多煤层条件下高位钻孔瓦斯抽采层位优选研究

为解决多煤层条件下多来源卸压瓦斯高位钻孔抽采层位不清的问题,引入同位素识别技术,并通过现场实测煤层解吸瓦斯及不同层位高位钻孔抽采瓦斯气体组分及碳氢同位素值,计算得出山西腾晖煤矿607工作面高位钻孔瓦斯抽采来源及比例,确定了其高位钻孔瓦斯抽采的最佳层位。结果表明:随着高位钻孔层位的增大,本煤层采空区遗煤瓦斯及下邻近层卸压瓦斯来源占比逐渐增加,上邻近层卸压瓦斯来源占比减小;确定了有效控制本煤层及下邻近层瓦斯的最佳高位钻孔低层位,即距开采煤层顶板7.9～14.2 m,以及有效控制本煤层及上邻近层瓦斯的最佳高位钻孔高层位,即距开采煤层顶板42.1～45.4 m。     

高位定向长钻孔抽采技术在上隅角瓦斯治理中的应用

根据象山矿井5#煤层煤系地层赋存条件,分析了采空区瓦斯富集区层位,设计施工5个顶板高位定向长钻孔进行采空区瓦斯抽采治理。现场抽采结果表明:顶板高位定向长钻孔布置层位高度20~22m,水平内错距离0~45m较为合理;通过进行5#煤层顶板定向长钻孔抽采技术应用,工作面日产量大幅提升,而工作面上隅角瓦斯浓度由此前长期维持在0.7%降至0.4%左右,有效遏制了上隅角瓦斯超限事故,实现了取消高位裂隙钻孔和采空区埋管抽采的目标。     

突出煤层综放工作面高位抽采巷抽采瓦斯应用研究

为了解决九里山矿突出煤层综放工作面上隅角瓦斯问题,提出了突出煤层高位抽采巷瓦斯抽采解决方案,通过理论分析采空区"三带"和"O"型圈,结合15081工作面顶板岩层情况,确定了高位抽采巷层位,研究了高位抽采巷防火花新型支护方法和自动防漏气密闭墙,并统计分析了工作面瓦斯涌出量变化,考察了高位抽采巷瓦斯抽采效果。结果表明:15081工作面高位抽采巷最佳层位为距煤层25 m,高位抽采巷抽采稳定后平均瓦斯抽采纯量达2.6 m~3/min,工作面瓦斯涌出量降低了29.3%。     

基于高位定向长钻孔的采空区瓦斯抽采技术研究

为了研究高位定向长钻孔抽采采空区瓦斯效果,以吉宁煤矿2102工作面为研究对象,采用理论分析与数值模拟相结合的手段确定顶板高位定向长钻孔布置层位及钻孔结构,现场设计了五个高位定向长钻孔进行采空区瓦斯抽采。研究结果表明：煤层开采后,覆岩垮落带高度为20m,导水裂隙带高度为66m|裂隙区和压实区所呈嵌套关系的外侧梯形底角61°,内侧梯形底角50°,内外梯形之间宽度约为8.4m|高位钻孔应布置在煤层顶板以上40～60m,帮距15～48m,有效解决采空区上隅角瓦斯超限问题,瓦斯抽采效果良好,在保证安全生产的同时,实现了高效稳定治理采空区瓦斯的目的。     

高抽巷联合高位钻孔治理上隅角瓦斯合理层位研究

针对黄岩汇煤矿"U"型通风综采工作面高抽巷层位高、错距大,导致的上隅角瓦斯超限问题,提出了高抽巷联合走向倾斜高位钻孔立体化抽采技术来治理上隅角瓦斯涌出。以黄岩汇煤矿15108、15105综采工作面为研究对象,现场跟踪考察了高抽巷和高位钻孔联合抽采的合理布孔层位及上隅角瓦斯治理效果。研究表明:高抽巷层位在50～60 m时,抽采瓦斯纯量稳定,平均抽采纯量可达到80 m3/min,可以有效地阻截邻近层瓦斯涌向采空区,降低采空区瓦斯总量。走向倾斜高位钻孔作为高抽巷的补充措施,其层位布置在煤层顶板以上25～30 m时,能够较好地发挥对采空区上隅角瓦斯流场的干预作用,达到较好的瓦斯防治效果。在联合层位下,高抽巷和高位钻孔联合抽采作用下,能够将上隅角瓦斯浓度控制在0.3%以下,该技术对相似条件下上隅角瓦斯治理具有指导作用。     

