Hydrogeochemistry and Contamination of Trace Elements in Cu-Porphyry Mine Tailings: A Case Study from the Sarcheshmeh Mine, SE Iran

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

“…As suggested by other authors (e.g., Cravotta 1994;Lin 1997;Khorasanipour and Eslami 2014), formation and dissolution of secondary minerals, especially simple hydrous metal sulfates, can release metals, acidity, and sulfate into the water. This process is responsible for the low pH (from 2.5 to 4.1) and high concentrations of contaminants in the water samples associated with the highly weathered tailings (Khorasanipour and Eslami 2014).…”

“…Fine grain size increases the water retention capacity and capillarity force of the tailings, resulting in higher mobilization of water to the surface and enrichment of bivalent cations, Cl − , and SO 4 −2 in water soluble phases. Significant upward mobilization of Al, Na, Cl, Cd, Co, Cr, Cu, Mg, Mn, Ni, Se, SO 4 −2 , and Zn takes place during the dry seasons in the Sarcheshmeh mine tailings (Khorasanipour and Eslami 2014). Upward migration is later superimposed on the general trend of downward mobilization during the rainy season.…”

“…Evaporation of tailings water, especially from weathering zone, commonly leads to super-saturation, which controls the precipitation of mainly water soluble secondary sulfate minerals (Johnson et al 2000;Dold and Fontboté 2001;McGregor and Blowes 2002). As suggested by other authors (e.g., Cravotta 1994;Lin 1997;Khorasanipour and Eslami 2014), formation and dissolution of secondary minerals, especially simple hydrous metal sulfates, can release metals, acidity, and sulfate into the water. This process is responsible for the low pH (from 2.5 to 4.1) and high concentrations of contaminants in the water samples associated with the highly weathered tailings (Khorasanipour and Eslami 2014).…”

“…The dam, which currently consists of several ponds, has been operating as a cross valley type since 1976, and has been filled gradually and sequentially (Khorasanipour and Eslami 2014). The annual output of roughly 11.4 million m 3 of tailings with specific gravity of 1.28 t/m 3 was used as a basis for prediction of tailings dam volume.…”

“…According to Khorasanipour and Eslami (2014), dissolution of soluble secondary mineral phases, which are formed at and near the surface of the old weathered tailings, is responsible for the development of highly contaminated waters in short periods of time in the dry impoundment of the Sarchshmeh mine tailings. Fine grain size increases the water retention capacity and capillarity force of the tailings, resulting in higher mobilization of water to the surface and enrichment of bivalent cations, Cl − , and SO 4 −2 in water soluble phases.…”