硫酸介质中P507萃取Fe~(3+)的实验研究

本文以硫酸铁为料液,用2-乙基-己基膦酸-单2-乙基己基酯(P507)萃取剂在硫酸介质中萃取Fe3+。研究了温度、时间、P507的浓度、初始酸度、相比等因素对Fe3+萃取率的影响,以及有机相的反萃工艺。研究结果表明:温度为25℃,平衡时间为35min,初始氢离子浓度为0.4 mol/L,相比A/O=2/1,P507的体积分数为35%的条件下,水相经过四级逆流萃取,Fe3+的萃取率可达99.66%;反萃酸度为4 mol/LHCl,相比A/O=1/2,反萃时间为7min,经三级逆流反萃,反萃率可达到99.90%,有机相可以循环使用。     

D401大孔树脂吸附锰铁混合液中Fe~(3+)的热力学和动力学研究

采用D401树脂对锰铁混合液进行静态吸附性能及热力学、动力学研究,考察了Fe3+浓度、pH值和温度等对静态吸附Fe3+的影响,探讨吸附Fe3+的动力学过程,并采用Langmuir和Freundlich吸附模型对D401树脂吸附Fe3+的静态等温曲线进行了拟合。结果表明,在pH=1.5,温度313 K,Fe3+的最大静态吸附量是115.7 mg/g;D401对Fe3+吸附遵循Langmuir方程;△H Fe3+>0,ΔG Fe3+<0,表明D401对Fe3+的吸附是自发吸热过程;D401树脂对Fe3+的吸附符合拟二级动力学方程,颗粒扩散过程是吸附的控速步骤。静态吸附实验表明,D401大孔树脂能有效的对锰铁混合液中铁锰离子进行分离。     

海藻酸纤维对水溶液中Fe~(3+)的吸附动力学研究

以海藻酸纤维作为吸附材料研究了纤维对水溶液中Fe3+的吸附性能,用准一级动力学方程、准二级动力学方程、Elovich方程、粒子扩散方程、双常数方程和指数函数方程数学模型对不同Fe3+浓度、吸附时间的吸附曲线进行分析,研究了其吸附的动力学机理。结果表明:在研究的浓度和条件范围内,准二级动力学模型、Elovich方程和双常数方程的拟合度较好,模拟值与实验值吻合较好,说明海藻酸纤维吸附Fe3+是复杂的非均相扩散的化学吸附过程。粒子扩散方程表明颗粒内扩散不是控制海藻酸纤维吸附Fe3+过程的唯一步骤,而是由膜扩散和颗粒内扩散联合控制。     

P204-HCl-H3AOH萃取Pr（Ⅲ）的动力学实验研究

采用恒界面池法以P204-HCl-H3AOH萃取氯化稀土溶液中的稀土Pr (Ⅲ),研究了萃取过程中搅拌速度、温度、比界面面积、酸度、萃取剂浓度以及配合剂柠檬酸浓度等因素对萃取速率的影响,经理论验证确定P204-HCl-H3AOH萃取Pr(Ⅲ)的过程属于扩散控制机理,并得出萃取正向反应速率方程.     

非离子表面活性剂TX114浊点萃取D2EHPA的规律

引言浊点萃取[1-2]是利用表面活性剂水溶液的增溶和分相行为实现溶质富集的分离技术。由于分相后表面活性剂的富集相(亦称凝聚相)与水相的体积比非常小(0.007～0.04)[3],所以,对于被增溶的物质能够提供非常高的富集倍数和萃取效率。目前浊点萃取技术主要广泛应用于痕量有害物质     

D2EHPA萃取回收Cr(Ⅲ)的研究

以回收废水中Cr(Ⅲ)为目的,选择2-乙基己基磷酸(D2EHPA)为萃取剂,煤油为稀释剂,进行了萃取回收Cr(Ⅲ)的实验研究.考察了皂化剂种类、溶液pH值、助溶剂种类、萃取剂浓度等因素对于萃取平衡影响以及三种无机酸、两种有机酸对于负载Cr(Ⅲ)的D2EHPA反萃效果的影响.结果表明,pH值是影响D2EHPA/煤油萃取Cr(Ⅲ)的重要因素, 在pH＜2时,D2EHPA几乎不萃取Cr(Ⅲ),通过萃取剂的皂化,提高水相pH值,可以实现D2EHPA萃取Cr(Ⅲ).随平衡水相pH值的升高,D2EHPA显示出良好的萃取效果.NaOH溶液作为皂化剂比氨水的分相效果好.加入助溶剂后萃取效率提高,其中10%～20%正辛醇是适宜的助溶剂选择.D2EHPA/正辛醇/煤油萃取Cr(Ⅲ)后立即用无机酸或有机酸反萃,其中硫酸、盐酸或草酸的反萃率能够达到90%以上.     

