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1.
应用仪器中子活化(INAA)、电感耦合等离子体原子发射光谱(ICP AES)和原子吸收光谱(AAS)对神华集团马家塔露天矿2-2#煤层中Hg、As、Se、Pb、Be、Cr、Cd、Ni、Th、U、Mn、Mo、Co、Sb和Br共15种有害痕量元素的质量分数进行测定。结果表明,绝大部分痕量元素的质量分数都明显低于中国煤中元素质量分数的平均值,只有Hg和Mn的质量分数偏高,其中Hg的质量分数异常高;通过分析痕量元素在煤层垂向剖面上的质量分数变化特性,揭示出痕量元素在煤层中分布的非均一性,分析了影响痕量元素分布与富集的因素;通过痕量元素之间以及与黄铁矿硫、Fe、Al、Ca、P的聚类分析,研究了痕量元素之间以及与煤中不同矿物组分之间的亲和特性。  相似文献   
2.
This case study uses empirical data gathered at an Australian refinery to verify the assumptions for queue distributions before using special-purpose software to plan the off-road-truck hauling of titanium dioxide to a refinery (n = 773). Easy-to-use spreadsheet software is utilized to verify assumptions for queue models. Managers are able to make decisions based on economic implications of queue models to avoid making costly planning mistakes. Analysts can use nonparametric hypothesis-testing techniques to verify distribution assumptions for optimization without having to write hard-to-maintain and complex algebraic linear equations or nonlinear search routines.  相似文献   
3.
Abstract

Dow 2200 is a selective ore flotation agent, consisting mainly of Nethyl, 0-isopropyl thionocarbamate (IF'ETC). This paper describes a GLC method for the estimation of IPETC, and compares it with the conventional U.V. spectrophotometric procedure.

An aliquot of a cyclohexane extract of IPETC (prepared for spectrophotometric analysis) is chromatographed on a column of SE-30 or OV-17/QF-1 at 125°C and the IPETC peak is estimated in a 3H electron capture detector (ECD). The ECD is superior in sensitivity and linearity of response to the flame photometric detector operated in the S-mode. The ECD-GLC procedure is comparable in sensitivity to the conventional U.V. absorbance method, and offers an independent and complementary procedure useful for confirmation of low levels of IPETC.  相似文献   
4.
Take the cores and surface weathered soil from the Cretaceous red beds in the western of Dongshengmiao mine of Inner Mongolia and analysis with near-infrared spectroscopy. The result shows that near-infrared spectroscopy can identify mineral quickly through the characteristic absorption peaks of each group. The Cretaceous red beds in the western of Dongshengmiao mine is argillaceous cementation, it is mainly composed of quartz, feldspar, montmorillonite, illite, chlorite, muscovite etc, the mineral composition is mainly affected by the upstream source area. The clay mineral like montmorillonite water swelling and uneven drying shrinkage expands the original crack and creates new cracks, reduces its strength, which is the mainly reason of its disintegration. According to the composition of clay mineral, we speculate its weathering process is mainly physical weathering, the climate during the weathering is cold and dry. The results can not only improve the geological feature of the mining area, but also show that the near-infrared spectroscopy technology can analyze the mineral composition of soil and rock effectively on the basis of Mineral spectroscopy, which demonstrates the feasibility of the near-infrared spectroscopy can analyze minerals in soil and rock quickly, that shows the feasibility in geology study, provides new ideas for the future research of soil and rock.  相似文献   
5.
1H NMR and LC-MS, commonly used metabolomics analytical platforms, were used to annotate the metabolites found in potato (Solanum tuberosum L.) irrigated with four different treatments based on FA to AMD ratios, namely: control (0% AMD; tap water), 1:1 (50% AMD), 3:1 (75% AMD is 75% FA: AMD), and 100% AMD (untreated). The effects of stress on plants were illustrated by the primary metabolite shifts in the region from δH 0.0 to δH 4.0 and secondary metabolites peaks were prominent in the region ranging from δH 4.5 to δH 8.0. The 1:3 irrigation treatment enabled, in two potato cultivars, the production of significantly high concentrations of secondary metabolites due to the 75% FA: AMD content in the irrigation mixture, which induced stress. The findings suggested that 1:1 irrigation treatment induced production of lower amounts of secondary metabolites in all crops compared to crops irrigated with untreated acid mine drainage treatment and with other FA-treated AMD solutions.  相似文献   
6.
