南埃塞俄比亚莱加登比金矿床的地质特征对泛非金矿勘查的意义

莱加登比矿床是埃塞俄比亚最大的产金矿山。它位于南北向的迈加多火山沉积带的晚前寒武纪变质沉积岩中,这个火山沉积带构成南埃塞俄比亚阿多拉晚元古代花岗岩-绿岩地体的一部分。脉金矿化产于一个向西陡倾,沿下伏长石质片麻岩与迈加多带火山沉积地层间构造接触带发育的南北向石英脉系中。此接触带还是区域规模的莱加登比-阿夫拉塔左旋走滑剪切带向最北部延伸的标志。矿化和石英脉在离此构造接触带不超过80m范围内的富含石墨的沉积物中最为发育。热液围岩蚀变包括阳起石/透闪石-黑云母-方解石-绢云母组合和绿泥石-方解石-绿帘石组合。金优先产于绢云母蚀变带中;在此蚀变带中金与方铅矿紧密共生和交生。金-石英脉的不同变形表明,金矿化是该剪切带膨胀部分横向剪切作用过程中的同构造期矿化。除构造控制外,金矿化几乎只产在富含石墨的变质沉积物中表明金的沉淀还受岩性控制。这种密切关系表明,金的沉淀是区域含矿流体化学还原作用的结果。矿化的温度条件是通过阳起石-黑云母蚀变组合和毒砂的化学成分限定的,它们表明,矿质沉淀发生在或接近高绿片岩相到低角闪岩相的变质高峰条件下。绢云母的Rb-Sr年龄测定表明热液蚀变和金矿化的年龄约为545Ma。莱加登比的金矿化型式、构造样式和岩性组合与太古代花岗岩-绿?

非造山带型金矿——胶东型金矿的陆内成矿作用

综合了全球有关金矿床的资料 ,Goldfarb和Groves等发表了著名的造山带金矿的论述 ,提出了与造山带有关的金矿在全球范围和从中太古代到整个显生宙的地质时期有广泛的分布和周期性。该类金矿的特点是与变形和变质的中地壳岩块共生 ,特别是在空间上与相应的地壳构造一致。金矿出现在造山带的不同构造部位 ,与不同的金属共生或伴生成矿。胶东作为一个重要的金矿矿集区 ,以不到中国领土面积的 0 .2 % ,而金矿产量占全国的 1 /4。国内一些地质学家也将胶东型金矿划归为造山带型金矿。最近的研究表明 ,胶东矿集区的东界与华北克拉通的东界吻合 ,金矿以华北克拉通变质岩及其有关的侵入岩为控矿围岩。主成矿期成矿时代为 (1 2 0± 1 0 )Ma ,约在不到 1 0Ma的短时限内。成矿物质具有多元性 ,既来自于控矿围岩———花岗片麻岩和变质岩 ,又来自于幔源的岩浆岩 ,特别是与中基性脉岩、偏碱的钙碱性花岗岩的侵入关系密切。除胶东金矿集区之外 ,华北克拉通的边缘和内部普遍含有金矿 ,而且金矿的物质来源、成矿方式、矿产类型、成矿围岩和成矿年龄都是一致的。这种大规模、短时限、高强度的成矿 ,被中国地质学家所重视并称为中生代成矿大爆发或金属异常巨量堆积。深部结构和成分的研究表明 。

铊元素分析在非卡林型金矿找矿中的应用研究

通过对陕西、新疆、青海等地金矿床 (异常 )研究 ,发现颇具特色的铊异常能准确反映金矿 (化 )体赋存部位 ,上、下盘 ,矿体边界 ,矿体剥蚀情况 ,微弱构造蚀变 ,隐伏金矿(化 )体等 ,说明方法非常成功 ,并具较高应用价值。认为铊可能是较广泛存在的类型各异金矿特征找金指示元素 ,这将在当前面临寻找隐伏矿任务加大的状况下 ,开辟新思路 。

