Extraction of Palladium from Acidic Chloride Media into Emulsion Liquid Membranes using LIX 984N-C^®

The extraction of palladium from hydrochloric acid solutions into emulsion liquid membranes (ELMs) using LIX 984N-C as the extractant was investigated. The influential factors and the total capacities of palladium extraction were determined by a batch method. The behavior of palladium extraction by ELMs under the operational conditions-pH of the external feed phase, surfactant and extractant concentration, internal stripping phase concentration, treat ratio and agitation speed were reported. Using LIX 984N-C, palladium was effectively extracted from the external acidic chloride feed phase into the internal receiving phase of W/O emulsions. More than 92% of palladium could be extracted at a feed pH of 2 with 3% Span 80, 9% LIX 984N-C and 7M HCl at a stirring speed of 300 rpm.

Recovery of Copper Ions from Wastewater by Hollow Fiber Supported Emulsion Liquid Membrane

Recovery of copper ions from wastewater using a hollow fiber supported emulsion liquid membrane (HFSELM) was studied with LIX984N as carrier, kerosene as diluents, and sulfuric acid solution as stripping phase. Effects of compositions of feed and emulsion liquid phase, flow rates on both sides of membrane, and hollow fiber module parameters were investigated. The stability of the emulsion liquid phase without surfactant and the effect of buffer in the feed phase on the extraction rate were also evaluated. It is found that the stability of the emulsion phase without surfactant is poor. Higher flow velocity gives shorter residence time for the emulsion liquid phase on the tube side, reducing the effect of particle coalescence on the separation process. The extraction rate increases with the increase of feed phase pH, carrier concentration, hydrogen ion concentration in the stripping phase, and ef- fective hollow fiber area. The phase ratio in the emulsion liquid phase has a negative effect on extraction rate. The flow rates on both sides have little influence on the extraction performance of the HFSELM, while buffer addition in the feed solution improves the extraction efficiency.

Rare earth extraction from wet process phosphoric acid by emulsion liquid membrane

The recovery of rare earths （RE） during the wet processing of phosphoric acid is very important, the method of emul- sion liquid membrane （ELM） with di（2-ethylhexly） phosphate （D2EHPA） as carrier has the high selectivity while cannot provide a satisfactory extraction rate. Here novel method of emulsion liquid membrane （ELM） using Aniline as carrier to extract RE from the feed solution was proposed. The method could increase the extraction rate of RE in the real sample to 93%. The effects of dif- ferent parameters such as type and concentration of carrier and surfactant, hydrochloric acid concentration, organic to internal phase volume ratio, membrane to external phase volume ratio on extraction of RE3＋ were investigated. Quantitative extraction （〉93%） of RE3＋ was observed with 6 vol.% Aniline and 4 vol.% T 154 liquid membrane at external to internal phase volume ratio of 10 for the feed solution. The proposed method of ELM using Aniline as carrier can be expected to provide a practical, efficient, and economical method for extracting RE from phosphate leach solution with high acidity in the industry of wet process phosphoric acid.

Extraction of Neodymium by Emulsion-Liquid-Membrane within Hollow-Fiber-contactor and Its Mass Transfer Properties

A non-dispersive extraction technique, using an emulsion liquid membrane within a hollow-fiber-contactor for the extraction and enrichment of Nd^3＋ from the dilute feed aqueous, was applied. The emulsion system is consisted of span80 [ sorbitian monooleate], paraffin oil, D2EHPA [ 2-（ 2-ethylhexyl- phosphonic acid）], kerosene as well as HCl solution. The extraction under various conditions such as the span80 concentrations, the flow rate of aqueous, the extraction time and HCl concentrations in receiving phase were studied. Results show that the lower the flow rates of aqueous are, the higher the extraction percentage and enrichment-fold are, and the extraction percentage increases with the increasing of HCl concentrations. When the initial Nd^3＋ concentration in feed is maintained at 1000 mg· L^-1 and the emulsion is recycled with 70 times by a counter-flow,

Extraction of rare earth ions from phosphate leach solution using emulsion liquid membrane in concentrated nitric acid medium

It is very significant to recover rare earths （REs） from wet-process phosphoric acid, in terms of extraction rate and selectivity, the current carrier di（2-ethlhexly） phosphate （D2EHPA） out there is still inferior. Based on this question, our team modified D2EHPA to synthesize new extractants. This paper presents a comprehensive study on the extraction of rare earth ions （RE3＋） from phosphate leach solution using emulsion liquid membrane （ELM） in concentrated nitric acid medium. The ELM system is made up of （RO）2P（O）OPh-COOH as carrier, polyisocrotyl succinimide （T154） as surfactant, sulfonated kerosene as diluent, phosphoric acid （H3PO4） as stripping solution. Different chemical parameters such as type and concentration of carrier, surfactant, stripping solution, volume ratio of oil phase to internal phase, and volume ratio of emulsion ratio to external phase were analyzed. The extraction of RE^3＋ was evaluated by the yield of extraction. In addition, the demulsification process was also investigated. The proposed method of ELM using （RO）2P（O）OPh-COOH as carrier can he expected to provide an efficient, simplify operation, and facilitated method for extractine RE^3＋.

