非离子表面活性剂Triton X-100/Na2SO4双水相体系萃取分离钨钼的研究

采用非离子表面活性剂Triton X-100与硫酸钠构成的双水相体系，研究了水溶液中钨和钼的萃取分离性能。考察了温度、pH值、钼络合剂种类及用量等对钨和钼分离性能的影响。结果表明：在酸性条件下，络合剂酒石酸钠、柠檬酸钠能与钼形成稳定的络合物、从而抑制钨钼杂多酸的形成，实现钨、钼的高效分离；在pH=2.0,温度为343.15K,络合剂酒石酸钠质量分数为3%时，钨、钼分离效果最好，分离因子可达328。借助紫外光谱、红外光谱等分析手段研究了钨、钼萃取机理。结果表明，钨依靠仲钨酸B阴离子与表面活性剂分子中质子化的聚氧乙烯拟阳离子间产生的静电引力被萃取到表面活性剂相，而钼则以亲水性络合物形式留在水相。     

电喷雾质谱法示踪钨回收过程离子的转化路径

将环隙式离心萃取器(ACCs)与电喷雾飞行时间质谱(ESI-TOF-MS)相结合，在线监测了回收过程中的钨萃取行为(宏观)和钨形态的转化路径(微观)，发现宏观萃取反应和微观离子形态转化同时发生并相互补充。伯胺N1923萃取钨在144 s内即可达到萃取平衡，萃取率高达98%以上，同时，酸钨比n(H)/n(W)是一个关键变量，当酸钨比n(H)/n(W)=2.4时，全流程钨回收率超过93%。最后，得到了基于钨形态监测的萃取机理，同时，减少原料液中W1含量，增加W10含量，可有效提高钨回收效率。     

无机阴离子对丙酮酸络合萃取的影响

采用三元模拟体系 ,以三辛胺为萃取剂 ,在不同离子类型及离子强度下对丙酮酸的络合萃取过程进行了研究 ,证实无机阴离子的存在对萃取效果产生极大的消极影响 ;通过理论分析及实验验证 ,对于无机阴离子的作用机理进行了讨论 ,初步推测无机阴离子可能是通过同离子竞争 ,削弱丙酮酸根离子与络合剂的离子对缔合作用 ,从而使萃取过程只能以氢键缔合方式进行     

离子液体在萃取分离领域的研究进展和应用

综述了近几年来离子液体在石油化工领域中萃取分离的应用,主要包括对于脂肪烃和芳烃的萃取分离、烷烃和烯烃的萃取分离、燃料油中的脱硫脱氮,并概述了离子液体在萃取分离过程中的萃取机理和影响因素。此外,针对离子液体回收难度较大的问题,概述了主要的回收方法,包括减压蒸馏、液液萃取和双水相分离等方法。结合离子液体的优势和存在的问题,对其工业化的应用提出展望。     

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。     

基于离子液体的“可设计性”和“软酸”性质萃取分离电镀污泥中Cr~(6+)/Fe~(3+)

基于离子液体的"可设计性"和"软酸"性质对于其在电镀污泥酸浸液中铬铁萃取分离方面的应用及其机理进行研究。结果表明:咪唑环上烷基链的长度对于铬铁萃取分离效果有较大的影响,阴离子为[BF_4]~-的离子液体对于铬铁萃取分离能力大于阴离子为[PF_6]~-的离子液体。在所研究的离子液体中,[Omim][BF_4]对于铬铁具有较好的萃取分离效果,实现了电镀污泥中铬铁分离。结合斜率法、红外光谱分析、Raman光谱分析,[Omim][BF_4]萃取铬符合离子缔合机理,可推测[Omim][BF_4]咪唑阳离子与Cr_2O_7~(2-)阴离子形成离子缔合物而进入有机相,达到萃取分离,从而实现电镀污泥资源化目的,具有一定的应用性。     

