Hydrogeochemical Characteristics of Limestone Water in Taiyuan Formation of Hengyuan Coal Mine and Its Response to High Pressure Grouting Project.

Years mining activities have changed the distribution characteristics of groundwater hydrochemical field, which may lead to the deterioration of groundwater quality and the occurrence of mine water inrush disasters. The study of groundwater hydrogeochemical evolution can provide a theoretical basis for the prevention of mine water inrush disaster and the rational utilization and protection of groundwater. Using the Piper trigram, Person correlation analysis matrix, Gibbs diagram, ion proportion coefficient diagram, and mineral saturation index to study the hydrogeochemical evolution mechanism of Taiyuan Formation limestone water before grouting (2010) and after grouting (2020) in this study. The results show that the concentrations of anion and cation in the limestone water of Taiyuan Formation have the same change trend before and after grouting in the study area, the anion concentration changes to SO42-> HCO4- >Cl-, the cation concentration changes to Na+ + K+ > Ca2 +> Mg2+. The correlation coefficient between most ions of limestone water after grouting is reduced. The hydrogeochemical type is gradually transformed from Na+ + K+ -SO42- type to Mg2+-SO42- type and Ca2+-SO42- type. Rock weathering and cation exchange are the main factors affecting the hydrogeochemical characteristics of limestone water. The higher concentration of SO42-is related to the dissolution of gypsum and the oxidation of pyrite. [ABSTRACT FROM AUTHOR]