用二(2-乙基己基)二硫代磷酸-三辛胺协萃体系分离锌和镉

分别应用二（2-乙基己基）二硫代磷酸（D2EHDTPA）和D2EHDTPA-三辛胺（TOA）协萃体系进行了锌、镉分离的研究。D2EHDTPA萃取锌和镉的等摩尔系列法、红外光谱、核磁共振的测试结果表明,萃合物的组成可能为CdA_2和ZnA_2。应用D2EHDTPA-甲苯体系时,镉容易完全萃取,但有机相中的镉很难反萃下来。应用D2EHDTPA和TOA组成的协萃体系时,镉能从硫酸锌溶液中选择性萃取,也能很容易地从有机相中反萃下来,实现镉与锌的分离。萃取速度的控制步骤是界面反应。     

湿法炼锌中性浸出液中铜、镉的萃取分离无渣净化工艺

用ＡｃｏｒｇａＭ５６４０萃取剂对硫酸锌浸出液优先萃取分离铜．用二（２－乙基己基）二硫代磷酸（Ｄ２ＥＨＤＴＰＡ）和三辛胺（ＴＯＡ）协萃体系进行锌、镉分离．应用Ｄ２ＥＨＤＴＰＡ－甲苯体系时,镉完全萃取,但有机相中的镉很难反萃．应用Ｄ２ＥＨＤＴＰＡ－ＴＯＡ协萃体系时,镉能从硫酸锌溶液中选择性萃取,也能很容易地从有机相中反萃,实现镉与锌的分离．提出了从硫酸锌中性浸出液萃取分离铜、镉的无渣净化新工艺．     

二（2-乙基己基）磷酸/磷酸三丁酯复合萃取剂协萃对氨基苯甲酸

为强化两性官能团化合物的萃取分离性能,以对氨基苯甲酸（PABA）为被分离溶质,二（2-乙基己基）磷酸（D2EHPA）/磷酸三丁酯（TBP）/正庚烷的混合物为萃取剂进行了萃取平衡特性的研究,考察了溶液的pH值、D2EHPA浓度、TBP浓度对于萃取平衡的影响,建立了复合萃取剂协同萃取PABA的萃取平衡分配系数的表达式.结果表明,D2EHPA/TBP/正庚烷复合萃取剂萃取PABA具有明显的协萃效应,协萃机理为D2EHPA及TBP分别与PABA的Lewis碱性官能团（—NH2）和Lewis酸性官能团（—COOH）缔合形成亲油性更强的萃合物,且D2EHPA与TBP的浓度差异越小,协萃效应越明显.根据萃取平衡分配系数表达式拟合求取了表观萃取平衡常数,复合萃取剂的值远大于D2EHPA、TBP单独作为萃取剂的值,进一步证明了本文提出的协萃机理.     

溶剂萃取法分离锌锰金属离子的实验研究

以软锰矿和锌精矿同槽酸浸取得到硫酸锌、硫酸锰混合液,研究了从混合溶液中萃取分离锌离子、锰离子的萃取剂的选择以及适宜的萃取条件.实验结果表明,磷酸二(2-乙基己基)酯(P204)萃取锌的能力优于磷酸三丁酯(TBP),在室温、相比A/O=2∶ 1、萃取时间10 min、萃取级数5级、溶液pH为4.0,P204的体积分数为40%时,萃取率达到95%,萃取相锌质量浓度为27.15 g/L.反萃液为0.8 mol/L的稀硫酸,4级反萃,反萃液锌质量浓度可达到89.9 g/L,在此基础上提出了从软锰矿和锌精矿同槽酸浸取液中用P204萃取锌的工艺.     

