Effects of Polar Organic Solvent on Separation of Y （edta）^-／Nd （edta）^- Complexes on Polyacrylic Anion Exchangers

The use of polar organic solvents for the separations of rare earth elements ( Ⅲ ) is effective especially for their extensive separations despite the solubility limitations.The study shows that polyaerylate anion exchangers, particularly the weakly basic, gel anion exchanger Ambedite IRA 68,can be applied to the separation of rare earth complexes with EDTA in H20-metthanol and H20-ethanol systems.In most cases the determined distribution coefficients of Ln^3 complexes with EDTA in mixed media like water-methanol on polyacrylate anion exchangers are larger than those in pure water media.     

Investigation on the Use of the Weakly Basic Polyacrylate AnionExchanger Amberlite IRA-68 for Sorption and Separation of Iminodiacetate Complexes of Rare Earth Elements

Based on the determined affinity series of rare earth element complexes with IMDA for the anion-exchangers, purification of macroquantities of Nd^3 from Y^3 , Sm^3 from Ho^3 , La^3 from Nd^3 and La^3 from Pr^3 on the weakly basic gel anion-exchanger Amberlite IRA-68 was studied. Using the presented method on 1 L of Amberlite IRA-68 in the acetate form, it is possible to obtain about 240 g Nd2O3 purified from Y2O3. Great difference in affinity of La^3 and Nd^3 as well as Pr^3 complexes for this anion-exchanger in the acetate form indicates the possibility of applying this process for purification of lanthanum on the increased scale. On 1 L of Amberihe IRA-68 in the acetate form it is possible to obtain about 1125 g La2O3 purified from Nd2O3. On the basis of these results it can be assumed that unique properties of polyacrylate anion-exchangers enable their application for separation of rare earth elements.     

Application of monodispersive anion exchangers in sorption and separation of y3+ from Nd3+ and Sm3+ complexes with dcta

Rare earth complexes with trans-1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid (DCTA) of the Ln(dcta)- ype exhibited an unusual sequence of affinity on the polystyrene anion exchangers: pm3 >Nd3 >Sm3 >pr3 >Ce3 >Eu3 >Gd3 >La3 >Sc3 >Tb3 >Dy3 >Ho3 >y3 >Er3 >Tm3 >yb3 >Lu3 [1]. Taking into account the position of Y3 , Sm3 , and Nd3 in this affinity series, for the monodispersive polystyrene anion exchangers, Lewafit MonoPlus M 500, Lewatit MonoPlus M 600, Lewatit MonoPlus MP 500, Lewatit MonoPlus MP 64,and for the heterodispersive anion exchanger, Lewatit MP 62, the weight (Dg,) and bed (Dv) distribution coefficients of these complexes and working ion exchange capacities (Cw) were determined. Based on these values, purifications of Y3 from Nd3 and y3 from Sm3 in the macro-micro component system on these anion exchangers were studied. The application potential of this method was highlighted for the separation of yz3 in the presence of Nd3 and Sm3 . With 1 L of monodispersive and strongly basic polystyrene gel anion exchanger Lewatit MonoPlus M 500 in the acetate form, it is possible to obtain approximately 79 g Y2O3 purified from Nd2O3 and 70 g Y2O3 purified from Sm2O3 in the same process condition.     

Study on Separation of Lanthanum from Praseodymium Complexes with IMDA by Gel and Macroporous Anion Exchangers

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2,3,5-吡啶三酸与重稀土配合物的合成、表征及光致发光性质

采用水做溶剂,用2,3,5-吡啶三酸做配体和重稀土铽、镝、铒、镱、镥、钇六种稀土元素的氯化物在常温下反应合成了六种重稀土的配合物。通过EDTA络合滴定分析,确定了六种配合物中稀土离子含量;并对配合物进行了熔点测定、红外光谱测试,并测试了铽和镝配合物的光致发光性质,结果表明,铽和镝配合物在紫外光的激发下具有良好的发光性质。     

