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71.
The significance of organic matter origin for carbon oxidation via sulfate and iron reduction in the sediments of three acid mine lakes is analyzed. Carbon reactivity was estimated by fitting first‐order expressions to measured rates. Carbon oxidation rates via sulfate and ferric iron reduction ranged from 3.4 to 4.7 mmol m–2 d–1 and resembled those reported for freshwater lakes. The estimated reaction constants increased from about 10–3 a–1 at the interface to the former mine grounds to 0.05 to 0.2 a–1 at the current sediment‐water interface. Aquatic organic matter accounted for an estimated 45...75% of total carbon oxidation rates while it amounted only to about 5...14% of the total organic matter that had been deposited. The results of this study suggest that in highly acidic mine lakes the reactivity of the deposited organic matter can rapidly increase after flooding, enhancing carbon oxidation and internal neutralization rates in the sediments. 相似文献
72.
HSE管理是现代企业走出国门、承揽国际大型项目的必备条件,并且在现代工程管理中具有越来越重要的地位。土耳其卡赞天然碱矿水溶开采对接井工程的实施过程中,在借鉴国内外相关行业经验的基础上,结合项目自身特点,成立了HSE管理机构,加强了人员安全培训和机械设备的升级改造,使之符合当地的行业安全标准。引入了JSA工作安全分析工具,建立了切实可行的HSE管理体系,并强调了现场监督,从而实施了行之有效的HSE管理,为该项目的顺利运行提供了有力的安全保障。 相似文献
73.
This study develops a three-dimensional heterogeneous numerical model to simulate the water inrush process and predict the water yield for mineral exploration in Yangzhuang Iron Mine in Anhui Province. To identify the hydrogeological parameters of the aquifer in the study area, the model was calibrated and validated using the observed heads through the integrated trial-and-error and automated techniques. Also, the sensitivity analysis of the model was performed to evaluate the uncertainty associated with the calibrated model. According to the mine construction plan at different mining levels of -500 m, -600 m, and -700 m, the calibrated model was then applied to predict the water yields dependent on the different mining levels. As indicated by the prediction results, the numerical simulation model can systematically describe the groundwater system in the mining area and determine the source of water inrush in this iron mine. In conclusion, numerical analyses carried out in this study can provide guidance to decision-makers in balancing the iron ore mining and mine dewatering in the future. 相似文献
74.
75.
广西南丹大厂矿区地震活动特征分析 总被引:1,自引:0,他引:1
本文收集了2009年12月至2010年4月广西南丹大厂矿区地震监测台网记录到的421次ML≥0.5可定位地震事件(含爆破)时空分布情况, 从实际调查和波形特征分析排除爆破记录后, 研究震级较大的几次矿震震源机制解, 按小时段统计爆破频次与能量释放关系。 结果表明, 矿震断裂走向与区域构造较为一致。 矿山地下开采量增加以及之前出现的近半年历史上罕见的干旱气象因素, 在震级较大的人工爆破触发下, 影响了局部构造应力场的稳定性, 由此引发了一系列矿震。 相似文献
76.
《Chemie der Erde / Geochemistry》2017,77(4):614-624
Water samples (springs, creeks, mine adits) from different former mining districts of the Harz Mountains and the nearby Kupferschiefer (copper shale) basin of Sangerhausen were analysed for major ions and trace metals. Due to more intensive water rock interactions including the ore minerals, the mine water concentrations of main components and trace metals are generally higher compared to non mining affected surface waters of the mountain range. Furthermore, the content of major ions in mine water is enriched by mixing processes with saline waters from Permian layers in the Kupferschiefer district and at the deeper levels of the mines in the Upper Harz Mountains. The waters of the different mining districts can be distinguished by trace metal occurrences and concentrations derived from the different ore bodies. Water from the Kupferschiefer mines shows the highest Na, Cl, Cu, Mo and U concentrations, whereas a combination of elevated As and Se concentrations is typical for most of the samples from the mines around St. Andreasberg. However, there are exceptions, and some water samples of all the investigated mining districts do not follow these general trends. Despite the influence of mining activities and ore mineralisation, hydrochemical effects due to rain water dilution can be seen in most of the waters. According to the elevation of the mountain range, higher precipitation rates decrease the ion concentrations in the waters of springs, creeks and mine adits. 相似文献
77.
78.
To study the geochemical anomaly structure of multi-element associations in the South Mining District of the Fenghuangshan Copper Mine,samples were collected and analyzed for their trace element contents.Multi-element anomaly associations were divided according to the correlations between Cu and each of the other elements,and the distribution characteristics of multi-element anomaly associations were also described.Among them,the anomaly distribution of metallogenic element Cu indicates the environment of mineralization.This study provided the basis for research on the metallogenic prediction and geochemistry of the Fenghuangshan Copper Mine. 相似文献
79.
80.
Michael F. Gazley Julie K. Vry Ettienne du Plessis Monica R. Handler 《Journal of Geochemical Exploration》2011
Stratigraphy, structure and host-rock chemistry are dominant controls on the location of Au in Archaean greenstone-hosted Au deposits, but the stratigraphy in such deposits is seldom obvious due to the monotonous nature of the host rocks or pervasive alteration associated with Au mineralisation. Portable, hand-held, X-ray fluorescence (pXRF) spectrometry provides a method to rapidly collect large amounts of whole-rock geochemical data that can yield new insights into both stratigraphy and Au localisation. Here we present results of pXRF analyses of samples from a representative section through Au-mineralised amphibolite-facies metabasaltic rocks at Plutonic Gold Mine, Western Australia. These data illustrate a geochemical stratigraphy in which individual lava flows can be identified on the basis of element concentrations. The most evolved basalts are at the structural base of the succession, and the least evolved at the top of the sequence, confirming previous geochemical interpretations and textural evidence that the sequence is overturned, and demonstrating for the first time that the presented section does not involve significant structural repetition. In conjunction with Au assay data, the pXRF data reveal that Au commonly occurs along basalt flow boundaries. The elemental concentration data clearly demonstrates for the first time the stratigraphic control on Au mineralisation that is not readily apparent at the macroscopic level. The methods described in this paper are readily applied, and have the potential to enhance the understanding of otherwise unclear stratigraphy and its control on mineralisation in many different types of deposits worldwide. 相似文献