氧化锌纳米粒子形态与制备条件的关系

通过一步法和二步法两种制备方法的主要制备条件的变化,探讨了氧化锌纳米粒子形态与制备条件的关系。温度对一步法直接合成纳米氧化锌的影响较大,当温度较低时,可以得到纤维状粉体,随温度升高,其形貌也逐渐向短棒状、类球状转变,在100℃反应时可以获得近球状颗粒;二步法的热分解反应为固相反应,粒度受反应温度和反应时间的影响,随热分解温度的升高和反应时间的延长,晶粒逐渐变大,但温度的变化影响最为显著。试验与理论分析表明,纳米氧化锌的粒度与形貌除受其晶核的形成与生长机制的影响外,在很大程度上还受到制备方法和制备条件的影响。一步法制备纳米氧化锌时,粉体的晶粒粒度与粉体的成核速度有关,成核速度越快,得到的粉体粒度越小;提高反应温度或增大反应物浓度都能使成核速度增快,因而制得的粉体粒度减小;同时伴有取向连生现象出现,这表明了氧化锌极性晶体的生长习性。     

沉淀-热分解二步法制备纳米氧化锌的试验研究

以氯化锌和碳酸钠为原料，采用沉淀－热分解二步法制备纳米氧化锌，结合TG－DTA热分析，X－射线衍射分析，透射电镜观察等表征手段研究纳米氧化锌粉体的结构和形貌。结果表明，热分解反应因素应因素的影响明显大于沉淀反应，其中热分解温度的影响最为显著。在试验工艺条件下，制备出结晶及分散性良好，粒径为10nm左右的纳米氧化锌，过程可控性好，简单易行。     

载银多孔SiO2的抗菌性能

通过吸附制备载Ag多孔SiO2．用XRD和最小抑菌浓度（MIC）对样品进行表征，研究反应条件对银吸附量的影响及焙烧温度对抗菌性能的影响。结果表明，溶液pH和Ag^＋浓度是影响多孔SiO2银吸附量的重要因素。随pH增加，吸附量先增加后减少，并在pH=10时达到最大值。随Ag^＋浓度增加，吸附量不断增加并在Ag^＋浓度为5．5mg／mL时开始保持不变，而吸附效率不断降低。反应时间和温度对多孔SiO2吸附银没有影响。随焙烧温度升高．载银多孔SiO2抗菌性能逐渐降低。     

纳米粘土/EP复合材料性能研究

采用正交方案，蒙脱石通过HDTMAB阳离子插层制备纳米粘土，冲击实验表明最佳条件为：反应温度90℃、矿浆浓度5％、反应时间2h。在EP中加入5％纳米粘土，制得的纳米粘土／EP复合材料的抗冲击强度和弯曲强度，分别比纯EP提高303．2％和45．5％。     

真空度控氧制备四脚状纳米氧化锌晶须及影响因素

通过调节真空度来改变反应体系的含氧量.从而控制反应过程的锌氧比例,制备四脚状纳米氧化锌晶须.考察了温度、真空度、反应时间对产物形貌和粒度的影响.在反应温度为860-900℃时,以金属锌为原料.空气为氧源制得了形貌规整,长径比较大的四脚状纳米氧化锌晶须.     

氧化铁-云母纳米薄膜材料的制备研究

本文利用加碱中和法在天然白云母基片上沉积氧化铁纳米颗粒薄层，制备出Fe2O3—云母纳米薄膜材料，并探讨了实验条件对结果的影响，总结得到Fe2O3—云母纳米薄膜材料的最佳实验制备工艺参数。结果与分析表明，工艺条件如pH、温度等因素的不同设置，将带来不同的成膜效果，如薄膜材料的均匀性、包覆率，及其颜色。实验得到的Fe2O3—云母纳米薄膜材料的最佳制备工艺为：氯化铁溶液浓度为0．2mol／l，其用量与云母粉料比为11：1；成膜过程：pH值控制在3左右，反应温度为70～80℃，滴定速度为1．0～1．4ml／min；焙烧阶段：650℃、900℃煅烧2小时，即可获得带有金黄光泽的Fe2O3—云母纳米薄膜材料。     

纳米ZnO的制备

探讨了均匀沉淀法制备球形纳米ＺｎＯ的新工艺,获得最佳的工艺条件为：反应温度９５℃,反应时间３～５ｈ,ｎ（Ｚｎ（ＮＯ３）２＝１．２ｍｏｌ／Ｌ,ｎ（ＣＯ（ＮＨ２）２）／ｎ（Ｚｎ（ＮＯ３）２＝３．０～５．０,热解温度３５０℃,热解时间３ｈ,制得的样品粒径分布为５０～８０ｎｍ,平均粒径为６５．１ｎｍ,ＺｎＯ回收 率为９２．２６％。     

膨润土纳米层间的有机改性及其影响因素

对膨润土纳米层间进行有机改性以扩大层间距，是制备有机物／蒙脱石纳米复合材料的前提步骤。采用正交试验法，系统考察了膨润土纳米层间改性过程中反应体系的温度、pH值、固液比、季铵盐用量、反应时间等工艺条件对改性效果的影响。结果表明，在所有这些工艺条件中，对膨润土001晶面间距的影响顺序为：季铵盐用量＞膨润土／水(固液比)＞反应时间＞反应温度＞pH值，从而获得了膨润土层间改性的适宜工艺条件。     

自吸式搅拌反应器制备纳米碳酸钙新工艺研究

以碳化机理及反应动力学为理论基础，开发了以自吸式搅拌反应器为主要碳化反应设备制备纳米碳酸钙的新工艺。该工艺所制备的纳米CaCO3粒度分布均匀且易于控制，还可强化碳化反应，提高CO2的利用率，碳化反应时间也比传统鼓泡法缩短75％－90％。     

钛基特种催化剂载体的制备研究

以工业偏钛酸(TiO₂含量约380 g/L)为原料, 采用均匀沉淀法制备钛基特种催化剂载体, 研究了获得最小粒度的纳米TiO₂的工艺条件。结果表明:在硫酸浓度92%、酸钛比3∶1、反应温度110 ℃、反应时间1 h条件下进行酸解, 工业偏钛酸的溶解度最大; 在反应温度100 ℃、TiOSO₄浓度38 g/L、尿素实际用量与理论用量比值为1条件下, 水解2 h并熟化30 min, TiOSO₄水解率最大, 得到了同等条件下粒径最小的纳米TiO₂; 在煅烧温度400 ℃、煅烧时间3 h条件下, 可获得锐钛型纳米TiO₂, 且粒径最小; 加入BaCO₃解聚剂, 可促进偏钛酸中的硫酸根生成BaSO₄, 沉硫的同时解聚二次团聚粒子; 活性添加剂WO₃可使催化剂载体具有特有的活化性能, 并可提供位阻效应, 有效防止煅烧环节颗粒的聚集。     

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