大型金属矿体开采地应力场变化及其对采区岩体移动范围的影响分析

根据金属矿地下开采引起的地应力场变化对岩体移动变形范围影响的工程实际,采用现场实测和数值分析方法,对深埋破碎金属矿体开采引起的地应力场变化及其对地质环境影响并导致岩体移动变形范围不断扩大这一客观现象进行了具体计算分析。结果表明,矿体开采后,随着采深的增加地应力明显增大,岩体移动变形的影响范围也随之而增大。另一方面,地应力场变化,尤其是水平方向的构造应力场变化和影响是不可忽视的。

SYT天然电磁波法在探测金属矿体中的应用研究

利用天然电磁波场源进行地球物理勘探的SYT法,多年来一直应用在煤炭、石油、水利、工程领域。能否利用SYT法对地下的金属矿化带或矿体在地面上与地表呈不同倾角直接探测,达到相当于打一钻孔,马上给出地下的矿化带或矿体的埋深和厚度,列举了两个矿点的探测事例以及对该种物探方法勘探SYT法精度的验证结果。

承德千层背地区金属矿体成长特征及地质研究

文章通过对承德千层背地区金属矿体中正长斑岩的年代学和地球化的研究,首次探讨了金属矿体中正长斑岩体的形成年代及成因。结果显示,正长斑岩体主量元素显示高硅、富碱的特征,属于准铝质—过铝质高钾钙碱性系列岩体;轻、重稀土元素分馏明显,具明显的负铕异常,岩体相对富集Rb、Th、La、Nd、Zr、Hf和LREE,相对亏损Ba、Nb、Sr、P、Ti。综合认为正长斑岩具有I型花岗岩的地球化学特征。该区正长斑岩锆石U–Pb测年结果显示岩体形成于134.30Ma±0.86Ma,为早白垩世产物。Hf同位素分析结果显示,?值介于-8.95471～15.7947之间,TDM2介于1749.925Ma～2182.814Ma之间。表明金属矿体来源于2.0Ga左右的古老下地壳,形成于伸展环境。

基于大宝山矿的多金属铜硫矿体开采优化

大宝山铜硫多金属矿区具有复杂的地质条件和开采历史,影响其开采效率和矿石质量。为优化开采流程,提高采矿稳定性并降低成本,通过分析矿区地质特征、采空区情况、采矿方法、管理流程及外部环境因素,提出了一系列开采优化方法。具体方法包括精确采矿点品位、优化采场采剥顺序、合理制定采矿比例以及创新采矿方法。实际工程应用中,明确了采矿管理流程,总结了采矿原则,并注重系统创新研发。结果表明,这些优化措施有效提升了采矿指标的稳定性,降低了采矿难度,确保了矿石品位的稳定性和质量标准。研究结论为类似复杂矿区的开采优化提供了参考。

面向金属矿山的矿体三维构模系统开发

主要介绍面向金属矿山的矿体三维构模系统的总体设计思想、地质数据库特点、地质数据库表结构的设计和系统主要模块功能。系统能够在三维环境下很好地表达矿体空间延展的各种特性,解决矿床的品位分布及成矿规律研究、储量准确计算等问题,为矿山企业的设计、生产和管理提供准确、全面及科学的决策依据。

海底大型多金属硫化物矿体内的流体过程

海底多金属硫化物矿体内热场和流场分布控制着多金属硫化物矿体的形成过程和成矿机制。在大洋钻探计划(ODP)和已有模拟实验研究的基础上,构建了一个具有三层结构的非均质海底多金属硫化物矿体模型,并利用地下热水系统体系模拟软件(Hydrothermal)模拟了不同渗透率情况下多金属硫化物矿体内部热场和流场的形态特征。模拟结果表明:(1)在均质海底硫化物矿体内随着瑞利数的增加,流体对流加强,运移速度加快,矿体温度降低;(2)多金属硫化物矿体的分层和介质的不均一性是控制矿体内的温度场结构、流体运移模式的重要因素,在很大程度上影响着矿体内部海水与热液流体的混合、矿物的沉淀/溶解等;(3)在大型多金属硫化物矿体区,热液流体的集中喷溢("黑烟囱")主要分布在矿体内部热源位置的上方,介质渗透率分布特征是影响烟囱区位置的重要因素。

