有机溶液中稀土总量的快速分析

根据康普顿散射强度与样品平均原子序数有关的原理,提出了用单道γ谱仪对有机溶液中稀土总量的快速分析。推导了稀土溶液中平均原子序数和稀土总量的关系。研究了溶液中稀土元素个数的多少和杂质对测量的影响。该方法不需要制样,操作简单、快速,一分钟可测一个样。在0.01～0.15M浓度范围内与化学分析对照相对偏差小于3.1%。     

分光光度法测定混合稀土中的钕

采用分光光度法,以740 nm为测定波长测定混合稀土样品中的钕含量。在此波长下,吸光度-浓度工作曲线的线性相关系数大于0.9999。对已知组成的6个轻稀土混合物样品的测量结果表明,回收率介于98.97%-101.9%之间,检测下限为2.0 mg Nd2O3/ml。本方法可准确测定镨钕混合物、混合轻稀土等产品或中控样品中的钕含量,具有测量结果可靠、速度快、仪器常规和实验条件简便易行等特点,适用含钕样品的快速测定。     

氟碳铈矿稀土抛光粉与氟碳酸盐稀土抛光粉性能研究

采用差热热重分析、Ｘ射线粉末法、电子显微术、物理及化学分析等手段，对比分析了氟碳铈矿稀土抛光粉和氟碳酸盐稀土抛光粉的外观形貌、晶体结构、化学成份及物理性能，并探讨了两种试制样品性能差异的机理。     

同位素X萤光载流分析富稀土矿浆浓度的研究

本文叙述了一种新的测量方法—同位素X萤光背射法,用低能光子源激发稀土矿浆样品,使之产生特征X射线峰和反散射峰。反散射峰的强度与矿浆浓度存在单值对应的非线性关系。浓度越低反散射峰强度越高,由此可直接测量矿浆浓度。它解决了选矿过程中高原子序数介质的矿浆浓度的在线测量问题。这种新的放射性同位素应用技术,与同位素射线吸收法测量矿浆浓度在原理上有着根本不同。目前,此方法未见公开报导。     

轻稀土氟化物的微波固相快速合成法

在微波场作用下，采用轻稀土氧化物和氟化氨的固相反应快速合成了轻稀土氟化物、氟氧化物以及氟化物复盐，通过XRD及场发射扫描电镜(FE—SEM)等方法对样品的组成、结构进行了分析表征，并讨论了轻稀土氟化物的反应历程以及微波合成条件对产物的影响。研究表明：在微波场作用下，采用NH4F和轻稀土氧化物直接反应合成氟化稀土，具有方法简单，易于操作，高效节能等特点。     

河北汉诺坝玄武岩稀土元素特征

本文主要对河北汉诺坝碱性玄武岩和拉斑玄武岩十七个样品的稀土元素含量进行了测定。两种玄武岩在球粒陨石标准化模式图上有明显富集轻稀土的特征，且均具有正的微弱Ｅｕ异常，稀土元素丰度变化受岩性变化的控制。     

钢铁中稀土总量和轻重稀土分量的测定

随着稀土在冶金中应用的发展,要求有相应的稀土总量与轻重稀土分量的测定方法。 我国稀土资源丰富,矿源轻重比例各不相同,这就反映到加入钢铁中的稀土元素轻重比例也各不相同。尽管以前测定稀土总量的灵敏显色剂很多,但大多数对轻稀土的发色能力强、摩尔吸光系数较大;而对重稀土含量高的样品,测其总量就存在着因轻重稀土比例不同而检量线不同的问题。     

轻稀土Ce对Nd-Fe-B永磁材料的结构与磁性能影响

轻稀土铈替代稀土永磁材料钕铁硼中的钕是降低生产成本、平衡稀土资源利用比较有效的方式。本文首先通过调节合金成分研究了制备Nd_2Fe_(14)B单相的工艺,其次以轻稀土铈部分替代钕的方式通过X射线衍射仪、扫描电镜及振动样品磁强计分别研究了(Nd_(1-x)Ce_x)_(11.76)Fe_(81.39)B_(6.85)(x=0.0,0.1,0.2)物相的晶体结构、微观组织及磁性能。研究结果表明替代后的物相均为Nd_2Fe_(14)B型的四方相。通过在600℃下烧结2小时,随着铈添加的含量增多合金的内禀矫顽力以及剩磁虽然有所下降,但当铈含量添加到20%(x=0.2)时,合金的内禀矫顽力和剩磁仍然可达到9.31kOe和98.80emu/g。     

