Numerical Simulation Of The Migration Of Fluoride From A Tailing In Panzhihua

The tailing pond is a vital part of the mining area environment protection facilities.With the development of numerical simulation,the simulation of pollution migration of the tailings is receiving more and more attention.In search of the pollution migration path and scale during the use of the tailings,this thesis uses Visual Modflow to establish the groundwater flowing model of the research area,within which lies a tailing,select fluoride as the simulating factor,run the simulating of the pollution migration through MT3 DMS module and see the process and laws behind.Then by using the PEST module of the software,the thesis researches the uncertainty of the model brought by the selecting of different parameters.1.By analyzing the hydrogeological conditions in the study area,results of doubleloop water injection test in the field and information obtained indoor,a groundwater flow model is established.Then through continuous adjustment,the initial values of the parameters of the model that fit the real world time situation are set.2.Based on the groundwater flow model the pollutant transport model is established to reproduce the contaminant migration process,which shows that the main migration path of the contaminant are the two gullies,particularly the gully NO.2.The contaminant spread fan-shaped after downstream and reach the bottom of the gullies,then under the influence of An Ning River,show the tendency of going South.3.Concluded from the PEST results of parameter Conductivity,the main source of the model uncertainty is K4 and K5.By using the method of Parameter optimizing of cross-validation,we differ five different value of both K4 and K5 within the confidence interval of witch,then put the twenty-five different pairs of the new value set in the model and chose the best pair of all,which is K4=0.658 m/d and K5=1.335 m/d according to the simulation results.after putting the optimized parameter value into the model and run the simulating of the pollution migration,the results shows that in five years time the contaminant concentration increases along the original preferred migration path with time,and the area with limit-exceeding concentration is getting bigger,reaching to An Ning River and the villages.