Synergistic extraction of rare earth by mixtures of 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester and di-(2-ethylhexyl) phosphoric acid from sulfuric acid medium?

The extraction of Nd3 and Sm3 , including the extraction and stripping capability as well as the separation effect of Nd3 or Sm3 , from a sulfuric acid medium, by mixtures of di-(2-ethylhexyl) phosphoric acid (HDEHP, H2A2(0)) and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester (HEH/EHP, H2L2(0)) were studied. The distribution ratios and synergistic coefficients of Nd3 and Sm3 in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm3 or Nd3 . The chemical compositions of the extracted complex were determined as Nd·(HA2)2·HL2 and Sm·(HA2)2·HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.     

Synergistic extraction of cerium from sulfuric acid medium using mixture of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester and Di-（2-ethyl hexyl） phosphoric acid as extractant

Synergistic extraction of cerium(IV) from sulfuric acid medium using mixture of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester(HEH/EHP, HL) and Di-(2-ethyl hexyl) phosphoric acid (HDEHP, HA) as extractant was investigated. The results indicated that the maximum synergistic enhancement coefficients were obtained at the mole fraction of HEH/EHP=0.6, and cerium(IV) was extracted into organic phase in the form of Ce(SO4)0.5HL2A2. A cation exchange mechanism was proposed for the synergistic extraction of Ce(IV). The equilibrium constants and thermodynamic functions such as △G, △H, and △S were determined in the extraction of Ce(IV) from sulfuric medium using mixture of HEH/EHP and HDEHP.     

Study on thorium recovery from bastnaesite treatment process

Thorium (Th) stripping behavior from HEH/EHP (2-(ethylhexyl) phosphoric acid mono-2-ethylhexyl ester) with H2SO4, HCl and HNO3 were investigated. The results indicated that H2SO4 was the most effective stripping reagent compared with HCl and HNO3. Selecting H2SO4 as the stripping reagent, the effect of phase ratio, acidity, H2SO4 amount, HEH/EHP concentration and Th loading in HEH/EHP on Th stripping were systematically investigated. As a result, the optimum stripping conditions of Th(IV) were obtained as the concentration of H2SO4 solution was 3.50 mol/L, phase ratio was 4:1. Low HEH/EHP concentration was benefit for Th stripping. Based on the results, pilot test for new Bastnaesite treatment process was carried out and the recovery of Ce, F and Th were more than 99%, 98% and 95% separately.     

Synergistic extraction of rare earth by mixtures of 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester and di-（2-ethylhexyl） phosphoric acid from sulfuric acid medium

The extraction of Nd^3＋ and Sm^3＋, including the extraction and stripping capability as well as the separation effect of Nd^3＋ or Sm^3＋, from a sulfuric acid medium, by mixtures of di-（2-ethylhexyl） phosphoric acid （HDEHP, H2A2（0）） and 2-ethylhexyl phosphoric acid mono-2-ethylhexyl ester （HEH/EHP, H2L2（0）） were studied. The distribution ratios and synergistic coefficients of Nd^3＋ and Sm^3＋ in different acidities were also determined. A synergistic extractive effect was found when HDEHP and HEH/EHP were used as mixed extractants for Sm^3＋ or Nd^3＋. The chemical compositions of the extracted complex were determined as Nd.（HA2）2-HL2 and Sm.（HA2）2-HL2. The extraction equilibrium constants, enthalpy change, and entropy change of the extraction reaction were also determined.     

中钇富铕稀土矿萃取分离新工艺研究

报道了萃取分离中钇富铕稀土矿新工艺，第一步La～Gd/(Gd)TbDy(HoY)/Ho～LuY萃取分离，出口水相La～Gd组份再Nd/Sm分组；中间出口的(Gd)TbDy(HoY)组份Tb/Dy分离。进行了扩大试验和工业生产应用。与中钇富铕稀土Nd/Sm先分组的传统工艺相比，处理能力提高约35%，P507存槽量减少约40%，贵重Tb、Dy稀土从第一步就出口，流程短、收率高。     

1，2-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)乙二酮-[1，2]与三正辛基氧化膦协同萃取RE(Ⅲ)的性能和机理研究

研究了1，2-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)乙二酮-[1，2](H     

氨化HEH/EHP膜基萃取钕、钐及传质研究

本文采用自制聚偏氟乙烯中空纤维膜器,在氨化ＨＥＨ／ＥＨＰ煤油体系中对钕、钐的萃取及传质性能进行了研究。结果表明,无论萃取剂氨化与否,膜器中的萃取反应均可视为准一级反应;探讨了氨化ＨＥＨ／ＥＨＰ对膜阻的影响及其在膜萃取过程和同级萃取反萃中,稀土离子、氢离子及氨离子的交换规律     

