Study On Prevention And Control Of Mine Water In Deep Mining Of Maoping Pb - Zn Mining Area In Northeastern Yunnan Province

The Maoping lead-zinc ore deposit in northeastwen Yunnan province has a long exploitationary history of more than 300 years, and can be dated back to the Ming and Qing dynasties. In recent years, with the mining exploration scale increasing, the mine district has already formed a united production tunnelsystem with 6 midpieces. On the eastern side of the Luoze river, the mine elevation has developed at least 670 meters level, and to 503 meters level on the western side up to now.And the elevation of the water head of Luoze river is about 880 meters, so the elevation gapbetween the lowest developmenttunnel and the Luoze river is about from 210 to 380 meters.This deposit is a karst-fracture aquifer groundwater directly filling type deposit. With the stretching of mine exploitation, and the mining level increaseing deep, the mine water inflowingis increasing obviously. In the mining area,the mine water inflowinghas increased up to 16000 m3/d,which has become the important restriction factor of the normal production of mine, and the potential risks of the mining safety is becoming remarkable.In order to find out the minutehydrogeological condition and ming water filling factors of the karst-fracture groundwater system inthis mine area, and putting forward the reasonable mine water prevention and controlling methods and measures, has become the urgent demand of the nine currently.Throughthe detailed hydro geological surveying, the hydro geological observation,the special field hydro geological test, and the comprehensive analysis and research of the karst-fracture groundwater system in the Maoping mining area, this article has achieved the following main results:Firstly, as an underwater deep mining deposit, the main water filling source of the Maoping Pb-Zn deposit include the direct lateral recharge of the karst-fracture aquifer and the cross-layer suppliesofthe adjacent aquifers along the fault zone, and the surface water is also an important water filling source.Secondly, the Maoping Pb-Zn mining area is composed of three relatively independent hydrogeological units which are separated by two confining layers and three aquifers. These hydrogeological units has independent recharge sources, flow paths and discharge channelsrespectively.Their hydrogeological conditions and the mine water filling condition shave been relealed.Thirdly, through drillhole pumping test and dewatering testin tunnel, the hydrogeological parameters of the main aquifers have been obtained. The permeability coefficient (K) of the karst-fissure aquifers in the Carboniferousformation is 0.18 m/din the eastern side of the Luoze river, and is 0.3 m/din the western side of the river,and that of the Devonian formation in the east of the river is 0.39 m/d.Fourly, through using the Hydrological Geological Analogy method and the Analytical method, the normalmine water inflowing yield of the 610 meterlevel in the eastern sideof the Luoze river and the 550 meter level in the western side of the Luoze river has been predicted respectively. After a comprehensive comparing and analysing, their largest mine water inflow is determined as 23495 m3/d and 6368 m3/drespectively. These data can be used as the basis for the deep mining design.Lastly, through the plan comparsion and optimization, the plan of the aquifer into water or orebody surrounding implementation of curtain grouting, mine water prevention and control scheme of high-risk has been put forward. Confirmed by the effect of mine water prevention and controlling projects, the engineering measures provided by this plan is appropriate and effective, and meet the technical requirements for the governan ceeffect.This is furtherly confirmed that the hydrogeology conditions understanding of the karst groundwater system in the Maoping mining area is realistic.