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抗拉强度是尾砂胶结充填体的重要强度参数,但由于缺少合适测试方法导致对尾砂胶结充填体抗拉强度的研究不足,不利于胶结充填体的稳定性分析,对矿山安全生产造成隐患。本研究利用将压缩转换成拉伸加载方式,提出一种新的适用于尾砂胶结充填体的直接拉伸试验方法,验证了其可靠性。应用该试验方法测得了多种配比、龄期尾砂胶结充填体的抗拉强度,分析了抗拉强度随灰砂比、质量浓度、龄期的变化规律以及敏感性,可为矿山充填配比设计及抗拉强度测定提供指导。 相似文献
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为探究大水矿山充填体的力学性能变化,将充填体试块置入高压水体中使其内部形成孔隙水压,研究孔隙水压下充填体的抗压强度、抗拉强度和含水量等指标的变化。试验以孔隙水压、浸入时间、充填配比和料浆浓度为主要影响因素,开展29组充填体强度试验。方差分析表明,料浆浓度和充填配比对充填体抗压强度影响极显著,孔隙水压影响显著;浸入时间对充填抗拉强度影响显著。相同充填配比和料浆浓度下的充填体抗压和抗拉强度随孔隙水压和浸入时间增长而下降,其中抗拉强度下降幅度较大。充填体含水量随孔隙水压增大而增大,增长趋势和充填体强度增大趋势相吻合。 相似文献
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为研究煤基固废膏体充填体在煤矿深部高地温环境下的固结承载性能,采用单轴压缩和声发射试验,测试不同养护温度(20、35、50℃)和龄期(3、7、14、28 d)影响下膏体充填体强度与破坏特征;通过SEM测定充填胶结体微观形貌和矿物组成,从微观角度揭示养护温度对水化反应的影响规律。研究结果表明:伴随养护温度的升高,其对水化反应的影响逐渐从促进转变为抑制,28 d抗压强度在养护温度为35℃时达到最大值;声发射事件主要发生在压密和破坏阶段,养护温度提高促使声发射活动提前活跃,充填体破坏形态逐渐由延性破坏转变为脆性破坏;由于热损伤作用,高温养护加快了充填体早期水化反应速率,而对养护后期充填体内C-S-H和孔隙结构造成破坏,对其长期强度的增加产生不利影响。 相似文献
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为研究异质界面的爆破振动传播规律,结合矿山生产实际,采用模型实验的研究方法对不同强度的胶结充填体进行振动监测。结果表明:在异质界面中,胶结充填体的减震效果会随着其强度的增加而减小,其中强度为3.2 MPa的胶结充填体减震效果最差,减震效果最好的是强度为0.45 MPa的胶结充填体;爆破地震波在向外传播时,其传播方向和路径会发生改变,同时其波形还会相互转换;观察得知,强度为0.45 MPa的胶结充填体反射能力最强,透射能力最弱,而强度为3.2 MPa的胶结充填体反射能力最弱,透射能力最强。 相似文献
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针对河钢矿业中关铁矿超细全尾砂充填采矿法存在的胶结体强度低和胶凝材料成本高等问题,利用钢渣、矿渣和脱硫石膏固体废弃物,开展钢渣基固结粉充填胶凝材料研究。对矿山可以利用的钢渣、矿渣和脱硫石膏等固废物料,进行物化特性分析与质量评价;开展尾砂全固废固结粉胶结充填体强度的正交试验,以及全尾砂充填料浆流变特性研究。试验结果显示,脱硫石膏对胶结体7 d强度的影响大于钢渣微粉,而钢渣微粉对胶结体28 d强度的影响大于脱硫石膏。根据矿山对胶结体强度和充填料浆流变特性的要求,确定钢渣基固结粉胶凝材料的优化配方为:钢渣30%,脱硫石膏10%、矿渣60%。基于胶砂比1∶4和质量分数为64%进行胶结充填体强度测试,其充填体7 d、28 d强度分别达到了1.98 MPa、3.3 MPa,满足矿山对胶结充填强度的要求。固结粉胶凝材料成本分别比42.5水泥和市售胶固粉降低38%、28%,中关铁矿工业化充填试验结果证明其值得在铁矿山推广应用。 相似文献
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为达到完全回采矿石,深部采矿过程中胶结充填体被用来充填回采过程产生的采空区。胶结充填体强度配比设计是基于满足采矿过程充填体应稳定暴露的要求。通过工程类比法和理论分析计算法,确定了能够满足安庆铜矿井下采空区所需的胶结充填体强度要求,为矿山充填配比设计提供了强度依据。同时也得出胶结充填体强度与暴露高度和宽度的关系,揭示具有稳定性的胶结充填体力学强度变化特性。 相似文献
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<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 相似文献
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《中国稀土信息(英文版)》2014,(6)
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 相似文献
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YANG Li 《中国稀土信息(英文版)》2014,(6)
<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 相似文献
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Gao Wei 《中国稀土信息(英文版)》2014,(11)
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 相似文献
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《中国稀土信息(英文版)》2014,(8)
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 相似文献
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Bai Wenping 《中国稀土信息(英文版)》2014,(12)
<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 相似文献
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《中国稀土信息(英文版)》2014,(9)
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 相似文献
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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。 相似文献
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Chen Zhanheng 《中国稀土信息(英文版)》2014,(5)
<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 相似文献