Evaluation of dispersion and chemical partitioning patterns of heavy metals in the Sar Cheshmeh porphyry copper deposit: geochemical data from mine waste, water and stream sediments

Abstract

The Sar Cheshmeh copper mine, located in the Urumieh-Dokhtar volcanic belt, is one of the largest porphyry copper deposits in Iran. This study examines transport and sediment-water partitioning of trace metals (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Sn, Zn) in acid mine drainage (AMD) and water–sediment system. It is shown that waste dumps and tailings dam are major causes of AMD generation. An elevated level of heavy metals viz. Mo, Mn, Pb, Cr, Cd, Fe, Cu and base metals like Na, K in AMD-impacted water and sediments results from the metal leaching effect of AMD. Factor analysis identified three factors responsible for data structure explaining 86.07% of total variance in water samples. The distribution coefficient (K _d) values vary from 1.1 × 10⁶ for Fe to 5.1 × 10³ for Mn and increases in the sequence of Fe > Pb ≈ Al > Mo ≈ Sb > As > Cr > Sn > Cu > Ni ≈ Zn > Co ≈ Cd > Mn. The results of sequential extraction analysis indicate that among non-residual fractions, Fe–Mn oxides are most important for retaining trace metals in the sediments. Calculation of mobility factor (MF) shows that in the Sar Cheshmeh copper mine, the heavy metal MFs display the following decreasing trend: Cd > Mn > Co > Zn > Cu > Ni > Cr > Sb > Al > As > Sn > Pb > Mo > Fe.

Keywords:

• Sar Cheshmeh copper deposit
• Iran

Acknowledgements

The authors wish to express their gratitude to the Research and Development Department of Sar Cheshmeh Copper Complex. We also thank Shiraz University Research Council for providing the means for this research.