高应力泥岩顶板巷道围岩失稳特征及控制分析

通过对高应力泥岩顶板回采巷道破坏特征、力学变形机制及失稳原因分析,建立了回采巷道锚杆-锚索支护区变形协调方程,提出了高应力泥岩顶板回采巷道围岩控制关键技术,确定了预留断面高强预应力锚杆-锚索协调变形支护方案,并对设计方案进行了数值计算与工业性试验。结果表明:高应力泥岩顶板巷道表现为顶板破碎严重及离层量大、两帮呈非对称收敛变形与底鼓量大的特征;高应力及泥岩顶板软弱围岩是巷道围岩产生破坏的内在原因,锚杆-锚索支护强度过低及锚杆-锚索支护区非协调变形则是巷道围岩破坏失稳的外在原因;古汉山矿13051回采巷道围岩为高应力-节理化-膨胀性复合型(HJS)软岩,为Ⅰ_(AB)Ⅱ_(AB)Ⅲ_(ABD)复合型力学变形机制,采用设计支护方案后,巷道围岩变形能利于释放,围岩压力减小,锚杆-锚索受力均匀,巷道围岩变形保持在可控范围内,预留断面高强预应力锚杆-锚索协调变形支护利于巷道围岩稳定。     

深井大断面软岩巷道围岩破坏机理与支护研究

根据滕东煤矿深部开采的地质条件,针对深部大断面巷道围岩变形破坏特征,通过现场观测和理论分析,深入研究了软岩巷道变形破坏机理;高地应力、低强度岩体、复杂的地质构造、支护体力学特性与围岩力学特性不耦合,支护时机不合理,是造成巷道持续性大变形与失稳的主要原因。为此,提出了深部软岩巷道支护原则和超前卸压与支护+锚网喷+高强鸟巢锚索+注浆加固联合支护方案。现场巷道位移监测结果表明,该方案可有效控制深部大断面巷道大变形。     

高强耦合支护在大断面全煤巷道中的应用

针对大断面全煤巷道支护难题,详细分析了高强耦合支护系统在控制深部复杂困难围岩中的作用。结合某煤矿的工程实际条件,分析了某煤矿顺槽失稳机理,采用注浆加固技术和高预应力强力耦合支护系统对巷道围岩进行了加固,结果表明:注浆加固技术使围岩裂隙得到填充,裂隙发育减少;高预应力强力支护系统有效控制了巷道围岩的变形。     

孤岛煤柱下破碎软岩巷道支护技术研究

为解决孤岛煤柱下破碎软岩巷道支护困难的问题,针对许疃煤矿82联络巷地质条件和巷道变形破坏特征,分析巷道失稳破坏的原因,提出了棚-索协同支护+全断面注浆加固+底板高强锚网索支护的全断面联合支护技术。结果表明:该支护技术能减小巷道围岩塑性区和低应力区,并能改善U型钢支架受力状况。82联络巷围岩变形在25 d后趋于稳定,两帮移近量最大为58 mm,顶底板移近量最大为35 mm,有效控制了巷道围岩变形,保证了巷道长期正常使用。     

高应力动压巷道高强锚索支护技术

针对1×7普通钢绞线锚索用于高应力动压巷道支护时破断力小、延伸率低、预应力小,控制围岩变形效果差的问题,根据高应力动压巷道围岩变形特点及支护系统要求,提出了1×19矿用钢绞线高强锚索支护技术。通过对高强锚索支护材料的试验分析,测定了新型1×19矿用钢绞线的拉断载荷及其延伸率,确定了其配套锚具、托板及锚固剂,并结合试验巷道81202回风巷的采矿地质条件,设计了1×19矿用钢绞线高强锚索支护方案。最后,现场工业性试验表明:相对于1×7普通钢绞线锚索支护,1×19矿用钢绞线高强锚索支护有效控制了巷道围岩变形,围岩变形量减小了约30%左右,巷道断面收缩率控制在5%以内,保证了巷道的正常使用。     

大断面矩形巷道支护参数设计研究

文章针对坚硬顶板下矩形巷道断面加大后的围岩稳定性控制问题,对未支护过的大断面矩形巷道进行锚杆支护设计,介绍了扁椭圆巷道围岩破坏范围的计算方法,并对大断面矩形巷道的锚杆锚索联合支护进行计算设计,采用数值模拟探究支护后的巷道围岩变形情况,最后对巷道的围岩变形及变形速率进行现场长周期监测。数值模拟结果显示,围岩应力主要集中于顶板左右边角处。巷道围岩最大主应力和水平应力均在锚杆承力范围内。现场监测结果显示,锚杆支护后,围岩顶板最大位移158mm,两帮最大位移61mm。围岩变形相对大断面较小,并在检测周期结束时,围岩几乎不再变形。文章介绍了坚硬顶板大断面巷道锚杆支护计算方法,并通过数值模拟和现场监测验证了支护效果,可对相关巷道断面扩大围岩支护工程提供一定经验。     

软岩巷道锚注索联合支护技术应用

以平煤股份二矿某软岩巷道变形失稳为研究对象,通过分析得出该巷道变形原因与围岩裂隙发育及支护强度有关,需要提高巷道破碎围岩的残余强度,同时加大一定范围内的支护力度,控制围岩变形;决定采用浅部高强锚杆、中部注浆、深部注浆锚索加固的三层组合拱联合支护结构对巷道进行维修,通过对维修后的巷道进行围岩变形监测,得出该支护方式有效地减少巷道围岩变形量,解决了该软岩巷道大变形失稳的问题。为该矿后续巷道支护以及相近条件下巷道的治理提供了借鉴。     

采空区下主要运输巷道支护方式研究

通过对新景矿43108工作面掘进后工字钢顶梁压弯变形,棚腿弯曲向内移等问题的研究,得到巷道失稳变形的主要原因及不同支护方式下巷道围岩变形位移和工字钢支架弯矩分布特征。研究结果表明:提高围岩残余强度,发挥围岩承载能力,加强支护以及形成稳定有效的承载结构对于巷道围岩变形能够起到有效的控制作用。提出了以高强预应力锚杆和锚索联合支护为主、工字钢支护为辅的高稳型支护方式,实践结果证明该支护方式对于巷道围岩变形的控制效果良好。     

油页岩回采巷道稳定机理及控制技术

针对油页岩回采巷道难支护特点,结合油页岩物理化学性质分析,指出围岩层理结构及风化作用是巷道变形失稳的根本原因,并通过数值模拟研究确定锚杆支护参数。在此基础上提出了"高强预紧,适度让压,喷浆护表"的围岩控制技术,通过高强预应力让压锚杆、锚索配套大面积碟形托盘实现围岩稳定控制。在埋深800～850 m的回采巷道应用该技术与以往的支护效果进行对比分析,表明提出的围岩控制技术有效控制了巷道变形破坏,保证了巷道的稳定性。     

大断面松软巷道高强预应力锚杆支护技术

为保障新元矿9105进风巷大断面松软围岩的稳定,针对巷道围岩特征,提出采用高强预应力锚杆支护技术,并对支护方案进行了设计。现场应用结果表明,采用该支护方案后,巷道掘进期间围岩变形量较小,满足了巷道的正常使用。     

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