Study On Groundwater Pollution Evaluation And Prevention In A’xi Gold Mine, Xinjiang Uygur Autonomous Region

The mineral resources are fairly abundant in Xinjiang. The mine of gold is one of theimportant mineral resources in Xinjiang. A’xi gold mine is one of the largest mines inXinjiang. In recent years, the groundwater makes impacts on the surrounding environmentand organisms. To some extent, this is due to the large-scale development and utilization ofmineral resources, mining, selecting, smelting of the waste rock, surface water, undergroundwater peakage, tailings (sand), oxidation and decomposition of the wastewater, whichcarrying large amount of heavy metal elements into surface water or groundwater. Therefore,to strengthen the evaluation of groundwater pollution and to protect the groundwaterenvironment, which have an important theoretical significance and practical value.The paper collects and analyses the environment background data in A’xi gold mine.Combined with the evaluation of groundwater pollution in mine and mine groundwa terpollution prevention, this paper applies the theoretics and methods of field investigation,indoor water quality mathematical model analysis experiment and quantitative evaluation ofprediction. The main research contents and results are as follows:⑴According to the hydrogeology investigation of A’xi gold mine, the source ofgroundwater environment pollution investigation, and analysis of mining, dressing, smelting,tailing process. It concluded the source of pollution with two main types: the source of solidpollution and liquid pollution. The former is tailings in the cyanide containing waste--cakeand tailings; the latter is mainly cyanide environmental library in wastewater, which containsammonia nitrogen and cyanide composition of ammonia nitrogen pollution ingredient.⑵Through the analysis of the source, pollution of groundwater characteristics andpollution route of ammonia nitrogen in mine area, which determined arsenic cyanide, copper,lead, cadmium, zinc as the evaluation index. Using single factor evaluation method, theNemero index method and fuzzy comprehensive evaluation method to evaluate the A’xi GoldDeposit of groundwater pollution, it concluded the degree of groundwater pollution is v inmining area; it is more objectively reasonable and widely applicable by using fuzzycomprehensive evaluation method. Combined with the geological and hydrogeologicalconditions of mining area, which can be concluded mainly ammonia, cyanide severelyexceeds the standard in the groundwater pollution.⑶According to the data of various monitoring, A’xi gold mine groundwater qualityevaluation map is built by taking fuzzy comprehensive evaluation method; Groundwaterpollution prevention and controlling division of A’xi gold mine is completed under the groundwater quality evaluation, sources and kinds of polluted water of a mine. It is dividedinto three areas: non pollution controlling area, general pollution prevention area, keypollution controlling area.⑷In the key pollution controlling area, the analytic method was used for predictingtailing on groundwater environment. The results show that as the time of the leakage oftailings wastewater lasts, the content of cyanide and arsenic at the same distance in the layerincreased, as well as the range of effects of contaminants did. During the same period, withthe distance ranging from near to distant, there appeared a law that the content of the cyanideand arsenic in the layer ranged from high to low. As a result, some supervisory controllingsteps were put forward.