采空区顶板高位定向钻孔差异化布置与抽采效果分析

为解决高瓦斯矿井采空区上隅角瓦斯超限问题,基于回采工作面回采过程中顶板破坏规律,结合顶板高位定向钻孔抽采采空区和上隅角瓦斯治理技术原理,提出采空区顶板高位定向钻孔差异化布置。通过数值模拟寺河矿E5302工作面顶板破坏规律,得到距回风侧煤壁90 m范围内不同位置张拉破坏高度关系式,为高位定向钻孔在回采面回风侧横向一定范围内差异化精准布置提供参考依据,确定采空区顶板高位定向钻孔布置层位为距顶板垂直距离30~45 m;现场试验期间,差异化布置顶板高位定向钻孔抽采瓦斯浓度高、流量稳定,整体抽采效果较好,有效抽采瓦斯时间达50 d以上,在抽采稳定时期钻场钻孔平均纯瓦斯抽采量达15.5 m~3/min,上隅角瓦斯体积分数控制在0.44%左右,保障了矿井回采期间安全。     

采煤工作面高位钻孔抽采采空区瓦斯技术研究

为解决鹿台山煤矿2^#煤层回采工作面上隅角瓦斯浓度频繁超限的问题,以2205工作面为例对高位钻孔抽采技术进行优化。通过UDEC软件模拟研究表明,采空区导气裂隙带发育高度为80 m,“O”形圈宽度范围为距采空区边缘10～46 m,确定最佳布置层位为距煤层顶板50 m,设计高位钻孔的布置参数。工作面回采期间,高位钻孔平均抽放量31 246.5 m³,上隅角瓦斯浓度稳定在0.14%～0.47%,抽采效果良好,保障了工作面的安全高效生产。     

数值模拟研究确定高抽巷最佳位置

为了确定高抽巷抽采瓦斯的合理位置,通过构建19201工作面采空区瓦斯运移模型,借助FLUENT软件模拟分析高抽巷距回风巷不同平距、煤层顶板不同垂高条件下的瓦斯抽放效果,结果表明:在垂距为40 m的层位下,高抽巷距回风巷水平距离为30 m时,其所能抽采的瓦斯浓度最大,工作面上隅角瓦斯浓度为0.48%;在水平距为30 m的基准条件下,当高抽巷距离采空区底板垂直高度为40 m时,高抽巷抽采瓦斯浓度最大,抽采瓦斯纯量最高。从而确定了高抽巷的最佳位置为距离回风巷水平距离30 m,距离采空区顶板垂直距离40 m。     

高河煤矿高抽巷合理位置的选择

通过对高河煤矿E1305工作面布置高抽巷及高位裂隙带钻孔进行瓦斯抽放试验,结果表明顶板岩石水平巷道合理层位的选择,对于采空区瓦斯的抽放效果起着决定性的作用。高抽巷应布置在顶板裂隙的中下部采动裂隙比较发育的范围内,才能达到理想效果。针对高河煤矿3号煤层瓦斯抽采现状,应当将高抽巷布置在3号煤层顶板上方35~45 m层位处,距回风巷水平距离为65~86 m处。高抽巷的合理布置可以有效提高瓦斯抽采利用效率,对消除高河煤矿瓦斯突出、保障矿井安全生产提供了必要的技术支持。为类似矿井瓦斯抽采提供了参考依据。     

高瓦斯油气伴生矿井高位定向长钻孔合理布设参数研究

针对黄陵矿区高瓦斯油气伴生矿井采空区瓦斯涌出量较大的现状,建立了以含气层分布为主,结合地质地层、采空区裂隙带高度预测、普通高位钻孔布置参数分析等多因素相结合的高瓦斯油气伴生矿井高位定向长钻孔合理布设方法,综合确定黄陵二号煤矿205工作面高位定向长钻孔施工层位为七里镇砂岩、施工高度距煤层顶板20~21 m、水平位置距回风侧11~23 m。以此为基础,在205工作面施工了1组顶板高位定向长钻孔,最大孔深774 m,钻孔平均瓦斯抽采浓度28%、最高83%,工作面上隅角瓦斯由0.81%下降到0.48%,钻孔利用率高达87%。     

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。