三烷基胺萃取丙酸的动力学特性

为研究胺类萃取剂萃取有机酸的动力学行为 ,以丙酸稀溶液为分离溶质 ,三烷基胺 ( 730 1)为萃取剂 ,正辛醇和煤油的混合物为稀释剂 ,采用恒界面池法考察了萃取剂和溶质浓度、搅拌速率、两相接触面积、温度等操作参数对丙酸萃取动力学的影响。结果表明 :730 1萃取丙酸为准一级反应萃取过程 ;且萃取发生在相界面 ,即界面反应萃取机制 ;表观活化能为 2 8.5kJ/mol,萃取速率受温度的影响不显著 ;经计算 ,在一般的萃取塔操作条件下 ,该体系的萃取过程为反应和传质过程的混合控制。     

P204钠皂萃取Mn(Ⅱ)动力学

用恒界面池法研究了硫酸盐介质中P204钠皂萃取Mn(Ⅱ)的动力学.考察了搅拌速度、温度、界面面积、P204钠皂浓度、水相Mn(Ⅱ)浓度对其萃取速率的影响.Mn(Ⅱ)萃取速率随搅拌速度增大而增大,当搅拌速度大于104 r/min后,萃取速率不再受搅拌速度影响;Mn(Ⅱ)萃取速率随温度升高和界面面积增大而增大.P204钠皂...     

丁酸乙酯从盐湖卤水中萃取锂的动力学研究

采用恒界面池法研究丁酸乙酯从盐湖卤水中萃取锂的动力学过程,考察界面面积、丁酸乙酯浓度、水相锂浓度和温度等因素对萃取速率的影响.实验结果表明:丁酸乙酯萃取锂的反应主要发生在界面区域.增加丁酸乙酯浓度可增大正向反应动力,提高萃取速率.萃取速率随温度的升高而增大,萃取反应的表观活化能为16.72 kJ/mol,该萃取反应过程...     

伯胺N1923在硫酸介质中萃取Mn（Ⅶ）的动力学

本文用恒界面池法考察了萃取剂浓度、水相ＳＯ４＾２－浓度、温度等因素对Ｎ１９２３在硫酸介质中萃取Ｍｎ（Ⅶ）的速率的影响，导出了萃取速率方程。实验结果表明，萃取机理为界面控制阴离子交换反应，并求得该萃取反应的表观活化能Ｅｆ＝１５．７ｋＪ／ｍｏｌ。     

反胶团萃取磷酸溶液中镁的动力学

采用恒界面池研究了二壬基萘磺酸(DNNSA)-煤油-磷酸体系萃取镁离子的动力学.考察了搅拌转速和传质界面积对萃取速率的影响,实验结果表明:磷酸中镁离子的萃取速率在200 r·min~(-1)时出现与搅拌强度无关的化学反应动力学"坪区",此时萃取速率正比于两相接触面积,说明萃取过程为界面化学反应控制过程.在动力学"坪区",镁离子萃取速率正比于萃取剂浓度和水相镁离子浓度,随着温度升高萃取速率增加;萃取反应活化能为70.01 kJ·mol~(-1),并得到了DNNSA萃取磷酸中镁离子的萃取动力学方程.     

反胶团萃取盐酸溶液中钛的动力学

为实现盐酸法钛白工艺中钛的有效萃取,在磷酸三丁酯-正癸醇对盐酸溶液中钛的反胶团萃取研究基础上,采用恒界面池法研究了磷酸三丁酯-正癸醇反胶团萃取盐酸溶液中钛离子的动力学。考察了搅拌速度、反应温度、两相界面面积、反应物浓度对钛萃取速率的影响。结果表明:盐酸中钛离子萃取速率随水相搅拌速度、两相界面积、反应温度、萃取剂浓度、钛离子浓度和氯离子浓度的增大而增大,萃取反应活化能为31.73 k J·mol-1,萃取过程为水相扩散-反应混合控制过程。并得到了磷酸三丁酯-正癸醇对盐酸溶液中钛离子的萃取动力学方程。     