离子液体在萃取分离领域的研究进展和应用

综述了近几年来离子液体在石油化工领域中萃取分离的应用,主要包括对于脂肪烃和芳烃的萃取分离、烷烃和烯烃的萃取分离、燃料油中的脱硫脱氮,并概述了离子液体在萃取分离过程中的萃取机理和影响因素。此外,针对离子液体回收难度较大的问题,概述了主要的回收方法,包括减压蒸馏、液液萃取和双水相分离等方法。结合离子液体的优势和存在的问题,对其工业化的应用提出展望。     

苯胺萃取法提纯三氧化钨—钼还原抑萃过程的研究

用芳胺类萃取剂萃取钨有很好效果。苯胺能从水相中以离子对络合形式将钨萃入有机相但对钨中之钼分离效果较差。本文提出用硫酸肼为还原剂,EDTA为抑萃剂使钼掩蔽不被苯胺萃取,从而大大提高苯胺萃取法分离钨钼的能力。     

中空纤维膜萃取镉离子的研究

处理重金属离子水溶液是环境治理中的一个重要方面 ,应用新型膜萃取技术对去除水溶液中镉离子进行了研究。首先测定镉离子在不同萃取体系中的分配系数 ,选择合适的萃取剂 ,在中空纤维膜器中研究膜萃取去除镉离子的分离效果和传质特性 ,探讨不同装填因子、两相流速、水相初始浓度等实验条件对分离和传质的影响。实验结果表明 ,体积分数为 5 0 %的P2 0 4 正庚烷溶剂对于镉离子有较好的萃取效果。当装填因子为 0 .732 8时 ,经 33cm长的中空纤维膜器一级萃取可将溶液质量浓度由 40 0mg/L降至 0 .2mg/L以下 ,证明了膜萃取的高效性     

基于离子液体的“可设计性”和“软酸”性质萃取分离电镀污泥中Cr6+/Fe3+

基于离子液体的"可设计性"和"软酸"性质对于其在电镀污泥酸浸液中铬铁萃取分离方面的应用及其机理进行研究。结果表明：咪唑环上烷基链的长度对于铬铁萃取分离效果有较大的影响,阴离子为[BF₄]^-的离子液体对于铬铁萃取分离能力大于阴离子为[PF₆]^-的离子液体。在所研究的离子液体中,[Omim] [BF₄]对于铬铁具有较好的萃取分离效果,实现了电镀污泥中铬铁分离。结合斜率法、红外光谱分析、Raman光谱分析,[Omim] [BF₄]萃取铬符合离子缔合机理,可推测[Omim] [BF₄]咪唑阳离子与Cr₂O₇^2-阴离子形成离子缔合物而进入有机相,达到萃取分离,从而实现电镀污泥资源化目的,具有一定的应用性。     

Separation of vanadium and tungsten in roasting-acid leaching solutions of the spent selective catalytic reducing denitration catalyst by co-extraction using hydroxyoxime extractant-quaternary ammonium salt extractant LIX984–N263 extractant

This study presents a synergistic extraction and recovery of vanadium and tungsten by mixed extractants (LIX984 and N263) from an acid leaching solution which was obtained from spent denitrification catalysts by chlorination heat treatment and acid leaching. Through thrice counter-flow extraction, 99.5% V and 99.7% W were extracted, while 3.0% Fe, 2.9% Ti, 2.1% P, and 3.3% Mg were co-extracted at a LIX984:N263 volume content of 22.0%, the phase ratio of 2.5 and the mother liquor's pH of 2.5. Then, at 0.80 mol/l NaOH and a phase ratio of 1, 99.9% tungsten and 99.1% vanadium were stripped from the organic phase to the aqueous phase. Subsequently, the aqueous phase's tungsten of 99.3% and vanadium of 98.1% were separated as calcium tungstate and ammonium metavanadate, respectively. In contrast, the residual solutions containing tungsten and vanadium can be returned to the following purification separation process to recover the valuable metals from the solution. Roasting converts the precipitated calcium tungstate and ammonium metavanadate to V₂O₅ and WO₃ products. In addition, the thermodynamic analysis found the separation and recovery of tungsten and vanadium from the acid leach solution with LIX984:N263 to be an exothermic process. This method can be effectively extended for the separation of vanadium and tungsten from spent denitrification catalysts by the proposed process and validates the conclusion that metals with similar properties can be extracted using a mixture of extractants.     