稀土标准分析方法中稀土元素分析谱线的述评

针对ICP-AES法测定稀土样品中稀土元素时,一些元素的分析谱线难以选择的问题,总结了稀土标准分析方法中利用电感耦合等离子体发射光谱法测定单一稀土金属及其氧化物中稀土杂质量,稀土矿石、稀土精矿、离子型稀土矿、氯化稀土、碳酸轻稀土及钐铕钆中的稀土配分量,氧化钇铕中的稀土杂质及氧化铕量,镝铁合金、钆镁合金中的稀土杂质量,稀土硅铁及镁硅铁合金中的稀土总量、镨钕合金及其化合物、钕铁硼废料中的配分量时,所选用的分析谱线。为分析检测类似样品时选择分析谱线方面起到一定的参考作用。     

经典分析方法是否能胜任轻稀土湿法冶金的中控分析

稀土资源中轻稀土镧、铈、镨、钕比重很大 ,光学玻璃、储氢材料、抛光粉、催化剂、颜料、永磁体等都使用大量的轻稀土。因此 ,氟碳铈镧矿、独居石的轻稀土分离更显重要〔1,2〕。在湿法冶金生产过程中 ,分析方法异常丰富 ,随着电感耦合等离子体发射光谱、Ｘ射线荧光等仪器分析的迅速发展 ,常规分析和产品分析日臻完善 ,形成了许多国家和行业标准〔3,4〕。快速、准确的仪器分析可随时掌握生产工艺的运行状态 ,从而保障产品质量的合格和稳定 ,但昂贵的大型仪器又制约中控分析的普及 ,较高的使用和维护费非一般规模项目所能承受。本文提出的经典…     

Mathematical Modelling of the Liquid-Liquid Extraction Separation of Rare Earths

Abstract

An empirical mathematical model has been developed for the simulation of an integrated solvent extraction circuit consisting of an extractor, scrubber and a stripper. This model is designed to simulate the separation of any lanthanide from a mixed lanthanide feed. The Kremser equation is used to calculate the separation occurring in each section of the circuit. The inputs required for the simulation are the feed composition, separation factors, equilibrium data of the key element under a wide range of conditions, the number of stages and flow rates of the aqueous and organic streams in the circuit. This model has been validated with the experimental data for the separation of Nd from a mixed lanthanide chloride feed with 2-ethylhexyl phosphonic acid mono 2-ethyl-hexyl ester (EHPNA) as an extractant.     

Study of Properties of Intermetallic Compounds of Rare Earth Metals by Artificial Neural Networks

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Progress on Study of Luminescence of Rare Earth Organic Chelates

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Enthalpies of Solution of Complexes of Rare Earth Nitrate with L-α-Histidine in Water

The enthalpies of solution in water of complexes of RE(NO3)3(RE = La - Nd, Sm- Lu, Y) with L-α-Histidine (His) were measured at 298.15 K. The standard enthalpies of formation of RE(His)^3 (aq) were calculated. The “tetrad effect” regularity was observed from the curve, which is the enthalpies of solution plotted against the atomic numbers of the elements in lanthanide series.     