Preparation and Ionic Conductivity of Ultrafine Li2+xRExSi1-xO3 by Sol-Gel Method

Ｒｅｃｅｎｔｌｙ ,ｓｔｕｄｉｅｓｏｎｌｉｔｈｉｕｍｉｏｎｃｏｎｄｕｃｔ ｉｎｇｓｏｌｉｄｅｌｅｃｔｒｏｌｙｔｅｓｈａｖｅｂｅｅｎｏｆｍｕｃｈｉｎｔｅｒ ｅｓｔｂｅｃａｕｓｅｏｆｉｔｓｌｉｇｈｔｗｅｉｇｈｔａｎｄｌｏｗｅｌｅｃｔｒｏｄｅｐｏｔｅｎｔｉａｌ.Ｌｉ2 ＳｉＯ3ｃａｎｂｅｕｓｅｄａｓａｎｉｄｅａｌｂａ ｓｉｃｍａｔｅｒｉａｌｏｆｆａｓｔｉｏｎｃｏｎｄｕｃｔｏｒｏｗｉｎｇｔｏｉｔｓｓｔｒｕｃｔｕｒｅｃｈａｒａｃｔｅｒ[1 ] .Ｓｉｎｃｅ 1 970ｓ,ｓｏｌ ｇｅｌｍｅｔｈｏｄｈａｓｂｅｃｏｍｅａｐｒｅｐａ…     

Study on Transfer and Interfacial Kinetics of Neodymium and Samarium in Membrane Based Extraction

Ｔｈｅｅｘｔｒａｃｔｉｏｎｔｅｃｈｎｏｌｏｇｙｏｆｈｏｌｌｏｗｆｉｂｂｅｒｍｅｍｂｒａｎｅ (ＨＦＭ ) ,ｗｈｉｃｈｗａｓｄｅｖｅｌｏｐｅｄｉｎｅａｒｌｙ 1 980ｓ ,ｉｓａｎｅｗｋｉｎｄｏｆｓｅｐａｒａｔｉｏｎｍｅｔｈｏｄｃｏｍｂｉｎｅｄｐｒｏｃｅｓｓｅｓｏｆｌｉｑｕｉｄ -ｌｉｑｕｉｄａｎｄｍｅｍｂｒａｎｅｅｘｔｒａｃｔｉｏｎ .Ｔｈｉｓｍｅｔｈｏｄｃａｎｏｆ ｆｅｒｓｅｖｅｒａｌａｄｖａｎｔａｇｅｓｃｏｍｐａｒｅｄｗｉｔｈｃｏｎｖｅｎ ｔｉｏｎａｌｅｘｔｒａｃｔｏｒｓ[1～ 2 ] .Ｉｔｃａｎａｌｓｏｐｒｏｖ…     

Synthesis, Characterization and Vulcanizing Properties of Rare Earth Complexes with 2-Mercaptobenthiazole

2 ｍｅｒｃａｐｔｏｂｅｎｚｏｔｈｉａｚｏｌｅｗａｓｆｉｒｓｔｒｅｐｏｒｔｅｄｂｙＨｏｆｍａｎｎ[1 ] ｉｎ 1 887.Ｉｔｈａｓｂｅｅｎｕｓｅｄａｓａｎａｃｃｅｌｅｒａｔｏｒｉｎｔｈｅｖｕｌｃａｎｉｚａｔｉｏｎｏｆｒｕｂｂｅｒｆｏｒｍａｎｙｙｅａｒｓ .Ｔｏｄａｙｉｔｉｓｓｔｉｌｌｂｅｉｎｇｕｓｅｄａｓａｍａｉｎａｃｉｄｉｃａｃｃｅｌｅｒａｔｏｒｉｎｒｕｂｂｅｒｉｎｄｕｓｔｒｙ .Ｂｕｔｉｔｈａｓｄｉｓａｄｖａｎｔａｇｅｓｏｆｖｕｌｃａｎｉｚａｔｉｏｎｒｅｖｅｒｓｉｏｎａｎｄｅａｓｙｓｃｏｒｃｈ[2 ] ｗｈｅ…     

Synthesis, Catalysis of Rare Earth Complexes with Aliphatic Noncyclic Polyether-Amino Acid Schiff Base

Coordination chemistry of rare earth with Schiffbase has developed rapidly in the last fewyears ,butthe majority of the complexes studied are derivedfromaromatic Schiff base .So far less papers of rare earthcomplex with aliphatic Schiff base have been rep…     

Study on separation of rare earth elements in complex system

The effect of the feed acidity,acetic acid concentration and rare earth concentration on the distribution ratio,separation coefficient and extraction capacity of light rare earth elements were studied in the P204(DEHPA)-HCl system and P507(HEH/EHP)-HCl system both containing acetic acid,respectively. The results showed that the distribution ratio and separation coefficient decreased with increasing of acidity,and increased with increasing of acetic acid concentration and rare earths concentration,and the extraction capacity increased with increasing of acetic acid concentration. When pH value of feed was 2.0,[RE]/[acetic acid] was 1:1 and rare earth concentration 0.35 mol/L,in P204(DEHPA) -HCl system with acetic acid,the maximum separation coefficient(β) reached to βCe /La=4.09,βPr/Ce=1.96 and βNd/Pr=1.53,and the separation ability of this extraction system was better than P507(DEHPA)-HCl system.     

