新疆弱粘煤自然发火标志性气体试验研究

为了掌握新疆浅埋、急倾斜弱粘煤层的上分层和本层采空区自然发火标志性气体生成规律,选取乌东煤矿弱粘煤样品进行程序控制升温试验研究,分析CO、烯烃、炔烃、烷烃及其比值的生成规律,以此确定煤自燃的临界温度和自燃预测指标。结果表明:CO出现的临界温度在25℃左右,标志着煤开始自燃氧化反应;C2H4出现的临界温度在106℃左右,标志着煤进入加速氧化阶段;C2H2出现的临界温度在348℃左右,标志着煤进入燃烧或阴燃阶段。CO、C2H4、C2H2气体作为煤自然发火的标志性气体,C2H4/C2H6作为煤自燃氧化的辅助标气。     

束管监测系统在煤层自燃预测预报中的应用

镇城底矿22208工作面采用束管监测系统监测采空区气体成分变化,预测预报煤自燃火灾.实验研究表明可以将CO、C2H4和C3H6、C2H4作为煤层自燃的标志性气体.根据监测数据划分了采空区自燃"三带"具体范围.     

束管监测系统在煤层自燃预测预报中的应用

镇城底矿22208工作面采用束管监测系统监测采空区气体成分变化,预测预报煤自燃火灾.实验研究表明可以将CO、C2H4和C3H6、C2H4作为煤层自燃的标志性气体.根据监测数据划分了采空区自燃"三带"具体范围.     

沿空掘巷工作面采空区自燃标志性气体识别试验

正益煤业有限公司11-110沿空掘巷工作面采空区存在较大的漏风自燃风险,通过升温氧化实验,对煤自燃标志性气体进行测试与优选,确定了自燃标志性气体以CO为主,H2、C2H2为辅,建立了预测预报指标体系,完善了煤自燃监测系统,通过合理的矿井火灾预测预报管理,实现了正益煤业的安全高效生产.     

德盛煤矿煤自燃标志性气体的实验与确定

不同煤质的煤在升温氧化过程中,会释放出不同成分和浓度的气体.根据这一特性,煤矿可选取适当的气体产物作为煤自燃的标志性气体进行监控.德盛煤矿利用"煤自燃特性综合测试系统"进行30～220℃的升温试验,结果发现2#和5#煤样中CO释放量随温度变化最为规律和稳定,并配合观测H2、C2H4或C2H6,对防范煤自燃有良好的效果.     

凤凰山矿煤自燃标志性气体优选研究

凤凰山矿采用Y型通风沿空留巷无煤柱开采,漏风规律复杂、漏风量大,属于自燃煤层,为了对煤炭自燃发火提前预测预报,采用自行研制的“煤自燃特性综合测试系统”进行试验研究,得到15#煤自燃以CO为主、C2H4和C2H2为辅的标志性气体体系,取得较好的效果。     

保德煤矿煤自燃标志性气体的确定研究

通过对保德煤矿8#煤层煤样的标志性气体实验数据的分析,重点研究了气体产物规律及特性、标志性气体分析与优选、煤自燃临界氧气浓度等。结果表明,CO、C2H4和C3H6气体出现的临界温度分别在62℃、165℃和220℃左右;CO可以作为预测预报煤自然发火的指标气体;煤炭自然发火的临界氧气浓度为7.0%。     

综放工作面遗煤自然发火及早期预报技术

通过对大阳泉煤矿工作面主副巷、密闭墙压能分布规律及标志性气体的检测分析,得到该矿采空区漏风情况、均压压力,以及O2、CO、CO2、C2H6、C2H4、C3H8等标志性气体浓度变化的规律,为确定2120、8124主巷密闭墙以内巷道煤体破碎带自燃危险区域范围及其形态提供了技术支持。根据采空区遗煤自燃特点,从加强通风管理、气体与温度检测、均压、灌注三相泡沫等方面制订了全面的遗煤自燃防控体系。     

山西矿区煤自燃指标气体预测研究

通过煤自燃指标气体实验系统,对山西某矿煤层自燃过程中产生的气体种类,以及各气体出现与煤温度的对应关系进行了对比分析,结合指标气体选择的一般原则,确定山西煤矿工作面煤自燃指标气体的选择应以CO和C2H4为主,并辅助参考C2H2指标气体。准确选择煤自燃指标气体对提高煤炭早期自燃预测、预报,防止矿井火灾具有重要指导意义。     

平朔矿区煤自燃宏观特性的关联性研究

对平朔矿区的井东煤业、井工一矿的两种易自燃煤样进行了综合指标气体测试和非等温热重分析实验.研究了指标气体及煤样质量变化与煤体温度之间内在关联.对煤自燃早期预报的单一指标气体CO进行扩展,并结合C2H4、H2、C2H2气体来作为煤自燃的综合指标气体,同时研究表明热分析法比物理吸附氧量法能更好地评价煤自燃的倾向性,热分析技术能够准确全面地反映煤自燃整个过程.     

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。