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951.
Open cast mining of lignite leads to dumps containing highly mineralised pore waters. To predict the impact of the dump waters on the undisturbed aquifers two steps are necessary. (1) The prediction of dump water quality at times when steady state flow conditions will be established. (2) The simulation of the dump ground water migration with a model that is able to handle the complexity of the homogeneous and heterogeneous interactions of the migration process.For the investigated site Jänschwalde, which is still dewatered, a chemical mass balance was performed. The predicted alkalinity potentials exceed acidity potentials for the dump as a whole. The distribution of these parameters show high alkalinity potentials for the northern part.In order to model the migration process the transport code PCGEOFIM® [Anwenderdokumentaion, IBGW Leipzig, (in German)] was coupled with the geochemical equilibrium code PHREEQC [USGS, Water-Resources Investigations Report]. This was done to simulate redox reactions, mineral dissolution and precipitation, and cation exchange in the ground water zone. The model is verified by a column flow test. The results of the simulations show a small effect of the migrating dump waters on the quartenary aquifer with respect to acidity changes. This results from calcite buffering and cation exchange. The impact on the quartenary aquifer by sulphate is much higher. 相似文献
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煤矿城市发展阶段划分探析 总被引:14,自引:1,他引:13
把煤矿城市的发展历程划分了4大阶段,初期扩大开发阶段,中期稳定开发阶段,后期开发阶段及煤炭资源耗竭阶段,并分析了不同阶段所具有特点。 相似文献
955.
湘潭锰矿酸性水的形成,与含矿岩系富含黄铁矿的黑色页岩密切有关。本文揭示了它的形成条件和影响因素及其对工农业生产的危害。作者根据当地酸性水的来源与分布。提出了一些防治措施,并对石灰中和法原理及其应用效果作了介绍。 相似文献
956.
Summary Optimization algorithms are developed to improve the selection of truck and shovel fleets for suface mine operations. These are based on performance estimation models developed by Fluor Utah (1977) and graphical display algorithms and other software within the SEAMPLAN system developed at Montana State University. The advantages and disadvantages of the method are considered. 相似文献
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The geochemistry of selenium associated with coal waste in the Elk River Valley,Canada 总被引:1,自引:0,他引:1
Selenium (Se) concentrations more than 12 times greater than the provincial freshwater quality guideline (2 µg/L) were detected in the Elk River downstream from the five open-pit coal mines in southeastern British Columbia's Elk River Valley. To identify possible sources of Se to the Elk River, samples from the coal-bearing Mist Mountain Formation were studied using X-ray diffraction, elemental and oxide analyses, sequential extractions and heavy liquid separation. Between 2.5 and 21.3% of the total Se in the five types of materials studied is water-soluble and 1.0 to 10.6% is associated with hydrous ferric and manganese oxides. Se associated with sulphides and organic material varies between 60 and 84% of the total Se and Se in the silicate structure varies from 5.9 to 24.7%. The ratio of sulphides to the total of organic carbon is well-correlated with the amount of Se in materials closely associated with coal seams containing less than 6 mg/kg of Se (r=0.916). This may suggest that the amount of organic matter present during deposition affects the amount of Se incorporated into sulphides. 相似文献
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贵州万山汞矿尾矿堆及地表水的环境地球化学特征 总被引:5,自引:0,他引:5
对贵州万山汞矿区尾渣堆(主要为炉渣组成)、地表水及河流沉淀物的汞迁移进行了研究。由于赋矿岩石为白云岩,高温煅烧的炉渣中含CaO等碱性物质,炉渣的风化作用释放出汞以及碱性水.流经尾渣堆的地表水碱性强(pH10.6-11.8)、电导率高,且具有明显不同的主要离子组成.万山汞矿矿石单一,主要为辰砂,其他矿石极少,因此炉渣及其渗滤水中除汞外的重金属含量很低.尾渣堆中的汞及碱性物质是对周围环境的主要威胁.在尾渣堆下游汞含量很快降低,约300n,范围内水中的溶解汞从300—1900,ng/L降至72ng/L,而且水的碱性也被中和.但是,由于尾渣堆中的汞及碱性物质含量高,尾渣堆的长时间风化及水流的溶解会将大量汞搬运到周围的土壤及水体并对生物产生不利影响. 相似文献