锂云母提锂渣对水泥基装饰砂浆性能的影响

利用锂云母提锂渣,研究锂渣作活性掺合料对水泥基彩色装饰砂浆抗泛碱性、力学性能、吸水性和干燥收缩的影响。结果表明,锂渣掺量在20%以内时能够抑制砂浆的泛碱、减小早期收缩值,而对砂浆的力学性能和吸水率影响较小。当锂渣掺量较大(大于30%)时,会使砂浆的泛碱增多、强度下降、吸水量和收缩值增大。     

钢渣粉对全固废混凝土强度的影响

以钢渣粉、矿渣、脱硫石膏为胶凝材料完全替代水泥熟料制备全固废混凝土,考察钢渣粉比表面积和掺量对全固废混凝土抗压强度的影响。结果表明：随着钢渣比表面积的增加,混凝土抗压强度逐渐提高;水化早期钢渣粉对混凝土抗压强度增长贡献小于矿渣粉;在钢渣比表面积为640 m2/kg,钢渣粉、矿渣粉、脱硫石膏粉分别占胶凝材料总质量的25%、63%、12%时,制备的全固废混凝土抗压强度最高。钢渣、矿渣、脱硫石膏相互作用,促进了钙矾石和C-S-H凝胶的形成和生长;钙矾石的生成是混凝土早期强度的主要来源,在水化反应后期,钙矾石和C-S-H凝胶相互交织,形成致密结构有利于混凝土抗压强度提高。     

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...     

铁尾矿—磷渣—脱硫灰三元固废混凝土抗压性能研究

为实现铁尾矿固废材料的再生利用,提高工业固废利用率,以铁尾矿、磷渣、脱硫灰作为掺合料部分代替水泥制备混凝土,研究三元体系下钙相固废与铁尾矿协同作用对混凝土抗压强度的影响,测试不同水胶比、铁尾矿研磨时间、掺合料掺量及掺合料比例对混凝土抗压强度的影响。结果表明,混凝土抗压强度与水胶比呈正相关关系,机械研磨提高了铁尾矿的比表面积,有利于铁尾矿表面与自由水发生水化反应,30%掺量混凝土后期抗压强度较20%掺量下降不大,在铁尾矿比表面积为1 589.3 m²/kg,铁尾矿、磷渣、脱硫灰分别占胶凝材料的6%、16%、8%时制备的混凝土抗压强度最高,28 d抗压强度达到40.9 MPa。通过采用压汞法（MIP）和背散射电子成像技术（BSE）研究了混凝土的微观结构,结果表明,掺合料的掺入优化了混凝土的孔隙结构,促进了界面过渡区的发展。铁尾矿、磷渣、脱硫灰三元体系在30%掺量下对混凝土强度影响较小,可代替水泥制备混凝土。     

基于不同机械活化方式的二元固废混凝土抗压性能研究

为了改善二元固废混凝土的抗压性能,基于不同机械活化方式研究了铁尾矿-粉煤灰复合掺合料对二元固废混凝土抗压性能的影响,并采用X射线衍射、扫描电镜和热重分析等检测手段探究了铁尾矿-粉煤灰复合掺合料混凝土抗压强度增强的水化机理。当采用先掺后磨的机械活化方式时,铁尾矿-粉煤灰复合掺合料的混凝土抗压强度增强效果最明显,28 d龄期可达70.6 MPa。不同机械活化方式导致水化产物结构不同,同时改变了掺合料参与二次水化反应的程度;采用先掺后磨的机械活化方式,能促进水泥熟料的进一步水化,消耗更多Ca(OH)2参与二次水化反应,生成更多更致密的网状C—S—H凝胶。从混凝土抗压强度及混凝土胶凝材料的水化硬化机理来看,采用先掺后磨的机械活化方式活化效果更优,利于二元固废混凝土的强度发展。     

磷石膏—磷渣基复合胶凝材料强度和水化特性研究

为实现磷石膏、磷渣固废材料的再生利用,提高工业固废的利用率,以磷石膏、磷渣作为主要原料,采用水玻璃、水泥熟料和磷石膏共同激发磷渣活性制备磷石膏—磷渣基复合胶凝材料。 分别探讨磷石膏掺量、水玻璃掺量和磷渣粉磨制度对磷石膏—磷渣基复合胶凝材料强度的影响;并运用 SEM、XRD 分析磷石膏—磷渣基胶凝材料硬化体的微观结构及组成形貌。结果表明:磷石膏掺量低于 50%时,复合胶凝材料各龄期强度与磷石膏掺量成反比;当 m(磷石膏) ∶ m(磷渣) ∶m(熟料)= 20 ∶72 ∶8,水玻璃掺量为 1. 5%时,胶凝材料 28 d 抗压、抗折强度均达到最大值,分别为 43、6. 3 MPa; 较单独粉磨磷渣与水泥熟料而言,混合粉磨制度会产生“微介质效应”,有利于提高复合胶凝材料强度;复合胶凝材料主要水化产物为 C—S—H 凝胶与钙矾石,钙矾石与未溶解的磷石膏作为骨架被生成的 C—S—H 凝胶包裹、充填、交织在一起,形成致密结构;复合胶凝材料用于替代水泥作为矿区充填材料时推荐磷石膏掺量为 20% ~ 40%。     

钢渣掺合料对碱集料反应抑制及有效性评估

利用ASTM C441方法进行钢渣掺合料抑制碱集料反应的有效性评估试验,钢渣掺合料抑制碱集料反应效果良好,砂浆棒膨胀率能够减少约50%;针对实际工程集料,采用提高养护温度和养护碱溶液浓度的优化试验方法进行有效性评估试验.试验结果表明,矿物掺合料达到胶凝材料总量的30%,单掺矿渣粉以及钢渣粉和矿渣粉复掺比例为1∶2时,钢渣掺合料对碱集料反应有较强的抑制效果.     

