预处理硅灰对水泥净浆和砂浆的性能影响

为充分利用硅灰的优良性能,对商品硅灰进行了不同pH值下机械化学分散预处理,用马尔文纳米激光粒度仪测试硅灰分散液的颗粒粒径和Zeta电位,并将预处理硅灰液掺入水泥中,成型水泥净浆和水泥砂浆试样,测试净浆试样室温和砂浆试样室温、冻融循环及高温下的性能。结果表明,提高分散水pH值、加入聚羧酸减水剂有利于硅灰分散细化,降低其沉降速度;掺预处理硅灰可以提高水泥净浆和水泥砂浆的力学性能,以及水泥砂浆耐高温和抗冻性性能。     

电石渣激发超细化铁尾矿水泥胶砂的力学与耐久性能研究

针对低活性铁尾矿固废资源,辅以湿法研磨手段,以电石渣为弱碱性激发剂,展开电石渣-超细化铁尾矿水泥胶砂复合材料体系的力学性能与耐久性能研究.结果表明:湿法研磨120 min可使铁尾矿中值粒径达到0.89 μm,且超细化处理与电石渣激发均可在一定程度上提升复合材料体系的力学性能与耐久性能,电石渣-超细化铁尾矿胶砂体系在30...     

深部奥灰水特性及其浓缩后在奥灰水害防治中的应用

减少矿井水排放、降低底板注浆费用,以深部奥灰涌出水改性底板注浆材料为研究对象,测试了矿井水的常规离子、悬浮物、微量元素,研究了矿井水加热浓缩后的水质变化特征,对比测试了浓缩矿井水改性黏土浆液和水泥净浆的水理和物理力学性能,并基于改性黄土的膨胀界限抗渗强度设计实施了工作面注浆工程。研究结果表明:矿井深部奥灰水有高矿化度、富含悬浮物、其他特殊物质不超标、高永久硬度等特征,其浓缩后有利于改性浆液的钙离子、硫酸根离子、氯离子等富集,不利于浆液改性的碳酸氢根离子浓度降低,用于改性黏土浆液使得双电层结构絮凝,提高了土样抗压强度,降低了渗透性,用于改性水泥净浆,水泥初凝时间缩短,1,3,28 d强度分别提高1.7~3.3,5.3~7.7,8.3~17.1 MPa。改性后黄土膨胀界限抗渗强度提高了19.5%,应用工作面在减少16%的注浆量下安全回采了煤炭资源。     

硅藻土对水泥铜尾矿粉胶凝材料性能的影响

针对铜尾矿粉-硅酸盐水泥力学强度差的问题，本文拟将硅藻土加入到该胶凝体系中，硅藻土以0.5%，1.0%，1.5%和2.0%等质量替代铜尾矿粉-水泥，测试了复合胶凝材料的流动度、凝结时间、吸水率、孔隙率、体积密度、力学性能和微观性能。结果表明，随着硅藻土掺量的增加，净浆的流动度降低，凝结时间缩短，吸水率和孔隙率减小，体积密度增大，砂浆的抗压强度和抗折强度增加。净浆养护28 d后，硅藻土的加入使得净浆中的SiO₂和Ca(OH)₂晶体含量减少，C-S-H(水化硅酸钙)凝胶增多，整体比较致密。      

尾矿基发泡水泥隔热材料性能增强工艺研究

以尾矿为原料制备发泡水泥隔热材料是实现尾矿大宗利用的有效途径,但尾矿的掺入会使发泡水泥隔热材料的综合性能受到影响。针对这一问题,通过对钼尾矿进行机械力活化来提高其火山灰活性,用活化后的尾矿制备发泡水泥隔热材料。通过对样品的抗压强度、抗折强度、导热系数、泡孔结构等进行表征,研究尾矿活性与材料保温隔热性能和力学性能的内在关系。结果表明,发泡水泥的保温隔热性能和力学性能随着尾矿活化指数的提高而增强。将尾矿在220 r/min的转速条件下球磨240 min,钼尾矿活化效果较好,所制发泡水泥隔热材料的综合性能最优。      

鳞片石墨湿法超细磨工艺参数研究

本文在条件实验的基础上，运用正交实验分析的方法，研究了立式搅拌磨湿法超细磨制各鳞片石墨微粒子的工艺参数。根据实验结果确定最佳工艺参数如下：不锈钢球直径为①5mm，研磨介质物料比为40：1，搅拌器转速250r/min，羧甲基纤维素钠(CMC)用量1％，起始浆料浓度35％。经实验证明，超细研磨效率好，连续研磨60h后，粉体中小于1μm微粒子含量达72．07%，小于2μm微粒子含量达98．65％，中位粒径(d50)可达0．71μm。     

