Separation of Red (Y_2O_3:Eu^(3+)), Blue (BaMgAl_(10)O_(17):Eu^(2+)) and Green (CeMgAl_(10)O_(17):Tb^3) Rare Earth Phosphors by Liquid/Liquid Extraction

A novel process for separation of red （Y2O3：Eu^3＋）, blue（BaMgAl10O17：Eu^2＋） and green （CeMgAl10O17：Tb^3） rare earth fluorescent powders was proposed. At first, the blue powder can be extracted selectively from an aqueous solution using a chelating collector 2-thenoyltrifluoroacetone （TTA） dissolved in heptane at alkaline pH condition, then, chloroform was used for extracting the green powder into organic phase. The red phosphor remains in aqueous phase with potassium sodium tartrate depressant （PST）. Therefore, three phosphors can be separated successfully from their artificial mixtures by liquid/liquid extraction, and grades and recovery of separated products reach respectively as follows： red is 96.9% and 95.2%, blue is 82.7% and 98.8%, green is 94.6% and 82.6%.

Separation of Red (Y_2O_3: Eu^(3+)), Blue (Sr,Ca,Ba)_(10)(PO_4)_6Cl_2: Eu^(2+) and Green (LaPO_4:Tb^(3+),Ce^(3+)) Rare Earth Phosphors by Liquid/Liquid Extraction

A novel process for separation of red （Y2O3： Eu^3＋）, blue （Sr, Ca, Ba）10（PO4）6Cl2： Eu^2＋ and green （LaPO4： Tb^3＋, Ce^3＋） fine tricolor phosphor powders was established. First, the green phosphor was extracted and separated from three phosphor mixtures in heptane/DMF（N, N-Dimethylformamide） system using stearylamine or laurylamine （DDA） as the cationic surfactant. Then, after being treated with 99.5% ethanol, the blue and red phosphors could be separated in Heptane/DMF system in presence of 1-octanesulfonic acid sodium salt as the anionic surfactant. Satisfactory separation results have been achieved through two steps extractions with their artificial mixtures. The grades and recovery of separated products reached respectively as follows： red product was 95.3% and 90.9%, blue product was 90.0% and 95.2%, and green product was 92.2% and 91.8%.

Extraction Behavior of Rare Earths with 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5 Using Solid-liquid Extraction Technique

The extraction behavior of rare earths was studied by using paraffin with ceresin as a diluent containing 1-phenyl-3-methyl-4-benzoyl-pyrazolone-5.In solid phase,the composition of complexes is REP_3.The equilib- rium extraction constants and pH_(1/2) values of solid-liquid extraction are higher than those of normal liquid-liquid extraction.The extraction efficiency tends to maximum when the ratio of phases is 1:1.When the extraction temperature is higher than the melting point of paraffin and the extraction time is over 10 min,the extraction efficiency keeps constant.Moreover,the relationship among separation factor,equilibrium extrac- tion constant,pH_(1/2) value and atomic number was obtained.The mechanism of solid-liquid extraction is analogous to that of liquid-liquid extraction.

Solvent impregnated resin prepared using task-specific ionic liquids for rare earth separation

A novel bifunctional task-specific ionic liquid(TSIL),i.e.[trialkylmethylammonium][sec-nonylphenoxy acetate]([A336] [CA-100]) was impregnated on intermediate polarized XAD-7 resin,and the prepared solvent impreganated resin(SIR) was studied for rare earth(RE) separation.Adsorption ability of the SIR was indicated to be obviously higher than that prepared by [A336][NO3] because of the functional anion of [A336][CA-100].Adsorption kinetics,adsorption isotherm,separation and desorption of the SIR were also stu...

Progress in the extraction and separation of rare earths and related metals with novel extractants: A review

Rare earths(REs) play a key role in high-tech fields and the associated thorium is a vital element for nuclear energy. However, to be used in high-tech industry or nuclear energy, these elements must first be recovered from the deposits and purified. As solvent extraction is the main technology for the recovery and purification of the metals, the review mainly presents our recent works on the extraction and separation of tetravalent cerium cation by neutral α-aminophosphonates, the individual rare earth separation by α-aminophosphonic acids, and the continuous preparation of high-purity thorium. The extraction and separation of some other metals are also discussed.

Extraction behavior of bifunctional ionic liquid [N_(1888)][SOPAA] and TBP for rare earth elements

Extraction and separation of yttrium in chloride medium using tri-n-octylmethylammonium（2-sec-octylphenoxy） acetate（[N（1888）][SOPAA]） as an extractant were studied in this article. Tri-n-butyl phosphate（TBP） was used as a phase modifier to accelerate phase separation and improve the stability of organic phase. The addition of TBP contributed to shortening phase separation time, increasing extraction capacity of rare earth elements（REEs） and decreasing viscosity of organic phase. The slope analysis method and infrared spectroscopy were conducted to investigate the ion-association extraction mechanisms. Extraction and stripping performances of the different systems were also compared. The article showed that the extraction performance of mixed [N（1888）][SOPAA] and TBP is superior to that of [N（1888）][SOPAA] for heavy rare earth element（HREE）.