泰国非金属矿业

泰国准备开采或已开采的矿产有40种,列为资源丰富和比较丰富的有锡、钨、锑、重晶石、萤石、石膏等。列入主要矿产储量表的非金属矿产共有10种:重晶石、萤石、石膏、高岭土、硅藻土、石灰岩、硅砂、岩盐、钾盐、磷。其中以盐类储量为最大:岩盐18000亿t(推定和推测储量90％、NaCl),钾盐270亿t(5％K_2O),其次是硅砂1000万t(55％SiO_2)、重晶石700万t、石膏400万t、高岭土和硅藻土各为450万t、萤石100万t。

DPM dissipation experiment at MST＇s experimental mine and comparison with CFD simulation

Diesel Particulate Matter （DPM） is regulated in the U.S. for both underground coal and metal/nonmetal mines. Today, many underground mines still face difficulty in compliance with DPM regulations. The DPM research carried out in Missouri University of Science and Technology （MST） is to use computational fluid dynamics （CFD） to study the DPM distribution in commonly used face areas. The result is expected to be used for selection of DPM reduction strategies and better working practices, which can help the underground mines to meet regulation limits and improve the working environment for the miners. An experiment was conducted at MST＇s Experimental Mine to validate CFD simulation. DPM was collected at four locations downstream of a stationary diesel engine. The experiment data were then compared with the CFD simulation results. The comparison shows that CFD simulation can forecast the location of DPM concentration with practical accuracy （less than 0.15 m）. CFD can be used to further study DPM distribution in commonly used working faces and give guidance to DPM reduction.

AN EXPERT SYSTEM ON ASSESSING ROCKBURST RISKS FOR SOUTH AFRICAN DEEP GOLD MINES

Expert systems are methods that can cope with rock engineer’s expertise effectively.An expert system on assessing rockburst risks for South African deep gold mines is described.Expertise was represented by rules, frames and mathematical models integratively. About 950 rules was built in the knowledge base, which can be learned by the suggested learning algorithm. A new uncertain reasoning algorithm was proposed. According to the features such as depth below surface, energy release rate (ERR), excess shear stress (ESS), geological structure, face angle with structure, distance from structure, extent of mining, mining type, width of bracket pillar, stope width, local support, regional support and gully support, rockburst risk is assessed either "Low", "Moderate", "High" or "Severe". A computer program system was developed by Turbo Prolog. The results of testing cases show its applicability of the system.

An intelligent system for calculating the scale of rational,enlarged production of an underground non-ferrous metal mine

The enlarged production scale of underground non-ferrous metal mines is affected by many uncertain factors difficult to describe mathematically with any level of accuracy.The problem can be solved by a synthesis of artificial intelligence.Based on the analysis of the major factors affecting the scale of enlarged production,we first interpreted in detail the design principles and structure of the intelligent system.Secondly,we introduced an ANN subsystem.In order to ensure technological and scale efficien- cies of the training samples for ANN,we filtrated the samples with a DEA method.Finally,we trained the intelligent system,which was proved to be very efficient.

Technological Progress,Structural Change and China's Energy Efficiency

China has witnessed rapid economic development since 1978, and during the time, energy production and consumption developed at a tremendous speed as well. Energy efficiency which can be measured by energy consumption per unit of GDP, however, experienced continuous decrease. Theoretically, the change of energy efficiency can be attributed to industry structural change and technological change. In order to explain the transformation of Chinese energy efficiency, we adopt logarithmic mean Divisia index techniques to decompose changes in energy intensity in the period of 1994-2005. We find that technological change is the dominant contributor in the decline of energy intensity, but the contribution has declined since 2001. The change in industry structure has decreased the energy intensity before 1998, but raised the intensity after 1998. Decomposed technological effects for all sectors indicate that technological progresses in high energy consuming industries such as raw chemical materials and chemical products, smelting and pressing of ferrous metals, manufacture of non-metallic mineral products and household contribute are the principal drivers of China's declining energy intensity.