Study of Soluble Tungstate Species by Solvent Extraction

Abstract

Tungsten is extracted from acidic tungstate solutions by the long-chain tertiary alkyl amine, tri-n-caprylamine, in benzene. Distribution data derived from solvent extraction are interpreted in terms of the predominating tungsten species present in the aqueous phase. The results show that the nature of the tungstate species extracted by tri-n-caprylamine changes markedly with the pH of the system. Further, the order of extraction is consistent with the order in which tungstate species should form as a function of the ratio of acid equivalents to moles of tungstate ions in solution.     

Speciation of Molybdenum (VI) In Aqueous and Organic Phases of Selected Extraction Systems

Abstract

The extraction study of molybdenum (VI) by 30% tri-n-butyl phosphate in n-dodecane and 0.2 M octyl (phenyl)-N,N-di-isobutylcarbamoylmethylphosphine oxide in 30% tri-n-butyl phosphate extraction systems was performed from aqueous solution containing HCl, HNO₃ and acetohydroxamic acid. Depending on extraction conditions, acetohydroxamic acid can significantly affect the speciation of molybdenum and can increase or decrease its distribution ratio. Our investigation confirmed the strong ability of the acetohydroxamic acid to form complexes with Mo even in highly acidic solutions. UV absorption spectra confirmed that a fraction of the Mo(VI)-AHA species can be present in the organic phase after extraction.     

脂肪酸-聚醚胺-CO2相行为及萃取性能研究

研究了脂肪酸-聚醚胺-水络合溶剂在CO₂触发开关作用下的相分离行为、开关性能及萃取水溶液中铜离子效能。通过辛酸-癸酸、辛酸-月桂酸、癸酸-月桂酸3种憎水性低共熔溶剂DES和辛酸、癸酸与聚醚胺D230水溶液配伍构建了系列开关型溶剂,并考察了不同脂肪酸与不同浓度聚醚胺D230水溶液配伍形成均相溶液的CO₂响应性能。实验发现,聚醚胺D230水溶液质量分数为10%、13%和15%时,极性逆转导致体系的相行为变化有所不同。借助脂肪酸-聚醚胺-水络合溶剂,实现了脂肪酸DES均相萃取水溶液中铜离子以及与水相的非均相分离萃取模式。实验结果表明,质量分数10%聚醚胺D230水溶液与脂肪酸组合具有良好的CO₂开关相行为,癸酸-月桂酸DES萃取铜离子的效果最佳。实验表明铜离子萃取率达到92.7%。     

Separation of tungstates from aqueous mixtures containing impurities (arsenate,phosphate and silicate anions) using ion flotation

Ion flotation, using dodecylamine as surfactant and magnesium ions as depressant agents, was found to be an effective method for the selective separation and recovery of tungstate from arsenate anions in dilute aqueous solutions. Arsenates represent the main impurity in tungsten-containing waste waters or leaching solutions of hydrometallurgical origin; magnesium chloride is a relatively common precipitant, used in tungsten hydrometallurgy. The main parameters affecting this process were investigated, namely concentrations of reagents (Mg²⁺ ions, dodecylamine, arsenate and tungstate), solution pH, co-existence and effective separation from other impurities, such as phosphate and/or silicate anions, and the effectiveness of the separation process in solutions of high ionic strength (using NaCl and Na₂SO₄ salts). It was found that at pH range between 2 and 5, tungstate anions can be quantitatively recovered from aqueous mixtures containing arsenates, phosphates and silicates, while the co-removal of the impurities was below 20%.     

