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传统的底板穿层瓦斯抽采钻孔原插接式封孔工艺存在易出现封孔管错位、钻孔漏气等问题,为实现一孔多用、提高钻孔抽采效率、降低钻孔封孔成本目的,以白龙山煤矿一井为工程背景,研究并应用了穿层瓦斯抽放钻孔定点封孔工艺。通过钻孔窥视仪选择钻孔内岩性相对较好的孔段作为封孔点,有效避开了巷道围岩松动圈、构造带,且缩短了封孔段距离。与原封孔方式相比,定点封孔方式由于实现整管一次性下管到位而提高了劳动效率,消耗的单孔材料降低了10%,定点封孔方式的抽采钻孔单孔瓦斯抽采浓度提高近15%。 相似文献
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为了考察不同封孔工艺在低渗透煤层中的瓦斯抽采效果,通过现场瓦斯抽采试验,对比分析了传统封孔、自胀式封孔、袋装封孔、封孔器封孔以及主动承压式封孔5种封孔工艺的钻孔瓦斯浓度变化特征,介绍了主动承压式封孔工艺的工艺原理。结果表明:主动承压式封孔工艺的钻孔瓦斯浓度在抽采初期呈上升趋势,随后缓慢降低并稳定在70%左右,钻孔瓦斯浓度出现显著衰减的时间为70~80 d,高瓦斯浓度抽采的时间长达91 d,远高于相同条件下采用其他封孔工艺的抽采钻孔;此外,采用该封孔工艺的钻孔瓦斯浓度自孔底向孔口仅衰减14%,为各类封孔工艺中瓦斯浓度衰减最低的封孔方式。综合对比各类封孔工艺下抽采钻孔瓦斯浓度变化特征、瓦斯浓度显著衰减时间和高浓度瓦斯持续抽采时间等指标,采用主动承压式封孔工艺可以取得良好的瓦斯抽采效果。 相似文献
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新疆艾维尔沟矿区大倾角碎软低渗煤层存在预抽瓦斯浓度低且衰减快问题,抽采效果不理想。为解决该技术难题,基于围岩应力和裂隙带分布特征确定合理封孔参数,根据管流流体力学理论,研发了抽采钻孔封孔参数检测装备,实现了封孔深度、密封效果等参数的检测检验;提出了径向膨胀主动承压注浆封孔工艺,设计研制新型浆体膨胀封孔材料及工艺装备,形成了适合新疆地区大倾角多煤组赋存条件的高效封孔提浓成套技术装备。结果表明:通过在新疆焦煤二一三〇煤矿应用试验,经检测抽采钻孔封孔深度应超过12 m,试验钻孔封孔注浆压力达到1.5 MPa,单孔瓦斯抽采浓度提高比例在96%以上,抽采效果大幅改善。 相似文献
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为解决孟津煤矿12070工作面瓦斯抽采过程中封孔质量难以保证,部分钻孔抽采浓度衰减快等问题,采用理论分析、实验室试验、现场工业性试验相结合的方法,分析了导致瓦斯抽采钻孔封孔质量差的原因,研究了封孔剂、封孔压力、囊袋长度等因素对封孔效果的影响,针对原两堵一注封孔工艺的不足,提出了改善封孔剂配比,确定合理封孔压力,加大囊袋长度等封孔工艺优化措施。工程实践表明,优化封孔措施后,孟津煤矿12070工作面瓦斯抽采稳定阶段浓度是优化前的11倍,且第50天仍有初始平均浓度的45%。 相似文献
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<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 相似文献
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《中国稀土信息(英文版)》2014,(6)
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 相似文献
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YANG Li 《中国稀土信息(英文版)》2014,(6)
<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 相似文献
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Gao Wei 《中国稀土信息(英文版)》2014,(11)
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 相似文献
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《中国稀土信息(英文版)》2014,(8)
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 相似文献
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Bai Wenping 《中国稀土信息(英文版)》2014,(12)
<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 相似文献
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《中国稀土信息(英文版)》2014,(9)
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 相似文献
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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。 相似文献
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Chen Zhanheng 《中国稀土信息(英文版)》2014,(5)
<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 相似文献