侧限高应力条件下充填体压缩变形规律分析

为了研究充填体在侧限高应力下的变形规律,根据现场调研结果试验室内选取灰砂比为1∶10,浓度为70%的充填体试块进行9级加载蠕变试验,得到每级加载应力下充填体的轴向变形规律。通过对充填体的压缩特性分析,得到了不同加载应力条件下充填体试块的侧限压缩系数和压缩模量;通过压缩变形应变-时间图,对侧限高应力条件下充填体试块的压缩变形机理进行分析,分析结果为新城金矿矿山充填设计及安全生产提供科学依据。     

高阶段胶结充填体强度的变化规律

根据企业降本增效要求,矿山使用的充填胶结材料由原来的P.C32.5标号水泥改为新型胶结材料--胶固粉。按照设计要求的充填配比,发现地表实验室料浆试块和井下充填体取芯的强度存在很大差异。在-400 m中段的14-1#和10-3#充填采场中,提取不同深度的地表实验室和井下充填体的岩芯,分析2种胶结材料在不同养护条件下所对应的强度变化规律。对于水泥充填的采场,充填体取芯的强度要比实验室试块的强度高1.8 MPa以上;对于胶固粉充填的采场,灰砂比分别为1∶4、1∶5、1∶6时充填体取芯的强度要比实验室试块强度高2.0、1.35和0.7 MPa以上,且随着充填灰砂比的降低而降低。研究结果为进一步优化充填灰砂比提供了可靠的依据,进而可减少充填材料的消耗,降低充填成本。     

全尾砂新型充填胶凝材料在月山铜矿的应用研究

根据月山铜矿的充填胶凝材料选择和充填料配比参数设计,开展了全尾砂新型胶凝材料胶结充填体和水泥胶结充填体的强度对比试验。通过研究全尾砂的基本物理力学特性,并在此基础上采用全面试验法测试了不同灰砂比、不同料浆浓度全尾砂充填体试块单轴抗压强度。结果表明:该铜矿全尾砂的中值粒径为d50=0.0426mm,大于0.074mm的尾砂占36.8%,全尾砂颗粒细;灰砂比1∶6、浓度70%、28d养护龄期的水泥胶结试块抗压强度为1.32MPa,而相同条件下新型胶凝材料胶结试块抗压强度是水泥胶结试块的3.53倍即4.66 MPa。因此,提出了适合矿山的胶结充填参数:推荐充填料浆浓度68%~70%,新型胶凝材料与全尾砂之比为1∶6~1∶8进行工业充填试验。工业试验结果表明,1#和2#钻孔充填体试样强度均能够满足月山铜矿对充填技术和充填质量的要求,且强度仍有富余,建议矿山进一步优化充填料配比,减少胶凝材料用量,从而节约充填成本。     

某钨矿全尾砂充填胶凝材料优选

针对湖南某钨矿充填胶凝材料的优选,研究了全尾砂的物理化学性质,并以两种胶固粉以及P·O42.5水泥为胶凝材料,对尾砂胶结充填体抗压强度进行了研究,测定了3种胶凝材料胶结块在不同灰砂比、不同龄期下的单轴抗压强度。试验结果显示:胶固粉1的胶结试块强度增长龄期主要集中在0～3d,胶固粉2与P·O42.5水泥胶结试块强度增长龄期主要集中在7～28d。两种胶固粉的胶结充填效果优于P·O42.5水泥,且在灰砂比为(1∶4)～(1∶8)时,胶固粉1胶结试块强度优于胶固粉2胶结块;在灰砂比为(1∶12)～(1∶20)时,胶固粉2胶结试块强度优于胶固粉1胶结块。针对矿山采矿所需充填体强度要求,并将其进行经济对比,推荐胶固粉2作为最佳的胶凝材料。     

毛坪矿充填体流变特性与强度影响规律实验研究

毛坪矿采用机械化下向水平进路充填法开采,为保证充填料的顺利运输和充填体强度满足下向水平进路法开采的要求,通过试验对充填浆料流变参数特性及充填体强度影响规律进行研究。结果表明:充填料浆各流变参数之间存在一定的相关性,充填料浆浓度越高,其坍落度越小;灰砂比为1∶4的充填体试块的抗压强度在各个龄期明显高于灰砂比为1∶8的充填体试块的抗压强度,并得出充填体试块强度与龄期的拟合关系式;充填体强度在地表环境和井下自然环境下存在较大差异;经过饱水处理的充填体,较前两种养护条件,强度值下降更加明显,体现出矿井水、地温等井下环境条件对充填体质量的劣化影响。     