磷酸三丁酯萃取分离钛铁矿亚熔盐反应产物酸解液中Fe3+及金红石型TiO2的制备

在盐酸介质中以磷酸三丁酯(TBP)为萃取剂、磺化煤油为稀释剂,从钛铁矿与氢氧化钾亚熔盐反应产物的酸解液中萃取分离Fe3+,并利用萃取后的含钛液水解制备二氧化钛. 考察了萃取剂浓度、盐酸浓度、有机相和水相体积比(O/A)和萃取时间对铁萃取率的影响. 结果表明,钾系亚熔盐法分解钛铁矿的分解率在96%以上. 萃取率随着TBP浓度及盐酸浓度的增加和O/A值的减小而增大;通过调节萃取条件,萃取率可以达到99%以上. 用1.0 mol/L的NaCl溶液进行反萃,反萃率可达98%以上. 萃取后含钛液经水解可以制得纯度高于98%的金红石型TiO2球状颗粒.     

Recovery and Separation of Lanthanum(III), Aluminum(III), Cobalt(II), and Nickel(II) from Misch Metal by Solvent Extraction Using Bis(2-ethylhexyl) phosphinic Acid

Abstract

This paper describes use of bis(2-ethylhexyl) phosphinic acid as a reagent for extraction and mutual separation of lanthanum(III), aluminum(II), cobalt(II), and nickel(II) in 1.0 mol/L sodium nitrate. The extraction and stripping behavior of the four metal ions has been investigated using the extractant in Solvesso #150 as a diluent. The mutual separation and recovery of the metal ions from their mixtures has been tested by multistage extraction with a conventional separator funnel. A set of separation schemes has also been proposed for a continuous countercurrent multistage extraction which is comprised of ten extraction stages, four scrubbing stages, and seven stripping stages. Lanthanum(III) and aluminum(III) are coextracted but separated by selective stripping into different concentrations of hydrochloric acid. Cobalt(II) can be extracted with the nickel(II)-preloaded extractant solution, whereas nickel(II) remains in the aqueous phase. The successful separation of these metal ions from a misch metal-simulated sample is presented.     

超声萃取分离瓦斯泥硫酸浸出模拟液中的铟铁离子

采用探头超声和震板超声两种强化工艺萃取分离高炉瓦斯泥硫酸浸出模拟液中的铟和铁离子,通过与传统溶剂萃取工艺比较,得出超声强化可在保证较高铟萃取率和反萃率的同时,明显缩短萃取和反萃时间,提高萃取效率. 其中,震板超声较适合铟离子的萃取过程,探头超声较适合铟离子的反萃过程. 采用两种超声强化工艺萃取分离瓦斯泥硫酸浸出模拟液中铟、铁离子的适宜工艺条件为：硫酸浓度1 mol/L,震板超声萃取1 min,铟萃取率达96.5%,铁萃取率为8.5%;盐酸浓度2 mol/L,探头搅拌反萃2.5 min,铟反萃率达71%,铁反萃率为3.8%.     

Electrodialytic Separation of Phosphorus and Heavy Metals from Two Types of Sewage Sludge Ash

During sewage sludge incineration phosphorus (P) is retained in the ash in a form not directly available to plants. As P is a sparse resource, it is important to develop techniques for recovery of P from incinerated sewage sludge ashes (ISSA). Heavy metals are concentrated in ISSA and separation of P and heavy metals is required. The present work is an experimental screening of a new combination of acid extraction and electrodialysis–electrodialytic separation (EDS) for simultaneous P recovery and removal of heavy metals. Experiments were conducted with two different ashes; rich in Fe or Al. The separation method was best suited for the Fe-rich ash, where it was possible to separate P into one processing solution, heavy metals (Cu, Zn, Ni, Pb) into another, keeping the ash suspended in a third solution (which though still contained P after 1 week of EDS). For the Al rich ash, the separation was not similarly encouraging. The high release of Al during the extraction influenced the speciation of P and negatively charged P complexes were not prevailing. On the contrary to Al, the Fe containing ash particles were insoluble so Fe did not interfere with P speciation and separation after extraction.