搅拌参数对尾盐充填料浆流动特性及强度的影响

为了提高尾盐充填料浆的质量,实现矿山尾盐低成本、高质量充填,研究了机械搅拌因素对尾盐充填料浆质量的影响.通过分析不同搅拌时间和不同搅拌转速下尾盐料浆的扩展度、塌落度以及试块的3 d、7 d和28 d强度测试结果,探究了不同搅拌条件下充填料浆的搅拌效果.结果表明:随着搅拌转速和搅拌时间的增加,尾盐料浆的均质性有所提 升,料浆中的大块颗粒明显减少;机械搅拌强度的增加能够提高充填料浆的流动性,当搅拌转速为1120 r/min、搅拌时间为150 s时,搅拌叶轮对充填料浆的搅拌效率最高,此时料浆的流动性较好;搅拌时间和搅拌转速的增大可以提高料浆中物料颗粒的碰撞次数,从而强化尾盐和氧化钙之间的反应效果,在一定范围内提高尾盐充填体的强度.     

钢渣——脱硫灰基全固废胶凝材料及其砂浆界面过渡区的研究

为提高冶金行业伴生固废的资源化利用率,将钢渣粉与烧结烟气脱硫灰复配组成全固废胶凝材料,添加粉煤灰调整其硅铝矿相组成,取三异丙醇胺（Triisopropanolamine,TIPA）作为激发剂,首先对净浆的力学性能、水化产物组成、水化产物微形貌和孔结构以及水化放热表征分析,探究矿相调整与化学激发对钢渣—脱硫灰基全固废胶凝材料水化硬化过程的影响规律。然后采用铁尾矿砂与上述胶凝材料制备全固废砂浆,考察砂浆力学性能发展规律,并探究全固废胶凝材料与固废骨料之间界面过渡区的特征。结果表明:单掺20%的粉煤灰明显促进水化硅酸钙（C—S—H）生成,使净浆14 d抗压强度提升1.86倍,但粉煤灰掺量增大至50%则对3、7 d的强度不利;单独使用TIPA激发则可帮助净浆3 d抗压强度从0.52 MPa提升至11.44 MPa,借助TIPA对铁离子的络合作用,可促进高掺量（50%）粉煤灰的全固废胶凝材料的水化,3 d抗压强度可达3.69 MPa;钢渣—脱硫灰全固废砂浆界面过渡区内Ca（OH）₂生长在C—S—H骨架中而不与骨料直接接触,矿相调整后界面过渡区出现了垂直生长在骨料表面的钙矾石...     

机械动能磨制备硬质高岭土微粉的工艺参数研究

为了避免高岭土在传统的湿法和普通机械磨超细粉碎过程中引入大量其他杂质,从而造成高岭土纯度降低,研究采用绵阳流能粉体设备有限公司的LNI-330A型机械动能磨对高岭土进行超细粉碎。在分级机转速为1 087 r/min,粉碎主机转速为120 m/s,系统风量为5 400 m³/h,二次风量为465 m³/h,主气流流量为3 523 m³/h情况下,最大产量为397 kg/h,激光粒度分析和扫描电镜分析表明,高岭土微粉的d₅₀<4 μm,呈现结构有序和形貌定型化的特征。     

渠道修补用硅粉砂浆试验及其工程应用

概述渠道修补用硅粉砂浆及丙乳净浆界面处理剂性能.试验研究设计了一组基准砂浆组,三组掺加硅粉剂砂浆组,分别测试了砂浆的物理力学性能,包括抗压强度、抗拉强度、抗折强度、抗冲磨强度以及丙乳净浆处理界面后与原有混凝土(砂浆)及硅粉砂浆之间的粘结抗拉强度,提出渠道修补用丙乳净浆、硅粉砂浆参考配合比,给出了硅粉砂浆、丙乳净浆施工工艺技术,结合不同破损程度的渠道提出了不同的修补设计方法.     

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     

Annual Report analysis of Chinese rare earth-related listed companies in 2013

<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     

Market opportunities and challenges for rare earth polishing powder

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     

Baotou Research Institute of Rare Earths developed a new RE alloy preparation technology

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     

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     

2014 second batch of rare earth quota released

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矿用防爆轴流对旋主要通风机叶片ANSYS模态分析及应用

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。     

2013 NdFeB export analysis

<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