大倾角综采工作面片帮冒顶原因分析及控制

煤矿综采工作面在生产中经常发生片帮冒顶事故,不仅使工作面产量降低,同时对人身安全造成严重威胁。通过对综采工作面片帮冒顶的机理及特点进行分析,提出综采工作面片帮冒顶的控制措施。     

陈四楼矿2102工作面片帮冒顶的治理及预防

陈四楼矿南一采区第二个综采工作面片帮冒顶严重。介绍了综采工作面片帮冒顶的主要原因,提出了片帮冒顶的处理及预防措施,在实践中取得了较好的效果。     

综采大倾角工作面局部片帮冒顶原因分析及其控制

煤矿综采工作面在生产中经常发生片帮冒顶事故,不仅使工作面产量降低,同时对人身安全造成严重威胁。通过对综采工作面片帮冒顶的机理及特点进行分析,提出综采工作面片帮冒顶的控制措施。     

深埋大采高长壁综采工作面矿压规律研究

为解决煤矿深埋大采高综采工作面冒顶以及煤壁片帮问题,研究该矿综采工作面、回采巷道矿压分布规律,对工作面煤壁片帮、冒顶情况和回采巷道支护效果进行系统观测。观测结果表明:在综采工作面中部易发生冒顶片帮;回采巷道变形位移较大;周期来压时工作面与回采巷道有明显的来压现象。对观测结果进行分析,根据工作面矿压分布规律提出控制冒顶片帮的合理化建议,优化回采巷道支护方案,防止冒顶片帮事故发生。     

综采工作面局部片帮冒顶原因分析及其控制

综采工作面在生产中经常发生片帮冒顶事故,这不仅使工作面经常处于半停产状态,而且造成机械设备的损坏,采煤机开机率下降,导致综采工作面产量和效益的降低,同时对人身安全造成严重威胁。本文通过对综采工作面片帮冒顶的机理及特点进行分析,提出了综采工作面片帮冒顶的控制措施。     

复合顶板工作面片帮冒顶机理与防治对策

铜川矿区5-2煤层直接顶属于较为破碎的复合顶板,综采工作面在回采过程中煤壁片帮、端面漏冒事件时有发生,严重影响了工作面的正常生产.矿方与科研院所联合,开展了煤壁片帮冒顶的现场实测研究,找到了煤壁片帮的主要原因,提出了片帮冒顶的防治对策.在后续工作面的回采过程中,液压支架的运转工况得到了显著改善,煤壁片帮冒顶的发生几率显著降低,工作面回采较为顺利,为在同等条件的工作面生产安全、提高工效做了积极的探索.     

大采高综放工作面煤壁稳定性分析

采用FLAC3D模拟分析了工作面长度、推进速度和俯(仰)斜开采角度对大采高综放工作面煤壁稳定性的影响。模拟结果表明,当工作面长度小于某一范围时,片帮深度和冒顶高度都会随着工作面长度的增加而增加;当工作面长度超过某一范围后,最大片帮深度和最大冒顶高度都不会随工作面长度的增加而增加。工作面推进速度越快,发生片帮和冒顶的概率越小。俯斜开采有利于减小片帮和冒顶,仰斜开采则相反。     

“三软”煤层综放工作面片帮冒顶维护技术

新安矿12261面为三软不稳定煤层综放工作面,片帮、冒顶经常发生。根据工作面煤层地质特点,分析研究片帮、冒顶发生的原因,采取设备改制、煤层注水、降低采高等技术措施,进行综合预防和治理,有效地控制了片帮、冒顶,取得了较好的效果。     

孤岛煤柱开采煤壁片帮控制与预防

通过对孤岛综采工作面片帮冒顶的机理及特点进行分析,提出了针对在孤岛工作面实现综采时出现的片帮冒顶进行有效控制和预防措施。     

仰斜综采工作面局部片帮冒顶原因分析及控制

综采工作面片帮冒顶是常见的顶板事故,片帮冒顶事故不仅治理困难,影响工作面的正常生产,而且严重威胁工作面的生产安全,甚至引发人身伤害事故,必须引起煤矿的高度重视。本文通过对霄云煤矿1307工作面局部片帮冒顶事故的原因分析,总结出了一套快速、安全、高效的治理技术,具有很好的参考价值。     

