厚煤层窄煤柱沿空掘巷围岩稳定性控制技术研究

针对厚煤层窄煤柱沿空掘巷围岩稳定性控制问题,以成庄矿53151巷为背景,通过数值模拟分析不同煤柱宽度塑性区的分布,确定了合理的窄煤柱留设宽度为6 m,并提出了锚杆支护、注浆加固和辅助支护相结合的围岩协同控制技术。现场试验表明,留设6 m窄煤柱沿空掘巷,巷道围岩变形可控,支护体受力稳定,巷道能够安全使用。     

孤岛工作面高应力区域沿空掘巷强力支护技术

针对成庄矿孤岛工作面高应力区沿空掘巷巷道围岩受力大、支护特别困难等问题,对高应力区沿空掘巷巷道围岩的变形情况及变形的原因进行了详细的调查与分析,运用数值模拟等手段分析了该巷道采用强力锚杆锚索支护系统巷道围岩的变形情况。结果表明高预应力强力锚杆锚索支护系统能控制巷道围岩的大变形;根据数值模拟的结果,将强力锚杆锚索应用到4310放顶煤工作面的4220副巷,巷道变形得到有效控制,顶板下沉量控制在200mm以内,两帮移近量控制在500mm以内,保证了巷道的安全,提高了经济效益。     

中厚煤层窄煤柱沿空掘巷围岩稳定性研究

以恒源煤矿487工作面窄煤柱沿空掘巷为工程背景,基于该矿工程实况采用理论计算、数值模拟等手段综合确定487工作面回风巷最优护巷煤柱宽度为5m;基于数值模拟分析了487工作面回采后沿空掘巷超前段顶板、实体煤以及煤柱内围岩应力分布、围岩变形与塑形区演化特征,针对性提出了高强锚杆索组合非对称支护技术,并分析了巷道支护应力场的...     

回收残留煤柱巷道布置方式与控制技术研究

采用理论分析、数值计算与现场工业性试验等综合研究手段,基于对残留煤柱内支承应力分布规律的分析,确定了采空区边缘煤体应力降低区的范围为0~5m,通过对不同护巷煤柱宽度下窄煤柱应力分布规律与变形特征的数值分析,合理确定护巷煤柱宽度为4m;并针对性提出沿空掘巷围岩控制对策:高强度高预应力锚杆(索)联合支护;水力膨胀锚杆全长锚固加固窄煤柱帮,确定了试验巷道围岩控制技术与参数,成功应用于现场工业性试验,围岩控制效果显著。     

采动影响留巷煤柱内沿空掘巷强力锚网索支护技术

结合成庄矿4310放顶煤工作面的地质条件和生产状况,通过地质力学测试、围岩强度测定和围岩钻孔窥视全面了解了受采动影响护巷煤柱的破坏和受力状况,运用强力支护理论,阐述了留巷煤柱内沿空掘巷围岩控制原则,提出巷道支护设计,选择合理的支护材料,在4220副巷得到成功应用,有效解决了采动影响留巷煤柱内沿空掘巷的支护难题。     

综放沿空掘巷合理位置及控制技术

采用理论分析方法,建立了沿空掘巷的结构力学模型,推导出“内应力场”宽度表达式,确定了合理的沿空掘巷位置,预计了沿空巷道围岩变形量,进而确定巷道断面参数。提出顶板高强度高预应力锚杆支护和高强度锚索加强支护、减小窄煤柱帮锚杆间距和实体煤帮二次支护的非对称综放沿空掘巷围岩控制技术,采用系统信息设计方法确定了锚杆支护参数,成功地应用于工程实践。     

三软煤层孤岛工作面沿空巷道围岩控制技术研究

某矿21101工作面沿空掘巷机巷原采取4 m窄煤柱护巷,36U型钢支架支护,巷道掘出不久即严重变形。基于沿空掘巷上覆岩体大小结构模型分析了沿空巷道围岩控制原理,理论计算结合数值模拟分析确定了煤柱留设宽度为6 m,对新型棚-索协同支护效果进行了对比分析,结果表明留设合理尺寸的窄煤柱,采用棚-索协同支护,能较好控制三软煤层工作面沿空巷道的强烈变形。     

特厚煤层综放开采沿空掘巷窄煤柱围岩控制

针对某矿特厚煤层综放开采沿空掘巷宽煤柱护巷时带来的巷道变形量大,煤炭损失严重等问题,提出了窄煤柱护巷技术.以该矿8305工作面为工程背景,结合内外应力场理论和极限平衡区理论,得出基本顶断裂线位置距采空区为3m,并最终确定窄煤柱宽度为6m.基于对特厚煤层窄煤柱护巷围岩控制难点分析,提出了顶板以高强高预应力锚杆支护系统、组合锚索支护系统和多锚索-钢带桁架系统的强力联合支护技术,煤柱帮采用强力锚杆支护系统和喷浆加固的围岩控制技术,以及实体煤帮钻孔卸压处理和强力锚杆、锚索支护系统对特厚煤层沿空掘巷围岩稳定性的控制.现场实践表明,5305巷道围岩控制效果良好,能够实现对特厚煤层沿空掘巷围岩稳定性的控制.     

特厚煤层大采高综放面沿空掘巷支护技术

以塔山矿特厚煤层大采高综放工作面开采技术条件为工程背景,针对采用大煤柱护巷所造成的煤柱损失大、煤柱内应力集中程度大、巷道处于应力增高区支护难度大等问题,提出采用沿空掘巷技术来减小煤柱损失、改善围岩应力环境。对高强度锚杆(索)高预应力支护进行模拟,得出附加预应力场分布规律,通过对比分析确定了沿空掘巷围岩支护形式和参数,试验并分析了巷旁支护对煤柱的加固效果。现场监测结果表明:巷道掘进过程中顶、底板移近量最大57mm,两帮移近量最大64mm;工作面回采过程中顶、底板移近量平均131mm,两帮移近量平均221mm,设计的支护方案较好地控制了围岩移动;巷旁支护可以减小煤柱侧煤壁变形,但造成实体煤侧煤壁变形量增加。     

综放沿空掘巷锚梁网支护

结合工程实例介绍综放沿空掘巷锚梁网支护。通过理论计算和数值模拟合理确定综放沿空掘巷窄煤柱的宽度 ,使巷道处于应力降低区而围岩相对完整 ,易于维护。树脂药卷加长锚固高强度螺纹钢锚杆支护系统对围岩提供较大支护阻力的同时 ,具有较大的延伸率 ,适应综放面沿空巷道大变形的特点。因此综放沿空掘巷采用高强锚杆支护可有效维护巷道稳定     

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 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     

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.     

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.     

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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