非平衡体系络合交换分离钆铒的研究

以P204为萃取剂及二乙基三胺五乙酸（DTPA）为水相络合剂,研究了用非平衡溶剂萃取法从氯化稀土溶液中分离钇 铒的水相pH值,适合时间,DTPA浓度等因素对分离钇铒的影响,结果表明,在水相加入DTPA,钇的萃取速度较快,铒的萃取速率较慢,控制两相混合时间,用非平衡溶剂萃取法可有效分离钇铒。     

萃取分离Sm、Eu、Gd小型试验报告

前言关于 Sm、Eu、Gd 的分离,国内外均做了大量工作。一般多是利用 Eu 的还原性首先分离 Eu,然后再用萃取法分离 Sm 和 Gd。我们和包钢有色三厂曾研究了从包头矿中提取Sm、Eu、Gd 的工艺流程,并在工厂进行了生产试验,取得了较好结果。但对萃取     

水相组成对金属萃取行为的影响

<正> 一、前言 萃取法提取、分离金属工艺研究中的重要课题是选择理想的萃取体系。其中包括既要筛选高效的萃取剂,又要注意研究水相组成对金属萃取行为的影响。虽然高效萃取剂十分吸收人,但人们对来自水相的影响也有一定的研究。如萃取分离镍钴时,在硫酸—盐酸体系中的分离系数比单一硫酸体系中高,又如在混合介质中锌镉的分离系数大大提高。而用TBP萃取锌时其分配系数,在氯化锂(或CaCl_2)体系中比氯化钾体系中高的多。 为了更确切的阐明这些现象,本工作仅以D_2EHPA萃取铜为例,作些初步探讨。     

用示踪原子法研究铕的还原萃取

本文探讨了用示踪原子法在NH_4SCN—HCL体系中以P_(350)为萃取剂、以锌粉为还原剂、从Sm、Eu、Gd富集物中萃取Sm、Gd从而使Eu得到分离的一些基本条件。初步讨论了萃合反应及萃合物的组成,在一些条件下它可能是R~( )(SCN~-)_3·2P_(350)。讨论了影响提高Eu收率的主要因素及其矛盾地位依条件的变化。在某些条件下,单级萃取铕的收率在86.6％～95.57％之间;铕可以富集到3.8～6.7倍。     

预分离萃取法及其分离低钇离子稀土矿新工艺

预分离萃取法是首先用少量级数对待分离的原料进行预先分离,然后再流入级数较多的、进行相邻元素间分离的细分离工艺,从而减少进入级数较多的相邻元素分离工艺的料液量。因而,整体工艺的萃取槽体积减少25%～40%,有机相、水相及稀土金属的存槽量减少25%～40%,酸碱消耗也减少30%～40%,废水排放量大为减少。预分离工艺有多种形式,相邻元素间的细分离工艺也有多种类型。本文介绍了预分离萃取法的形成缘由、基本原理,使用这种方法的基本原则和它的各种工艺形式,以及用预分离萃取法分离低钇离子稀土矿的新工艺。     

铝在稀土萃取分离流程中的分布及分离方法研究(I)

本文对非稀土元素铝在P507-HCl体系稀土萃取分离流程Sm/Eu/Gd和～Gd/Tb/Dy中的分布和走向进行了研究,并对其各自的水相料液,进料级、水相出口、三出口和萃取有机相出口的两相稀土组成、浓度和铝含量进行了分析。结合进料级和三出口附近的元素组成计算了铝与钐的分离系数,通过物料平衡计算了铝的进出平衡情况。阐明了铝在其中的分布和走向规律,并提出了氢氧化钠和草酸沉淀等除铝方法。     

P204-kerosene-EDTA体系萃取分离钨钼

系统研究了以P204（磷酸二（2-乙基己基）酯）为萃取剂,乙酸丁酯、二甲苯、煤油为稀释剂,从硫酸体系中萃取分离钼的性能。实验结果表明,P204与三种稀释剂组成的有机相均对钼有良好的萃取性能,萃取效率与水相的pH值、萃取时间、酸体系有关。实验证实该体系对钨基本不萃取。基于钨、钼在酸性溶液中易形成聚合杂多酸并考虑稀释剂成本以及环境污染问题,选定以煤油为稀释剂与P204构成有机相,在水相加入EDTA（EDTA∶Mo=2）为络合解聚剂,获得了在酸性介质中萃取分离钨钼的满意结果。实验证实萃取过程为离子交换缔合机理。     

三出口萃取工艺极值公式

为了缩短工艺流程,提高分离效率,许多单位都相继进行了三出口萃取分离工艺的研究。研究结果表明,三出口工艺不仅可应用于稀土元素的分离,而且还可应用于非稀土元素的分离。若采用三出口工艺分离Sm、Eu、Gd或Gd、Tb、Dy,可一次得到三个产品,即纯Sm、Gd及富Eu、或纯Gd、Dy和富Tb。由于缩短了工艺流程,从而提高了贵重稀土元素Eu和Tb的收率。三出口工艺应用于Cu、Co、Ni的分离时,可同时得到较纯的Cu、Ni及含量高于90％的Co产品,缩短了工艺流程,降低了消耗。     

