沙曲矿北翼回风大巷过突出煤层瓦斯抽排技术研究

沙曲矿北翼回风大巷在施工过程中要经过3+4#煤和5#煤层,这两层煤均具有突出危险性,瓦斯含量高,瓦斯压力大。为保证揭煤施工安全,需要对3+4#煤、5#煤层采取瓦斯抽放措施。阐述了瓦斯抽排钻孔布置及瓦斯抽排设备选型,通过瓦斯抽排效果检验,保证了回风大巷安全揭过突出煤层。     

深井煤层大巷矿震发生机理及防治研究

以山东赵楼煤矿二集下山3条煤层大巷频繁发生矿震为工程背景,通过理论分析和微震监测手段,研究了二集下山大巷频繁发生矿震的主要原因。研究结果表明:5301采空区侧向支承压力和F15断层构造应力叠加形成的高应力是诱发二集下山大巷频繁发生矿震的主要原因。根据理论计算结果分别对二集下山3条煤层大巷的冲击危险性进行了评价。巷道围岩的高应力状态并非发生冲击地压的充分条件,冲击地压的发生还受巷道围岩稳定性的影响,通过将赵楼煤矿二集大巷布置层位由煤层优化到岩层中,有效防治了大巷矿震和冲击地压灾害。     

地勘阶段煤层瓦斯围岩封闭能力评价与应用

运用瓦斯地质学理论分析影响煤层瓦斯围岩封闭性能的地质因素,得出煤层顶底板岩性、煤层封闭层泥岩比、有效岩层厚度效应系数为围岩封闭层主控地质因素。提出了有效封闭能力综合指数(ESCI)并建立了煤层瓦斯围岩封闭能力评价模型。以评价模型为基础对马依西一井3号煤层瓦斯围岩封闭能力进行评价。结果表明:研究区3号煤层的封闭层划分为Ⅰ-Ⅳ类,西翼3号煤层围岩封闭类型属于Ⅰ-Ⅱ类,具有强至较强的封闭能力,东翼3号煤层围岩封闭类型主要属于Ⅲ-Ⅳ类,封闭能力中等偏弱,在Ⅲ与Ⅳ类之间,有一小块属于Ⅱ类围岩封闭。总体上,西翼较东翼的围岩条件好,封闭瓦斯能力强,瓦斯含量高,随着围岩封闭条件自南西向北西逐渐变差,围岩封闭瓦斯能力减弱,瓦斯含量降低。     

基于模糊一灰色理论的煤层突出危险性综合评价方法

在分析现有的鉴定指标使用情况、临界值和局限性的基础上,根据不同矿区影响煤层突出危险性因素的多样性和差异性,探讨了利用模糊-灰色理论对影响煤层突出危险性进行评价的方法,对煤层埋深、瓦斯压力、煤的吸附常数、瓦斯放散初速度及煤的挥发分等主要指标进行重要性排序,并通过层次分析法对各因素进行分析,最终确定不同指标因素的权重.根据贵州省南山煤矿5号煤层的实测参数对其进行了综合评价,为煤层突出危险性判定提供了新的途径和依据.     

矿井煤层冲击危险性多层次综合评价研究

为了更合理评价矿井煤层冲击危险性,减少不同指标之间的相互影响,避免造成评价结果的不准确,应用模糊综合评价模型对矿井煤层进行冲击危险性综合评价,提出了基于层次分析法的矿井煤层冲击危险性模糊综合评价模型;得到了基于层次分析法的矿井煤层冲击危险性影响因素,即:开采深度、冲击倾向性、煤层顶底板性质、地质构造、开采技术;确定了评价因素集,建立了模糊综合评价关系矩阵,进行了模糊综合评价,创建了矿井煤层冲击危险性模糊综合评价模型;最后对矿井煤层冲击危险性做出无冲击危险性、弱冲击危险性、中等冲击危险性和强冲击危险性的定量评价,提高了评价结果的精确度。以内蒙古某矿评价应用为例,选取2-1煤层进行模糊综合评价,通过应用基于层次分析法的矿井煤层冲击危险性模糊综合评价模型,得出2-1煤层最大隶属度指数x=0.43,评价结果为中等冲击危险性,与采用综合指数法评价得到的结果一致,表明了该模型可以用于评价矿井煤层冲击危险性。应用该模型在对矿井煤层进行模糊综合评价时,更注重各影响因素之间的相互关系对结果的影响,因而得到的评价结果更合理。研究为矿井煤层冲击危险性模糊综合评价研究提出一种新的评价角度。     

三角模糊数层次分析法在煤巷布置评估的应用

根据影响煤巷布置的因素,建立多因素多级指标评价体系,采用模糊层次分析法和模糊综合评价模型相结合的方法对煤巷布置开拓可靠性进行综合评价,得出影响煤巷布置的主要因素是煤层适应性。结果表明,通过该方法来确定煤巷布置评估的指标权重是可行的,具有一定的理论意义和实用价值。     

模糊综合评价法在瓦斯突出预警系统中的应用

煤与瓦斯突出造成的安全事故时有发生,定性的评价方法难以满足瓦斯突出预警的需求,因此将模糊评价法与层次分析法结合构建模糊综合评价体系对瓦斯突出进行预警。分析瓦斯突出的影响因素,构建瓦斯突出预警指标体系,对各指标进行分级,构建其隶属度函数,确定模糊综合评价的分析流程。以1~#矿井部分煤层为例,计算瓦斯危险性,计算结果显示：总体危险性为严重,物理特性为严重,赋存特性为一般,开采特性为严重。     

未确知测度理论在煤与瓦斯突出评价中的应用研究

针对煤与瓦斯突出危险性评价中存在诸多不确定性因素的问题,为提高煤矿安全生产管理水平,通过对影响煤与瓦斯突出危险性因素的研究,综合信息熵和未确知测度理论方法建立了煤与瓦斯突出危险性评价模型。根据渣渡矿区5个煤与瓦斯突出矿井实际主要影响因素,选取煤层开采深度等8个影响因子作为未确知测度模型的判别指标,并依据实测数据建立各个评价指标的未确知测度函数,通过信息熵计算各指标权重,最后采用置信度识别准则对5个煤与瓦斯突出矿井进行等级判定,为煤与瓦斯突出危险性研究提供了一种新的方法。     

西沟煤业3号煤层瓦斯压力测定及煤与瓦斯突出危险性分析

为对西沟煤业现开采区域3号煤层煤与瓦斯突出危险性进行评价,采用在待测区域布置测压钻孔的方式对待测区域煤层瓦斯压力进行测定,同时为验证煤层瓦斯压力的测定结果,采用数据拟合分析验证,并通过测定区域煤层瓦斯含量,对测定区域煤与瓦斯突出危险性进行综合判定。结果表明:测定区域3号煤层的最大瓦斯压力和煤层瓦斯含量分别为0.15 MPa和4.98 m~3/t,无煤与瓦斯突出危险。     

模糊综合评价法在林华煤矿2093回采工作面的应用

为了更加有效地对林华煤矿2093回采工作面进行消突效果评价,在选择影响该工作面评价因素(地质构造因素、煤层瓦斯参数因素、煤体结构特征因素和煤层瓦斯赋存条件因素)的基础上,建立了突出煤层回采工作面消突效果评价指标体系,采用模糊综合评价法对2093回采工作面进行消突评价。评价结果表明：2093采煤工作面为无突出危险工作面,这与采用残余煤层瓦斯含量和残余煤层瓦斯压力对该工作面评价结果一致。     

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