Synthesis, Characterization of α-Oxopentanedioic Acid-Isonicotinoyl Hydrazone Rare Earth-Complexes and Relaxivity of Gd-complex

Themagneticresonanceimaging (MRI)tech niqueforthemedicineisveryusefultodiagnosepre tumorandbloodvesseldiseaseinheartandbrainandothermalignantpre diseases .Therefore ,specialatten tionhasbeenalsopaidtoMRIcontrastagents ,whichareindispensablediagnosingdrugsforthemagneticresonanceimagingtechnique[1,2 ] .Gadolinium (Ⅲ)complexwithsomepolycarboxylicandpolyaminelig ands ,suchasGd(DTPA)·nH2 O ,waswidelyusedincliniclongago .OurpreviousworkshowsthatsomepolycarboxylicSchiffbasecomplexeswithrareea…     

Synthesis and Thermal Decomposition Mechanism of Rare Earth Benzoates

Rareearthbenzoatesareakind0fstablecompounds.Theco0rdinationcomP0undsf0rmedbyrareearthandcarboxylicacidshaveunusualstructuresandinterestinglundnesceniProperties.Bymeansoff0rmingc0njugaedcomplexes,rareearthmetalsandcarb0xylicacidscanf0rmnetorlayerp0lymerandchangetheirlundnescentprop-erties.S0merareearthcomplexeshavebeenap-Pliedinagricultureaslight-transfeedngmaeri-al8-Althoughthermaldecompositi0nmechanismofrareearthbenz0ateshasbeenreported,itdealswith0nlys0lidphaseproducts["'1,litdeab0utgasPha…     

Oxidative dehydrogenation of ethane over RE-NiO （RE=La, Nd, Sm, Gd） catalysts

RE-NiO(RE=La,Nd,Sm,Gd) catalysts were prepared by a modified sol-gel method and characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),BET surface area analysis,H 2 temperature-programmed reduction(H 2-TPR),and O 2 temperature-programmed desorption(O 2-TPD).The oxidative dehydrogenation of ethane(ODHE) to ethylene was applied to evaluate catalytic performance of the samples.The results showed that the doping of RE affected the physicochemical properties of the catalysts.The strong interaction between Gd and NiO played an important role in the lessened reducibility and the distribution of adsorbed oxygen species,consequently influenced the catalytic performance.The best yield to ethylene of 29% was obtained over the Gd-NiO catalyst with an ethane conversion of 56%.     

Synthesis and Characterization of Rare Earth Complexes of Ferrocenylcarbonylhydrazine

Ｔｈｅｍｅｔａｌｃｏｍｐｌｅｘｅｓｏｆｈｙｄｒａｚｉｄｅｓｈａｖｅａｔｔｒａｃｔｅｄｃｏｎｓｉｄｅｒａｂｌｅｉｎｔｅｒｅｓｔｏｗｉｎｇｔｏｔｈｅｉｒａｎｔｉｆｕｎｇａｌａｎｄａｎｔｉｂａｃｔｅｒｉａｌａｃｔｉｖｉｔｉｅｓ[1 ,2 ] .Ｔｈｅｙｃａｎａｌｓｏｂｅｕｓｅｄａｓａｎａｌｙｔｉｃａｌｒｅａｇｅｎｔｓ[3 ]ａｎｄｅｘｔｒａｃｔｉｎｇａｇｅｎｔｓｆｏｒｍｅｔａｌｓａｌｔｓ[4 ] .Ｍａｎｙｃｏｍｐｌｅｘｅｓｏｆｈｙｄｒａｚｉｄｅｓｈａｖｅｂｅｅｎｓｙｎｔｈｅｓｉｚｅｄａｎｄｃｈａｒａｃｔｅｒｉｚｅｄ[5]…     

Complexation of N＇- [1-（3-aminophenyl）ethylidine] isonicotinohydrazide with La3＋, Pr3＋, Nd3＋, Sm3＋, Eu3＋ and Gd3＋ ions and associated thermodynamics

