Study On Hydrological Effect Caused By Coal Mining And Rational Utilization Of Mine Water

In recent years, with the strategic implementation of coal industry in China movingwestwards, coal industry has become a pillar industry of Yulin city of Northern Shaanxienergy base. However, serious shortage of water resources in this region restricted the rapiddevelopment of coal industry to some extent. Increasing number of coal mines and miningscales made some problems and contradictions that had been ignored in the past emergedobviously. Among others, the most serious ones are environmental problems in Yulin areaand social problems due to environmental deterioration. Lacking unified management ofusing and discharging mine water, so plenty of mine water as an associated resource has beenwasted. It wasted precious water resources but also polluted environment. Therefore, thereasonable development and effective use of mine water resources has important strategicsignificance for alleviating the contradiction of water supply and demand, ensuring thesustainable development of economic society and ecological environment in Yulin city.Based on the comprehensive summarizing the effect of coal mining on groundwaterresources and utilization situation of mine water both at home and abroad, the impact ofmining on water environment and water cycle in Yulin mining areas had been studied deeplyand systematically. Meanwhile, hydrogeological analogy method was employed to evaluatethe discharging situation of coal mine drainage in2011using the survey data of coal minedrainage and usage in Yulin. Furthermore, mine water inflow quantity was also simulated andestimated. The utilization status and development potential of mine water was studied indetail. In view of the existing problems and reasons of mine water drainage and usage, thecountermeasures for reasonable developing and effective utilizing mine water were putforward finally. The main conclusions include:(1) The overlying aquifers of coal seams were damaged by widespread coal exploitation,which caused water level declining continually and variable groundwater flow field. Both ofspring flow and river base flow reduced and groundwater quality changed at the same time. It also intensified the hydraulic connection within the groundwater aquifers and changed theconversion relationships among precipitation and groundwater as well as groundwater runoffcharacteristics.(2)In2011, the total productive capability of209coal mines and total amount of minedrainage water and tons of coal discharge in Yulin is2.832*10~8t,1.4*10~8m~3and0.49m~3/t,respectively. In the whole, annual mine discharge and average annual tons of coal dischargein Yulin area were lower than counterparts of Shannxi and other regions in China. Relativelower tons of coal discharge in Yulin reflected the advantages of coal mining conditions atleast. With the increasing mine exploitation, mine drainage discharge would increasegradually. The estimation result showed that mine drainage discharge would be3.11in2016.It would be doubled comparing with that of2011.(3)From the sample survey of coal mine drainage water use, the main utilization ways ofmine water included production water, industrial water, domestic water, fire landscaping andecological conservation water, irrigation water use and discharge. While the general processmodes were precipitation, filtration and disinfection. Now the comprehensive utilization ofmine water of many coals has achieved good effects, a lot of experience had also beenaccumulated. However, there were39.20%of mine water still could not be used, which waslow undoubtedly for serious water shortage in Yulin area.(4)According to the sampling survey data of drainage water discharge andhydrogeological conditions of each mining area in Yulin city, the utilization prospect of coalmine drainage is not optimistic for Fugu and Shenfu mining area. By contrast, groundwaterabundance was rich and its corresponding groundwater exploitation of tons of coal per unitwas large both in Yushen and Yuheng mining area. Thus the reasonable development andutilization of mine water in these areas would have broad prospects.(5)Aiming at the existing problems and reasons in the process of utilizing mine water inYulin coals, measures of reasonable development and effective utilization of mine water hadbeen put forward in this paper. policy security system of coal mine water use should also beconsummated and established. In addition, strengthening mine water the propaganda andchanging thought as well as improving mine water treatment technology were all proposed.