Extraction and Enrichment of Copper by Liquid Emulsion Membrane Using LIX 664N

Process intensification using liquid emulsion membranes (LEMs) for extraction of copper has been studied in this work. In LEM process the extraction and stripping processes are combined in one stage. The solubility of the solute or the chemical affinity between the solute and carrier reagent in the membrane results in the separation of the solute from the feed mixture. In this work the membrane phase comprised of LIX 664N as the extractant dissolved in kerosene and Span 80 as surfactant. The stripping phase was sulfuric acid with 180 g/l concentration and feed phase had copper concentration of 3.5 g/l. Effect of various process parameters such as batch contact time, speed of agitation, W:O ratio and treat ratio has been experimentally investigated to get better insight of the process. The maximum enrichment of copper in the internal phase obtained was 11.6 times with batch contact time of 10 minutes, agitation speed of 300 rpm and treat ratio of 6:1.

Extraction of Copper from Waste Solution Using Liquid Emulsion Membrane

The extraction of copper from acidic medium using Liquid Emulsion Membrane LEM as contactors was studied. b diketone LIX 54 as an extractant ,sesqueoleate which is nonionic surfactant with HLB value 3.7 and 0.1 M H2SO4 as stripping solution were used. The influence of initial concentration of copper in the aqueous feed phase, pH of external and internal aqueous phase, stirring speed, and concentration of extractant on the extraction rate was examined. The results obtained showed that practically all the copper content was removed from the acidic feed solution. The recovery of copper attained 96–100% and concentration ratios of about 40-fold could be achieved.

锌冶炼过程中提取镓的技术研究及其进展

针对镓从锌冶炼过程中回收占比低的问题,总结分析了锌冶炼过程中镓回收技术研究进展.在鼓风炉炼锌(ISP)工艺中,镓主要富集在鼓风炉炉渣里,其质量分数通常在0.025%~0.031%,从鼓风炉炉渣中回收镓主要有还原蒸发法、高温氯化挥发法、硫酸浸出法、碱熔–浸出法、还原熔炼–电解法和还原熔炼–熔融造渣法等方法,但这些工艺普遍流程长,回收率低,加工成本偏高,部分工艺环境污染大,难以工业化应用.传统的湿法炼锌工艺中,大于93.5%的镓富集在浸出渣中,浸出渣处理以火法还原挥发工艺为主,在回转窑挥发浸出渣工艺中90%的镓保留在窑渣中,导致镓的回收流程长且回收率低,湿法处理浸出渣存在镓和铁分离的难题,至今未得到有效解决.氧压浸出炼锌工艺中,镓主要富集在锌粉置换渣里,锌粉置换渣采用酸性浸出和萃取工艺分离富集镓,最终制备金属镓,镓的综合回收率达到71%.通过对火法和湿法炼锌中镓回收工艺进行分析,对镓回收工艺中存在的关键问题和分离技术进行了总结,提出萃取分离、乳状液膜和树脂吸附有望成为锌冶炼过程中回收镓的绿色高效短流程关键技术.

用乳状液膜法分离浓缩L-苯丙氨酸

以煤油 -N2 0 5-P2 0 4 -HCl组成的乳状液膜体系 ,在喷射提取柱内分别对L -苯丙氨酸及L -苯丙氨酸和L -天冬氨酸的混合溶液进行提取 .实验结果表明 ,用 10 0 0mL乳状液对初始浓度为 2 1.2 5g/L的单一L -苯丙氨酸水溶液提取 3次后 ,外相浓度降到 0 .95g/L ,内相最高浓度为 12 6 .10 g/L ;对L -苯丙氨酸浓度为 8.6 4 g/L的混合溶液提取两次后 ,外相L -苯丙氨酸浓度降至 0 .90 g/L ,内相L -苯丙氨酸最高浓度为 6 0 .0 0 g/L ;L -天冬氨酸的存在不影响L -苯丙氨酸的分离提取效率 ;每次操作溶胀均不超过 2 6 % ,同时对喷射提取柱能有效减小溶胀发生的机理进行了讨论 .

皂化P_(204)/煤油微乳体系分离L-苯丙氨酸的研究

研究了P204-煤油-NaOH组成的微乳液膜配方及其稳定性。通过该液膜体系对L-苯丙氨酸水溶液进行提取实验,考察了P204的浓度、乳水比、外水相pH值、膜相重复使用次数、分离时间等对提取效率的影响。实验结果表明,微乳液膜不仅稳定性好,无明显溶胀和泄漏,分离速度快,而且分离效果好,可自动破乳,油相可重复多次使用,对L-苯丙氨酸的一次性提取率达88.25%。

密差分相式液膜法提取L-苯丙氨酸

采用密差分相液膜分离技术 ,以P2 0 4 为载体 ,H2 SO4 为反萃剂 ,以初始浓度 15 .2 8g/L的L -苯丙氨酸水溶液提取 5次后 ,浓度降至 1 92 g/L ,反萃相中L -苯丙氨酸浓度达 5 4 35g/L ,膜溶胀和破裂均较小 ,过程不需要制乳和破乳 ;对反萃剂也进行了后处理 .

