Analysis Of Environmental Impact Due To Exploitation Of K Li B Mine And Optimization Of Exploitation Scheme In Qinghai West Taijinar Salt Lake

Potash deposit, magnesium deposit, boron deposit and lithium deposit are mainly contained in salt lakes around the world. The West Taijinar Salt Lake Mining that is located in the center of Qaidam Basin in Qinghai Province is a large deposit with liquid brine based and solid-liquid coexistence. The useful components of liquid minerals contains KCl,B2O3,MgCl2,NaCl.etc in addition to LiCl.Though brine mining ore exploitation has high economic benefits, it can bring out great negative impact on land resources and soil environment with the mine's construction and development. The decline of groundwater level and other environment problems have been becoming obvious caused by brine mining with the expanding of underground brine mining quantities.For the purpose to minimize the interference and damage to the mining environment, carry out protection and restoration of mining environment, and avoid greater environmental problems, the article not only assess the environment problems may be caused by mining construction and exploitation activities but also optimize the exploitation program based on environmental status in order to provide scientific basis for mineral exploitation, geological environmental protection and ecological restoration. As follows:1, Mine is located in the central Qaidam basin, it's hydrogeology condition is controlled clearly by topography, lithology and geologic condition, intercrystalline brine deposit in silt rock salt layer(WⅡ-2) are the mainly deposit and phreatic aquifer.2, Through the analysis and evaluation of mining area environmental impact, we draw the conclusions as follows:The impace because of the development of mine mainly included:the occupy of land, Destruction of vegetation, Changes of landforms, Soil Pollution, water losses and soil erosion,.etc Damage of Water balance is the most serious factor.3, Through the comprehensive analysis of a large number of meteorological, hydrological, geological and hydrogeological data, the three-dimensional steady numerical simulation model is established using finite difference method. For the main problems that exist in water resources exploitation of the mining area, based on validation and verifying of the model, the special research is carried out from the view of resources exploitation and environmental protection.Taking using of the numerical model after Zone Budget Adjusting the parameters,and the error of the recharge water of Brine channels and the actual extraction is 9.56×104m3, the relative error is 0.23%, consistent with accuracy.4, Through the brine of the roller in different time settings, design five new programs. Adjusting the head value of head boundary of the exploitation of "Drain", the amount of the exploitation of new programs within a decade is as same as the one of original program, and then analyzed the groundwater flow field after the exploitation.In the same time period, in the same case, A new scheme's effect on underground water level obviously less than the original proposal,and the disturbance and damage on groundwater environment is alos less than the old scheme, when the roller time of mining program is less than 183 days, the longer the roller time, the smaller the drawdown; when the roller time of mining program is more than 183 days, the effect of the brine mining on the groundwater environment no longer changes significantly. From this, the roller time of specific mining programs, can be set to more than 183 days according to production needs.