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121.
Study on detecting spatial distribution availability in mine goafs by ultra-high density electrical method
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The purpose of this research is to explore the spatial distribution and influence range of the mined-out area of a coal mine in Hebei Province, the advantages of ultra-high density resistivity method, such as large data volume, high efficiency and high precision, are brought into full play, the abnormal patterns of dislocation and partial drainage area of shallow continuous aquifer caused by subsidence zone are detected, and then the spatial distribution patterns of subsidence and fractures caused by deep mining subsidence zone are deduced, this method not only extends the exploration range of high-density resistivity method in mining subsidence disaster assessment, but also improves the accuracy of measurement, the distribution and influence range of mined-out area are revealed accurately, and good exploration results have been obtained in this project. How to select reasonable geophysical prospecting methods and give full play to the role of geophysical prospecting methods according to the geological characteristics of the study area, this exploration work is not only a good combination of geophysical prospecting methods and actual geological conditions, it also provides a valuable reference version for the exploration work under the same geological conditions. 相似文献
122.
Deep Seabed Mining: Past Failures and Future Prospects 总被引:8,自引:0,他引:8
G. P. Glasby 《Marine Georesources & Geotechnology》2002,20(2):161-176
The first attempt to exploit deep-sea manganese nodules ended in failure as a result of the collapse of world metal prices, the onerous provisions imposed by the U.N. Convention on the Law of the Sea (UNCLOS), and the overoptimistic assumptions about the viability of nodule mining. Attention then focused on Co-rich manganese crusts from seamounts. Since the mid-1980s, a number of new players have committed themselves to long-term programs to establish the viability of mining deep-sea manganese nodules. These programs require heavy subsidy by the host governments. Au-rich submarine hydrothermal deposits located at convergent plate margins are now emerging as a more promising prospect for mining than deep-sea manganese deposits. 相似文献
123.
124.
During the summer of 1989 surface sediment samples were collected in Lake Coeur d'Alene, the Coeur d'Alene River and the St Joe River, Idaho, at a density of approximately one sample per square kilometre. Additional samples were collected from the banks of the South Fork of the Coeur d'Alene and the Coeur d'Alene Rivers in 1991. All the samples were collected to determine trace element concentrations, partitioning and distribution patterns, and to relate them to mining, mining related and discharge operations that have occurred in the Coeur d'Alene district since the 1880s, some of which are ongoing. Most of the surface sediments in Lake Coeur d'Alene north of Conkling Point and Carey Bay are substantially enriched in Ag, As, Cu, Cd, Hg, Pb, Sb and Zn relative to unaffected sediments in the southern portion of the lake near the St Joe River. All the trace element enriched sediments are extremely fine grained (mean grain sizes « 63 μm). Most of the enriched trace elements, based on both the chemical analyses of separated heavy and light mineral fractions and a two step sequential extraction procedure, are associated with an operationally defined Fe oxide phase; much smaller percentages are associated either with operationally defined organics/sulphides or refractory phases. The presence, concentration and distribution of the Fe oxides and heavy minerals indicates that a substantial portion of the enriched trace elements are probably coming from the Coeur d'Alene River, which is serving as a point source. Within the lake, this relatively simple point source pattern is complicated by a combination of (1) the formation of trace element rich authigenic Fe oxides that appear to have reprecipitated from material solubilized from anoxic bed sediments and (2) physical remobilization by currents and wind driven waves. The processes that have caused the trace element enrichment in the surface sediments of Lake Coeur d'Alene are likely to continue for the foreseeable future. 相似文献
125.
Arching is a well known phenomenon, which effects stress developments which were investigated and compared using analytical
and numerical solutions. Marston’s (1930) solution was extended to a generalised 3-dimensional rectangular stope and later modified for square and circular stopes
for comparison with FLAC results. Aubertin et al. (2003) & Li et al. (2003) models were improved significantly by placing the backfill within narrow stopes as lifts or layers in numerical modelling
where the normal stress variation with depth were found to be more realistic. The FLAC results were compared with analytical
solutions which were developed by previous researchers and modified by the authors to evaluate the arching effects in backfilled
placed in narrow and circular stopes. It appeared from the investigation herein that δ = 0.67 ϕ and K = K
o condition gives a very close match with the numerical model solutions obtained from FLAC. Many laboratory tests were conducted
to find out friction angles for four Australian mines, which were between 30 and 49 degrees. 相似文献
126.
Paul L. Younger 《Geoforum》2007,38(5):828-840
Pro-poor water engineering aims to deliver water services to individuals and communities in a manner that yields obvious and significant net-benefits to the poorest people. Technology transfer in the field of pro-poor water engineering has too often been seen as one-way (north to south), with industrialised nations exporting their supposedly superior technologies and organisational priorities to the ‘grateful poor’ in the under-developed world. While north-to-south technology transfer can boast significant successes, failures are more numerous, arguably due to the contrast between technocratic (northern) and communitarian (southern) traditions of water management. There is much the northern countries might learn from the southern perspective. One concrete example illustrates how direct experience of community-based, NGO-fostered development of borehole water supplies in Bolivia led to the conscious adaptation of this model for application to problems of remediation of severe contamination of streams in a former mining district in the UK. This application was highly successful, leading to the development of robust community organisations that have gone on to tackle other social and environmental problems. This experience has in turn prompted the testing of the low-cost, technological approaches to acid drainage treatment developed in the UK case for potential application to similar problems in Bolivia. Following further ‘acclimatisation’ of the technology, field trials proved successful and led to plans for full-scale application of the approach with community-based NGOs in Bolivia. Lessons are drawn for furthering the implementation of pro-poor, participative strategies in water management in both the North and the South, with brief critical analyses of Participación Popular in Bolivia, and of both policy and polity in relation to community engagement in aspects of water management in Europe. 相似文献
127.
128.
构建矿业权与土地物权的冲突解决机制 总被引:1,自引:0,他引:1
万俊 《云南地理环境研究》2005,17(6):87-90
为解决现实生活中广泛存在的矿业权与土地物权的冲突,在明确矿业权和土地物权的定义及其权利范围的基础上,探讨了矿业权的主体、客体和内容,以及土地物权的各种物权形态,进一步挖掘了矿业权与土地物权的内涵。同时,针对现实中矿业权与土地物权的冲突现象,运用法学的观点对其形成原因和特点进行了分析,最后给出了解决矿业权与土地物权冲突的价值导向及其协调机制的构建。 相似文献
129.
淮南矿区煤的稀土元素地球化学 总被引:25,自引:2,他引:23
采用INAA测试了淮南矿区 13个煤层煤样的稀土元素含量,研究了稀土元素地球化学特征,得出以下认识 :各煤层样品的稀土元素含量、分布模式变化都很大。煤中稀土元素主要来源于陆源碎屑,来源于海水和植物的不多;稀土元素在粘土矿物中含量高,主要以高岭石的形式赋存。稀土元素具有指相意义,随着成煤沼泽中海水影响的减弱,陆源影响的增强,煤中稀土元素的含量增加;煤的稀土元素分布模式也作有规律的变化,从类似于海相生物的分布模式到类似于陆源碎屑岩的分布模式。Eu异常是由源岩继承下来的,Eu负异常的减弱,估计是由于陆源控制减弱、海水影响增强引起的。在成煤沼泽环境中,海水的影响并未造成Ce严重亏损。 相似文献
130.