板集煤矿地下水稀土元素地球化学特征

Rare earth elements possess stable and similar geochemical properties, making them widelyutilized in the study of groundwater-aquifer interactions and geochemical processes. In this study, tak⁃ing the Banji Coal Mine in the Huainan Coalfield as the research area, water samples including sand⁃stone water, gray overburden water, and mixed water from mined-out areas were collected. These sam⁃ples were tested and analyzed for their rare earth element contents, as well as conventional water chem⁃istry ions. The objective was to investigate the hydrochemical characteristics of groundwater in the min⁃ing area, the distribution of the rare earth element as well as the related controlling factors. The resultsshowed that the average mass concentrations of Na+ +K+, Cl-, and HCO3 in the groundwater of themining area were determined to be 669.1, 820.3, and 344.0 mg / L, respectively. Based on the waterquality types, we classified the groundwater primarily into Cl - Na type, Cl - HCO3 - Na type, andHCO3-Na type. Generally, the rare earth element contents in the groundwater fell within a lower con⁃centration range. However, three mixed water samples exhibited significant enrichment of heavy rareearth elements, while most of the water samples demonstrated light rare earth enrichment. Notably, Eudisplayed the highest content, primarily due to its separation from the rare earth element group duringcrystallization and precipitation with calcium minerals. Correlation redundancy analysis unveiled alinear relationship between Eu and Fe in the groundwater samples of the area. The adsorption of Fe ox⁃ides with rare earth might be a significant controlling factor influencing the rare earth element content.This study is of significance to a comprehensive understanding of the geochemical processes in thegroundwater system of the Banji Coal Mine in the Huainan Coalfield. Furthermore, it provides a scien⁃tific basis for the evaluation and management of groundwater in the mining areas.