改性赤泥对复合胶凝材料的性能影响

以工业固废拜耳法赤泥、电解锰渣、钢渣为主要原料制备复合胶凝材料,研究各组分的最佳配比,在此基础上对拜耳法赤泥进行高温煅烧改性,确定最佳煅烧制度。采用DWS-51钠离子测试仪分析煅烧后拜耳法赤泥的碱溶出情况,借助X射线衍射(XRD)仪和扫描电镜(SEM)研究煅烧后拜耳法赤泥的矿物组成、复合胶凝材料水化产物的成分及形貌。结果表明,拜耳法赤泥、电解锰渣、钢渣质量比为1∶3∶2时,活性指数达到93.2%;拜耳法赤泥的煅烧温度为700℃时,可溶性碱的质量分数最大,为2.58%,改性拜耳法赤泥-电解锰渣-钢渣复合胶凝材料的活性指数达到108.1%,抗硫酸盐侵蚀系数为1.18;水化产物结构致密、Ca(OH)₂生成量少是复合胶凝材料抗蚀性较好的主要原因。     

广西平果拜耳法赤泥的水硬胶凝特性

借助XRD、FTIR、TG-DSC和SEM测试表征了广西平果拜耳法赤泥在电石渣和脱硫石膏复合激发作用下的水化产物及硬化浆体的微观结构,研究了该赤泥在复合激发下的水硬胶凝特性。结果表明：该赤泥在电石渣和脱硫石膏的复合激发下水化3、7、28 d的抗压强度均大于4 MPa,表现出一定的水硬胶凝特性;该体系水化反应生成了钙矾石、C-S-H凝胶、富钠钙柱石、无水芒硝和氢氧化铝等。钙矾石晶体相互搭接形成骨架结构,成为胶凝材料硬化浆体强度的主要来源,C-S-H凝胶等胶结或充填在钙矾石中间,加固并致密了凝结硬化体的结构。以上研究成果可为拜耳法赤泥用于地下采矿胶结充填胶凝材料提供理论参考。     

煤系高岭土固化拜耳法赤泥的强度机理研究

通过测试不同煤系偏高岭土掺量下,煤系偏高岭土固化拜耳法赤泥形成复合体的抗压强度,发现煤系偏高岭土可有效固化拜耳法赤泥。结合X射线衍射(XRD)、微观扫描电镜(SEM)及煤系偏高岭土水化的化学反应方程式,对复合体的物相组成和微观结构进行分析,阐明了煤系偏高岭土固化拜耳法赤泥的强度机理,利用强度机理解释了随着煤系偏高岭土掺量变化,宏观抗压强度变化的原因。     

石油焦渣和电石渣复合激发赤泥活性的研究

利用石油焦渣和电石渣复合激发拜耳法赤泥,确定三元体系最佳配比制备高活性粉体;比较几种不同辅助性胶凝材料对赤泥复合粉体的改性作用,制备碱激发胶凝材料;利用XRD分析水化产物,并采用SEM观察净浆试样的微观形貌。赤泥、石油焦渣和电石渣的固相质量比7∶2∶1时,制备胶砂28 d抗压强度为11.3 MPa;矿渣对赤泥基高活性复合粉体改性效果最好,掺加30%制备的胶砂28 d抗压强度最高为18.2 MPa;通过XRD与SEM分析,赤泥基碱激发材料主要水化产物为Aft晶体和C-S-H凝胶。     

钢渣电解锰渣赤泥复合胶凝材料的水化热研究

本试验选用电解锰渣、赤泥、钢渣作为混合材制备复合胶凝材料,系统优化混合材配比,利用微量热仪法测试了不同掺量混合材的复合水泥水化热,结合复合水泥胶砂强度情况,采用X射线衍射分析了混合材对水泥早期水化及其火山灰放热行为的规律和影响机理。结果表明:当混合材掺量为50%,赤泥:电解锰渣:钢渣为1∶2∶3时,复合水泥胶砂28 d强度可达到38.6 MPa;与普通硅酸盐水泥相比,钢渣、电解锰渣、赤泥的掺入可消耗多余Ca(OH)2,有助于水泥水化产物中钙矾石的稳定,并且C-S-H凝胶矿物相发育得到一定改善。复合胶凝材料水化放热速率降低,放热峰延缓出现,放热总量显著减少。     

硫铝酸盐水泥改性脱硫石膏复合材料研究

在脱硫石膏复合材料中掺加硫铝酸盐水泥(SAC),探究SAC对其力学性能、干缩性能、耐水性能和耐干湿性能的影响,并从微观角度揭示SAC的作用机理。结果表明,SAC能够显著提高硬化体的抗压强度和早期抗折强度,但掺量超过6%后,28 d绝干抗折强度出现倒缩现象;SAC掺量越大,硬化体膨胀越大;硬化体的软化系数随SAC掺量的增加先增加后减小,干湿强度系数先增加后减小最后再增加,SAC掺量为3%时,脱硫石膏复合材料的耐水性能和耐干湿性能较优。综合分析,SAC的建议掺量为3%～6%。SAC水化生成不溶于水的水化产物,改变体系的孔结构,提高结构的致密化程度,使得脱硫石膏复合材料各项性能均得到改善。     

