals from dredged anoxic sediments (<250 mu m) using a lab scale flotation cell with a selected anionic collector. A sediment fraction selected for flotation tests was potentially contaminated with a copper concentration of about 1763 mg/kg. The sequential extraction study of sediments showed that copper was mainly incorporated, between 70%-85% in the sulfide-organic fraction. The mineralogical analysis of sediment particle by scanning electron microscopy identified that chalcopyrite was the predominant copper sulfide form in the sediments. Flotation tests under controlled, predetermined experimental conditions showed selective flotation removal of copper (70.4%) among other metals with less mass recovery (froth mass).