草酸强化三价铁离子的反萃性能

二(2-乙基己基)磷酸(P204)常作为溶液净化除铁的萃取剂，P204-磺化煤油体系中Fe³⁺与有机相形成络合能力较强的萃合物，使得Fe³⁺反萃比较困难，需采用较高浓度的酸作为反萃剂，但高浓度的酸会破坏有机分子的结构，影响萃取剂循环利用。针对P204-磺化煤油负铁有机相反萃困难的问题，提出利用草酸为反萃剂对负载1g/L铁的P204-磺化煤油有机相的反萃行为进行研究，考察了反萃转速、草酸浓度、反萃温度、反萃时间和相比对Fe³⁺反萃率的影响。结果表明：以反萃转速200r/min，草酸0.4mol/L，反萃时间10min，反萃温度40℃，反萃相比1∶1，采用二级逆流萃取方式，铁的反萃率可以达到99%以上；Fe³⁺反萃过程是吸热反应，其反应的焓变为81.58kJ/mol，反萃过程符合准一级反应动力学方程，对应活化能为49.5kJ/mol。进一步研究了反萃后P204-磺化煤油有机相对Fe³⁺的萃取性能。结果表明：经5次草酸反萃后的P204-磺化煤油有机相萃铁性能几乎不变，对比于高浓度的酸反萃，草酸反萃简化了反萃流程，降低了萃取剂的消耗。     

次氧化锌酸性浸出液中直接萃取铟

针对现行湿法炼锌综合回收铟过程中存在的铟分散损失严重和直收率低的问题,采用直接萃取法从次氧化锌酸性浸出液中回收铟,考察了萃取剂浓度、混合时间、硫酸浓度和萃取温度等因素对铟及主要金属离子萃取率及盐酸浓度和相比对铟反萃率的影响,绘制了萃取平衡等温线和反萃平衡等温线,进行了小型模拟实验和连续逆流萃取-反萃实验,重点考察主要金属离子在萃取和反萃过程中的分布与走向.结果表明,以10%P204为有机相,在相比(A/O)为2/1、逆流萃取级数为3级的条件下,浸出液中铟萃取率达99.9%,杂质铁、锌和镉的萃取率分别为1.5%,0.5%和1.1%.得到的负载有机相采用6 mol/L盐酸反萃,相比为1/5时4级反萃后,铟反萃率达100%,镉、锌和铁基本被全部反萃,反萃后的贫有机相可循环使用.     

LK-C2萃取分离废线路板酸浸液中的铁和镍

针对废线路板酸浸液的硝酸介质体系,探讨了用LK-C2分离铁（Ⅲ）和镍的萃取及反萃条件。pH值为3.00和10.00时分步采用20%LK-C2-煤油二级逆流萃取铁（Ⅲ）和镍,萃取率分别为96.14%和99.35%。分别采用2.00 mol/LHCl二级逆流反萃回收铁和3.00 mol/LH₂SO₄三级逆流反萃回收镍,反萃率分别为99.18%和98.32%。     

2-丁基-2-乙基-1,3-丙二醇从地下卤水中提硼的研究

研究了以2-丁基-2-乙基-1,3-丙二醇为萃取剂,三氯甲烷为稀释剂,从四川平落地下卤水中萃取提硼。通过萃取条件的考察和筛选,最终确定萃取剂浓度为1.0mol/L,相比为1∶1,萃取时间为10min,萃取级数为二级的最优萃硼条件,此时萃取率可达98.56%,萃取剂的饱和萃取容量达44.25g/L(以H3BO3计)。同时,探究了以氢氧化钠溶液作为反萃剂的最佳反萃条件:反萃剂浓度为0.3mol/L,反萃相比为1∶1,反萃时间为8min,反萃级数为二级,其反萃率达到95.49%。在最优萃取和反萃条件下,经两级萃取和两级反萃,硼酸的回收率达到94.87%。     

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。     

盐酸胍与溴化十六烷基吡啶从碱性氰化液中萃取Au(Ⅰ)

以正戊醇为稀释剂,考察了盐酸胍与溴化十六烷基吡啶总浓度为0.06 mol/L时,体系对Au(Ⅰ)的协萃效应.结果表明,在整个浓度组成范围内均有协萃效应(协萃效应系数R>1),且有机相中盐酸胍与溴化十六烷基吡啶的浓度分别为0.05和0.01 mol/L时,Au(Ⅰ)的协萃系数为13.98.考察了平衡时间、相比、待萃液pH值及Au(Ⅰ)浓度对Au(Ⅰ)协同萃取性能的影响.对盐酸胍与溴化十六烷基吡啶萃取Au(Ⅰ)的可能机理进行了分析.分别用Na2SO3和KSCN为反萃剂反萃Au(Ⅰ),KSCN的反萃性能明显比Na2SO3好,KSCN浓度为12 g/L、反萃时间30 min、相比.A/O=1时,Au(Ⅰ)的反萃率为98.5%.     