Synthesis of 2, 6 Bis(1′-Phenyl- 3′- Methyl-5′-Oxopyrazole- 4′) Pyridinediacyl and Its Solid Liquid Extraction Behavior for Ce(Ⅲ)

diketone type chelating ligands have high coordinative activity and selectivity, and are widely applied in analytical chemistry. In order to obtain profounder understanding to the properties of bis(4 acylpyrazolone 5), A new 4 acylpyrazol 5 one derivative (H 2BPMPP) was syntheszed, which contains a heterocyclic ring between two 1 phenyl 3 methyl 4 acylpyrazol 5 one rings. The new compound was characterized by element analyses, UV, IR and 1H NMR spectra. The equilibrium of the keto enol tautomerism was studied. The results show that a lower dielectric constant of solvent favors the enol form which has a higher λ max . Due to special merits of paraffin wax, the solid liquid extraction behavior of Ce(Ⅲ) with molten paraffin wax as a diluent was also investigated at higher temperature. The value of the pH 1/2 was 3.19 and the value of log K ex was 3.467. The chemical composition of the complex was obtained by the slope analysis method.

Extraction and recovery of cerium(Ⅳ) and thorium(Ⅳ) from sulphate medium by an α-aminophosphonate extractant

In the present work, a novel α-aminophosphonate extractant（Cextrant 230） was synthesized for the extraction and recovery of cerium and thorium from sulphate medium. The introduction of amine group into the phosphate molecule would enhance the extraction of Ce（Ⅳ） and Th（Ⅳ）. The effects of extractant concentration, H2SO4 concentration and temperature on the metal extraction were investigated in detail. It was found that the extraction of Ce（Ⅳ）, Th（Ⅳ） and REs（La, Gd, Yb） in sulphate medium decreased in the following order： Ce（Ⅳ）〉Th（Ⅳ）〉REs（Ⅲ）. A solvent extraction process to extract and recover cerium and thorium from bastnasite leaching was proposed, in which the purities of cerium and thorium products reached 99.9% and 99% with yield of 92% and 98%, respectively.

乳状液膜技术从稀土浸出液中提取钍的试验研究

采用煤油-Span80-P507-HC l组成的液膜体系,研究了自稀土浸出液中提取钍的基本原理,考查了制乳条件、油内比、水乳比、pH值和提取时间等因素的影响。

离子液体在稀土萃取分离中的应用

稀土元素萃取分离是获得高纯单一稀土的关键步骤之一,开发对稀土元素具有高效分离能力的新材料和新过程是全球科技工作者研究的热点。离子液体作为一类代表性的新材料,因具有不挥发、不易燃、稳定性好、结构性质可调等独特的物理化学性质,近年来在稀土元素萃取分离领域的应用受到广泛关注。在稀土元素萃取分离过程中,离子液体不仅可用作萃取剂,也可作为稀释剂、协萃剂或同时作为萃取剂和稀释剂。系统评述了离子液体在稀土元素萃取分离中的研究进展,对非功能化离子液体和功能化离子液体在稀土元素萃取分离中的萃取行为和萃取机理进行了分析。同时,对该领域的发展所面临的主要问题和进一步的研究工作进行了探讨。

钍与稀土的固-液萃取分离研究及应用

以切片石蜡为溶剂，ＴＢＰ为萃取剂，在ＮＨ４ＳＣＮＨＮＯ３介质中考察了高温下钍与稀土的萃取行为。斜率比法表明钍萃合物的组成为Ｔｈ（ＳＣＮ）４·２ＴＢＰ，测出了钍萃取反应平衡常数及热力学参数。研究了钍与稀土相互分离的条件。用于矿样中钍与稀土分离获得了满意的结果。

PMBP为载体的乳状液膜提取钪的研究

研究了以１－苯基－３－甲基－４－苯甲酰基吡唑酮－５（ＰＭＢＰ）为流动载体的乳状液膜（ＥＬＭ）法提取钪，确定最佳液膜体系组成为０．４％ＰＭＢＰ－３％Ｓｐａｎ８０－５％液体石蜡－煤油－３ｍｏｌ／ＬＨＣｌ，Ｒｏｉ＝１：１（油内比）．Ｒｗｅ（水乳比）可达２０：１．用该体系对钪与混合稀土进行分离，钪的回收率可达９５．５％，分离系数β（ＳＣ／ＲＥ）＝３２．０。

