| The Mudu Chaideng Coal Mine is located in the Hujierte Mining Area,Dongsheng Coalfield,Inner Mongolia.The normal water inflow of the mine reaches1400m~3/h?1480m~3/h.The overlying confined aquifer of the Yan'an Formation is the main direct water-filled water source of the mine,and its groundwater mineralization is the highest at 1.6g/L,the pH reached a maximum of 11.7,and the fluoride ion concentration exceeded the standard.Based on the above-mentioned hydrogeological background,this paper has carried out research on the surface water-saline lake water chemical characteristics and genetic mechanism,groundwater dynamic conditions and hydrochemical characteristics regularity.Through on-site sampling,pumping test,and indoor experiment,surface water quality test,hydrogeological parameters of the water-bearing rock group and main mineral components were tested.And through field sampling,pumping test,indoor experiment,the surface water quality and the hydrogeological parameters and main mineral composition of the water-bearing rock group,were tested.Finally,through profile flow field simulation and reverse hydrogeochemical simulation,the causes of groundwater hydrochemical characteristics with high salinity,strong alkalinity and high fluoride ion content in the study area were comprehensively analyzed.The main research results of this article include:(1)Field surveys and hydrochemical analyses were carried out on 7 surface natural saline-alkali lakes in the study area.Most of the surface lakes in the study area also have hydrochemical characteristics of high salinity,strong alkalinity and high fluoride ion content,Hydrogen and oxygen isotope analysis shows that there is a hydraulic connection between the surface saline-alkali lake and shallow groundwater.(2)The hydrogeological parameters and water chemical composition of the main aquifers in the study area were obtained through field investigation,sampling and laboratory experiment analysis,and the hydrochemical characteristics of groundwater were analyzed using cluster analysis and correlation analysis methods.The comprehensive drilling data,pumping test data,and the relationship diagram of the surface water and groundwater quality tree in the study area prove that due to the lack of a stable water-blocking layer,there is a hydraulic connection between surface water(saline-alkali lake)and groundwater,which has also become one of the causes of groundwater's strong alkalinity.(3)Through the GMS simulation software,a two-dimensional numerical model of groundwater steady flow was established,revealing the evolution of the flow field on the profile and plane of the study area;and based on the groundwater dynamic field,the evolution of the groundwater hydrochemical field in the vertical and horizontal directions was studied.(4)Through R-factor analysis of groundwater and rock sample collection and analysis of aquifer,the"possible mineral phase"of hydrogeochemical reaction on the simulated path was selected.On this basis,the horizontal and vertical water-rock interactions in the study area were geochemically simulated,and the formation process of highly alkaline and highly mineralized groundwater was further analyzed and studied. |
PDF Full Text Request