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.     

电化学法制备纳米锑粉

以加有乳化剂OP-10的稀盐酸溶液为电解液,以锑为阳极,不锈钢网为阴极,采用电化学方法制备了颗粒细小、形态稳定的纳米锑粉.采用X射线衍射(XRD)、透射电子显微镜(TEM)及傅立叶变换红外光谱(FT-IR)等对所制备的纳米锑粉的结构、形貌、粒径大小进行分析和表征.结果表明,所制备的纳米锑粉分散性较好,尺寸较为均匀,颗粒...     

电化学法制备纳米锑粉

以加有乳化剂OP-10的稀盐酸溶液为电解液,以锑为阳极,不锈钢网为阴极,采用电化学方法制备了颗粒细小、形态稳定的纳米锑粉.采用X射线衍射(XRD)、透射电子显微镜(TEM)及傅立叶变换红外光谱(FT-IR)等对所制备的纳米锑粉的结构、形貌、粒径大小进行分析和表征.结果表明,所制备的纳米锑粉分散性较好,尺寸较为均匀,颗粒直径约为20～40nm.乳化剂OP-10作为表面活性剂时,纳米锑粉可有效地被其包覆,不仪阻止了纳米锑粉与氧气的接触和氧化,而且也可防止纳米锑粉的团聚,起到提高纳米锑粉稳定性和分散性的作用.     

水溶液球磨制备氧化亚铜粉末的研究

以铜粉、氧化铜粉末为原料, 采用球磨法制备Cu₂O粉末, 研究了球磨时间和不同pH值的水溶液对反应速率及产物形貌、颗粒尺寸的影响。对样品进行了物相分析、颗粒形貌和尺寸分析, 结果表明, 在不同pH值条件下, Cu和CuO粉末球磨时可生成Cu₂O化合物, 随球磨时间的增加, Cu₂O量增加; pH值不同, 球磨反应速度不同, 产物颗粒尺寸大小也不一样。在pH=3时, 球磨反应速度较高; 但pH=12时, 产物颗粒尺寸较小; 在球料比30∶1, 球磨时间90 h, pH=3或pH=12的条件下, 反应完全, 生成Cu₂O, 颗粒形状为立方体、六方体、八面体及其它不规则多边形状, 颗粒尺寸为30～100 nm。     

液相还原法制备单分散纳米金与纳米银颗粒北大核心

以氯金酸和硝酸银为原料,水合肼为还原剂,明胶为分散剂,采用液相还原法制备了平均粒径分别约为50 nm和45 nm的单分散球状纳米金与纳米银颗粒。利用紫外分光光度计(UV-vis)、X射线衍射仪(XRD)、红外光谱仪(FT-IR)和扫描电子显微镜(SEM)等分析测试设备对所得到的纳米金与纳米银颗粒进行了表征,探讨了在纳米金与纳米银颗粒制备过程中工艺参数条件对纳米金与纳米银颗粒结构和性能的影响。结果表明:所得到的纳米金与纳米银粒度分布均匀;前驱体溶液用量、还原剂用量和明胶溶液用量等对纳米金与纳米银的粒径与形貌影响较大,随着前驱体溶液溶用量、还原剂用量和明胶溶液用量的增加,纳米颗粒的粒径呈现出先减小后增大的趋势,当明胶溶液用量为5 mL、前驱体溶液用量为2 mL、水合肼用量为2 mL时,所制备纳米金与纳米银的平均粒径最小。     

生物模板法制备纳米Ni粒子的研究

研究了沉积环境、pH值、沉积时间、铁蛋白浓度对生物模板法制备纳米Ni粒子的影响。研究结果表明, 最佳制备条件为: 在N₂保护环境下, 向含2 mg/mL脱铁铁蛋白, pH=8.0的Tris缓冲溶液中加入Ni(Ac)₂, 沉积2.5 h后, 加入还原剂NaBH₄, 得到黑色溶液。将溶液在pH=8.0的Tris缓冲溶液中透析除杂, 就可以制备出黑灰色的含Ni的铁蛋白溶液。利用Zeta激光粒度仪测试、TEM检测和EDX分析, 表明制备的纳米Ni样品具有平均粒径5 nm, 粒度分布均匀, 分散性好的特点。     

超声波-化学共沉淀法制备纳米ITO粉

以In、Sn硫酸盐为原料,采用超声波与化学共沉淀相结合的方法制备纳米ITO粉末,用TEM,sEM.XRD,BET等现代分析测试手段对制备的粉末进行表征.在反应温度为60-75℃,In3 浓度＜160g/L,氨水浓度＜400g/L,终点pH为6.8～8的条件下.得到的纳米ITO粉末颗粒呈球状,团聚少、分散性好,In2O3:snO2(质量)=9:1.平均粒径＜50nm,比表面积＞15m2/g.     

混煤燃烧过程中飞灰颗粒排放特性试验

为了解混煤燃烧对飞灰颗粒尤其是超细颗粒排放特性的影响,在一维沉降炉上对平朔、大优及神木3种烟煤及其混煤进行燃烧试验.采用激光粒度分析仪对收集的飞灰颗粒尺寸分布进行测定,并对混煤飞灰颗粒的体积平均直径及可吸入颗粒物（PM₁₀）、超细颗粒物（PM_2.5）所占比例的计算值与测量值进行比较.结果表明：合理混煤能增大飞灰颗粒的粒径,减少可吸入颗粒物（PM₁₀）及超细颗粒物（PM_2.5）的排放;混煤的飞灰颗粒粒径分布受组成煤种、灰分含量及煤灰成分等因素的影响.     

Ti增强镁基复合材料搅拌铸造中颗粒分散行为的研究

利用材料性能模拟软件JMatPro对Mg-Al系合金进行热力学和相转变的计算,得到镁合金在半固态和液态不同温度下粘度变化的规律。使用CFD方法对镁合金熔体的固-液混合过程进行了模拟,计算不同粒径Ti颗粒在不同熔体粘度下在搅拌槽中的分布情况,以及Ti颗粒分散性的变化趋势,并通过在树脂中添加不同比例稀释剂调控粘度值,研究纳米Ti颗粒在不同粘度下的分散行为。结果表明:随着Ti颗粒粒径减小,熔体粘度增加,这有利于Ti颗粒在搅拌槽中各区域分布;在相同搅拌速度下,随着搅拌时间增加延长和熔体粘度提高,Ti颗粒团聚行为明显降低,微观区域明显改善。     

凹凸棒颗粒稳定的Pickering乳状液的制备条件及形成机理研究

选取凹凸棒作为乳化剂,系统研究pH值、颗粒质量分数、油相体积分数以及不同价态盐对橄榄油/水型Pickering乳状液稳定性的影响.结果表明,体系pH值在4~9范围内可制备出稳定的乳状液;颗粒质量分数提高可增强乳液的分层和聚结稳定性;乳液液滴直径随油相体积分数的增加先增大后减小;无机盐的引入不会对乳液相及水相体积产生影响,但对乳液液滴的尺寸分布影响显著,其中NaCl浓度的增加有利于乳状液液滴数均直径的增加,而CaCl2浓度增加时,乳状液液滴数均直径呈现先增大后减小的变化趋势.显微镜图片显示,凹凸棒颗粒主要以聚集体网状结构的方式附着在油-水界面处,从而起到稳定乳液液滴的效果.     

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。