WATER-ROCK INTERACTION AND STABLE ISOTOPES (34S,lsO) AS GEOCHEMOCALTRACING SOURCE OF SULFATE IN ABANDONED MINE WATER: A CASE STUDY OF THE FENGFENG COALFIELD IN NORTH CHINA

摘要

In this study,to investigate the geochemical source of sulphate content of abandoned mine (AM) water in the Fengfeng carbonate coalfield,six AM water samples,five Ordovician limestone water samples,four shallow groundwater samples,two river water samples,and three coal bedrock water samples were collected for analysis.The variation of 534S(S04) and 5180(H20) as well as water-rock interactions were investigated.The results showed that the AM water originated from the Ordovician limestone water,even though it was weakly alkaline with high SO42" and total dissolved solid concentrations.Moreover,the results revealed that the pyrite oxidation process was the primary source of SO42" in the AM water.The investigation of water-rock interactions revealed the transition of carbonate minerals from calcite to dolomite during the neutralisation of H+ in the AM drainage water.Moreover,the water-rock interaction between the AM water and the ion exchange process primarily contributed to the high Na+ and K+ concentrations in the AM water.