Speciation and Mobility of Heavy Metals in Tailings from Dachang Mine, China
Two carbonate tailing samples were collected from Dachang mine tailing reservoirs, Guangxi Province, China. The chemical speciation of Zn, As, Cd and Sb contained in tailing samples were determined by Dold seven-stage sequential extraction procedure, as well as mineralogical and chemical analysis. Then the potential migration abilities of these heavy metals were evaluated. The tailing analysis results showed that the main minerals were calcite, quartz, sphalerite and pyrite, the major elements were Si, S, Ca, Fe and Al, and the trace heavy metals included Zn, As, Cd and Sb. Zn mainly existed in secondary sulfide, primary sulfides and residual fraction, and As was in primary sulfide and residue, but Sb and Cd was residual fraction. The mobility of heavy metals followed the order: Zn > Sb > Cd > As.