Mining and smelting activities of the world largest Antimony (Sb) mine which is located at Xikuangshan area of Hunan Province, China, constitute important sources of Sb pollution throughout the rivers in or around the mine. Water samples show high levels of Sb (2-6384 µg/l) relative to the average concentration of the world rivers (1 µg/l) and it occurs mainly in oxidized form. Sb has a higher affinity for the particulate phase than for the aqueous phase. Its contents in sediments decreased along with the distance from the mine (from 7316 to 57 mg/kg) and had good correlation relationships (p < 0.001) with porewaters. In addition to the major pools in the Fe-Mn oxide (22.2-66.4%) and residual fractions (5.66-53.5%), Sb was relatively abundant in strongly adsorbed fraction. Laboratory experiments of the contaminated sediments show that with increasing amounts of Sb in the sediment, an increasing amount of Sb was leached and went into solution. Although Sb(V) was the predominant form, the release of Sb(III) in oxic conditions was also observed during laboratory experiments. And the amount of Sb released into solution was higher in anaerobic conditions than in oxygenated water.  相似文献   
7.
Iron ore tailings have become one kind of the most hazardous solid waste. Beneficiation of iron ore tailings is a significant issue in the world steel industries, from the point of view of both pollution control and secondary resources. This investigation addressed the processing of tailings with high sulphur content from an iron ore concentrator to produce pellet feed fines and to prevent acid mine drainage. This study was the lab-scale testing of an integrated method consisting of froth flotation combined with gravity and magnetic separation. Reverse flotation located at the end of the primary treatment circuit (high- and low-intensity magnetic separation) will lower a large amount of the sulphur from magnetic separator concentrate. The effects of various operating parameters such as concentrations of collector, frother, depressant and activator, pH, solid-in-pulp concentration have been studied on the sulphur removal using reverse flotation. According to the data presented in this study, the maximum recovery of total sulphur was obtained when the operational parameters were set to the PAX dosage160?gr/t, MIBC dosage 140?gr/t, CuSo4 100?gr/t, air flow rate 10?l/min, pH 8.5, and pulp density 30%. With these optimum parameters, final concentrate with the grade of 63.7% Fe and 0.085% S was obtained. The results of this study indicated that, with this method, a great amount of iron concentrate is produced and, simultaneously, the sulphidic fraction is separated that can later be managed more easily owing to the reduced volume.  相似文献   
8.
This paper discusses the use of a cylindrical spring to increase the stability of a tunnel of circular cross section. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 46, No. 3, pp. 141–148, May–June, 2005.  相似文献   
9.
层滑带在华北断陷盆地中具有普遍性,是影响地下矿山工程围岩稳定的重要因素之一。本文以鲁西矿区为例,阐述了断陷盆地层滑带的发育特征及其形成机制,进行了开挖、运营条件下层滑带再变形分析,并指出了层滑带发育区巷道设计及维护中应注意的某些问题。  相似文献   
10.
矿井通风系统具有随机性、模糊性和不确定性等特征,一般单一的赋权评价法难以对其进行准确的优化评价.采用模糊层次分析法和熵权法的组合赋权法不仅可以提升对目标评价的准确性还能避免单一赋权的偶然性和局限性,结合可拓学的优度评价法,依据优度排序,得到最优方案.事实证明,基于组合赋权的可拓评价模型较其他评价方法更为客观,评价结果更加符合实际,可为解决类似优化方案问题提供一种新思路和方法.  相似文献   
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