REDUCTION OF PTE AVAILABILITY BY LIMING OF TAILING HEAPS

Abstract

Tailing heaps are a source of potentially toxic elements (PTE) in the environment. Their oxidation increases release of these elements and the subsequent acidity causes severe environmental impact. The management of large volumes of mine residues involves very high cost that nobody wants to face. Therefore, it is necessary to seek economic and efficient procedures to control the dispersion and oxidation of these materials. Evaluation of amendments to reduce PTE availability and the problems derived from the acidity of mine residues runoffs is indispensable for technology development. The
effect of the addition of five amendments, on Cd, Cu, Zn and Pb availability was evaluated in acid mine residues. The addition of high doses of amendments induced a clear reduction of the extractable concentration of PTE, except Pb. Therefore, liming is suggested to decrease the availability of Cd, Cu and Zn. It is recommended to continue looking for amendments that decrease Pb extractable concentrations.