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。     

ZnFe2O4的制备及其酸溶特性研究*

本文对分析纯的ZnO和Fe₂O₃超声波分散25min后烘干,高能球磨预处理5h,采用恒温焙烧法制备非纳米ZnFe₂O₄,对铁酸锌产品进行粒度分析、XRD分析及SEM分析,研究焙烧温度对产品的粒度特征、结晶状况、微观形貌的影响。所制铁酸锌产品经机械活化后进行微波焙烧处理,并对其进行孔径和比表面积分析。利用插值法和响应曲面法对微波处理后产品的硫酸浸出实验数据进行分析,研究始酸浓度、浸出温度对铁酸锌酸溶特性的单因素影响及交互作用影响。     

两种方法制备的纳米水滑石晶体结构与热稳定性的比较研究

分别采用共沉淀法和机械力化学/原位结晶法制备纳米水滑石,通过X射线衍射(XRD)、场发射扫描电镜(FE-SEM)、热重-差示扫描量热分析(TG-DSC)及红外光谱(IR)等方法对比分析了两种纳米水滑石在表观形貌、晶体结构和热稳定性等方面的差异。结果表明,与共沉淀法制备的纳米水滑石相比,机械力化学/原位结晶法制备的纳米水滑石结晶度更高、晶粒呈规则的六边形片状形貌、晶粒粒径约为40 nm、粒度分布均匀,且在TG-DSC曲线上的吸热峰面积、失重量和失重速率较小,热稳定性更好。     

纳米CeO2抛光液的制备及其抛光性能研究

在水体系中采用沉淀法制备了纳米CeO2粉体,并用XRD、SEM、TEM等对其晶体结构、粒度与形貌等进行了表征.将所得粉体配成水基纳米CeO2抛光液,研究了其抛光硅片的性能与机理,并与纳米SiO2抛光液作对比.结果表明,粒度在100 nm以下的CeO2对硅片具有良好的抛光效果,抛光后硅片表面形貌有很大改观,表面划痕被抛掉,在面积172μm×128μm的范围内得到了表面粗糙度Ra为0.689 nm的超光滑表面.     

高效绿色颜料铋黄的制备研究

以Bi(NO3)3.5H2O、NH4VO3和(NH4)6Mo7O24为原料,研究了加料方式、反应物浓度、pH值、反应温度、煅烧温度、煅烧时间等工艺条件对纳米级铋黄粉末制备的影响。采用X射线粉末衍射表征其物相结构,透射电子显微镜表征产物的形貌和微观结构。产物粒径及比表面积采用激光粒度分布测试仪和比表面积测试仪测定。得出以下结论:采用并加沉淀法制备的纳米级铋黄颜料,与同类颜料比较性能优越。     

单分散菊状坡缕石-CaCO3纳米复合粉体的制备及表征

摘 要：本文采用液相沉淀法制备了坡缕石-CaCO3（PG-nanoCaCO3）纳米复合粉体,用X-射线衍射（XRD）法和透射电子显微镜（TEM）对其物相组成和微观形貌进行了表征,以热重分析法对其热稳定性进行了分析,并对其相对白度进行了测试,结果证明：所制备的坡缕石-CaCO3纳米复合粉体的微观形貌为菊状单分散结构,平均粒度为 2μm左右, 相对白度达到95.83, 热稳定性比纯坡缕石有极其显著的提高。     

单分散菊状坡缕石-CaCO_3纳米复合粉体制备及表征

本文采用液相沉淀法制备了坡缕石-CaCO3(PG-nanoCaCO3)纳米复合粉体,用X-射线衍射(XRD)法和透射电子显微镜(TEM)对其物相组成和微观形貌进行了表征,以热重分析法对其热稳定性进行了分析,并对其相对白度进行了测试,结果证明:所制备的坡缕石-CaCO3纳米复合粉体的微观形貌为菊状单分散结构,平均粒度为2μm左右,相对白度达到95.83,热稳定性比纯坡缕石有极其显著的提高。     

ZnO半导体纳米线的制备

采用物理气相沉积技术在镀金Si衬底上制备一维ZnO纳米线。利用SEM、XRD及PL技术对ZnO纳米结构的形貌、晶态结构及生长模式进行了分析。结果表明,ZnO纳米线结构的生长满足气液固生长机制,且呈现纳米线顶端生长模式,且主要由晶态ZnO组成。     

焙烧条件对单一铁基催化剂性能影响的研究

阐述了采用并流沉淀法制备一系列单一铁基催化剂的实验过程,通过对催化剂焙烧条件进行研究,对采用浆态床反应器时催化剂的性能进行了评价.研究结果表明,焙烧温度和焙烧时间对催化剂的比表面积和催化剂粒度都产生重要影响,进而对催化剂的活性和选择性产生重要影响.     

电池级氧化钴制备新工艺

研究基于并流沉淀法,采用表面包覆技术制备电池级氧化钴的新工艺,用XRD、SEM和IR对产品电池级氧化钴的粒度、形貌和表面包覆进行表征.制备电池级氧化钴的最佳工艺条件为:乙醇浓度20%的底液、硫酸钴溶液浓度0.5mol/L、碳酸氢铵溶液浓度0.8mol/L、硫酸钴溶液滴加速度20mL/min、碳酸氢铵溶液滴加速度15mL/min、分散剂种类为阴离子分散剂、搅拌速度为500r/min、煅烧温度为400℃.制得的电池级氧化钴呈球形,粒度分布均匀且范围窄,平均粒径为6μm,颗粒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     

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     

2014 second batch of rare earth quota released

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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