New Opportunities for Lanthanide Luminescence

Trivalent lanthanide ions display fascinating optical properties. The discovery of the corresponding elements and their first industrial uses were intimately linked to their optical properties. This relationship has been kept alive until today when many high-technology applications of lanthanide-containing materials such as energy-saving lighting devices, displays, optical fibers and amplifiers, lasers, responsive luminescent stains for biomedical analyses and in cellulo sensing and imaging, heavily rely on the brilliant and pure-color emission of lanthanide ions. In this review we first outlined the basics of lanthanide luminescence with emphasis on f-f transitions, the sensitization mechanisms, and the assessment of the luminescence efficiency of lanthanide-containing emissive molecular edifices. Emphasis was then put on two fast developing aspects of lanthanide luminescence: materials for telecommunications and light emitting diodes, and biomedical imaging and sensing. Recent advances in NIR-emitting materials for plastic amplifiers and waveguides were described, together with the main solutions brought by researchers to minimize non-radiative deactivation of excited states. The demonstration in 1999 that erbium tris(8-hydroxyquinolinate) displayed a bright green emission suitable for organic light emitting diodes (OLEDs) was followed by realizing that in OLEDs, 25% of the excitation energy leads to singlet states and 75% to triplet states. Since lanthanide ions are good triplet quenchers, they now also play a key role in the development of these lighting devices. Luminescence analyses of biological molecules are among the most sensitive analytical techniques known. The long lifetime of the lanthanide excited states allows time-resolved spectroscopy to be used, suppressing the sample autofluorescence and reaching very low detection limits. Not only visible lanthanide sensors are now ubiquitously provided in medical diagnosis and in cell imaging, but the feasibility of using NIR emission of ions such as YbⅢ is now being tested because of deeper penetration in biological tissues.     

Features of Solvent Extraction of Lanthanides and Actinides

Abstract

Solvent extraction is a powerful method for lanthanide and actinide intra- and inter-group separations. Apart of the general parameters governing the extraction.f-electron elements exhibit several peculiarities of the process. Two of them are described in the paper: double-double (tetrad) effect in the lanthanide and actinide series and itinerant properties of the actinides (III) in respect to the lanthanide series, as well as the effects of inner- and outer-sphere hydration of the extracted species.

Extraction chromatography is presented as the most powerful technique of the extractive separation.     

Study on Differential Rate Kinetics Analysis Based on the Substitution Reaction of Rare Earth-PHA with CyDTA

The kinetic behaviours of the substitution reaction of rare earth-PHA with CyDTA were studied systemati-cally.The relationship between the rate constant and atomic number was discussed.The rate differentiation val-ue R_d(R_d=lgk_(z n)-lgk_z)was proposed to evaluate the possibility of differential kinetic analysis.The R_d valuebetween the neighbouring lanthanide ions first increases and then decreases along with increasing atomic number,so that the middle and heavy rare earth mixture(such as Sm-Gd and Gd-Y)are ideal systems for thedifferential rate kinetic analysis.     

Co、Ni、Fe、Pr和Nd元素离子本色光度分析方法的应用研究

文章考察了本色光度法的相关条件。控制标准与试样在相同（或相近）的相关条件下测定是获得准确分析结果的必要条件。概述了本色光度法在一些过渡金属元素和镧系元素试样分析中的应用。本色光度法具有简便、快速、高选择性、经济、绿色、自然的优点。     

Status of Research on Application of High Purity Rare Earth Oxides in Solid Oxide Fuel Cells

The solid oxide fuel cell (SOFC) is a high-efficient and environmentally friendly power generation system.The rare earth oxide materials are used extensively in the manufacturing of SOFC components.In particular, the CeO2doped with Gd2O3 or Sm2O3, lanthanide perovskite oxides are indispensable and key materials for developing the intermediate temperature SOFC.The research and development status of application of high purity rare earth oxides in SOFC was overviewed.The rare earth oxide-based and -doped materials were discussed for the SOFC components.Concerning the rare earth oxides applicable to SOFC, several topics were also pointed out for further researching and developing.     

Investigation of Polyacrylate Anion-Exchangers for Separation of Rare Earth Element Complexes with EDTA

The rare earth complexes with EDTA, Ln(edta), show an unusual sequence of affinity for the anion-ex-changers. The sorption and chromatographic separation of y3 for Nd3 complexes with EDTA was studied by using the strongly basic gel and macroporous polyacrylate anion-exchangers, Amberlite IRA 458 and Amberlite 958, and the weakly basic gel polyacrylate anion-exchanger, Amherlite IRA-68. The investigations on sorption and separation of rare earth complexes with EDTA on the polyacrylate anion-exchangers applied mainly in the environment protection so far indicate that they can he applied in anionexchange separation of lanthanide complexes with aminopolycarboxylic acids. It was shown that the weakly basic polyacrylate gel anion-exchanger Amberlite IRA-68 is the most effective in purification of y3 from Nd3 in comparison with the strongly basic anion-exchangers of this type.