以铁尾矿为主的多元固废混凝土抗压性能与微观结构研究

为实现铁尾矿、煤矸石等固废再利用,降低混凝土水泥用量,并缓解铁尾矿单独作为混凝土掺合料对抗压性能的不利影响,以铁尾矿-煤矸石-粉煤灰为复合掺合料,考察了复合掺合料掺量和配比对混凝土抗压强度及微观结构的影响。结果表明:(1)复合掺合料的掺入降低了混凝土的抗压强度,掺量为20%时对后期抗压强度影响较小,28 d抗压强度可达42.1 MPa,达到C40混凝土标准;掺量为30%时28 d抗压强度最高可达38.4 MPa。(2)铁尾矿材料活性较低,单独作为掺合料劣化了混凝土抗压性能,但其具有填充效应以及分散作用;粉煤灰和煤矸石都具有一定的火山灰活性,粉煤灰活性较高且具有滚珠效应,对混凝土抗压强度的贡献高于煤矸石;铁尾矿与粉煤灰、煤矸石协同作用缓解了铁尾矿单独作为掺合料对混凝土抗压性能的劣化,最优掺入比例为1∶2∶2。(3)掺量为20%的复合掺合料促进了界面过渡区附近的水泥水化,但劣化了整体孔结构,掺量为30%的复合掺合料优化了混凝土孔结构,明显降低了界面过渡区的孔隙率,但对水泥水化产生了消极影响。研究结果表明,复合掺合料改变了界面过渡区的孔隙率和水化进程,平衡界面过渡区的孔结构和水化进程是提高混...     

胶结充填采矿协同资源化利用垃圾焚烧飞灰固化机理研究

为确定低成本、安全、高效处置危废城市垃圾焚烧飞灰(MSWI)的方法,以钢渣微粉、矿渣粉、脱硫石膏、垃圾焚烧飞灰和尾砂为充填材料,进行了砂浆流动性能和胶结充填料强度试验,根据胶结充填料强度确定了胶凝材料的最优配比,并通过X射线衍射(XRD),红外(FTIR)和扫描电镜(SEM)分析了净浆试块的微观结构和水化产物。试验结果表明,当垃圾焚烧飞灰掺量为15%、钢渣微粉掺量为4%、脱硫石膏掺量为14%、矿渣粉掺量为67%时,料浆的流动度为260 mm,满足自流型胶结充填的流动性需求,充填料试块28 d的抗压强度为24.54 MPa,满足矿山充填强度要求;充填料试块养护28 d重金属离子浸出浓度全部低于饮水标准;冶金渣-垃圾焚烧飞灰胶凝材料水化产物主要有钙矾石、C—S—H凝胶和Friedel盐。     

铁尾矿基多元体系抗压强度及水化特性研究

以铁尾矿、磷渣、脱硫灰为复合掺和料部分替代水泥，确定掺量为30%的情况下，考察复合掺和料不同配比对水泥砂浆试件抗压强度的影响，采用扫描电镜(SEM)和热重-差示扫描量热(TG-DTG)分析了水化产物数量及微观结构。结果表明，当铁尾矿、磷渣、脱硫灰质量比为1∶2∶2时强度最佳，7 d和28 d强度分别达到24.2 MPa和34.6 MPa。复合掺和料体系中，铁尾矿活性较低，主要起到微集料填充效应，使体系颗粒级配均匀；磷渣、脱硫灰中活性SiO₂、Al₂O₃可以通过二次水化反应进一步为体系提供强度，三者存在耦合效应，协同水化，生成水化硅酸钙(C-S-H)等水化产物促进强度提升。     

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.     

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     

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.     

China rare earth market review

正November 1~10,2014Chinese rare earth market was still inactive.Demand for rare earth products was weak.Consumers took a wait-and-see attitude for lower price.As it was an off season for rare earth products,it was expected that prices of rare earth could continue turbulence at the bottom in short terms.Due to a sharp drop,demand for rare earth from downstream recovered.Affected by new energy vehicles,wind powder and energy-efficient appliances,production of rare earth permanent     

China rare earth market review

正August 1~10,2014 There was some good news in rare earth industry recently.Restructuring plans of rare earth groups led by Baotou IronSteel Group and Xiamen Tungsten Group respectively have been approved by MIIT.And rare earth storage policy,which had been expected for a very long time,has been launched officially.Pushed by the good news,rare earth price started to rebound since August 5.Price of didymium oxide and dysprosium oxide rose about 1% to 2%,averagely.About 10% of     

China rare earth market review

正July 1~10,2014Due to weak demand from downstream industry and slow transactions,rare earth market remained weak and price of rare earth products continued to decline.There was no sign of recovery in downstream market.The market of NdFeB magnetic materials and phosphor was depressed.Catalyst,     

New energy vehicle:an opportunity for rare earth magnets

<正>Extracted from Securities Guide 1.Popularity of new energy vehicles—an irresistible market trend1.1 Progress of new energy vehicles Chinese Premier Li Keqiang said recently on a visit to Xi'an BYD Autos that new energy vehicles,especially new energy bus,can lessen environment and noise pollution.He encouraged the use of new     

Brief news

正Corun invested another 50 million yuan in power battery for HEV Hunan Corun announced on 27 June that they had signed the cooperation agreement to jointly built Corun(Shaoxing)Autos Power Battery System Co.,Ltd.in Shaoxing Binhai New City.According to the announcement,total registered