Studies of sorption and separation processes of rare earth element complexes on the anion-exchanger Wofatit SBW in the CH3OH–HNO3 system

For the 90% v/v CH₃OH–10% v/v 7 M HNO₃ system the affinity series of nitrate complexes of rare earth elements(III) for the strongly basic anion-exchanger Wofatit SBW×4% DVB was determined. The effect of ammonium nitrate and polar organic solvent addition on the effectiveness of separation of the ion-exchanging pair Y(III)–Nd(III) on Wofatit SBW×4% DVB as well as that of macrocomponent (yttrium) concentration on the yield of the purification process on Wofatit SBW×6% DVB were investigated. The weight and bed distribution coefficients for individual rare earth elements(III) were determined. It was shown that the neodymium content in the purified yttrium(III) can be decreased from 1% to 10⁻³% under controlled conditions.     

On the extraction of various base metal chlorides from polar organic solvents into cation and anion exchange resins

Equilibrium loading isotherms for the extraction of various metal chlorides from polar organic solvents and organic/aqueous solvent mixtures by the anion exchanger, Amberlite IRA 400, and the cation exchanger, Zerolit 225, are presented. The metals studied are copper(II), cobalt(II), nickel(II), iron(II), zinc(II), lead(II) and iron(III), and the solvents are acetonitrile, propylene carbonate, sulpholane, dimethylsulphoxide, dimethylformamide and dimethylacetamide. It is shown that the selectivity of the resins for the various metal ions may be explained on the basis of the chloro-complex stability of the metals and the solvating power of the solvents. Enhanced distribution coefficients and separation factors may be obtained in mixed water/organic systems.     

Chemical precipitation of copper from copper–zinc solutions onto selective sorbents

The selective sorption and multiple concentration of copper in the form of an ultradisperse precipitate from a diluted Cu²⁺–Zn²⁺-solution has been investigated. The selective sorption is accomplished by means of weakly basic anion exchangers in their free base forms. Regeneration of the sorbent and conversion of Cu²⁺ to Cu⁰ is carried out by means of a chemical reduction in the resin phase. Thus the resins can be reused for sorption of further copper ions. The process has been investigated in both, batch and packed bed experiments. After multiple saturation–reduction cycles an accumulation of metallic copper on the surface and in the pores of the sorbent is observed. The presence of finely dispersed metallic copper leads to the additional sorption of the Cu²⁺ ions due to a synproportional reduction–oxidation reaction. The total uptake of copper after several cycles amounts to more than 300 % of the anion exchange capacity.     

钙沉淀-EDTA返滴定法测定稀土分离废液中草酸

采用过量加入钙标准溶液以沉淀稀土分离废液中草酸,过滤后,再以EDTA返滴定的方法测定了废液中草酸的含量。在样品溶液中加入400 g/L NaOH溶液调pH值至7.0～10.0,再加入10 mL NH₃-NH₄Cl缓冲溶液(pH 10.0),然后过量加入钙标准溶液沉淀废液中草酸,滤液再以NaOH溶液调pH值至12.0～12.5,铬蓝黑R为指示剂,用EDTA标准溶液返滴定过量钙。废液中大部分RE³⁺、Fe³⁺、Al³⁺等杂质离子在高pH值下可形成氢氧化物沉淀而得以分离,滤液中残余的Fe³⁺、Al³⁺用三乙醇胺等络合剂可消除其对铬蓝黑R指示剂的干扰。采用方法测定稀土分离废液合成样品中草酸的含量,结果与参考值一致。将方法应用于稀土分离废液实际样品中草酸的测定,测得结果相对标准偏差(RSD,n=6)为0.98%～1.9%,回收率为99%～101%。     