有机含磷及含氮萃取剂萃取分离锆铪研究进展

锆和铪是两种性质接近、分离困难的稀有金属,主要应用于核工业.目前,针对湿法分离锆铪,工业上多采用溶剂萃取法.从有机含磷(膦)萃取剂、有机含氮萃取剂、协萃体系三方面,分别综述溶剂萃取法分离锆和铪的研究进展.发现对有机磷(膦)萃取剂研究较多,分离效果较好.对于新型萃取剂和萃取工艺的开发,如萃取剂二(2-乙基己基)-1-(2...     

铕钆萃取分离的动态平衡计算及程序编制

本文用FORTRAN 语言编制了应用电子计算机技术完全模拟“分液漏斗法”的实验操作,对皂化P507盐酸体系的Eu/Gd 分离进行了动态平衡计算。得到了人工实验中无法获得的信息和结论。本程序不仅适用于Eu/Gd 分离,而且也适用于任一恒定混合萃取比体系的双组份分离。     

Extraction kinetics and kinetic separation of La(III), Gd(III), Ho(III) and Lu(III) from chloride medium by HEHEHP

According to the tetrad-effect, 14 elements of lanthanides can be divided into four groups. In our previous study, a new approach was proposed for the kinetic separation of four rare earth ions La(III), Gd(III), Ho(III) and Lu(III) coming from four groups. In that study, four rare-earth ions were kinetically separated from their coexisting mixed aqueous solutions, by performing liquid-column elution using the aqueous solution containing four lanthanide rare-earth ions as the stationary phase and the dispersed organic oil droplets containing HEHEHP (2-ethyl hexyl phosphonic acid mono 2-ethyl hexyl ester) extractant as the mobile phase. The study of extraction kinetics is very important for understanding the kinetic separation of rare earth ions, which was carried out in this paper. The extraction kinetics of La(III), Gd(III), Ho(III) and Lu(III) by HEHEHP diluted in heptane were investigated using single drop method. The different parameters affecting the extraction rate such as column length, specific interfacial area, rare earth ion concentration, extractant concentration, hydrogen ion concentration and temperature were separately studied and the rate equations are deduced. It is first order with respect to rare earth ion and HEHEHP concentrations, and negative first order with respect to hydrogen ion concentrations. The rate constants at 293.15 K are 10^−6.23, 10^−5.73, 10^−5.58 and 10^−5.43, respectively. The experimental results demonstrate that the extraction rate of La(III), Gd(III), Ho(III) or Lu(III) is diffusion-controlled, and the extraction reaction takes place at the interface rather than in the bulk phase. The extraction model was proposed. Besides, the kinetic separation of rare earth ions by HEHEHP oil drops was discussed.     

Application of the Phase Transfer Catalysis in Rare Earth Solvent Extraction

ＡｐｐｌｉｃａｔｉｏｎｏｆｔｈｅＰｈａｓｅＴｒａｎｓｆｅｒＣａｔａｌｙｓｉｓｉｎＲａｒｅＥａｒｔｈＳｏｌｖｅｎｔＥｘｔｒａｃｔｉｏｎＹａｎＣｈｕｎｈｕａ（严纯华）；ＺｈａｎｇＹａｗｅｎ（张亚文）；ＬｉａｏＣｈｕｎｓｈｅｎｇ（廖春生）；ＪｉａＪｉａｎｇ...     

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。     

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).     

Efficient extraction and stripping of Nd(III), Eu(III) and Er(III) by membrane dispersion micro-extractors

The extraction of low concentration rare earth elements at high phase ratio was investigated. The traditional extraction set-up, such as mixer-settler, have drawbacks of easy emulsification, difficult separation and low efficiency if operated at the above condition. Membrane dispersion micro-extractor, owing to its well-dispersed, high surface-to-volume ratio and fast mass transfer rate, was employed in our work. Nd(III), Eu(III), Er(III) were chosen to represent light, medium, heavy rare earth elements (REEs). The extraction process of REEs with 2-ethylhexyl phosphoric acid-2-ethylhexyl ester (P507) was investigated by membrane dispersion micro-extractors. Firstly, the extraction equilibrium of these three elements was explored in the stirred conical flasks, and it is indicated that the extraction efficiencies can be 0.95, 0.97 and 0.98, respectively within 40 min at phase ratio of 100:1. Then the effects of operational conditions such as the residence time, organic and aqueous flow rates on extraction efficiency were also explored in micro-extractors. The results indicate that the efficiency decreases and then increases if increasing aqueous phase flow rate, residence time and droplets' diameter are the key factors of this process. Increasing the phase ratio reduces the extraction efficiency significantly. When the REEs solution has an initial pH of 4.00, the flow rates of continuous and dispersed phase are 40 and 1.6 mL/min, respectively, and 90 mg/L Nd (III), Eu(III) and Er(III) is extracted by 1 mol/L P507 at the out-let length of 8 m. The extraction efficiencies are 0.978, 0.983 and 0.991, respectively. Finally the stripping process was also studied with the micro-extractor. The stripping efficiencies of Nd(III), Eu(III) and Er(III) can reach 0.99, 0.96 and 0.91, respectively when the out-let length is 8 m and the concentration of hydrochloric acid is 1 mol/L. The developed approach offers a novel and simple strategy on the fast extraction and enrichment of low concentration rare earth elements from waste water.     

