风化灰岩覆盖厚煤层沿底巷道支护技术研究

11912综采面为葛泉风井东翼的第一个工作面,工作面内共2个煤层,分别为8#煤和9#矿煤.顶板为大青灰岩,巷道在掘进巷道300 m后,11912两巷8#、9#煤直接顶大青灰岩分别出现了风化严重,裂隙发育,有黄泥填充,树脂药卷无法穿过破碎带,锚索线不能正常使用.对此条件下顶板支护工艺的研究不仅将在全煤巷道支护工艺研究方面取得进展,而且对掘进巷道实现快速安全的、高效的具有直接现实的意义和广阔的应用前景.     

近距离煤层采空区下顶板支护研究

五虎山煤矿9#、10#煤层平均层间距3.85 m,且受9#煤采动影响,10#煤顶板岩层已失去完整性,使得回采巷道应用锚杆支护十分困难。为了能够安全、高效地掘进10#煤巷道,分别采用了桁架、架棚支护,但都未达到预期的效果,最后在1004运输巷内进行桁架-架棚联合支护实验,取得了良好的支护效果,为类似条件的矿井提供了借鉴。     

深部动压巷道冒顶原因分析及支护对策研究

新景矿15#煤为主采煤层,埋深较大,采用放顶煤或一次采全高工艺进行回采。工作面顺槽巷道沿顶板掘进,受采动和埋深影响,巷道顶板压力及围岩变形量较大。为了保证巷道掘进安全施工,15028工作面回风巷采用高预应力锚网支护,掘进期间控制效果较好。但是在回采期间,巷道出现了局部冒顶现象,并且这一现象在该类型巷道回采期间时有发生。新景矿一直以来都在摸索解决这个支护难题。     

寺河矿东井区底抽巷岩性对比研究

寺河矿东井区3#煤层瓦斯含量高,煤层透气性差,抽放效率低,为了有效解决问题,提高掘进进尺、抽放打钻效率,对东井区西回风大巷进行岩性分析。原有方案为东井区西回风大巷沿K6灰岩底板掘进,新方案为巷道底板沿K6灰岩顶板掘进,而该岩属坚硬岩石,新方案掘进时抽放打钻将不穿透K6灰岩,从而提高抽放进尺与效率,提前抽放煤体,降低劳动强度,为寺河矿东井区底抽巷岩层位置与岩性选择提供参考意义。     

高瓦斯矿底板岩巷快速掘进岩层层位选择

寺河矿西井区3号煤层由于瓦斯含量高、涌出量大,为加快岩巷进尺速度,通过底板岩巷岩层性质分析,开展高瓦斯矿井大采高工作面底板岩巷层位选择技术研究,结果表明:将原底板岩巷沿5号煤掘进变更为沿K₆灰岩掘进。原底板岩巷沿5号煤掘进平均进尺为2 m/d,巷道月进尺为60 m,底板岩巷K₆灰岩掘进平均进尺为5 m/d以上,巷道月进尺为150 m左右。按照底板岩巷对掘贯通,提前6.4个月完成底板岩巷的掘进,打破寺河矿采掘衔接紧张局面。变更层位之后按照提前6.4个月底板岩巷掘进到位,省去人工费用合计640万元。由于5号煤顶板为K₆灰岩,属坚硬岩石,变更后底板岩巷打钻将不穿过K₆灰岩岩层,加快了打钻速度,降低施工强度。通过对岩巷层位选择技术研究,对寺河矿岩巷掘进以及岩巷层位选择提供了依据。     

正珠煤业11502工作面材料巷沿空掘巷支护技术研究

为解决正珠煤业11502工作面材料巷沿空掘巷的支护技术难题,本文以沿空掘巷工作面支撑压力分布和掘进巷道围岩变形规律理论为基础,根据矿压显现规律并结合实际地质条件,确定了合理的煤柱宽度为10m,以锚网索联合支护为基本支护体系。经实践观测:掘进期间巷道两帮累计位移接近200mm,巷道顶板下沉量控制在20mm以内,掘进工作面沿空掘巷支护技术有效的控制了巷帮移近量及巷道顶板下沉量,保证了掘进巷道的成型,为巷道掘进提供了安全的支护保障,取得了良好的经济效益。     

“三软”煤层综采工作面沿空留巷技术应用

为实现巷道快速掘进,解决21001与21021工作面接替问题,在分析沿空留巷的必要性及"三软"煤层巷道围岩控制难点的基础上,结合该矿地质特点及回采工作面矿压显现规律,提出综放工作面锚网+架棚支护、工作面后方木垛+袋装矸石充填的下顺槽沿空留巷支护方案,详细分析了超前巷煤帮加固支护、工作面超前煤帮支护等方案,针对沿空留巷围岩控制难度大的难题,提出对于实体煤帮、顶板采取高强度、高预应力锚索主动支护,及时支设充填体等围岩控制对策。通过沿空留巷技术方案的实施,取得了较好的支护效果,缓解了常村煤矿工作面接替紧张的局面。     

厚层灰岩直接顶沿空成巷切顶断裂条件及围岩移动规律研究

基于沿空留巷原理,分析了厚层灰岩直接顶板下巷旁充填沿空留巷和超前切缝断顶卸压法沿空留巷巷道顶板断裂位态,分别建立了2种不同顶板断裂位态下的结构力学模型,推导了巷道顶板支护阻力计算方法。研究表明:当切顶阻力Q≤ql时,巷道顶板沿煤壁内一定深度内断裂,沿空巷道侧向顶板悬臂结构可向沿空巷道围岩传递采场岩梁和上覆岩层移动压力;而当切顶阻力Q≥ql,巷内加强支柱+巷旁切顶墩柱+巷旁切缝的联合切顶作用时,可使得侧向坚硬灰岩顶板沿切缝结构面断裂滑落,实现顶板断裂位态主动控制,降低了坚硬灰岩顶板传递上覆岩层压力的移动变形压力,优化了顶板承载结构和围岩应力,降低了巷旁支护体承受的附加载荷。相关设计方法及研究成果应用到南屯矿厚层灰岩直接顶切顶留巷试验,取得了良好的应用效果。     

锚索梯网组合支护在沿空巷中的研究与应用

为了解决薄煤层沿空留巷顶板采用锚杆喷浆支护后,在巷道复用前其顶板破坏变形严重的问题,研究了巷道在施工时,采用锚索+金属梯(或金属网)组合支护巷道顶板.应用结果表明:薄煤层沿空留巷在施工时采用锚索梯网组合支护巷道顶板,在巷道复用前其顶板的破坏变形已基本消灭.结论:薄煤层沿空留巷在施工时采用锚索梯网组合支护巷道顶板,将大大减少巷道修复工程量,提高安全生产水平.     

二次沿空留巷围岩结构稳定性与控制技术

为将沿空留巷复用后继续保留下来作为回风通道长期使用,需采用二次沿空留巷。论文阐明了二次沿空留巷上覆岩层运动规律,建立了顶板二次沿空留巷结构模型,提出了二次沿空留巷围岩支护结构概念。研究表明:二次沿空留巷上覆岩层"大结构"运动经历3次调整后才趋于稳定;指出二次沿空留巷围岩支护结构由两侧充填体、顶板锚杆索组合体、巷内支护体及底板组成;提出"多分区耦合支护"围岩控制方法,该方法可保证二次沿空留巷围岩结构稳定;制定详细的支护方案、施工工艺并进行了成功实践,对类似条件巷道支护具有一定的参考价值。     

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     

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     

2014 second batch of rare earth quota released

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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