基于正交试验的全尾砂胶结充填配比方案优化

为获得全尾砂胶结充填最优配比,降低矿山充填成本,保证空区稳定,以全尾砂胶结充填体试块为研究对象,试块的单轴抗压强度为指标,综合考虑充填体强度的影响因素,采用正交试验开展研究,并运用极差和方差分析法对充填体强度影响因素的敏感性和显著性进行分析。研究表明:试验最优配比方案为浓度75%,灰砂比1∶6,养护龄期28 d;影响试块的敏感性顺序是养护龄期灰砂比浓度;养护龄期对充填体强度的影响最显著。因此,矿山在生产实际中要保证充填体的养护时间。     

安庆铜矿分级尾砂胶凝材料配比试验及应用研究

根据安庆铜矿的充填胶凝材料选择和充填料配比参数设计,开展了分级尾砂新型胶凝材料胶结充填体和水泥胶结充填体的强度对比试验。结果表明:在灰砂比为1∶10、质量浓度为70%、28 d养护龄期的条件下,新型胶凝材料胶结试块抗压强度是水泥胶结试块的1.9倍。通过数值模拟方法,计算典型一步骤采场充填体的实际强度需求为1.525 MPa,并在此基础上推荐充填浓度不低于70%,新型胶凝材料与分级尾砂比为1∶10进行工业充填试验。采场充填体现场取样测试结果表明,新型胶凝材料充填体试样平均抗压强度为2.01 MPa,满足矿山对充填强度和充填质量的要求,胶凝材料用量降低了21.8%,从而节约了充填成本。     

新型固化剂对铜矿全尾砂充填体抗压强度的影响

针对铜矿全尾砂颗粒细及胶结充填成本高问题,进行了新型固化剂对铜矿全尾砂充填抗压强度影响的研究。研究结果表明：当充填总浓度分别为65%、68%、70%,灰砂比为1∶8时,使用新型固化剂试块的28 d抗压强度达到2.556、3.333、3.842 MPa,比使用水泥时提高了650%、520%、461%;当总浓度为70%,灰砂比为1∶8,养护龄期为3、7、28 d时,使用新型固化剂试块的强度分别为1.454、2.983、3.842 MPa,比使用水泥提高了516%、665%、461%;当总浓度为70%,养护龄期为28 d,灰砂比为1∶10、1∶9、1∶8时,使用新型固化剂试块的分别为2.076、2.738、3.842 MPa,比使用水泥时提高了382%、449%、461%。该新型固化剂满足矿山生产要求,克服了水泥全尾砂充填体强度低及充填成本高等技术难题。     

尾砂胶结充填体强度影响因素正交分析

大尹格庄金矿2#矿深部矿体采用尾砂胶结充填采矿法回采,为了确定合适的配合比,对不同尾砂的充填体试块进行单轴抗压强度试验,得到不同养护条件下充填体试块的单轴抗压强度,从而得出料浆浓度、灰砂比、养护龄期对充填体试块强度的影响规律。通过正交分析确定了充填体试块强度的主要影响因素。试验研究结论可靠,为大尹格庄金矿充填采矿法的实施提供了依据,同时也对其他矿山充填设计具有一定的指导和参考作用。     

基于BP神经网络模型的充填体强度值预测

在探究充填体强度值大小时为了减少人力、物力的损耗,尝试利用BP神经网络模型对某矿山的四种尾砂材料浇筑的充填体试块进行预测。建立了输入层为8,隐含层为9,输出层为2的BP神经网络模型,并用该模型对某矿山四种不同尾砂材料浇筑的充填体试块进行预测试验。在随机选择的8种试块预测试验结果中,去除误差较大的情况后,充填体27天强度预测平均误差5.8%,充填体60天强度预测平均误差为5%,其中最优预测值与实际偏差值仅为1%。实利了利用BP神经网络模型在不同胶凝材料、不同灰砂比、不同浓度等多个条件下对充填体强度的预测。为其它矿山充填体强度的预测提供一种新的思路。     

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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