Selection of leading industries for coal resource cities based on coupling coordination of industry's technological innovation

Taking the city of Qitaihe is as an example in order to provide practical methods for the selection of leading industries for coal resource cities, this paper establishes the specific operation scheme for selection of leading industries according to the actual situation of coal resource cities based on the theory of coupling coordination together with the coupling coordination for technological innovation. The results show that the degree for coupling coordination of the technological innovation for each alternative industry differentiates with the development of coal resource cities. For example, the average degree of food processing industry from agricultural produce is 0.9. Therefore, coal resource cities should develop some industries related to coal industry, such as coking industry, some chemical and medicines industry and non-metallic mineral products manufacturing, in the near future, however, some industries with greater market and influence potentials and low carbon emissions should be attached much importance to in the future.

Energy Mineral Resources of Greece

Greece, in relation to many other countries of similar size, is very advantageous for the mineral wealth it possesses. Great variety, mostly industrial and metallic minerals, and energy mineral raw materials such as lignite, are in its subsoil. The probable and proven reserves of most of the mineral resources of Greece are unknown, as detailed investigations （e.g., drillings, measurements, analyses, etc.） are lacking. In our assessment the total value of the reserves is about ε1.5 trillion and is four times its total debt （ε360 billion）. The total value of the indicated reserves of the Industrial Minerals ＆ Rocks is ε60 billion. The total value of the indicated reserves of the Metallic Minerals is ε72 billion. The total value of the indicated reserves of the Energy Mineral Raw Materials is ε1,362 billion, of which ε268 billion belong to the lignites which are exploited for decades to produce only electricity. The indicated oil reserves are 10 billion barrels with current value of E685 billion and the corresponding of natural gas 3.5 trillion m3 with current value of ε409 billion.

Coordinated Urban and Rural Development in Yiling

YILING,the largest district in Yichang City,Hubei Province,is noted for its non-metallic mines,tea planting,citrus fruit cultivation,and folk art.In recent years,Yiling＇s focus has been on urban-rural integration.Human Development The strategies of Yiling District include inheriting traditional culture and ensuring sustained development.

Influence of surfactants on bioleaching of arsenic-containing gold concentrate

To shorten the bioleaching cycle of arsenic-containing gold concentrate, surfactants were used to promote the interaction between bacteria and ore to increase the arsenic leaching rate. Three different kinds of surfactants were used to evaluate the effects of surfactants on the growth of bacteria and arsenic leaching rate of arsenic-containing gold concentrate. The mechanism underlying surfactant enhancement was also studied. Results show that when relatively low-concentration surfactants are added to the medium, no significant difference is observed in the growth and Fe2+ oxidation ability of the bacteria compared with no surfactant in the medium. However, only the anionic surfactant calcium lignosulfonate and the nonionic surfactant Tween 80 are found to improve the arsenic leaching rates. Their optimum mass concentrations are 30 and 80 mg/L, respectively. At such optimum mass concentrations, the arsenic leaching rates are approximately 13.7% and 9.1% higher than those without the addition of surfactant, respectively. Mechanism research reveals that adding the anionic surfactant calcium lignosulfonate improves the percentage of bacterial adhesion on the mineral surface and decreases the surface tension in the leaching solution.

Industrial structure optimization in central China under the energy constraint

Optimizing industrial structure is an important research object of human-economic geography, and it is also the object of government departments to strengthen macro-control. This has become even greater problem that China has entered the "new normal" in recent years. The study uses a multi-regional input-output model, with linear programming to build an optimal model of industrial structure as well as a model of optimization degree under the energy constraint. The results of the study revealed that:(1) the degree of optimization of industrial structure in Anhui Province is optimal(0.763), while that of Shanxi Province is the lowest(0.662);(2) the degree of optimization of industrial structure is negatively related to energy consumption per unit output value and the proportion of heavy industry; and(3) overall, central China should maintain or moderately increase the proportions of resource-based industry, greatly increase the proportions of manufacturing, including transport and telecommunications equipment, computers and other electronic equipment, and moderately reduce the proportions of smelting and pressing of metals and non-metal mineral products. In terms of service industries, the region should greatly increase the proportions of the production and supply of natural gas and tap water, moderately reduce or maintain the proportions of transport and storage as well as tourism, and maintain or moderately reduce the proportions of wholesale trade, retail trade and catering services.