基于三联吡啶衍生物的Fe~(2+)/Fe~(3+)化学比色敏感器

合成和表征了一种新的化合物(E)-4-′(4-(2-(2-萘)乙烯基)苯基)-2,2′:6′,2″-三联吡啶L.用Fe2+或Fe3+来滴定时,L的溶液(三氯甲烷和乙醇的体积比为1∶20)颜色分别从无色变成洋红色和橙红色,相应的紫外可见吸收光谱都在374和574 nm出现特征吸收峰.此外,即使存在其它过量金属阳离子时,L对Fe2+或Fe3+离子仍然表现出很强的敏感性和选择性.另外,还研究了L对Fe2+或Fe3+离子及两者共同存在时的线性检测浓度范围和最低检测极限(LOD).     

碱性溶液萃取大黄蒽醌类产品动力学的研究

以大黄酸为代表,利用恒界面池法对碱性溶液萃取分离大黄蒽醌类产品的动力学进行了初步研究,以确定大黄中蒽醌类物质的萃取类型。研究结果表明,KHCO3水溶液萃取大黄酸的萃取动力学模式为化学反应控制模型。     

基于蒽酰亚胺基团的新型Fe~(3+)和Hg~(2+)化学敏感器

含蒽酰亚胺基团的化合物N-(2-(6-氨基吡啶))-9-蒽酰亚胺(L1)对Fe3+表现出灵敏的荧光增强响应.L1的衍生物N,N-′(2,6-吡啶基)-二(9-蒽酰亚胺)(L2)对Hg2+在紫外-可见吸收光谱和荧光光谱上显示了良好的识别性.即使在其它金属阳离子存在下,L1和L2分别对于Fe3+和Hg2+仍然表现出较好的选择性.     

D2EHPA对高浓度盐酸介质中钛的萃取

研究了D2EHPA对盐酸介质中钛的萃取和反萃性能。研究结果表明:萃取液中钛以TiOCl2.2D2EHPA的形式存在。钛萃取率随无机相中氯离子浓度和有机相中萃取剂浓度的增加而增加。D2EHPA对钛的饱和承载量为8.98 g/100 g D2EHPA。红外光谱研究进一步表明了Ti-D2EHPA螯合物的性质。在0.5～12 mol/dm3的盐酸介质中,D2EHPA对钛的萃取率随盐酸介质浓度的增加而增加,而对铁、铝、钙、镁无萃取性能。以7%H2O2+3 mol/dm3H2SO4为反萃剂,有机相中的钛可实现一次完全反萃。     

Comparative Study on Reactive Extraction of Nicotinic Acid with Amberlite LA‐2 and D2EHPA

Abstract

The comparative study of reactive extraction of nicotinic acid with Amberlite LA‐2 and D2EHPA in three solvents with different polarity indicated that the extractant type and solvent polarity control the extraction mechanism. Thus, the reactive extraction with Amberlite LA‐2 in low‐polar solvents occurs by means of the interfacial formation of an aminic adduct with 3 or 2 extractant molecules. If solvents with higher polarity are used, each reactant participates with one molecule to the interfacial reaction. The mechanism of reactive extraction with D2EHPA involves in all cases the formation of a salt as the product of the interfacial reaction between one molecule of each reactant.     

Extraction and Stripping Behavior of Iron (III) from Phosphoric Acid Medium by D2EHPA Alone and Its Mixtures with TBP/TOPO

In the present study an attempt has been made to understand the extraction and stripping behavior of iron (III) with D2EHPA alone and its mixture with TBP or TOPO in phosphoric acid medium. Effect of variables such as concentrations of iron (III), phosphoric acid, and phosphate in the aqueous phase, D2EHPA, TBP, and TOPO concentrations in the organic phase and temperature on the extraction process has been studied. The extraction of iron (III) decreased with increase in phosphoric acid concentration. The increase in D2EHPA concentration increased the extraction of iron (III). The presence of TOPO or TBP with D2EHPA showed antagonism. The increase in temperature decreased the extraction of iron (III) with D2EHPA alone and its mixture with either TOPO or TBP showing the exothermic nature of the extraction reaction. The stripping of iron (III) by various reagents followed the order: oxalic acid > phosphoric acid > hydrochloric acid > sulphuric acid > mixture of sulphuric and hydrofluoric acids > ascorbic acid > citric acid irrespective of extraction systems. Higher temperature favors the stripping. The effect of diluents on iron (III) extraction has also been studied. The mechanism of extraction has been explained in the light of the results obtained.     