纳滤膜对稀土离子的动态吸附行为及截留特性

采用经碳纳米管改性的亲水化纳滤膜浓缩提取稀土浸出液中的稀土离子,探究纳滤膜表面对La3+、Nd3+、Pr3+、Ce3+和Y3+5种稀土离子吸附动力学行为,考察稀土离子半径的大小对纳滤膜吸附性能和截留性能的影响.结果表明,Freundlich吸附方程比Langmuir方程能更好地描述稀土离子在纳滤膜表面上的动态吸附行为,用Freundlich吸附方程拟合后的结果相关度系数R2能达到0.999以上;在初始浓度为5×105 μg/L,温度为25 ℃,运行压力为0.6 MPa的实验条件下,纳滤膜对稀土离子的浓缩提取过程中,初始阶段的截留机理取决于纳滤膜表面的吸附作用和膜孔的机械筛分效应,膜面吸附达到平衡后以膜孔的机械筛分效应为主,此时La3+、Nd3+、Pr3+、Ce3+和Y3+的截留率分别为94.21 %、81.25 %、85.80 %、89.90 %和81.18 %,表明经碳纳米管改性的亲水化纳滤膜能高效浓缩截留稀土浸出液中的稀土离子.      

Adsorption of Ce（ Ⅳ ） Anionic Nitrato Complexes onto Anion Exchangers and Its Application for Ce （Ⅳ） Separation from Rare Earths （ Ⅲ ）

Ceriumis one of the cheapest[1]and most abun-dant rare earths (RE) .However ,high purityis usual-ly required for its utilization in industry , where it isusedfor sulfur control insteels ,pyrophoric alloys ,ce-ramic ,catalyst support ,polishing powders ,etc .In its minerals ,as well as in the spent nuclearfuel ,ceriumis accompanied by other RE.They basi-cally exist in solution as stable RE(Ⅲ) species ,which makes their mutual separation rather difficult .In contrast to other RE, Ce(Ⅲ) can…     

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…     

Process of Extraction of Gallium from Technological Solutions with the Use of Ion Exchange Resins

Metallurgist - D-403 weakly basic anion exchange resin is used for the sorption extraction of gallium in the form of hydroxo complexes from alkaline aluminate solutions. The thermodynamic...     

稀土(Ⅲ)硝酸盐与香兰素缩己二胺配合物的合成与性质

在非水体系中合成了稀土（Ⅲ）硝酸盐（Ｌａ、Ｎｄ、Ｅｒ、Ｙ）与双希夫碱香兰素（４－羟基－３－甲氧基苯甲醛）缩己二胺的固体配合物,用元素分析、摩尔电导、红外光谱、紫外光谱、差热－热重分析等手段研究其组成和性质。     

氮,氮,氮′,氮′-四辛基-3-氧戊二酰胺色谱柱分离-电感耦合等离子体质谱法测定混合稀土氧化物中重稀土

电感耦合等离子体质谱法(ICP-MS)测定稀土元素时,轻稀土元素Ce、Nd、Sm的氧化物等复合离子严重干扰重稀土元素Tb、Dy、Ho、Er的测定,因此对混合稀土中重稀土元素进行测定前一般需要先对其分离富集。实验在样品溶解后,将N,N,N′,N′-四辛基-3-氧戊二酰胺(TODGA)用硅藻土吸附后装柱,以0.1 mol/L HNO₃为样品溶液介质上柱,通过控制洗脱液的种类、酸度以及洗脱液流速,实现了轻稀土元素La、Ce、Pr、Nd与重稀土元素Tb、Dy、Ho、Er、Tm、Yb、Lu的分离和富集,建立了ICP-MS测定混合稀土氧化物中重稀土元素的方法。实验表明:控制洗脱流速为2.0 mL/min,用pH 2.0的HNO₃淋洗至淋洗体积约为500 mL,继续收集洗脱液,并用ICP-MS检测其中Nd₂O₃含量,直至洗脱液中Nd₂O₃的质量浓度小于200 ng/mL,可将轻稀土元素La、Ce、Pr、Nd及少量Y、Sm、Gd洗脱;再改用350 mL 1 mol/L HCl洗脱重稀土元素,可实现重稀土元素与La、Ce、Pr、Nd及部分Y、Sm、Gd的分离;通过选择¹⁵⁹Tb、¹⁶³Dy、¹⁶⁵Ho、¹⁶⁷Er、¹⁶⁹Tm、¹⁷²Yb、¹⁷⁵Lu为测定同位素可消除质谱干扰。将实验方法应用于混合稀土氧化物中重稀土元素的测定,加标回收率在93%～110%之间,相对标准偏差(RSD,n=8)在1.1%～10%之间。     

