基于时空属性的黄陵矿区瓦斯精准化预抽实践

为了实现黄陵矿区井下瓦斯精准化预抽,在综合分析煤矿瓦斯含量分布规律、有效抽采半径与抽采时间关系、以及"采-掘-抽"衔接关系基础上,从时空的角度提出了一种预抽钻孔进行分区段布置的煤矿井下瓦斯精准化预抽方法,并在黄陵矿区二号矿207综采工作面进行了现场验证试验。试验结果表明,该方法提出的钻孔分区布置方案可有效解决瓦斯抽采空白带和抽采达标问题,且明显优于统一钻孔间距6 m和12 m两种方案,较2种方案可分别节约预抽时间36、146 d,有效缓解"采-掘-抽"工程衔接不平衡,经济效益显著,实现了煤矿井下瓦斯的精准化预抽。     

余吾煤业地面钻井抽采采空区瓦斯的技术实践

针对余吾煤矿N2105工作面瓦斯涌出量大、瓦斯超限难以治理的问题,进行了地面钻井抽采采空区瓦斯的工程试验。地面钻井共抽采瓦斯27 d,累计抽采纯瓦斯19.04×104 m3,抽采期间工作面瓦斯涌出量降低约10 m3/min,且工作面瓦斯预警次数几乎为零,工作面瓦斯治理效果明显。运用FLAC3D软件研究了采动作用下套管的受力特性,结果表明钻井布置在靠近回风巷比布置在采场中部的受力要大。     

基于流固耦合模型瓦斯抽采钻孔参数优化研究

确定合理的顺层钻孔参数是提高煤矿瓦斯抽采效率的重要手段。考虑了瓦斯抽采过程中煤体变形产生的基质收缩以及瓦斯压力变化,借助COMSOL模拟软件,以瓦斯压力小于0.74 MPa的抽采区域为有效抽采半径区域,分析了不同钻孔间距下双孔及三孔瓦斯抽采效果,并在9306巷道进行瓦斯抽采试验。结果表明：双孔布置下瓦斯抽采效果随钻孔间距增加呈现出两个阶段,钻孔间距小于3 m,抽采时间较短时抽采效率高但后期下降较快,间距大于3 m,抽采效果均低于钻孔间距d=3 m的抽采效果,三孔布置下钻孔间距d=3.5 m时抽采效果最佳。此外,制定了每个钻孔有效抽采区域面积量,通过比较得出了三孔布置且间距d=3.5 m时瓦斯抽采效果最好,在9306巷道进行了瓦斯抽采试验,试验结果与模拟值相差约2.8%,证明该模型在试验矿井具有良好的适用性,可为钻孔的设计和优化提供一定的理论依据。     

浅析中兴煤矿底抽巷布置层位优化

汾西矿业中兴煤矿可采煤层有2#、4#、5#、6#、8#、9#煤层,现开采2#煤层,为了解决上组煤瓦斯治理难题,通过分析底抽巷的优越性,结合矿井实际确定了底抽巷布置方案,并从支护成本、瓦斯治理效果、服务年限和掘进效率等方面进行了分析比较,认为底抽巷布置在4#煤层下10 m左右的砂质泥岩中对上组煤工作面开采瓦斯治理更为合理,并针对布置的层位优化巷道支护参数,保证了底抽巷施工的安全。     

高瓦斯矿井两层煤同时开采瓦斯抽采方案设计

为解决高瓦斯中近距离煤层群安全开采问题,针对阳泉大贤煤矿9号与15号煤层开采条件及瓦斯赋存特征,根据矿井瓦斯涌出量构成关系,对两层煤同时开采瓦斯抽采可行性进行分析,设计了瓦斯抽采方案,并研究确定了工作面瓦斯抽采巷道布置、抽采钻孔技术参数及采空区瓦斯抽采参数,可为类似低渗透性煤层瓦斯的治理提供很好的借鉴。     

