Determination of Elements Leachability from Sarcheshmeh Porphyry Copper Mine Tailings: Application of Toxicity Characteristic Leaching Procedure

The Toxicity Characteristic Leaching Procedure (TCLP) was applied in order to determine the leachability and mobility of different trace metals and metalloids from the Sarcheshemh Cu mine tailings. Twenty one solid samples were collected from weathered and fresh tailings and also from evaporative secondary minerals and efflorescence salts associated with the oxidation zone of dried tailings. According to the TCLP results, the most leachable and mobile trace elements are Ag, Al, Cd, Ni, S, Se, Co, Cr, Cu, Fe, Mn and Zn. These contaminant elements were concentrated in the surface evaporative layer formed on the top of old weathered tailings. Very high concentrations of Al (27,600 mgL-1), Cu (56,900 mgL-1), Mn (13,260 mgL-1), S (151,800 mgL-1), and Zn (3,935 mgL-1) were observed in the TCLP results of the evaporative samples (mean values are presented). The results obtained from evaporative and efflorescence samples were higher than the regulatory levels for Al, Cu, Cd, Ni, Se, and Zn. The maximum leachability was found for Al and Cu, followed by Ni, Cd, Zn, and Se. The results of this study are useful for the prediction of contamination potential of trace elements and environmental management of mine tailings. © 2014 Springer International Publishing Switzerland.