地下开采引起地表沉陷的数值模拟

以石人沟铁矿为研究对象，运用FLAC软件，采用数值模拟的方法，对石人沟铁矿地表沉陷数学模型的开采过程进行分步开挖模拟，并总结出了地下开采引起的上覆岩层和地表的移动规律，给出了不同开采阶段的地表动态移动曲线。     

书记沟铁矿地下开采岩层移动界线的圈定

书记沟铁矿地下开采导致地表沉陷垮塌，沉陷坑影响范围可能波及周边村庄，设计采用工程类比法确定岩层移动角，通过现场实地调查运用数值模拟软件对该矿地下开采过程进行模拟分析研究，最终确定出岩层移动角为：斜长角闪岩上盘62.5°，下盘62°，走向65°，第三系、第四系移动角取45°。     

综放开采作用下地表影响范围及煤柱留设参数研究

基于概率积分法和计算机分析软件,将开采沉陷预测方法应用于综采放顶煤开采中,研究了地表下沉盆地的形成过程,探讨覆岩移动规律并提出了开采沉陷对地表的影响方式。基于数值模拟方法对88301工作面开采沉陷影响进行分析,利用FLAC3D软件对岩层状态进行分析和处理,对综放采场覆岩的受力破坏过程进行了模拟,直观反映出开采沉陷对岩层与地表影响程度及范围。通过与地表观测数据实际情况的对比分析,验证分析结果的适用性,研究结果对综放采场岩层控制有参考价值。     

厚煤层综放开采覆岩移动规律数值模拟分析

为了掌握高河矿综放工作面上覆岩层移动规律,为工作面布置及“三下”开采提供参考,结合高河矿E1302综放工作面地质情况,采用数值模拟方法,对工作面地表移动、上覆岩层移动及岩层破坏特征进行模拟分析。研究表明:岩层移动在基岩内衰减较为明显,在松散层内近似整体沉降,厚基岩具有一定的控制地表沉陷变形的能力;导水裂缝带发育髙度最大约为140 m,裂高采厚比为20;综放开采强度大,地表的沉陷变形值增大,地表裂缝增加,从而导致地表下沉系数增大。     

基于FLAC~(3D)的矿区地表沉陷预测方法研究

为实现地表建构筑物的安全以及井下煤炭资源的安全开采,需要对开采引起的覆岩运移规律及其对地表沉陷的影响进行研究。以谢桥矿为研究对象,通过理论分析以及FLAC~(3D)数值模拟的方法,构建井下煤层开采模型,并分析总结煤层开采引起的覆岩和地表沉陷移动规律,为预测地表沉陷提供依据。     

深部崩落法开采地表沉降特征数值模拟研究

随着矿山开采深度的增加,岩体所处的力学条件变得复杂,深部崩落法开采引起的地表沉陷规律不同于浅部。基于有限差分法和岩石力学理论,研究了崩落法开采过程中,上覆岩层的移动变形规律与应力场分布特征,研究结果可为深部矿体开采岩层移动角及地表沉陷范围的确定提供一定的借鉴。     

条带开采中上覆岩层岩性对地表沉陷影响的数值模拟研究

对水平煤层条带开采进行了二维有限元数值模拟研究,分析了条带开采中上覆岩层的岩性变化对地表沉陷的影响,找到了条带开采中上覆岩层的软硬对地表沉陷影响的一些规律。     

考虑节理几何特征的地表沉陷预计方法

相似材料模拟试验结果表明,地下煤炭开采引起上覆节理岩体沉陷出现偏态特征。通过建立考虑节理倾角、迹长和迹宽的地质数学模型,运用随机介质理论,推导了地下煤炭开采引起上覆节理岩体沉陷的概率分布函数,认为单元岩块开采引起的地表沉陷概率分布符合n重Bernoulli试验概率分布规律;当n≥10时,采用Poisson分布来代替n重Bernoulli试验概率分布规律;考虑到地表沉降的连续性,采用Poisson分布实数域拓展后的Gamma分布代替Poisson分布,提出了考虑节理几何特征的上覆节理岩体沉陷预计方程。通过该模型计算的地表沉陷预计结果与相似材料模拟试验监测结果相比较,该模型能较好地预计地下煤炭开采引起上覆单组节理岩体沉陷,为开采沉陷预计和岩层移动监测提供了技术参考。     

基于非线性固液耦合模型的程潮铁矿地表变形研究

运用三维非线性孔隙介质固液耦合模型,研究了饱和介质条件下地下开采对上覆岩层变形和地表移动的影响,并利用OpenSees有限元平台,以程潮铁矿西区回采采用的充填开采法为例,模拟了-360m至-500m的水平开采过程;文中还研究了地表沉降在饱和孔隙介质中的响应规律、移动特征和破坏状态,并给出其破坏等级,为地表移动范围的设计提供了依据。     

条带开采覆岩运动对地表沉陷影响的模拟分析

村庄下采煤是涉及到控制地表沉陷的技术难题,受条带开采采动造成的上覆岩层活动对地表移动有着极大地影响。采用物理模拟方法对开采引起的覆岩运动规律进行分析,以及使用数值模拟方法对地表变形情况进行研究。结果表明,采宽60 m留宽70 m"三带"高度比采宽50m留宽70 m增加了58%,地表移动和变形各项参数的最大值增加了30%以上,为合理确定条带开采参数提供有利的依据。     