织金含稀土磷矿酸法浸出性能及预处理优化工艺试验

硫酸、盐酸、磷酸和硝酸对原生织金磷矿的稀土组分浸出效率不理想,总稀土浸出效率不到36%。采用焙烧活化—硝酸氨水混合预浸出处理织金磷矿,最适宜条件下,CaO和MgO的浸出率分别为24.55%和19.75%,相应的P_2O_5和稀土元素(Y、La、Nd、Ce)损失率为11.25%和3.61%。所得精矿中,Y、La、Nd、Ce和P_2O_5实现了不同程度的富集。预处理精矿的浸出性能较原矿显著改善,硝酸体系下P_2O_5和稀土元素(Y、La、Nd、Ce)浸出效率提高了近40个百分点。     

稀土硝酸盐与希夫碱邻香兰素缩丙氨酸盐及邻菲咯啉三元配合物的合成与表征

合成了稀土硝酸盐与希夫碱邻香兰素缩丙氨酸盐(以KHL表示)及邻菲咯啉的三种固体三元配合物。通过元素分析、差热-热重、红外光谱、紫外光谱及摩尔电导分析等手段,确定配合物的组成为［RE(L)(Phen)(H2O)］NO3,(RE=Y,Nd,Sm)。并对它们的配位方式及某些性质进行了研究。     

Purification of nickel sulfate using chelating ion exchangers and weak-base anion exchangers

Different types of chelating ion exchangers and weak-base anion exchangers were used in nickel sulfate purification from mixtures with Cu(II), Zn(H), Mn(II), Fe(III) by frontal analysis. Of the ion exchangers examined, the most suitable for selective separation of Cu(II) from NiSO, proved to be the amidoxine ion exchanger — Duolite ES-346, the polyethylenimine exchanger — Diaion CR-40, the macroreticular ion exchanger of the amino-acid type — Lewatit TP-207, and the polyfunctional weak-base anion exchanger — Merck II. Nickel sulfate is easily purified from Fe(III) on the amidoxine ion exchanger Duolite ES-346. The phosphonic ion exchanger Duolite ES-63 proved to be the most effective in Zn(H), Mn(II) and also FeIIII) separation. An amount of 10 kg of NiSO, was purified on 11 of this exchanger (in one run) under the optimal conditions, decreasing the content of copper and iron to < 0.0001%,, and zinc and manganese to < 0.001%.     

Extraction of rare earth elements from their oxides using organophosphorus reagent complexes with HNO3 and H2O in supercritical CO2

Direct extraction of metals from solids with complexing agents in supercritical CO2(SC-CO2) has recently attracted interests in separation,purification,recovery,and analysis of metals.In the present study,the static/dynamic extraction of rare earth elements(Nd,Ce) from their oxides(Nd2O3,CeO2) with organophosphorus complexes with HNO3 and H2O in SC-CO2 was investigated.The static extraction efficiency of Nd from Nd2O3 with the tri-n-butylphosphate(TBP)-HNO3 complex could reach 95% under optimized experiment...     

Effects of rare earth oxides on dielectric properties of Y2Ti2O7 series ceramics

A series of Y2Ti2O7 microwave dielectric ceramics were synthesized by conventional solid-state method. The effects of rare earth oxide (La2O3, CeO2, Nd2O3, Sm2O3, Eu2O3, Gd2O3 and Dy2O3) and Nd2O3 doping content on the microstructure and dielectric properties of Y2Ti2O7 ceramics were investigated. The experimental results showed that the rare earth ions were considered to dissolve in Y-sites of the pyrochlore structure, different rare earth oxides and concentration had different influences on Y2Ti2O7 cerami...