工作面平推过陷落柱技术及矿压显现特征

 以天煜恒晋煤矿9103综放工作面为背景,论述了综放工作面平推过陷落柱情况下的顶板管理、开采工艺等方面的技术措施。在对回采巷道中观测巷道受采动影响下的表面收敛量、锚杆的受力及两帮的裂隙发育等矿压显现的特征值进行观测记录,利用观测结果对该矿处理陷落柱的方式可行性进行论证,为该矿以后生产及类似情况下提供一定的技术参考和技术参数。     

41202工作面直接过陷落柱的应用实践

41202工作面回采中揭露有陷落柱,根据陷落柱位置、大小等因素,确定采用直接推过陷落柱的方案进行回采,结合顶板垂直应力分布及覆岩活动特征,将推进过程分为6个阶段,并制定不同的顶板控制措施。应用表明,直接推过陷落柱的方案安全可靠,相较于补道通过等方案,节省了时间和成本,提高了效率。     

轻型支架综放面过陷落柱及附属空巷技术研究

在轻型支架综放工作面回采中,如何使工作面安全、快速通过陷落柱及其附属空巷一直是采煤技术研究的难点。以赵庄二号井1310综放工作面通过陷落柱及其空巷为例,归纳综放工作面快速通过陷落柱及其附属空巷的技术要点,制订出在过陷落柱及附属空巷的具体工艺措施,并优化现场施工劳动组织和工作面安全质量标准化工作,从而取得了良好的技术经济效益。     

综放工作面快速过上松下硬陷落柱开采技术

针对五阳煤矿7803综放工作面开采受到陷落柱严重影响的问题,通过现场探查,得到47#陷落柱无存水、不导水,选择了强行推过的开采方案。采用FLAC2D数值模拟,分析了推进过程中工作面与陷落柱的围岩塑性区的变化。结果表明,工作面顶底板破坏范围可达到20 m,陷落柱周边的裂隙带由0.5 m发展到4 m,回采过程中陷落柱不会被活化。采用"陷落柱探测+超前注浆+浅孔放震动炮"煤机硬过的治理方法,实现了7803工作面的安全高效回采。     

综放工作面过陷落柱三角煤区域顶板支护研究

蒙泰不连沟煤矿综放工作面机头三角煤过陷落柱给顶板控制带来了非常大的难度,分析陷落柱及其周围顶、帮煤岩破碎程度,采用注入岩体加固材料、U型棚配合单体支柱及走向W钢带配合锚索等加强支护,根据陷落柱岩性调整综放工作面状态,该方案有效防止了冒顶事故的发生,控制了综放工作面三角煤区域破碎带对回采的影响。     

综放工作面过陷落柱加固机理及注浆技术

针对2309综放工作面过JDX16陷落柱问题,制定两顺槽超前深孔注浆方案,并进行现场试验。结果表明:工作面超前支承压力与陷落柱围岩支承压力耦合引起的应力升高是围岩失稳的诱因,通过浅层注浆封堵裂隙,可保障深层注浆充分扩散。     

综放面遇陷落柱围岩裂隙演化规律及推采控制探讨

为分析综放面回采遇陷落柱影响区造成的围岩应力和裂隙发育异常情况,以经坊矿3-802工作面为背景,基于弹塑性力学理论分析了陷落柱周边围岩应力场分区特征,并通过理论分析和FLAC3D数值模拟的方法,研究了工作面推采过程中陷落柱围岩裂隙发育规律,结果表明:理论计算得出的塑性区半径为59.7m,弹性应力升高区半径为87.4 m;当工作面推进至陷落柱影响区内时,原围岩裂隙与采动裂隙发生耦合,同时在采动应力的作用下,陷落柱边缘岩体内大量存在的垂直弱面受剪破坏形成纵向断裂裂隙。同时针对工作面采高、顶板控制和硬岩处理等提供管理措施,以确保工作面顺利地通过陷落柱。     

密集陷落柱区综放工作面快速推进技术

介绍了阳泉煤业集团五矿陷落柱对矿井生产影响,分析了综放工作面过陷落柱存在问题,提出了解决办法,实现了综放工作面快速推进。     

复杂条件下大采高综放工作面快速推进技术探讨

金庄煤业8203大采高综放工作面推进中遇到断层、陷落柱地质难题。通过加强顶板控制、减小进刀量、加强管理和设备维护等手段,通过了断层;从防治水及顶板控制的角度,采取确定陷落柱的范围和导水性、加强顶板管理及爆破破岩等技术,强行推过了陷落柱。以上技术措施节约了时间,确保了8203工作面安全高效掘进,具有良好的社会和经济效益。     

综放工作面过陷落柱影响区煤壁片帮防治技术

陷落柱影响区煤岩往往较为破碎,工作面回采过陷落柱时易出现煤壁片帮及冒顶情况,影响工作面安全开采.为保证工作面安全开采,以赵庄二号井2309工作面为工程背景,分析了综放工作面过陷落柱时的应力演化规律和顶板结构特征,通过采取分阶段细化工作面管理和重点区域超前注浆加固的煤壁片帮综合防治技术,有效预防了工作面煤壁片帮和冒顶.现...     

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。