Current situation and future trend of China rare earth luminescent material industry

<正>Rare earth luminescent material is one of the most important application sectors of rare earths.China enjoys the exceptional advantage to develop rare earth luminescent material for its abundant rare earth resources.After several decades'endeavor,China's rare earth luminescent material industry,headed by rare earth phosphor for lamp and LED and high efficient rare earth energy-saving light source,has been gradually developed into a scale industry.China has become a major production base of rare earth phosphor for lamps and rare earth     

China rare earth market review

正June 1~10,2014Rare earth market remained weak.Quoted price of rare earth products was similar to that in May.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,polishing powder and ceramic industries remained inactive.Demand from downstream industry was soft.Consumers purchased on their needs.Suppliers had strong intention to sell.Prices of rare earth products     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<正>Chinese rare earth-related listed companies have published their 2013 annual reports.It can be understood from their reports that production and operation activities of Chinese rare earth-related companies were still heavily affected by macro economy and industrial policies.They basically followed the steps of national economy.In 2013,world economy recovered slowly but the economy     

Market opportunities and challenges for rare earth polishing powder

正1.Status of rare earth polishing powder Rare earth polishing powder with high content of cerium oxide began to replace iron oxide for glass polishing and became one of the key materials in glass polishing process since 1940.Compared with traditional iron oxide,rare earth polishing powder has many advantages,such as fast polishing rate,high polishing quality and long service life.It can achieve good surface quality and improve operation conditions.For example,in lens polishing,the polishing work that cerium     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

正Pyrometallurgy Laboratory of Baotou Research Institute of Rare Earths had independently developed a new preparation technology of rare earth alloy for NdFeB.The alloy can remarkably enhance the coercivity of NdFeB magnet but also evidently reduce the production cost of the magnet.The new master alloy was prepared in the kA pilot-scale electrolytic cell by the independent technology.The rare earth master alloy can be used as the raw material for NdFeB.Compared     

矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

高效节能矿用防爆对旋主要通风机的叶片是主要通风机运行的关键部件,叶片在运行时不断受到气流的作用力,从而使叶片产生振动,当叶片振动的频率与叶片的固有频率接近时,容易产生共振从而导致叶片的断裂。一旦叶片断裂时,对主要通风机的安全运行产生致命的影响,从而导致矿山、化工等企业发生重大事故,将会产生不可估量的损失。基于有限元分析软件ANSYS,对高效节能矿用防爆轴流对旋主要通风机叶片进行模态分析及产生对应的六阶模态频率,对主要通风机叶片的运行频率、固有频率及产生的共振问题进行了原理分析,并且解决了叶片频率共振的问题,从而为主要通风机叶片结构设计提供理论依据,并对主要通风机叶片的安全运行提供保障。     

2013 NdFeB export analysis

<正>China totally exported nearly 24,000 tonsof NdFeB products during 201 3,including 18,825 tons of permanent magnet,valued USD 1.34 billion at an average price of 71.4 USD/kg;3,277 tons of NdFeB magnetic powder,valued USD 1 01 million at an average price of 30.9 USD/kg;1,334 tons of strip casting ribbon,with total export value of USD 74million at an average price of 55.3 USD/kg;and 586     

Market and recycling of NiMH battery

<正>Market status and future trend of NiMH battery1.Global market of small NiMH battery Global market size of small NiMH batteries declined year on year since 2011.The trend will continue to 2018,at the rate of 5%to 10%annually.Demand for small NiMH batteries will be stable gradually.Many electrical apparatuses are powered by the built-in lithium battery today,which is the main reason for the shrunk market of small NiMH batteries.But,for some products,small NiMH     

China rare earth market review

正September 1-10,2014 Affected by the National Day holiday,rare earth transaction was stagnant and the market showed a weak steady state.As there was no good news for downstream market,some products with flat demand would likely rally slightly for some time to     

唐口煤矿深部复杂开采工作面瓦斯分源涌出规律研究

研究工作面瓦斯涌出规律对工作面瓦斯治理有重要意义。为了得到唐口煤矿深部3号煤层复杂开采条件下工作面回采时期瓦斯涌出时空演化规律,选取6304工作面作为对象,采用实测方法研究6304工作面瓦斯涌出规律。结果表明:6304工作面瓦斯涌出量为6.534 m³/min,其中煤壁占34.27%,落煤占29.62%,采空区占36.11%;沿工作面倾向由低到高,瓦斯浓度整体为上升趋势,其中1—76号架工作面瓦斯浓度小于0.20%,76—102号架瓦斯浓度上升明显,最大为0.387%;上隅角的后部采空区是工作面的瓦斯主要涌出源,上隅角1号测点瓦斯浓度0.78%,上隅角周边3号、5号、7号、8号、9号测点瓦斯浓度平均为0.643%;周期来压时,上隅角瓦斯相对平时较高。研究为针对性的瓦斯分源监控与灾害防治提供基础。