Ningdong Coalfield Caused By Coal Mining Research On The Influence Of Regional Groundwater Environment And Its Characteristics

Through investigation and research on geological and hydrogeological conditions and coal seams of jinjiayi coal mine in ningdong coal mine.Application Cgis,Mapgis,Suffer and other comprehensive mapping software,the strata histogram and division of tectonic outline map,aquifer system diagram,the Jurassic groundwater system partition map,contour map of aquifer thickness,total average sulfur content of minable seam diagram,etc.Using office and other office software,the water inflow,the characteristics of coal seam elements,trace elements and chemical action of the water in the downhole were carried out in detail.Using the groundwater isotopic tracer technique and KZDL series automatic desulfurizer to test the coal sulfur,the water samples were tested and analyzed by atomic fluorescence spectrometer.Finally using the comprehensive index evaluation method,evaluation of groundwater single component method of former east ningxia coal mining,water quality data of the middle and later periods of the early stage of coal mining and coal mining in detail analysis and study.The effects and characteristics of coal mining on regional groundwater environment are obvious.?1?Through Jin Guqu coal mine wind even,machine which and cut the eye ShuFang water drilling water inflow,further confirmed the working face in the bottom of the main water filling aquifers are in conglomerate aquifer and bedrock weathering zone aquifer,water due to each borehole in different degree,that 18 coal upper aquifer common filling water,but water filling for small to moderate intensity.According to wind lane,and at the same time two different position of drilling machine lane ShuFang water actual situation shows that wind lane near as close to the north zhuang anticline,buried depth of coal seams is relatively shallow machine lane 18,18 coal seams and bedrock weathering zone aquifer spacing decreases,controlled by the anticline axis,to accept the upper aquifer of roof replenishment effect is stronger than the machine lane,the entire Shu Fang also reflects the wind lane in the process of drilling water is generally greater than drilling machine lane.At the same time,the number of boreholes with initial inflow in the wind tunnel is far greater than that of the machine lane,which indicates that the lower water filling of the lower layer of the rock weathered zone near the anticlinal axis is obviously stronger than that of the lane.The drilling of water in coal mine has greatly reduced the water inflow,and the production activities of coal mine have been discharged.In addition,according to the survey of the ground,not only mine water inflow is reduced,the ground water flow is reduced,ningdong coal product home well mining area of spring 12,due to the affected by coal mining,water yield decreased with each passing day,there are 90%of the spring water fell by more than 50%.?2?According to the groundwater isotope in the?D?‰?and?¹⁸O?‰?analysis,?¹⁸O?‰?values below 8.5‰,the?D?‰?values below-70‰,groundwater isotope water content is low,according to the measuring point the location of the rain line in China,shows that the water can be classified as infiltration replenishment.Water samples from the delta and the group?D?‰?and?¹⁸O?‰?values and summer precipitation?rain??D?‰?and?¹⁸O?‰?far,and the precipitation?snow??D?‰?and?¹⁸O?‰?values close to the delta,distributed in the same area,it shows that this group of groundwater is made after evaporation of surface water supplies.The value of?D?per thousand?was distributed at-76.1 per thousand to-32.9 per thousand,with the value of?¹⁸O?‰??per thousand?as-5.0 per thousand and-4.9 per thousand,respectively,and the sample source was Z6 jinjia canal fault fracture zone and Z8-1straight group aquifer groundwater.At the Chinese rainwater line,the values of these points tend to be SMOW values,indicating that the water is a mixture of residual water and seepage water.Through the study of first Jin Guqu coal mine mining area the characteristics of tritium in groundwater,Jin Guqu coal mine groundwater water samples of tritium content in the<1.0TU⁵.4±0.4TU between,according to this standard,all groundwater Jin Guqu coal mine belongs to the"old water"of 40 years ago,affected by the modern water are faint.?3?Through the study of Jin Guqu coal mine groundwater chemical composition,Jin Guqu coal mine groundwater mainly displays in the hydrolysis of rock minerals,leached,carbonate,and the roles of desulfurizing acid and cationic alternate adsorption,etc.In the process of groundwater flow,the mineral in the surrounding rock is dissolved in water and partially precipitated according to the degree of dissolution of the mineral in the groundwater.The study shows that the pH value of groundwater is increasing.?aquifer in coal field exploration phase pH 7.64⁸.55,with a mean of 8.16,after the construction of coal mines production and added hydrogeological exploration phase pH value of 8.25,the pH value increases indicate that the aquifer groundwater.Also,?aquifer and?aquifer in coal mine construction before and after the construction of coal mines are pH value increasing.It is also concluded that the concentration of sulfate ions,bicarbonate ions and chloride ions in the groundwater of jinjiatan coal mine gradually decreases.?4?By using comprehensive index evaluation model to the,to the east ningxia coal mining in the early,middle and later periods of the coal mining coal at different stages of the possible impact of groundwater environment,the evaluation of before and after the east ningxia coal mining groundwater quality are V class water,show due to mining activities for a long time,the area of groundwater pollution by continuous,leading to the groundwater quality is poorer.Through the analysis of single component statistical analysis in groundwater,the initial stage of the concentration of sulfate ion and chloride ion in aquifer is several times in the middle and later stage of exploitation,and the change is obvious.In the early stage,the concentration of sulfate ion and chloride ion in aquifer was decreased in the early stage of mining,but there was no change of several times.?5?Studies have shown that east ningxia coal mining caused significant changes have taken place in the groundwater environment,mine in construction phase conduction from top to bottom aquifer,groundwater in chemical interaction in a series of water flowing through the process,makes the water pH value increases,including pH value in middle and later periods of the coal mining water increases,whether it is the exploitation of the early Jin Guqu coal mine,still have the spirit of the mass production new coal mine and von ditch coal mine water quality data has showed.Therefore,direct discharge of water from coal mines in ningdong coalfields can harm the growth of surface organisms,contaminate surface soil,pollute surface water and shallow groundwater,etc.Therefore,the mine water should be treated before discharge and then utilized after meeting the corresponding standards.However,it is not easy to take advantage of the water resources of coal mine pits.The groundwater pollution itself has irreversible characteristics,and it is expensive to control.Therefore,from the following aspects,it has been taken as a precaution to establish long-term mechanism and generate a certain economic benefit to sustainable development.