赤泥制备硫铝酸盐水泥熟料的物相组成及水化性能

以赤泥为主要原料，经配方设计，在1300℃条件下烧制硫铝酸盐水泥熟料。运用X粉晶衍射（XRD）和扫描电镜（SEM）等手段，对水泥熟料形成历程、水化产物进行分析。结果表明，水泥熟料有较好的易烧性，熟料主要矿物发育良好。水化产物以花瓣状或片状的AFm、短柱状的AFt及C-S-H等胶体为主，浆体结构致密。水泥净浆试块强度测试结果表明，1d，3d，28d龄期的抗压强度分别为42MPa，50MPa，65MPa，抗折强度分别为8．0MPa，8.5MPa，12.5MPa，早期强度较高且增进稳定。     

某电解锰渣免烧砖抗压和抗折强度研究

用某些固体废弃物制备免烧砖是实现固体废弃物大宗利用的重要途径,为确定贵州某电解锰厂电解锰渣制备免烧砖的可能性,在进行了浸出毒性分析的基础上,研究了渣泥质量比、骨料掺量、水固质量比及成型压力对免烧砖抗压强度和抗折强度的影响。结果表明：随着渣泥质量比的增大,试块的抗压、抗折强度均先上升后下降,高点在渣泥质量比为5时;随着骨料掺量的增大,试块的抗压、抗折强度均先增大后减小,高点在骨料添加量为30%时;随着水固质量比的增大,试块的抗压、抗折强度先增大后减小,高点在水固质量比为0.30时;成型压力从1.0 MPa提高至2.0 MPa,试块7 d和28 d的抗压、抗折强度都显著上升,继续提高成型压力,试块7 d和28 d的抗压、抗折强度上升幅度趋缓。当渣泥质量比为5,骨料添加量为30%,水固质量比为0.3,成型压力为2 MPa时,电解锰渣免烧砖7 d的抗压、抗折强度分别达到10.63 MPa和2.21 MPa,28 d的抗压、抗折强度分别达到 14.89MPa和2.48 MPa,达到国家普通砖的强度标准。     

拜耳法赤泥强度特性的三轴试验研究

以某氧化铝厂拜耳法赤泥为对象,研究了拜耳法赤泥的物理力学特性。通过三轴压缩试验结果得出不同含水率赤泥的应力-应变关系曲线和赤泥的抗剪强度指标,利用简化的Bishop法进行了边坡稳定分析。研究结果对赤泥堆场的设计施工和赤泥在其他工程应用具有参考价值。     

利用焙烧铁尾矿制备透水砖的水化特征研究

利用铁尾矿制备透水砖是尾矿资源二次利用的重要途径之一，与普通铁尾矿相比，经焙 烧后的铁尾矿 可有效提高透水砖的强度。为查明焙烧铁尾矿提高透水砖性能指标的原因，在透水砖抗折强度 和抗压强度分析的基 础上，借助 X射线衍射分析和扫描电子显微镜分析技术，系统研究了铁尾矿用量和养护时间对 水化产物物相组成和 微观结构的影响。结果表明：增加尾矿用量使透水砖强度降低，延长养护时间则使透水砖强度 增加，焙烧铁尾矿用量 60%、养护 28 d时，透水砖的抗折强度和抗压强度分别为 3.34 MPa和 15.44 MPa。过量添加 焙烧铁尾矿不利于水化反 应的进行，导致水化产物的生成量减少，焙烧铁尾矿用量超过 60% 时尤为明显，而延长养护 时间可促进水化反应的 发生。水化产物呈现出 3种微观形貌，即簇状结构、网状结构和针状结构，此 3种形貌水化产 物的形成使砖体结构变 得密实，从而提高了透水砖的强度。研究结果对采用焙烧铁尾矿制备高性能透水砖有一定的指 导意义。     

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     

注浆加固技术在十三矿-685 m进风大巷中的应用

针对煤矿开采深度不断向深部延伸,掘进巷道受深部高应力的影响越来越大,巷道围岩整体稳定性差,矿山压力显现越剧烈现象,一般锚网喷加锚索支护无法从根本上控制巷道的变形。总结了平煤股份十三矿-685 m进风大巷注浆加固技术,依据对巷道掘进之后变形监测数据的采集,对巷道变形机理进行分析研究,并对注浆时段进行了合理选择,在对巷道的注浆工艺进行了充分论证的基础上,对巷道进行了注浆。注浆后效果表明:巷道滞后注浆时间段的选择非常重要,巷道在恰当的时间内进行注浆加固施工,能有效控制巷道的变形,巷道注浆后变形量明显减小,岩体的稳定性明显增强,减少了巷道日常维修工作,降低了矿井的生产成本,保障了矿井的安全生产。     

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 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