微晶萘固态萃取分离稀土及其在分析中的应用

报道了以微晶萘作吸附载体，固态萃取分离痕量稀土元素的新方法。在pH5.8～8．6和7．2～8．6时，Sc(3+)和Y(3+)，La(3+)，Eu(3+)，Yb(3+)，Lu(3+)与8-羟基喹啉（oxine）形成的金属螯合物，可被微晶萘固态选择萃取。对影响固态萃取的各种因素进行了考察与优化，发现加入适量的Co(2+)可有效地富集ng·ml(－1)级甚至更低浓度级的稀土元素。当富集倍数为50时，本法测定上述元素的检出限达0．04～0．32ng·ml(－1)，平均相对标准偏差为1．86％～3．78％。

稀土萃取分离工艺的改进与废水循环利用研究

通过采用有机相连续皂化技术、洗液和反萃液合并技术及一系列节能减排措施,优化改进了稀土萃取分离工艺,降低了能耗、物耗、新水使用量及废水处理成本,使废水循环利用率达到95%,不仅达到了清洁生产的目的,也增加了企业的经济效益。

固—液萃取分离测定球墨铸铁中的稀土元素

以切片石蜡为溶剂；铜试剂为萃取剂，用固—液萃取技术分离测定球墨铸铁中微量稀土元素．

PMBP—异戊醇—石蜡系统分离测定稀土总量

以石蜡为溶剂 ,用PMBP与异戊醇为萃取剂 ,利用固—液萃取法分离测定稀土元素 .试验表明 ,该系统可产生协萃效应 ,并且讨论了萃取剂PMBP用量对协萃系统分配比的影响 ,异戊醇加入量对协萃效应的影响 ,得出了最佳萃取条件 .该系统用于分离测定稀土矿样中稀土总量 ,萃取酸度范围扩大 ,回收率提高 .

离线固相萃取螯合富集分离-ICP-MS测定海水中的稀土元素

通过测定条件优化、方法比对等实验建立了一种固相萃取小柱离线螯合富集分离电感耦合等离子体质谱仪测定海水中稀土元素的方法。海水样品通过调节p H后,进入VAC ELUT SPS24 Agilent圆形固相萃取装置,其主要基体物质的去除率高于97%;萃取富集的优化条件是海水样品p H 4.0~7.0,海水进入萃取柱速率2 m L/min,硝酸洗脱液浓度为1 mol/L;方法对稀土元素的加标回收率为83%~108%,14种稀土元素的检出限为0.057~0.613 ng/L,RSD<10%;该方法与氢氧化铁共沉淀法富集稀土元素比对测定结果一致,方法具有准确度与精密度高、操作简便快速等优点,可用于海水样品中稀土元素的定量精确测量。

阳离子型稀土-铝高分子杂聚絮凝剂的合成及其在废弃钻井液处理中的应用

以稀土氯化物和结晶氯化铝为无机组分、丙烯酰胺和二甲基二烯丙基氯化铵为有机组分、过硫酸铵及亚硫酸氢钠为引发剂,合成了一种新型的阳离子型稀土-铝高分子杂聚絮凝剂。利用FTIR,TG,SEM等方法分析了该絮凝剂的结构和固液分离性能。实验结果表明,该絮凝剂中无机与有机组分之间形成了离子键杂化结构,因此同时具有无机絮凝剂与有机絮凝剂的特点,具有很好的吸附能力及团聚能力。对水基钻井液废液有很好的固液分离效果,加量为6000mg/L时,废液脱水率可达90%以上。钻井液废液经该絮凝剂处理后,所得液相呈中性,悬浮物含量极低,且KCl和NaCl的含量基本无变化,可循环用于钻井液配浆,实现液相零排放。

非皂化萃取工艺分离稀土研究进展

溶剂萃取法是工业生产中分离纯化稀土最主要的方法,该方法生产了全球绝大部分单一稀土产品,为稀土在其他领域的应用提供保障。随着绿色环保生产理念的深入,传统萃取体系面临巨大挑战,新型绿色萃取体系的研发至关重要。综述了几种非皂化萃取分离稀土的工艺,对协同萃取体系、离子液体萃取体系以及络合萃取体系等进行了对比分析,阐述了不同工艺方法存在的优势和弊端。在此基础上,介绍了离子印迹、氯化稀土热解以及电解分离等新型非皂化分离稀土的方法。同时,展望了稀土非皂化分离纯化技术研究的发展方向,为更加绿化高效开发利用稀土资源提供借鉴。

磷酸三丁酯固一液萃取分离稀土元素的研究

以切片石蜡为溶剂，用固—液萃取法研究了HNO3介质中TBP－NH4SCN对稀土元素的萃取行为，考察了几种因素对萃取率的影响。结果表明：在[TBP]=2．4mol·L-1，[NH4SCN]＝37mol．L－1时，各稀土元素的分配比D均大于14，将该体系用于矿样中稀土总量分离，回收率达90．5～91．6％。