均匀沉淀法制备纳米氧化锌

研究均匀沉淀法制备纳米氧化锌影响因素和最佳工艺条件。结果表明，均匀沉淀法可制备出六方晶系纳米氧化锌。随Zn^2＋浓度增加纳米氧化锌颗粒由棒状向球形转化，平均粒径49nm。对纳米氧化锌产率影响因素的显著性水平依次为反应温度、尿京与Zn^2＋物质的量之比、反应时间和Zn^2＋的浓度。最优工艺参数为：反应温度95℃、反应时间3．5h、Zn^2＋浓度0．6mol/L、尿素与Zn^2＋物质的量之比为2．5。以硝酸锌为原料可得到纯度较高的纳米氧化锌。     

一种制备纳米片状锌粉的新方法

根据振动混沌控制和应力释放原理,首次提出了一种制备纳米片状锌粉的新设备和新方法。试验研究证明,经过1 h振动加工后,150g中值粒度为1 0mm的球状雾化锌粉基本上都成了薄片状,薄片的厚度在10～15μm之间,直径方向尺度分布在20～100nm之间,这一转变过程的电力消耗只有0.12kW·h。延长研磨时间可使厚度继续减小,直径-厚度比继续增大,并使颗粒形状更加规则化和均匀化。     

溶胶-凝胶法制备纳米氧化锌新工艺

以不同络合剂与二水合醋酸锌为原料,采用溶胶-凝胶法制备纳米氧化锌.探讨络合剂、温度、反应pH值及复配表面活性剂对氧化锌粉体粒度、形貌及分散性的影响.用TEM,XRD对氧化锌粉体进行表征.结果表明,十二烷基硫酸钠和聚乙烯毗咯啉酮复配能有效地分散和控制颗粒的团聚,制备出粒径在35nm左右、纯度高、晶型良好、分散性好的纳米氧化锌.     

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.     

纳米级叶蜡石结构参数的表征

阐述了叶蜡石纳米化的必要性，并从晶体化学和晶体结构的角度，根据叶蜡石的晶胞参数、晶胞内原子排列的特点等，提出了叶蜡石最小颗粒的假设，从理论上得出叶蜡石最佳的纳米尺度。同时通过对叶蜡石颗粒的晶胞数、原子数、表面晶胞数以及平行(001)面的表面原子数的计算，列出了叶蜡石纳米结构参数的表征，讨论了它们与纳米级叶蜡石颗粒尺度大小的相关规律，并结合纳米微粒的特征对其进行了简要的分析。     

纳米锗颗粒膜的结构与拉曼散射

用直流磁控溅射方法制备的纳米Ge颗粒膜．通过XRD表征和LRS谱分析，发现沉积态颗粒膜主要为无定形态的Ge团簇，同时在溅射沉积过程中有少量Ge被氧化成非晶态的GeO．颗粒膜经过真空退火处理，形成纳米级的Ge晶和GeO晶体．退火态的膜层结构比沉积态的疏松．对于薄膜纳米颗粒的结构，提出Core—Shell结构模型。解释了Raman散射谱中新出现的150cm^-1和215cm^-1的Raman散射峰．     

用喷雾燃烧法制备ITO纳米级粉末的研究

将金属铟和锡先配制成合金，然后使Ｉｎ－Ｓｎ合金熔体过热，通过气雾喷粉工艺，由高压预热氧气使熔体雾化成微细的金属雾滴，并随即在高温反应室中进行直接地氧化燃烧而生成ＩＴＯ纳米级复合的氧化物粉体，其粒度≤３０ｍｍ，制备１ｋｇ的纳米级金属氧化物粉末仅仅需要的５０ｓ，并且生产过程无任何污染。     

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。     

pH值对电化学制备纳米铜粉的影响

在十二烷基硫酸钠、吐温80、十二烷基硫醇和硫酸铜混合而成的乳液中,采用电化学合成方法制备稳定的、粒径均匀的Cu纳米颗粒.应用XRD,TEM及FT-IR对所制备的Cu纳米颗粒的结构、形貌及粒径大小进行表征.结果表明,随着pH值的增大,纳米铜粉的尺寸、分散性及颗粒分布范围发生显著的变化.当pH为0.5时,可以制备得到尺寸较小、分散性较好,颗粒分布较窄的纳米球形颗粒.随着pH值增大,纳米颗粒的尺寸也随之增大.     

基于并流沉淀法研究纳米氧化锌的表面改性

本研究在应用并流沉淀法成功制备纳米氧化锌的基础上,利用超声波和微波技术研究纳米氧化锌的表面改性。通过表面改性剂种类的选择及分散介质、改性时间和温度、超声时间和功率等的试验研究,确定了表面改性纳米氧化锌制备的工艺条件。用XRD、SEM和IR对产品纳米氧化锌的形貌、粒度进行表征。结果表明所制取的纳米氧化锌呈类球形,其表面成功包覆了有机物。     

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     

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     

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     

唐口煤矿深部复杂开采工作面瓦斯分源涌出规律研究

研究工作面瓦斯涌出规律对工作面瓦斯治理有重要意义。为了得到唐口煤矿深部3号煤层复杂开采条件下工作面回采时期瓦斯涌出时空演化规律,选取6304工作面作为对象,采用实测方法研究6304工作面瓦斯涌出规律。结果表明:6304工作面瓦斯涌出量为6.534 m³/min,其中煤壁占34.27%,落煤占29.62%,采空区占36.11%;沿工作面倾向由低到高,瓦斯浓度整体为上升趋势,其中1—76号架工作面瓦斯浓度小于0.20%,76—102号架瓦斯浓度上升明显,最大为0.387%;上隅角的后部采空区是工作面的瓦斯主要涌出源,上隅角1号测点瓦斯浓度0.78%,上隅角周边3号、5号、7号、8号、9号测点瓦斯浓度平均为0.643%;周期来压时,上隅角瓦斯相对平时较高。研究为针对性的瓦斯分源监控与灾害防治提供基础。