大孔径钻孔大流量瓦斯抽采技术研究与应用

新田煤矿1901工作面为被保护层工作面,虽然通过保护层开采卸压后,但煤层瓦斯含量还是偏高,所以瓦斯治理工作任务仍然繁重,瓦斯抽采时间较长。该工作面在巷道掘进期间,经过探索研究,采取在巷道掘进面及钻场内布置大孔径钻孔,进行大流量瓦斯抽采的新技术,有效地提高了瓦斯抽采效果,确保了煤巷快速掘进。     

综采工作面上隅角瓦斯治理研究与应用

综采工作面采用"U"型通风方式时,上隅角容易发生瓦斯超限,影响工作面的安全生产,是工作面瓦斯治理的难点。以平安煤矿150502工作面为工程背景,对工作面瓦斯涌出特征进行分析,发现采空区瓦斯涌出导致上隅角瓦斯积聚,确定采用设置抽采巷道布置穿层钻孔及采空区插管抽采瓦斯治理的综合方案。现场实践表明,该方案能成功降低上隅角瓦斯积聚,保障了工作面安全回采,为其他工作面上隅角瓦斯治理提供了借鉴。     

单一突出煤层底板抽放巷优化布置方案研究

为考察单一突出煤层中采用底板瓦斯巷预抽瓦斯的消突效果,在平宝公司矿井单一突出煤层下10m处布置底板抽放巷,分别提出两巷道中心对中心垂直投影距离为0、10、20m以及煤巷外帮对岩巷内帮垂直投影距离为1m等4种钻孔布置方案。结果表明：第3、第4种方案相比第1、第2种方案,每组钻孔钻进距离分别减少20-83、11-74m,施工时间分别减少100-180、80-150min,百米巷道治理周期缩短2-3d,抽放瓦斯体积分数提高10％左右。采用第3、第4种方案后,虽巷道应力分布集中、变形量较大,但通过高强锚网索支护,完全可满足安全生产需要。     

单一煤层高位瓦斯抽采巷道布置位置研究

以常村煤矿2103工作面为工程背景,在煤层开采方向,通过分析煤层基本顶的受力状态,建立基本顶岩梁断裂前夕的力学模型,求解出基本顶的周期垮落步距;利用垮落步距,引入渗透率公式,重新建立力学模型,求解岩梁内部渗透率的分布状况,并按照渗透率分类标准,将高位瓦斯抽采巷道布置在煤层透气性较好的区域。在煤层倾斜方向,建立二维模型,确定出剪切破坏带的边界,通过分析将瓦斯抽采巷道布置在剪切破坏带以外。最终确定将瓦斯抽采巷道布置在轨道运输平巷上方27.03 m,与轨道运输平巷内错29.82 m的掘进方案。给出了高位瓦斯抽采巷道实际测得的瓦斯抽采量和巷道的变形特征,表明所设计的高位瓦斯抽采巷道的位置合理,能够保证煤矿安全生产需求。     

瓦斯突出矿井预抽巷布置方法

本文针对东曲煤矿+860水平九采区瓦斯预抽巷巷道的两种布置方案,在工作面低抽巷沿不同层位进行布置以及不同施工方式、抽采进度及难易程度、所产生的经济、回采衔接效益等各方面,进行了比较分析说明,最终采用方案一即瓦斯预抽巷道布置在煤层内为最佳施工方案。     

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     

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     

2014 second batch of rare earth quota released

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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     

China rare earth market review

正November 21~30,2014Due to weak demand from downstream industries,transactions of rare earth in Chinese domestic market were inactive.It was difficult to sell any rare earth products except for dysprosium oxide and terbium oxide.Suppliers lost confidence in recent market.Demand for rare earth products was soft.Consumers continued to take a wait-and-see attitude.Rare earth export market remained slow.     

Galaxy Magnets achieved the net profit of 34.02 million yuan in the first six months of 2014

正Galaxy Magnet announced its financial results for the first half of 2014 on August 14.For the first six months ended on 30 June 2014,Galaxy Magnet achieved operation income of RMB 182.3 million,up8.40% over the same period of 2013,and the net profit attributable to the shareholders of the listed company of 34.02 million yuan,increasing 35.49% over the same period of last year.Stable performance increase was led by development of new customers and application market of magnets.