L-赖氨酸在乳化液膜中的萃取行为

研究了以二(2-乙基己基)磷酸酯为迁移载体,环己烷为溶剂,Span 80为液膜增强剂,不同氢离子浓度为内外水相传质推动力,构成的液膜体系对L-赖氨酸的萃取行为。建立了以Fe2+为示踪的分光光度法测定液膜破损率方法。探讨了L-赖氨酸在液膜体系中的迁移机理。

含二(2-乙基己基)磷酸乳状液膜对L-谷氨酸的萃取研究

本文以ＤＺＥＨＰＡ为载体，ＥＣＡ４３６０Ｊ为表面活性剂，内外相Ｈ＋浓度梯度为推动力，研究了Ｌ－谷氨酸在乳状液膜体系里的传输，对影响液膜萃取的各种因素进行了系统阐述，确定了体系的最佳膜相组成和实验条件，实现了Ｌ－谷氨酸的萃取回收。

微乳液膜萃取L-谷氨酸的研究

用NaOH皂化HA/煤油溶液能形成稳定的微乳液。通过该微乳液对L-谷氨酸水溶液进行萃取实验。结果表明,该微乳液萃取L-谷氨酸的最佳工艺条件为:萃取时间20 m in,油相中HA的浓度为1.0 mol/L,乳水比(体积比)为1∶4,外水相pH值为3,L-谷丙氨酸的一次性萃取率可达89.33%。微乳液膜具有稳定性好、无明显溶胀和泄漏、萃取效率高、可自动破乳且油相可重复使用等优点。

含TOMAC乳状液膜萃取L-谷氨酸的迁移机理及应用

本文研究了液膜提取过程中的萃取和反萃取两个过程，推出了在整个液膜体系达到萃取终了时的内外相氨基酸浓度比公式，并以ＴＯＭＡＣ 为载体萃取Ｌ－ 谷氨酸为例，讨论了影响液膜萃取的控制因素，实现了Ｌ－

含TOMAC乳状液膜萃取L-苯丙氨酸的迁移机理及应用

以L 苯丙氨酸在液膜体系里的迁移机理为基础 ,把液膜萃取过程中的萃取和反萃两个连续过程结合起来加以研究 ,推出了在整个液膜体系达到萃取终了时的内外相氨基酸浓度比公式 ,并以TOMAC为载体萃取L 苯丙氨酸为例 ,讨论了影响液膜萃取的控制因素 ,实现了L 苯丙氨酸的有效回收。

乳状液膜法提取L-谷氨酸的研究

乳状液膜法提取Ｌ－谷氨酸的研究徐占林（四平师范学院化学系四平１３６０００）严忠张河哲（东北师范大学化学系长春１３００２４）关键词Ｌ－谷氨酸乳状液膜载体萃取中图分类号Ｏ６２３．７３６氨基酸作为重要的生化产品，广泛应用于食品、饲料、医药、化工等许多领域，...

用乳状液膜法提取浓缩L-苯丙氨酸

以膜相中D2EHPA[磷酸二（2-乙基已基）酯]为载体，煤油为有机溶剂，N-205为表面活性剂，内相中以1．5mol／，的盐酸为试剂，高速剪切制乳；在喷射提取往内，用1L，乳状液对6L左右的初始浓度为21g／L左右的外相L-Phe（基丙氨酸）水溶液进行了3次提取，第1次提取后，内相平均浓度达120g／L左右，外相最后平均浓度为0．95g／L左右；每次提取后，液膜破裂率均小于1％，溶胀询小于22％．

膜分离技术在酶法生产L-苯丙氨酸中的应用

酶法生产 L -苯丙氨酸的工艺中 ,反应液中含有大量的菌体及其碎片、酶和生物大分子等杂质。要去除这些杂质 ,得到高质量的清液很困难 ,以往采用分离机来分离反应液 ,清液质量很不理想。改用超滤分离技术后 ,解决了这一难题。超滤能有效截留反应液中的杂质 ,清液透光率达 90 %以上 ,而且费用低、效率高 ,保证了后续工序的顺利进行 ,极大地提高了产品质量 ,取得了明显的经济效益。

液膜法从金矿贫液中除氰及回收氰化钠的小型工业化试验

本文提出了一种用乳化液膜法处理金矿含氰废水的新工艺,建立了规模为日处理量10～20m^3的一套小型工业化试验的液膜装置。研究了传质的影响因素及操作参数对除氰和回收氰化钠的影响。经运转操作证明,用该工艺流程能有效地从锌粉置换后的含氰贫液中将氰化钠浓缩回收并可重复使用,同时,使排放液中的游离氰根离子浓度低于0.5mg/L,达到国家排放标准。整个过程,氰的去除率达99％以上,氰化钠的回收率高于90％。经三个月的运转操作进行了经济估算,证明液膜法较其它方法优越。