辛基羟肟酸在锡石表面吸附的动力学研究

本文在１５℃,２５℃,４５℃时测定锡石碳糊电极在辛基羟肟酸溶液中的微分电容（Ｃｄ）,作出微分电容随吸附时间（ｔ）的变化曲线,设电极在各个温度下于０．５ｍｏｌ／Ｌ硝酸钾溶液中的微分电容值为Ｃｄ,则Ｃｄ与之差为微分电容变化量△Ｃｄ,随时间（ｔ）的变化符合指数规律。从Ｌａｎｇｍｉｕｒ吸附等温式,可导出Ｉｎ（１－△Ｃｄ／△Ｃｄ°）＝Ｋｔ式,该式说明锡石碳糊电极吸辛基羟肟酸过程为一级反应。作Ｉｎ（１－...     

KF－AlF_3系热力学性质的计算

在ＫＦ－ＡｌＦ３熔体中采用络合离子逐级分解的模式，利用亚晶格溶液模型计算了ＫＦ－ＡｌＦ３熔体中的逐级解离常数和分解能。分解常数依次为ｋ１＝１．５５×１０－１，ｌ２＝４．２０×１０－２，ｋ３＝７．０１×１０－３；分解热依次为Ｈ１＝３７．８ｋＪ／ｍｏｌ，Ｈ２＝４８．２ｋＪ／ｍｏｌ，Ｈ３＝１２２．ｌｋＪ／ｍｏｌ，计算结果表明ＫＦ－ＡｌＦ３熔体中时比ＮａＦ－ＡｌＦ３和ＬｉＦ－ＡｌＦ３熔体中的都更稳定。本文还对ＫＦ－ＡｌＦ３熔体中各组成的摩尔浓度及其它混合热力学性质进行了计算，计算结果与实验测得结果吻合的较好。     

4-氨基吡啶树脂吸附铬(Ⅵ)的研究

４－氨基吡啶树脂（４－ＡＰＲ）对Ｃｒ（Ⅵ）的吸附在ｐＨ＝２时最佳,静态饱和吸附容量１６３．６ｍｇＣｒ（Ⅵ）／ｇ树脂,用４．５ｍｏｌ　Ｌ－１ ＮａＯＨ溶液能洗脱。测得２９８Ｋ时表观吸附速率常数ｋ２９８＝６．２５×１０－４Ｓ－Ｉ．等温吸附遵循Ｆｒｅｕｎｄｌｉｃｈ曲线,吸附机理表明４－ＡＰＲ功能上的Ｎ与Ｃｒ（Ⅵ）发生配位键合,配位摩尔比为１：１。     

大孔膦酸树脂吸附镨的研究

大孔膦酸树脂（ＰＡＲ）对 Ｐｒ（Ⅲ）的吸附在 ｐＨ＝６． ０时最佳。静态饱和容量为每克树脂（干） ２５４．８ ｍｇ，用０． ２０ ｍｏｌ／Ｌ ＨＣＩ＋０．５０ ｍｏｌ／Ｌ ＮａＣｌ，溶液能定量洗脱，再生树脂可以重复使用。测定 了树脂吸附Ｐｒ（Ⅲ）的Ｆｒｅｕｎｄｌｉｓｈ常数和反应的热力学函数等。对吸附反应机理进行了探讨。     

用磁铁矿精矿制取锶铁氧体工艺研究

介绍了依据磁铁矿精矿自身特点,采用新型添加剂Ｂ和Ｌ改善磁性能,生产出合格的铁氧体永磁材料。其磁性能指标：Ｂｒ ＝０ ．２１３ Ｔ, Ｈｃ ＝ １２９．８ ｋＡ／ｍ ,（Ｂ·Ｈ）ｍａｘ ＝ ７．２ ｋＪ／ｍ３ 。     

平果铝土矿机械活化溶出的研究

研究了机械活化反应器中，温度，溶出原液αｋ，溶出时间及液固比等因素对平果铝土矿溶出率的影响。在２２５℃，溶出原液αＫ３．２，Ｌ／Ｓ２．５，溶出２ｈ的条件下，Ａｌ２Ｏ３的溶出率达９６．６０％，比相同条件下的高压釜溶出率高１８％；动力学研究表明，在１３８－１７６℃范围内，试验结果能很好地模拟动力学模型１－（１－ｘ）＾１／３＝ｋａｔ，测得其表观活化能为７２．６４ｋＪ／ｍｏｌ，溶出过程属化学反应控制，研究     

金属羟基化合物在锡石表面吸附与糊精作用机理的研究

表在锡石表面吸附最佳ＰＨ值为７．６左右，而矿浆中锡石表面吸附Ｈ和ＯＨ离子等吸附点ＰＨ值为５．４。糊精主要是与锡石表面的Ｓｎ（ＯＨ）４组分发生作用而顺附。与锡石相比，赤铁矿表面吸附的糊精量明显较高，其最佳吸附ＰＨ值为６．６，展示了糊精对二者作用的选择性。     

大孔膦酸树脂吸附铽的性能及其机理

大孔膦酸树脂对Tb（Ⅲ）的吸附在HAc－NaAc缓冲体系中以pH为5．0最佳，树脂的静态和动态饱和吸附容量分别为252．8mg／g和239．4mg／g。用0．3mol／LHCl＋0．05mol／LNaCl溶液能定量洗脱。测得25℃时树脂吸附反应的表现速率常数K25c＝2．85×10－5／s；热力学参数西ΔH＝14．76kJ／mol、ΔG＝－40．51kJ／mol、ΔS＝185．5J／（mol·K）；配位摩尔比约为3：1（功能基：Tb（Ⅲ）。用化学和红外光谱等方法探讨了吸附机理。     

Nd—Fe基永磁材料的研究

Ｎｄ１５Ｆｅ７７Ｂ８永磁材料由具有极高磁单轴各向异性的化合物组成，它的主相Ｎｄ２Ｆｅ１４Ｂ呈四方相结构，其晶格常数ａ＝０．８８０ｎｍ，ｃ＝１．２２１ｎｍ，饱和磁感应强度值达１．６１Ｔ，Ｎｄ１５Ｆｅ７７Ｂ８产性能为：Ｂｒ＝１．２３，Ｔ，ＢＨｃ＝８８０ｋＡ／ｍ，（ＢＨ）ｍａｘ＝２９０ｋＪ／ｍ＾３，Ｂｒ的温度系数为－１２６０＊１０＾－６／Ｋ。     

Ni（OH）2热分解动力学的非等温技术研究

由Ｎｉ（ＯＨ）２在升温过程中的ＴＧＡ和ＤＳＣ曲线，研究其热分解反应的动力学，实验结果表明，Ｎｉ（ＯＨ）２粉体从４８９Ｋ时开始分解，６２６Ｋ时分解完毕，反应的活化能为１２５．２５ｋＪ／ｍｏｌ。化学反应是分解过程的控制环节。     

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