A novel method for synthesis of styryl phosphonate monoester and its application in La(III) extraction

Herein, styryl phosphonate monoester (SPE) was synthesized and first introduced as rare earth extractant. The solvent extraction of lanthanum (III) from nitrate solution using styryl phosphonate mono-iso-octyl ester (SPE108), di-2-ethylhexyl phosphoric acid (D2EHPA) and 2-ethylhexyl phosphonic acid-mono-2-ethylhexyl ester (EHEHPA) as extractants was investigated. The effects of experimental parameters including equilibrium time, extractant concentration, aqueous pH, phase ratio and salt concentration on the extraction process were studied. The results indicate that the extraction ability and capacity of the extractants follow the order: SPE108 > D2EHPA > EHEHPA. What's more, the extraction process is less affected by ammonium sulfate in the aqueous phase with SPE108. The results of the separation between lanthanum and adjacent lanthanides (Ce, Pr, Nd, Sm) show that SPE108 can separate lanthanides efficiently at low pH. The extraction mechanism of SPE108 is proved to be similar to D2EHPA, and the density functional theory (DFT) calculation results infer that SPE108 exhibits superior extraction ability due to its strong electron-accepting ability.     

Separation of Th~(4 ) and RE~(3 ) with Hollow Fiber Extraction

Ｔｈｏｒｉｕｍｉｓａｍａｉｎｓｏｕｒｃｅｏｆｒａｄｉｏａｃｔｉｖｉｔｙｉｎｔｈｅｒａｒｅｅａｒｔｈｍｉｎｅｒａｌｓ．Ｔｈｅｔｒａｄｉｔｉｏｎａｌｐｒｏｃｅｓｔｏｒｅｍｏｖｅｔｈｏｒｉｕｍｃｏｎｓｉｓｔｓｏｆｓｅｖｅｒａｌｓｔｅｐｓｉｎｃｌｕｄｉｎｇ...     

Separation of trivalent rare earths from nitrate medium using solvent extraction with a novel extractant 2-ethylhexyl ((2-ethylhexylamino)methyl) phosphonic acid

By introducing the amine group into the structure of P227, a novel extractant 2-ethylhexyl ((2-ethylhexylamino)methyl) phosphonic acid (EEAMPA, abbreviated as HA) was synthesized for the extraction and separation of trivalent rare earths (REs) from nitrate medium. The influence factors including extractant concentration, equilibrium time, HNO₃ concentration, separation factors, cycle regeneration, stripping acidity, and actual leach liquor of metal ions, were studied systematically. The results show that the extraction ability of EEAMPA for REs decreases with increasing acidity. A possible extraction mechanism is proposed and the extracted species as REHA₃(NO₃) are confirmed by the slope analysis method. The extraction equilibrium can reach faster than P227. It shows good chemical stability and cycling regeneration. Stripping studies show that HCl is an excellent stripping agent and REs can be effectively stripped from the organic phase.     

A novel extractant bis(2-ethylhexyl) ((2-ethylhexylamino)methyl) phosphine oxide for cerium(IV) extraction and separation from sulfate medium

By introducing the amine group into phosphorus extractant, a novel aminophosphine compound bis(2-ethylhexyl) ((2-ethylhexylamino)methyl) phosphine oxide (DEHAPO, abbreviated as A) was synthesized for the extraction of cerium (IV) (Ce(IV)) from sulfate medium (H₂SO₄). The influence factors including extractant concentration, H₂SO₄ concentration and temperature on the Ce(IV) extraction were investigated and discussed. It is found that the extraction ability of Ce(IV), thorium (IV) (Th(IV)) and rare earths (REs(III)) (La, Gd, Yb) decreases in sulphate medium in the following order: Ce(IV) > Th(IV) > REs(III). The extraction process is an exothermic reaction and the thermodynamic parameters were calculated. The extracted complex of Ce(HSO₄)₂SO₄·A in loaded organic solution was identified by the slope methods and further proved by FT-IR spectral analysis. Stripping studies indicate that Ce(IV) can be effectively stripped from the organic phase. The results of separation factors (β) and saturation loading capacity demonstrate that DEHAPO could be used to selectively extract Ce(IV) from sulphate medium with high separation efficiency and good extraction ability.