Separation and recovery of heavy metals from concentrated smelting wastewater by synergistic solvent extraction using a mixture of 2-hydroxy-5-nonylacetophenone oxime and bis(2,4,4-trimethylpentyl) -phosphinic acid

Extraction and separation of copper, zinc, nickel, and cadmium from calcium and magnesium in concentrated smelting wastewater by synergistic solvent extraction using a mixture of 2-hydroxy-5-nonylacetophenone oxime (Mextral 84H) and bis(2,4,4 -trimethylpentyl)-phosphinic acid (Cyanex 272) in an aliphatic diluent (DT-100) was studied. The effects of extractant concentrations, equilibrium pH, organic-to-aqueous phase ratios, system temperature, and extraction and stripping efficiencies on the extraction performance of the heavy metals were investigated. Extraction of pH isotherms showed that addition of Cyanex 272 to Mextral 84H causes obvious synergistic shifts for zinc and cadmium and a slightly antagonistic shift for nickel. The separation factor of cadmium over magnesium was 155.7 and the ΔpH₅₀ values between the metals were over 1.00 pH units. Semi-continuous tests for the metals extraction, scrubbing, and stripping were conducted in a continuous extraction apparatus with conditions further optimized for separation of the metals. Nearly 100% of the copper and nickel and over 98% of the zinc and cadmium were recovered with less than 0.1 mg/L copper and nickel, 26 mg/L of zinc, and 10 mg/L of cadmium remaining in the raffinate. A process in which all valuable metals are extracted simultaneously and stripped selectively at optimal conditions is proposed that is entirely feasible for the separation of copper, zinc, nickel, and cadmium from calcium and magnesium in concentrated smelting wastewater. The study determines the fundamental parameters for the treatment of smelting wastewater by solvent extraction.     

SYNERGISTIC EXTRACTION OF ZINC(II) BY MIXTURES OF PRIMARY AMINE N1923 AND CYANEX272

ABSTRACT

The extraction of zinc(II) and cadmium(II) from chloride solution by mixtures of primary amine N1923 and Cyanex272 (HA) was studied. The synergistic effect was observed for the extraction of zinc(II) while no synergistic effect for cadmium(II), which makes it possible to separate zinc(II) and cadmium(II) with the mixtures. The results showed that zinc(II) was extracted as (RNH₃Cl)₃·ZnClA instead of ZnA₂·2HA which was extracted by Cyanex272 alone. The extraction mechanism was discussed and the formation constants and thermodynamic functions were determined. The separation factors between zinc(II) and cadmium(II) were calculated.     

Extraction and Separation of Cadmium and Zinc with a Mixture of Di-(2-Ethylhexyl)- Dithiophosphoric Acid and Trioctyl Amine

The extractlon of cadmium and zinc with di-(2-ethylbexyi)-dithiophosphoric acid(D2EHDTPA)-toluene and D2EHDTPA-trioctyl amine(TOA)-toiuene has investiated. in-frared spectrum analsis,the nuclear magnetic resonance spectrum(NMR) analysis and conductivity measurements confirm that the probable structures of the extracted complexes are CdA2 and ZnA2, Cadmium can be extracted by D2EHDTPA very eui]y. Almost all the cadmium can be extracted, but stripping of cadmium from the organic phase is very difficult. When a mLxture of D2EHDTPA and TOA is used, selective extraction of cadmium from zinc sulfate solution can be achieved. Cad-mium can be easily stripped from the organic phase.     

