基于松动圈理论的破碎软岩巷道支护研究与应用

首旺煤矿综采工作面回采巷道顶板破碎,围岩软弱,变形量较大。基于围岩松动圈理论,对首旺煤矿回采巷道的破碎机理和围岩变形机制进行分析,并根据围岩松动圈支护理论,确定锚杆支护的具体参数,设计采用锚杆+注浆联合支护来控制巷道的破坏变形。基于数值模拟结果,对支护后工作面回采巷道的屈服破坏特征、巷道围岩垂直应力、巷道围岩位移特征进行了分析。现场工业试验表明,采用锚杆+注浆联合支护技术后,巷道顶底板移近量和两帮移近量明显降低,巷道完整稳定,可以很好的控制破碎软岩巷道变形,提高巷道的整体稳定性。     

综采工作面过陷落柱安全支护技术应用

针对掌石沟煤矿15103工作面煤壁出现片帮、顶板破碎现象,传统液压支架支护无法满足工作面安全高效回采,提出了"仰斜钻孔注浆加固+撞楔超前支护+锚索吊棚"联合支护技术。采取联合支护措施后,工作面过陷落柱期间未发生顶板垮落、破碎现象,保证了工作面安全快速回采,取得了显著应用成效。     

综采工作面尾端头应力区支护技术

基于长春兴煤矿303工作面回采期间受集中应力影响,工作面尾端头围岩破碎严重,导致工作面支架移架困难,回采难度大,通过技术研究决定对尾端头支护进行优化,提出了“可伸缩超前支架+注浆锚索棚”联合支护技术;通过实际应用效果来看,对尾端头支护优化后工作面在后期回采过程中未出现尾端头煤柱垮落、顺槽顶板破碎现象,取得了显著应用成效。     

采动条件下孤岛工作面回采巷道围岩变形特征及其支护技术

为了解决采动条件下孤岛工作面回采巷道支护难题,以平煤一矿戊9-23010采煤工作面回采巷道作为研究对象,进行现场调查巷道围岩变形特征,分析围岩矿物成分及强度,探测围岩内部节理裂隙调发育情况等;运用FLAC3D模拟了非孤岛工作面开采与孤岛工作面回采期间的应力分布特征.分析认为:巷道围岩整体加固,两帮加强支护是保障孤岛工作面回采巷道均匀协调变形的关键.在以上分析研究的基础上,提出具有针对性的"锚杆+锚索+金属网+喷浆+U型钢拱支架"综合支护方案,并应用于现场,经过132 d的监测,结果表明:该支护方案有效地控制了巷道变形,支护效果明显.     

综采工作面超前应力区围岩破碎机理及控制技术

由于挖金湾矿8107工作面回采期间受多重集中应力、煤层赋存、支护技术等影响,在工作面回采至450 m处时回风顺槽超前应力区出现严重破碎现象。为解决该问题,分析超前应力区围岩破碎机理,提出在超前应力区采用“深孔卸压+液压伸缩棚+水力膨胀锚杆”联合支护技术。现场应用效果,顶板下沉量控制在0.17 m以下,底鼓量控制在0.32 m以下,两帮收敛量控制在0.35m以下,有效控制了应力区围岩变形现象,大大提高了应力区巷道围岩成型效果,保证了工作面安全高效回采。     

破碎围岩巷道新型支护技术研究

针对松散破碎围岩回采巷道围岩破碎,掘进速度慢的问题,提出采用"短锚+轻架"联合支护方式,并对其支护机理和承载机构力学模型进行了介绍,通过在振兴矿1513工作面回采巷道进行工业性试验,结果表明该支护方式可有效控制巷道围岩变形。     

204工作面顶板冒落机理及治理措施

204综采工作面回采期间顶板出现破碎、冒落,导致工作面回采速度降低、移架困难、支架支护不到位,威胁着工作面回采安全。本文分析了顶板破碎、冒落原因,提出了"人工假顶+超前深浅孔注浆加固"联合治理措施。通过实际应用,控制了顶板冒落现象,取得了显著成效。     

基于顶板危险区域评价的巷道监测技术研究

五阳煤矿孤岛工作面所处的围岩环境比较复杂,回采巷道的支护是一大难题。为了解决该矿孤岛工作面回采巷道围岩破碎及变形严重的支护难题,以及潜在的巷道支护安全隐患,通过研究,开发出一套巷道围岩及支护质量监测技术,对全长范围内的巷道实行围岩及支护质量的监测、预警、评价与优化,提出合理的巷道支护方案,提高回采巷道支护质量,避免可能发生的顶板灾害事故。     

高应力软岩回采巷道沿空掘巷技术研究及应用

紫金煤业1203工作面回采巷道采用沿空掘巷布置方式,由于巷道处于高地应力区域,且巷道围岩松软破碎,再加上巷道原来支护设计不合理,使得巷道变形破坏现象严重,维护困难,严重地影响工作面的回采.根据1203工作面的生产地质条件,重新设计巷道支护方案及支护参数,采用“锚网梁+锚索+卸压”的综合技术措施对1203工作面回采巷道重新支护后,巷道变形量小,围岩稳定,新的支护起到了控顶固帮作用,为工作面的安全高效回采起到了保证作用,大幅地减小了巷道维修量,保障了井下的正常采掘接替,带来了巨大的社会经济效益.     

综采工作面过地质构造回采工艺优化

针对长春兴煤矿103工作面回采过断层期间破岩难度大、设备损坏严重以及工作面回采效率低等技术难题，采用深孔预裂爆破回采工艺，并对断层区围岩提出了“超前深孔注浆+超前管棚+JW型锚棚”等联合支护技术。实际应用效果表明，工作面过断层期间回采工艺优化后，工作面回采速度提高至5.4 m/d,设备故障率降低了65%,回采期间未出现顶板大面积破碎、垮落现象，应用成效显著。     

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