金属矿区矿体蚀变特征及成矿预测研究

本文对矽卡岩化、硅化的金属矿区矿体蚀变特征进行研究,同时,基于预测靶的确定以及成矿计算预测,完成金属矿区矿体蚀变特征及成矿预测研究。利用两种不同的成矿预测方法,进行成矿预测准确率仿真试验,得出提出的成矿预测方法具备较高的成矿预测准确率,结果表明,提出成矿预测方法具备极高的有效性。

甘肃省金塔县小红山铁多金属矿矿体地质特征及成因浅析

矿区内铁多金属矿体主要赋存于蓟县系平头山组下段大理岩与硅质板岩、粉砂质板岩的接触界面上,部分矿体赋存于板岩之中,顶底板围岩与赋矿岩石一致。矿带整体走向123°~303°,长度近1500m,宽度30m~250m,北西端呈分枝状尖灭于粉砂质板岩中,南东端为白垩系新民堡群含砾粗砂岩和第四系全新统洪积砂砾石层所掩盖。矿带内赋存的主要矿种为铁矿、锌矿、铜矿。矿区内圈定了Pb、Zn、Sn、Ag、W、Mo、Cu等元素异常,可以有效的指导找矿。

隐伏金属矿床上升气流微粒特征、形成及迁移

结合地球化学和纳米科学技术的理论和研究方法,研究隐伏金属矿床有关微粒的形成、迁移和特征。对十多个金属矿床的研究表明,隐伏金属矿体地表沉积物中上升气流微粒样品有单个微粒和微粒聚合体,单个微粒形态有球状、近球状、不规则状、规则多边形、长柱状,微粒有晶质、非晶质和部分晶质。聚合体形态一般是不规则状、球状和近球状。它们的矿物成分主要有自然Au、自然Cu、氯化物、氧化物、硫酸盐、氢氧化物等。成矿元素Au、Cu可以自然金属或自然合金形式存在,Cu、Pb、Zn等成矿元素可以氧化物或硫酸盐等形式存在,也可以存在于氧化物、氢氧化物、氯化物、硫酸盐等微粒中作为杂质元素,这些是隐伏金属矿体的指示微粒。成矿期后,与隐伏金属矿体有关微粒主要形成于断层作用、氧化作用和生物作用。在上升气流中,微粒呈"布朗运动"。

现代海底热液硫化物矿体微生物风化的几个重要研究方向

与现代海底热液系统所伴生的金属硫化矿床是人类未来矿产资源的可靠储备。热液硫化物矿体形成后,在相对漫长的后期改造过程中,金属硫化物成为深海微生物群落可靠而稳定的能量来源,并遭受着微生物的风化蚀变作用。而这种微生物与矿物之间的相互作用,已经逐渐成为目前地球科学与生命科学交叉研究的重要方向之一。简述了现代海底硫化物堆积体的微生物风化过程研究现状,从当前现存待解决的问题出发,展望了未来几个重要的研究方向:包括矿体尺度上微生物因素对风化作用的贡献程度及矿物蚀变次序、细胞尺度上的微观成矿机理、氧化蚀变过程中元素迁移富集及同位素分馏规律,以及涉及到蚀变作用中的微生物种属与有机生物标志物的特征等几个方面,以期加深人们对深海热液环境中微生物与矿物相互作用的理解,同时,为陆地环境中类似矿体的演化规律的研究提供现代视角上的有益思考。

安徽铜陵凤凰山铜矿成矿体特征分析研究

在铜矿找矿评价工作中,铜矿成矿体特征的分析至关重要。基于这种认识,本文以安徽铜陵凤凰山铜矿为例,通过分析矿床地层特征、矿床构造特征、矿床矿体特征和成岩与成矿的关系对矿区金属成矿体特征分展开了分析和研究,以期为关注类似话题的人们提供参考。