Separation of Cadmium from Cobalt Electrolyte Solution by Solvent Extraction Method Using Modified D2EHPA

Cadmium from high tenor cobalt electrolyte solution was selectively removed using modified di-(2-ethylhexyl) phosphoric acid (D2EHPA). In this study, D2EHPA was converted to Co-D2EHPA after replacing its functional group with Co²⁺ ions. The process parameters, such as pH, organic concentration, O/A ratio, kinetics, etc., were investigated. A significant amount of cadmium was extracted using Co-D2EHPA at equilibrium pH ～ 3.5 and the McCabe-Thiele diagram showed that 100% cadmium can be extracted through three stages using O/A ratio of 1. Stripping tests revealed that 100% cadmium can be stripped from the loaded organic using 0.4 M H₂SO₄ in a single contact.     

三烷基氧膦与二(2-乙基己基)磷酸协萃对氨基苯酚的研究和应用

为考察复合萃取剂萃取两性官能团溶质的协萃机理,以对氨基苯酚(PAP)为分离溶质,三烷基氧膦(TRPO)+二(2 乙基己基)磷酸(D2EHPA)+庚烷为萃取剂进行了萃取平衡特性的研究。结果表明,该萃取剂萃取PAP时,具有明显的协萃效应。协萃机理为TRPO与PAP的中性分子以及D2EPHPA与PAP的中性分子和阳离子反应生成(HP)2·NH2—C6H4—OH·TRPO或者P·NH3—C6H4—OH·TRPO萃合物;萃取剂中D2EHPA与TRPO的适宜协萃比为1∶3;pH是影响萃取能力的关键因素,起始pH值条件下PAP分子形态摩尔分数较大的pH值区域(6—8),分配系数出现极大值;采用适宜的萃取剂组成对PAP的工业生产废水进行处理,可有效去除废水中的PAP和苯胺。     

Synergistic extraction and separation of Fe(III) and Zn(II) using TBP and D2EHPA

Waste chloride pickle liquors from hot-dip galvanizing plants, steel plants and flue dust contain reasonable amounts of heavy metals such as Zn, Cr, Ni, etc. Iron is invariably associated with most of these materials and comes into solution during leaching. Thus, the synergistic extraction of zinc(II) and iron(III) from leach solutions in tri-n-butyl phosphate (TBP)–di(2-ethylhexyl) phosphoric acid (D2EHPA) system diluted in kerosene was investigated. The Zn and Fe concentrations in the leach liquor used in the present study were 2 g/L. Experiments were carried out in the pH range of 0.5–4.0, temperature of 25°C, using sole D2EHPA, sole TBP and D2EHPA–TBP mixtures at different ratios. Results showed that the co-extraction of zinc(II) and iron(III) increased with increasing equilibrium pH using D2EHPA. It is demonstrated that the mixtures of TBP and D2EHPA are more efficient and selective than D2EHPA alone. At low pH values, the separation factor is low when pure D2EHPA is used as an extractant; however, using TBP as a synergist, the separation factor increases and results in a better separation of zinc from iron. Increasing TBP to D2EHPA ratios in the organic phase caused a slight shift to the right in the extraction isotherm of iron and a marked shift to the right in the extraction isotherm of zinc, and the maximum separation factor of 13.3 × 10³ was achieved at a TBP to D2EHPA volume ratio of 4:1 (0.58 M TBP: 0.12 M D2EHPA). Furthermore, the effect of equilibrium pH, organic to aqueous phase ratio and Cl^? concentration on the selective extraction was investigated. Using two extraction stages at the O/A ratio of 2:1 and pH_e (equilibrium pH) of 3 and 1 for zinc and iron, respectively, 99% of zinc(II) and 96.25% of iron(III) were extracted.     

Solvent extraction modeling of Ce/Eu/Y from chloride media using D2EHPA

End-of-life fluorescent lamps are becoming essential in the rare earths (REEs) field and suppose a feasible secondary source for getting them, reducing thus their supply risk. Considering the proved viability of the cationic extractants, the present study aims at establishing a solvent extraction model using di-(2-ethylhexyl)phosphoric acid (D2EHPA) not only based on the individual Ce, Eu, and Y behavior in chloride media, but also bearing in mind the competitive extraction of these metals in Ce/Eu/Y mixtures, depending on the media variables. Furthermore, the model allow determining the optimal REEs separation conditions. The results disclose that Y could be separated from the mixture using 0.1 mol/L D2EHPA, acidity above of 3 mol/L of protons and chloride concentrations higher than 4 mol/L.     

