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矿井巷道掘进时,容易形成循环风,对煤矿安全生产影响较大。分析了掘进通风系统与矿井通风主系统的关系,利用压能分析方法,简述了局部通风机风筒出口直对工作面和风筒出口在掘进面一侧的两种局部通风方法,两种情况下掘进通风中各节点的能量关系,绘制了能量坡度曲线,利用能量坡度曲线很容易看出掘进通风中各节点能量大小及变化关系,利用压能分布分析了循环风的形成条件,对井下预防循环风形成具有及其重要的意义。 相似文献
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矿井巷道掘进时,容易形成循环风,对煤矿安全生产影响较大。分析了掘进通风系统与矿井通风主系统的关系,利用压能分析方法,简述了局部通风机风筒出口直对工作面和风筒出口在掘进面一侧的两种局部通风方法,两种情况下掘进通风中各节点的能量关系,绘制了能量坡度曲线,利用能量坡度曲线很容易看出掘进通风中各节点能量大小及变化关系,利用压能分布分析了循环风的形成条件,对井下预防循环风形成具有及其重要的意义。 相似文献
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在矿井生产过程中,普遍存在着掘进串联通风现象。通过对串联通风理论安全性及监控系统安全性分析,得到影响串联工作面的主要因素为工作面自身瓦斯涌出量和被串联工作面局部通风机的全负压供风量。通过控制掘进工作面的安全性来确保串联通风工作面安全性的实例,验证了串联工作面安全性控制措施。 相似文献
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李楼铁矿500万t工程项目2009-2010年基建期间,由于井下掘进工作面多,分布范围较广,同时未形成矿井通风系统,各井巷掘进工作面局部通风效果差,井下作业环境恶劣。为了解决基建时期矿井通风问题,改善井下-425 m、-325 m水平各掘进工作面的通风条件,保证基建工程顺利进行,从理论和实践上对李楼铁矿矿井基建过程中存在的通风技术问题进行了研究,提出了基建时期井下通风技术方案并加以实施和调整改进,达到预期效果,为500万t工程项目的安全顺利实现创造了有利条件。 相似文献
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通过对井下掘进工作面局部通风机控制的分析,采用智能局部通风系统变频和PLC控制,根据掘进工作面巷道长度、瓦斯、风速情况对局部通风机进行智能化控制改造,形成了PID闭环控制。从王庄煤业公司现场实际运行表明,该系统提高了掘进工作面局部通风系统的安全性、可靠性、智能性,既实现局部通风系统节能化,又促进了矿井安全管理。 相似文献
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针对煤矿超2 km巷道掘进局部通风难题,从通风方式、通风管理、通风技术3方面分析了我国长距离掘进局部通风的现状,对比了各通风手段的优缺点、适用条件,为选择合适的局部通风手段提供参考,解释了未来建设高产高效矿井与长距离掘进通风的矛盾,指出继续深入研究长距离掘进局部通风的重要性。 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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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
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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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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。 相似文献