河北省赤城县正沟银多金属矿激电异常特征及找矿效果的初步研究

以银、金、铅、锌为主攻矿种,在矿区内进行大功率激电法,圈定出多处激电异常,结合地质对激电异常进行综合分析,该矿区已知的破碎蚀变带上均有明显的激电异常。经钻孔验证,IP6异常深部发现铅银等金属硫化物矿体,取得了较好的找矿效果。

Fluid inclusion and mineralization of Dafulou tin deposit in Dachang metal district, Guangxi, south China

Based on the study of the petrology, mineralogy, structural geology and fluid inclusion of the Dafulou ore deposit in the Dachang ore field, the ore deposit geology and ore-forming fluids were analyzed. It shows that there are five main hydrothermal alteration types in the Dafulou ore district, namely the silicification, carbonate, sericite, pyrite and pyrrhotite. The mineralization types are composed of the stratiform type, interlayer type and stockwork type. The ore textures present as metasomatic texture, euhedral-subhedral granular texture and solid solution texture. The ore structure consists of massive structure, dissemination structure, fine veined structure, stockwork structure and brecciated structure. Four ore types are recognized, namely the disseminated ore, dense massive ore, veinlet ore and brecciated ore. Six types of fluid inclusions are determined, i.e. the single-phase gaseous fluid inclusions, single-phase salt solution fluid inclusions, two-phase vapour-rich fluid inclusions, two-phase liquid-rich fluid inclusions, three-phase CO2-rich fluid inclusions and solid（s）-bearing fluid inclusions, all of which form in three dominant temperature scopes, 120-150, 230-270, 350-460 °C. But, the majority of them form in the high temperature environment （350-460 °C）. The tectonism plays an important role in the mineralization, which usually controls the scale, occurrence and shape of the Sn orebody. There are four types of hydrothermal fluid systems, H2O-NaCl-CaCl2, H2O-CaCl2, H2O-NaCl-MgCl2 and H2O-MgCl2. Similar to the other ore deposits in the Dachang ore field, there also exists the multiple source of ore-forming fluids. Overall, the Dafulou ore deposit should be the result of the crust-mantle interaction.

Developments and prospects of microseismic monitoring technology in underground metal mines in China

Microseismic monitoring technology has become an important technique to assess stability of rock mass in metal mines.Due to the special characteristics of underground metal mines in China,including the high tectonic stress,irregular shape and existence of ore body,and complex mining methods,the application of microseismic technology is more diverse in China compared to other countries,and is more challenging than in other underground structures such as tunnels,hydropower stations and coal mines.Apart from assessing rock mass stability and ground pressure hazards induced by mining process,blasting,water inrush and large scale goaf,microseismic technology is also used to monitor illegal mining,and track personnel location during rescue work.Moreover,microseismic data have been used to optimize mining parameters in some metal mines.The technology is increasingly used to investigate cracking mechanism in the design of rock mass supports.In this paper,the application,research development and related achievements of microseismic technology in underground metal mines in China are summarized.By considering underground mines from the perspective of informatization,automation and intelligentization,future studies should focus on intelligent microseismic data processing method,e.g.,signal identification of microseismic and precise location algorithm,and on the research and development of microseismic equipment.In addition,integrated monitoring and collaborative analysis for rock mass response caused by mining disturbance will have good prospects for future development.

Analysis of microseismic activity in rock mass controlled by fault in deep metal mine

Aiming at evaluating the stability of a rock mass near a fault,a microseismic(MS) monitoring system was established in Hongtoushan copper mine.The distribution of displacement and log(/),the relationship between MS activity and the exploitation process,and the stability of the rock mass controlled by a fault were studied.The results obtained from microseismic data showed that MS events were mainly concentrated al the footwall of the fault.When the distance to the fault exceeded 20 m,the rock mass reached a relatively stable state.MS activity is closely related to the mining process.Under the strong disturbance from blasting,the initiation and propagation of cracks is much faster.MS activity belongs in the category of aftershocks after large scale excavation.The displacement and log(C/) obtained from MS events can reflect the difference in physical and mechanical behavior of different areas within the rock mass,which is useful in judging the integrity and degradation of the rock mass.

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.

