Chemistry of Groundwater from the Taiyuan Formation Aquifer in Liuyi Coal Mine, Northern Anhui Province, China and Its Implications for Water Rock Interaction in Deep Seated Environment

Abstract

Chemical compositions of groundwater from the Taiyuan formation aquifer in Liuyi coal mine, Northern Anhui Province, China have been measured for evaluating the hydro-chemical evolution in deep environments. The total dissolved solids values of groundwater range from 640 to 2567 mg/L and indicates moderate to highly mineralized and the ions are predominantly composed of (Na + K), Ca and SO₄ with their average concentrations are 225, 117 and 508 mg/L, respectively. The groundwater samples are saturated with calcite and dolomite and undersaturated with gypsum with their average saturation indexes are 0.25, 0.18 and -1.29, respectively. The main minerals incorporated in the water rock interaction include halite, albite, K-feldspar, gypsum, pyrite, calcite and dolomite: Na and K are originated from the dissolution of halite, albite and K-feldspar, SO₄ is from dissolution of gypsum and the dissolution and oxidation of pyrite, whereas Ca and Mg are originated from dissolution of calcite and dolomite.