Simple separation method of Zn(Ⅱ) and Cd(Ⅱ) from brine solution of zinc plant residue and synthetic chloride media using solvent extraction

In this work, the possibility of separation of Zn~(2+) and Cd~(2+) metal ions from chloride(brine) solutions was examined. For this purpose, simple solvent extraction(SX) experiments by di-2-ethylhexyl phosphoric acid(D2EHPA)in kerosene as a diluent was performed on synthetic and industrial chloride solution obtained from brine leaching of zinc filter cakes(by-product of zinc hydrometallurgical processing). The optimal conditions for separation were determined. The zinc extraction efficiency was 99% with negligible co-extraction of cadmium.Therefore, a high ΔpH_(0.5) value for Zn(Ⅱ) and Cd(Ⅱ) was achieved. FT-IR and slope analysis indicated that ZnClA·3HA and CdClA·3HA species were probably extracted.     

The separation and recovery of copper(Ⅱ), nickel(Ⅱ), cobalt(Ⅱ), zinc(Ⅱ),and cadmium(Ⅱ) in a sulfate-based solution using a mixture of Versatic 10 acid and Mextral 984H

We studied the separation and recovery of copper(Ⅱ), nickel(Ⅱ), cobalt(Ⅱ), zinc(Ⅱ), and cadmium(Ⅱ) from magnesium and calcium, using synergistic solvent extraction(SSX) in a typical hydrometallurgical waste solution. A mixture of Versatic 10 acid and Mextral 984 H, diluted with Mextral DT100, was used to obtain fundamental data on p H and distribution isotherms, as well as the kinetics of extraction and stripping. We also investigated the main effects and interactions of common solvent extraction factors: the extraction p H at equilibrium, the temperature, and the extractant concentration. The synergistic effect for extracting metals was confirmed. The results showed that the addition of Mextral 984 H enhanced the separation factors of copper, nickel, cobalt,zinc, and cadmium over magnesium and calcium. Compared with Versatic 10 acid alone, for a mixture of0.5 mol·L~(-1) Versatic 10 acid/0.5 mol·L~(-1)Mextral 984 H, Δp H50 values of copper, nickel, cobalt, zinc, and cadmium were found to be N 2.0, 3.30, 2.85, 0.95, and 1.32 p H units, respectively. The Δp H_(50)(Zn–Mg)and Δp H_(50)(Zn–Ca)values were 3.27 and 2.25, respectively, indicating easy separation and recovery of copper, nickel, zinc, cobalt,and cadmium. The extraction and stripping of copper, cobalt, zinc, and cadmium were fast, with 90% of the metal transferred in 2 min. We next studied whether the metals could be stripped from the extracted liquid selectively in sequence, by using sulfuric acid at different concentrations. The influence of the molecular structure of the oxime and carboxylic acid components upon the synergistic effects was identified by numerical analysis.Excellent separation of copper, nickel, cobalt, and zinc over magnesium and calcium was achieved with this synergistic solvent extraction system.     

Solvent Extraction Studies of Zinc and Cadmium with Aliquat 336-S in Aqueous Chloride Solutions

Abstract

New solvent extraction systems have been developed for the extraction of zinc and cadmium from aqueous chloride solution using Aliquat 336-S dissolved in the nonpolar solvents heavy aromatic naphtha and xylene as the extractant. Moderately high concentrations of the metalions (1 mg/ml zinc and 2 mg/ml Cd) can be extracted quantitatively from acid solutions with an equal volume of 5% Aliquat 336-S solution in 15 sec. Both zinc and cadmium can be stripped from the organic phase with a series of aqueous stripping solutions. When comparing zinc and cadmium, cadmium is the easier to extract and the more difficult to strip under the same experimental conditions.     

Extraction of Zinc with Long-Chain β-Diketones and 4-Acyl-5-pyrazolones

Abstract

The extraction of zinc with long-chain 4-acyl-5-pyrazolones and β-diketones was studied. For comparison with the commercial extractant LIX 54, the extraction parameters were studied for their dependence on pH and on the influence of ammonia and tartrate. Among the examined compounds, 1-phenyl-3-methyl-4-(2-ethylhexanoyl)-5-pyrazolone shows the best extraction results. Zinc as well as nickel and cadmium can be extracted from tartrate solution. The separation of zinc and cadmium is possible. The extraction is disturbed by the presence of complexing agents such as ammonia or cyanide.     

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.