Influence of sulfur addition/solids content ratio on removal of heavy metals from mine tailings by bioleaching

The effect of sulfur addition/solids content(SA/SC)ratio on heavy metals(e.g.copper,zinc and lead)obtained from mine tailings by indigenous sulfur-oxidizing bacteria was studied,and the changes in the chemical forms of heavy metals after bioleaching were explored.The results show that the solubilization of metals is significantly influenced by SA/SC ratio,and SA/SC ratio of 2.50 is found to be the best for bacterial activity and metal solubilization among six SA/SC ratios tested(such as 1.00,1.33,1.50,1.67,2.00 and 2.50)under the chosen experimental conditions.The pH decreases fast and the maximum solubilizations of copper and zinc are respectively 81.76% and 84.35% while that of lead only reaches 40.36%.After bioleaching,the chemical forms of heavy metals have changed.The metals remained in mine tailings are mainly found in residual fractions,which is harmless to the surrounding environment.

Adakitic rocks associated with the Shilu copper–molybdenum deposit in the Yangchun Basin,South China,and their tectonic implications

South China is famous for the extensive magmatism and polymetallic mineralization that took place there in the Mesozoic. Shilu is a large porphyry–skarn Cu–Mo deposit in the Yangchun Basin, South China. The lithology of the Shilu intrusion is granodiorite and quartz diorite, both of which are high-K calc-alkaline series, with high Sr([400 ppm) content along with low Y and Yb contents. Most of the samples have characteristics of adakite except for a few samples that have slightly higher Y and Yb contents, which may be plausibly explained by crustal contamination. Laser Ablation Inductively Coupled Plasma Mass Spectrometry zircon U–Pb dating revealed ages between 106.6 ± 1.3 and 103.9 ± 0.5 Ma, with multiple magmatic pulses. Molybdenite Re–Os isochron age of 102.2 ± 2.9 Ma(MSWD = 9.4) was determined, which is identical to the youngest zircon U–Pb age(103.9 ± 0.5 Ma) within error.The Shilu intrusion has high oxygen fugacity as indicated by high zircon Ce^(4+)/Ce^(3+) and Eu_N/Eu_N* ratios. Considering the geochemical characteristics(high Sr, and low Y and Yb contents), high oxygen fugacity, and copper mineralization of the Shilu intrusion, it was most likely formed by partial melting of a subducted young oceanic slab. Whole-rock Sr–Nd isotope-, zircon Hf isotope-, and whole-rock trace element analyses show that Shilu adakitic magmas may have interacted with type II enriched mantle and/or crustal materials during ascent. South China was affected by the Pacific tectonic regime to the east and the Neo-Tethys tectonic regime to the south in the Cretaceous. Based on the Pacific Plate drifting and rotation history, it is hard to explain how the Pacific Plate would have subducted and melted, forming adakitic rocks in the Shilu region. Considering the tectonic history of Southeast Asia and the South China Sea, the Neo-Tethys trench should have been much closer to the South China Block in the Cretaceous, and thus have had a greater impact on the South China Block. Based on the subduction direction, time of subduction,and distance between the Neo-Tethys subduction zone and the Shilu deposit, subduction of the Neo-Tethys ridge is the best mechanism for explaining the Shilu adakitic rocks and Cu–Mo mineralization.

Characteristics of the ore forming fluid from the zinc poly-metallic deposit in the Mopan mine area,Guangxi Nandan

Fluid inclusions from samples from the layered and veined mineralized belt in the Mopan mine area were studied using microscopic temperature measurements and laser Raman spectroscopy.Further studies were conducted on the nature and source of the ore forming fluid and on the mechanism of deposit formation.The results show that there are three types of inclusions that occur in both the layered and veined ore body.These are liquid inclusions,CO 2 inclusions with a liquid phase,and NaCl-H 2 O multiphase inclusions.The fluid inclusions in both the layered and veined ore bodies have similar characteristics.The ore forming fluid is strongly reducing,was exposed to low to medium temperatures,salinity,and pressures.The source of this ore forming fluid was a mix of submarine volcanic spring(blow-piping),magmatic hydrothermal jet,and underground water.