A novel Schiff base N′-[1-(3-aminophenyl)ethylidine]isonicotinohydrazide was prepared and its complexation behavior towards some selected lanthanides had been studied employing pH-metric and calorimetric titration and spectral techniques. pH-metric studies were carried out for the trivalent La, Pr, Nd, Sm, Eu, and Gd complexes in 30% aqueous-dioxane medium at constant ionic strength of 0.05 mol/L NaClO4 and at different temperatures of 293, 303 and 313 K. The proton-ligand formation constants of the ligand indicated the presence of only one dissociable proton while the metal-ligand formation constants were compatible with the formation of 1:1 Ln(Ⅲ) complexes. The sta-bility of the complexes followed the order: La3+Gd3+, showing a break at gadolinium. The thermodynamic parame-ters, ΔG, ΔH and ΔS associated with protonation and complexation reactions were negative which suggested that all reactions were exother-mic and enthalpy-driven. Isothermal calorimetric studies of Gd3+-aeINH systems at 303 K also showed exothermic nature of the complexation reaction and formation of 1:1 complex in agreement with the pH-metric data. Formation of 1:1 complexes was confirmed by the characteriza-tion of Nd(Ⅲ) complex. A seven coordinated geometry was assigned for the complex based on its elemental and spectral data.     

Study on Anticoagulation Factor I from Agkistrodon Acutus Venom by Rare Earth Ion Probes

Ｓｎａｋｅｖｅｎｏｍｓｃｏｎｔａｉｎｃｏｍｐｌｅｘｐｒｏｔｅｉｎｓｗｈｉｃｈｐｏｓｓｅｓｓｖａｒｉｏｕｓｂｉｏｌｏｇｉｃａｌａｃｔｉｖｉｔｉｅｓ ,ｉｎ ｃｌｕｄｉｎｇａｃｌａｓｓｔｈａｔａｆｆｅｃｔｓｃｏａｇｕｌａｔｉｏｎｓｙｓｔｅｍｗｉｔｈｃｏａｇｕｌａｎｔｏｒａｎｔｉｃｏａｇｕｌａｎｔａｃｔｉｖｉｔｉｅｓ .Ａｎａｎｔｉｃｏａｇｕｌａｎｔｆａｃｔｏｒ (ＡＣＦ)ｗａｓｐｒｅｖｉｏｕｓｌｙｉｓｏ ｌａｔｅｄｆｒｏｍｔｈｅｖｅｎｏｍｏｆＡｇｋｉｓｔｒｏｄｏｎａｃｕｔｕｓｆｒｏｍｓｏｕｔｈｅｒｎＡｎｈｕ…     

La0.65RE0.10Mg0.25Ni3.5Si0.15(RE=La,Ce,Pr,Nd,Sm)储氢合金的电化学性能及EIS分析

通过感应熔炼制备La0.65RE0.10Mg0.25Ni3.55i0.15(RE =La,Ce,Pr,Nd,Sm)合金.采用X射线衍射方法分析了合金的相结构,研究了其电化学性能,并采用电化学阻抗谱分析了合金电极的放氢动力学特性.研究结果表明,合金是以LaNi5、LaNi3为主相的多相结构,同时合金中少量的Si元素与Mg和Ni元素形成了少量的Mg2 Si相和Ni2Si相.Ce,Pr,Nd,Sm部分替代La以后,合金的放电容量下降,Ce的替代使合金容量大幅度降低.对于本系列合金,La被其他稀土元素部分替代后,合金经过100次循环后的容量保持率略有下降,但除了Pr元素以外,变化值均较小.合金电极的电化学阻抗谱分析表明,中低频区的容抗弧半径依次为Ce ＞La＞ Nd ＞Sm ＞Pr,这表明采用Nd、Sm、Pr替代La后合金电极在碱液中放电过程电荷传递电阻Rct减小,即合金表面活性增加,但Ce替代却导致Ret急剧增大,这可能与Ce在碱液中易形成氧化物降低了合金的表面活性有关.     

Preparation，Structural Characterization and Thermal Decomposition Mechanism of Rare Earth Salts of 3－Nitro－1，2，4－Triazol－5－One

Ｐｒｅｐａｒａｔｉｏｎ，ＳｔｒｕｃｔｕｒａｌＣｈａｒａｃｔｅｒｉｚａｔｉｏｎａｎｄＴｈｅｒｍａｌＤｅｃｏｍｐｏｓｉｔｉｏｎＭｅｃｈａｎｉｓｍｏｆＲａｒｅＥａｒｔｈＳａｌｔｓｏｆ３－Ｎｉｔｒｏ－１，２，４－Ｔｒｉａｚｏｌ－５－ＯｎｅＺｈａｎｇＴｏｎｇｌ...