China rare earth market review

正November 1~10,2014Chinese rare earth market was still inactive.Demand for rare earth products was weak.Consumers took a wait-and-see attitude for lower price.As it was an off season for rare earth products,it was expected that prices of rare earth could continue turbulence at the bottom in short terms.Due to a sharp drop,demand for rare earth from downstream recovered.Affected by new energy vehicles,wind powder and energy-efficient appliances,production of rare earth permanent     

China rare earth market review

正August 1~10,2014 There was some good news in rare earth industry recently.Restructuring plans of rare earth groups led by Baotou IronSteel Group and Xiamen Tungsten Group respectively have been approved by MIIT.And rare earth storage policy,which had been expected for a very long time,has been launched officially.Pushed by the good news,rare earth price started to rebound since August 5.Price of didymium oxide and dysprosium oxide rose about 1% to 2%,averagely.About 10% of     

China rare earth market review

正July 1~10,2014Due to weak demand from downstream industry and slow transactions,rare earth market remained weak and price of rare earth products continued to decline.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,     

New energy vehicle:an opportunity for rare earth magnets

<正>Extracted from Securities Guide 1.Popularity of new energy vehicles—an irresistible market trend1.1 Progress of new energy vehicles Chinese Premier Li Keqiang said recently on a visit to Xi'an BYD Autos that new energy vehicles,especially new energy bus,can lessen environment and noise pollution.He encouraged the use of new     

注浆加固技术在十三矿-685 m进风大巷中的应用

针对煤矿开采深度不断向深部延伸,掘进巷道受深部高应力的影响越来越大,巷道围岩整体稳定性差,矿山压力显现越剧烈现象,一般锚网喷加锚索支护无法从根本上控制巷道的变形。总结了平煤股份十三矿-685 m进风大巷注浆加固技术,依据对巷道掘进之后变形监测数据的采集,对巷道变形机理进行分析研究,并对注浆时段进行了合理选择,在对巷道的注浆工艺进行了充分论证的基础上,对巷道进行了注浆。注浆后效果表明:巷道滞后注浆时间段的选择非常重要,巷道在恰当的时间内进行注浆加固施工,能有效控制巷道的变形,巷道注浆后变形量明显减小,岩体的稳定性明显增强,减少了巷道日常维修工作,降低了矿井的生产成本,保障了矿井的安全生产。     

稀散金属产业的观察与思考

分析了近年来国内外稀散金属产业的生产、应用、资源与市场状况.铟锡氧化物靶材、砷化镓晶片、锗红外材料、铼高温合金和硒在电解锰及玻璃的应用等已成为稀散金属的主要应用领域.稀散金属的产量快速增长达到历史高位而导致了市场的失衡.以GaInP_2/GaAs/Ge,CIGS和CdTe为代表的非硅系太阳能电池是稀散金属的新兴应用领域,将给稀散金属带来日益增长的需求.     

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.     

Current situation and future trend of China rare earth luminescent materialindustry(continued)

<正>Developing ecological lighting source The world is facing the big problem of energy shortage today and the contradiction between economy development and environmental protection is worsened.Therefore,people are more likely to choose an ecological light source that is more energy efficient and environmental friendly.The choice provides great opportunity for the development of rare earth optical material industry in China.The concept of green lighting positions rare earth luminescent material as a leading player in illumination market.The light source of both rare earth luminescent lamp and LED lamp is ecological and energy saving.This is why     

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.     

Rare Earth Application in Steel in China

<正>China has rich rare earth resources.Output of rare earth and steel in China ranks the top first in the world.However,there is still certain distance between the steel produced in China and developed countries from the point of varieties and quality.China still has to import some types of steel.Improving the quality should be emphasiZed in future development of steel industry in China.Rare earth can be used to upgrade traditional steel