矸石粉煤灰压实特性对比实验研究

为了研究在单轴条件下矸石粉煤灰充填材料的压实特性,分别针对不同粒径的矸石以及不同配比的矸石粉煤灰进行实验研究。通过多次对比实验和理论分析,得到了矸石和矸石粉煤灰在单轴压缩情况下的压实特性、抗变形能力、矸石粉煤灰的最佳配比方案,为今后人们更加深入研究充填体的变形特征与充填体的级配选择提供理论依据。     

采后充填固体充填材料力学特性测试研究

采用物理化学测试方法,检测分析了矸石与粉煤灰充填材料矿物成分、压实度、流变等力学特性,研究了不同配比条件下含水量、密度,影响充填材料压实度及流变特性时间相关特性曲线,得出了最佳压实度和密度的矸石与粉煤灰的混合比例及充填料变形主要在加载初期。     

充填体压实率对综合机械化固体充填采煤岩层移动控制作用分析

以地面矸石、粉煤灰、黄土等固体废弃物为充填材料的综合机械化固体充填采煤技术为“三下”压煤的安全高效回收创造了条件.结合现场地质条件并根据等价采高的概念,分析了不同矸石与粉煤灰充填体压实率对等价采高的影响规律;并通过数值模拟分析了矸石与粉煤灰充填体不同压实率条件下对综合机械化固体充填采煤岩层移动控制与地表沉陷的控制作用,提出了保持地表沉陷在允许范围之内的充填体压实率为15％;最后通过工程实践得出综合机械化固体充填采煤技术工作面的岩层移动及地表沉陷控制效果良好,基本没有影响到地表的建筑和设施的正常使用,研究成果可为综合机械化固体充填采煤技术的有效实施提供技术参考.     

特厚煤层矸石充填控制岩层变形特性研究

为研究特厚煤层在矸石充填下岩层变形特性,以某矿矸石为充填材料,采用侧限压缩试验研究其在压应力下的变形特征,并采用FLAC^3D建立数值模型,将侧限压缩试验中压实8 MPa的矸石的弹性模量应用至数值模型中,对比分析充填和未充填两种开采模式下的岩层的受力及变形。研究结果表明,矸石充填体变形特征表现为随着载荷的持续增加应变量逐渐增加,且两者呈现对数函数关系,应变量前期变化明显,后期逐渐减小;矸石充填开采后,对比未充填时岩层的位移量明显减小,且应力在岩层中分布更加均匀。试验和模拟结果均表明,矸石的压密致使充填体的变形趋于稳定,从而可以承担上部压力。     

典型矿区固体混合充填材料力学特性试验研究

通过压实试验,得到了矸石和粉煤灰、矸石和黄土以及风积沙和黄土3种固体混合材料试样在不同配比下的应变-应力及变形模量-应力曲线,结果表明:随着各配比试样中矸石或风积沙质量的不断减少,矸石和粉煤灰、风积沙和黄土这2种混合材料试样的应变呈不断增大而变形模量呈不断减小的趋势;矸石和黄土混合材料试样的应变呈先逐渐减小而后逐渐增大的趋势,变形模量呈先逐渐增大而后逐渐减小的趋势;压应力从0～2 MPa过程是试样变形的主要阶段。通过优化得到矸石和粉煤灰较佳配比为1∶0.35,矸石和黄土较佳配比为1∶0.95,风积沙和黄土较佳配比为1∶0。对3种较佳配比试样进行时间相关特性试验,分析得出了各试样应变主要发生在第1个月,之后应变变化极小,已趋于稳定。在3个矿井的工程应用中,使用各自较佳配比的混合充填材料后可以满足有效控制地表变形的设计要求。     

垮落矸石注浆充填体压实特性的颗粒流模拟

利用PFC计算程序建立了垮落矸石充填体的颗粒流模型,通过颗粒流数值模拟试验,再现了煤层采出、顶板垮落、注浆充填、充填体压实整个动态发展过程.通过改变模型中颗粒数目、接触刚度和法向刚度等细观参数,研究了充填率、充填材料的胶结强度和弹性模量等宏观性质对充填体压实特性的影响.研究发现：充填率是影响充填体压实特性的最敏感因素,15％为试验模型的临界充填率,当大于15％时,充填体的压实曲线急剧改变;在相同充填率下,充填料的胶结强度决定充填体的结构屈服应力,是影响充填体压缩下沉量的关键因素,但对压缩下沉量极限值没有影响;充填率越小,弹性模量对充填体压实特性影响越显著.     

矸石固体充填材料胶结性能的实验研究

通过对矸石粉煤灰、矸石黄土作为固体充填材料的胶结性能的实验研究,分析矸石粉煤灰、矸石黄土充填体强度性能,并以水泥作为胶结材料,重点分析了水泥对矸石黄土固体充填材料的强度影响。实验结果表明,以矸石黄土进行固体充填,充填体强度高于矸石粉煤灰充填体;在矸石黄土固体充填材料中加入水泥,并随着掺量的增加,充填体强度特别是早期强度得到大幅度提高,且可缩短充填采煤周期,降低生产成本。     

矸石膏体优化配比及其力学性能基础试验研究

矸石膏体充填技术为"三下"压煤开采提供了一种新的方法。针对煤矿配制矸石膏体存在因素和水平较多的实际情况,提出用均匀设计法优化配比矸石膏体,并对固结后矸石膏体的力学性能进行了测试,结果表明:当煤矸石、粉煤灰、水泥的质量比为7.5∶3.5∶1,膏体材料的质量浓度为81%时,矸石膏体的管道输送和强度都满足要求,是本次试验的最优结果;矸石膏体的破坏主要发生在粗集料和胶结材料的界面,矸石膏体破坏前的变形较小,不超过2%。矸石膏体在不同围压作用下,充填体三轴压缩表现出线弹性变形阶段和塑性强化阶段的变形特征,基本不存在软化阶段。     

综合机械化矸石充填开采导水裂隙带发育高度研究

对不同试样的矸石充填材料进行压实测试,得出了应力-应变曲线及最佳配比方案,根据等价采高模型理论,计算了某试验矿井矸石充填开采时的导水裂隙带发育高度,提出了给矸石充填体施加一初始压实力可以极大地提高其抗压性能,进而有效地减小覆岩裂隙的发育高度,并采用数值模拟研究了不同压实性能的充填材料的导水裂隙带发育高度情况。研究结果表明,优化充填材料配比,增加初始压实力和提高采空区充填率都可以有效地减小导水裂隙带发育高度。     

煤矸石充填材料配比试验研究

为科学合理确定陕西青岗坪煤矿煤矸石充填材料配比,分析充填材料组分对煤矸石充填体强度的影响,采用正交试验的方法分析粉煤灰与水泥质量比、矸石与粉煤灰质量比、质量分数3个因素对煤矸石充填体强度的影响,并进行单轴抗压力学性能试验。结果表明:选择粉煤灰与水泥质量比1:3、矸石与水泥质量比1:7、质量分数为75%进行配比时,矸石料浆坍落度及充填体强度均可以达到较好效果。     

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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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.     

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     

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     

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.