针铁矿法分离铬铁矿硫酸浸出液中Cr3+与Fe3+

采用针铁矿法分离铬铁矿硫酸浸出溶液中的Cr3+与Fe3+. 结果表明,以Fe2(SO4)3溶液中加入适量KOH后生成的Fe(OH)3为前驱体,在120℃的水热条件下保温8 h后可制备出晶体发育良好的针铁矿晶种. 将铬铁矿硫酸浸出液的Fe3+浓度稀释至1 g/L以下并加入针铁矿晶种,在pH=2.5、温度90℃条件下保温4 h后,Fe3+以针铁矿晶体沉淀析出,能实现铁与铬的分离,除铁率为97%,铬损失率为33%.     

Selective and Synergistic Extraction of Nickel from Simulated Cr-Ni Electroplating Bath Solutions using LIX 63 and D2EHPA as Carriers

The main goal of the present study is to explain synergistic extraction of nickel from simulated Cr-Ni electroplating bath solutions (SEBS) using 5,8-diethyl-7-hydroxydodecane-6-one oxime (LIX 63) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) as extractants by emulsion liquid membrane (ELM) technique. The importance of membrane composition and aqueous phase properties on nickel extraction percentage has been highlighted for the selective extraction of nickel. Some important parameters like acid concentration, stripping solution type and concentration, mixing speed, extractant concentrations, phase ratio, and surfactant concentration was studied to improve the extraction and stripping efficiencies. Higher than > 99% of nickel was recovered at optimum conditions within 6 min. The higher separation factors (β_Ni/Cr) were obtained as 580. As a result, the nickel extraction kinetic with D2EHPA has been defined as faster than LIX63. So, the kinetic transport of nickel mainly depends on LIX63 than D2EHPA. According to these results, D2EHPA behaves as a synergistic extractant in the present extraction mechanism.     

Synergistic Effect of D2EHPA and Cyanex 272 on Separation of Zinc and Manganese by Solvent Extraction

The effect of bis-2-ethylhexylphosphoric acid (D2EHPA), bis (2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272), and tri-butyl phosphate (TBP) and their mixtures in various proportions for the separation and extraction of zinc and manganese from sulfate solutions were investigated. Experiments were carried out in the pH range of 0.5–5.0 at 25, 40, and 60°C. It was shown that the extraction of zinc and manganese by D2EHPA and/or Cyanex 272 can be increased by the increase in pH and temperature. The synergistic extraction and separation of zinc and manganese with a mixture of D2EHPA and Cyanex 272 was studied and the results showed that mixing the two extractants improved the extraction capacity of the mixture. Increasing the D2EHPA to Cyanex 272 ratio in the organic phase, caused a right shifting of extraction isotherms of manganese and zinc; shifting the manganese curve was more than zinc. The manganese curve had considerable right shifting with 5% D2EHPA and 15% Cyanex 272. TBP did not affect the zinc (Zn) and manganese (Mn) extraction. The stoichiometric coefficients of Zn and Mn were determined with 20% and 5% D2EHPA and 15% Cyanex 272 by applying the slope analysis method. The organic phase was stripped by sulfuric acid.     

3D打印多通道微反应器用于萃取分离In3+和Fe3+

将微流体萃取技术与新兴的3D打印技术相结合，设计并制造了一种结构较为复杂的多通道微流体萃取反应器，通过在微反应器内增加混合反应通道的数目来放大其处理量，以期使3D打印多通道微反应器在能够继承微流体单级萃取效率高优点的同时，也能够极大地扩大其处理量。反应器的结构特征主要包括两相入口、液滴筛板、混合萃取通道、混合液汇集腔及混合液出口等。将此种反应器用于不同初始条件下从硫酸溶液中萃取和分离In³⁺和Fe³⁺的实验，结果表明：随着两相接触时间的增长，萃取剂P204对于金属离子的萃取率呈现出先减小，再增大的趋势；溶液中In³⁺和Fe³⁺的分离系数在pH为0.7、接触时间为90s、萃取剂体积分数为30%时，达到最高值381.9。对初始溶液pH、萃取剂在油相中的体积分数、两相的接触时间等单因素对In³⁺和Fe³⁺的萃取率和分离系数的影响作了详细调查。