Hydrogeochemical analysis and assessment of mine water quality in Tangjiahui mining area, Inner Mongolia, China

Mine water plays an essential role in securing mine production and domestic consumption in arid mining areas. This study was conducted to analyse the hydrogeochemical characteristics, determine the hydrochemical processes and assess the quality of mine water in the Tangjiahui mining area in Jungar Coalfield, Inner Mongolia, China, by using the Piper trilinear diagram, Gibbs map and statistical methods. The results showed that the pH and EC of the mine water in the study area ranged from 7.10 to 7.90 and from 1684.70 to 3435.60 μS/cm, respectively. The TH and TDS were in the range of 219.52–390.6 mg/L and 926.61 to 1889.56 mg/L, respectively. The cation content in the mine water was ranked from the highest to the lowest as Na + > Ca 2+ > Mg 2+ , while the anion content was ranked as Cl − > HCO 3 − > SO 4 2− . The hydrochemical type of the mine water was Cl–Na. The main mechanisms controlling the major chemistry of the mine water were the dissolution of halite and gypsum, and reverse cation exchange. Due to its high concentration of major ions, TDS, EC, SAR, and Na%, the mine water in the study area was not suitable for human consumption and agricultural irrigation. These results are beneficial for the sustainable reuse and management of mine water resources in the mining area, and will also provide references for similar studies in other regions of the world.