Hydrogeochemical Characteristics of Groundwater at the Xikuangshan Antimony Mine in South China

The hydrogeochemical influence of the Xikuangshan antimony mine on groundwater quality was investigated by analyzing groundwater from 24 springs in the area for major and trace elements. The samples had a pH of 7.6–8.5; total dissolved solids ranged from 125 to 607 mg/L. The groundwater was dominated by alkaline earths (Ca 2+ + Mg 2+ ) over the alkalies (Na + + K + ), and weak acids HCO 3 - over strong acids SO 4 2 - + Cl - . Calcite was generally supersaturated and gypsum was always undersaturated, while dolomite was undersaturated in 34 % of the samples. Iron was negatively correlated with Ca 2+ , Mg 2+ , and SO 4 2 - , which is consistent with Fe removal during acid buffering. Scatter diagrams and correlation coefficients between the major ions indicate dissolution of carbonates and gypsum as major processes, which could promote calcite precipitation.