羟丙基-β-环糊精萃取苯基琥珀酸的动力学特性

为研究β-环糊精衍生物类萃取剂萃取芳香酸对映体的动力学行为,以苯基琥珀酸对映体（PSA）为分离溶质,羟丙基-β-环糊精（HP-β-CD）为萃取剂,采用恒界面池法考察了搅拌速率、两相接触面积、萃取剂和溶质浓度等操作参数对苯基琥珀酸对映体萃取动力学的影响。实验结果表明：HP-β-CD萃取PSA为准一级反应萃取过程;且萃取发生在相界面,萃取速率随PSA的初始浓度的增大而增大,且呈线性关系。     

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.     

复合体系下磷酸和硫酸的萃取动力学

为了深入了解萃取过程的机理和动力学特征,采用了恒界面池法研究了复合体系下磷酸和硫酸的萃取动力学,分别考察了比界面积、初始水相中磷酸浓度、初始水相中硫酸浓度对磷酸、硫酸萃取速率的影响,并提出了60℃下硫酸-磷酸复合体系中萃取磷酸和硫酸的动力学方程。实验结果表明:磷酸和硫酸的萃取速率随着比界面积增大而减小,随着初始水相中磷酸浓度的升高而逐步增加;初始水相中硫酸浓度的增大也有利于提高磷酸和硫酸的萃取速率。并研究了在60℃硫酸-磷酸复合体系中,磷酸和硫酸的萃取动力学方程,并用工业原料磷酸对萃取动力学进行了验证,表明拟合所得的方程计算的磷酸和硫酸萃取速率和实际测得的值相近。     

乙二醛溶液体系中乙酸络合萃取的动力学研究

采用恒界面池法研究了乙酸在乙二醛溶液中的萃取动力学，实验结果表明：萃取速率由界面化学反应所控制，且表观反应速率方程为：ｒ＝ｋｓＣＨＡｃ１．３６４１，在２５℃时的反应速率常数ｋｓ＝１．８２×１０－２ｍｏｌ／ｃｍ２·ｓ。此外，还研究了温度对反应速率的影响，求取了表观反应的活化能Ｅａ＝２３．２８３３ｋＪ／ｍｏｌ，从而进一步说明了萃取速率控制步骤为界面化学反应所控制。     

THE KINETICS OF ZINC,COBALT AND NICKEL EXTRACTION IN THE D2EHPA-HEPTANE-HC104 SYSTEM USING THE ROTATING DIFFUSION CELL TECHNIQUE

The kinetics of the extraction of zinc, cobalt and nickel from perchlorate solutions using di 2-ethyl-hexyl phosphoric acid (D2EHPA) dissolved in heptane were studied using the Rotating Diffusion Cell technique. The extraction of each metal was investigated individually over a wide range of metal concentration, extractant concentration, pH and temperature conditions.

The data were analysed in terms of a mass transfer with chemical reaction (MTWCR) mechanism. Hughes and Rod'/s generalized MTWCR model was used to fit the cobalt data using kinetic and equilibrium parameters. The zinc and nickel data were quantitatively described within the framework of the MTWCR model. The zinc extraction rate was so fast that mass transfer alone was rate controlling. The nickel extraction experiments were so slow that the metal-ligand complex formation was incomplete in the aqueous film. Some reaction was determined to be occurring in the aqueous bulk solution as well.     

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.     

Separation of Cobalt and Zinc from Manganese,Magnesium, and Calcium using a Synergistic Solvent Extraction System Consisting of Versatic 10 and LIX 63

Abstract

The Boleo leach solution contains large amounts of manganese (45 g/L), magnesium (25 g/L) and small amounts of cobalt (0.2 g/L) and zinc (1 g/L) in sea water. Due to the high manganese concentration, it is very difficult to separate cobalt and zinc from manganese, magnesium, and calcium using conventional solvent-extraction processes, which has led to the development of a synergistic solvent extraction (SSX) system consisting of Versatic 10 and LIX®63. By adding 0.4 M LIX 63 to 0.5 M Versatic 10, large synergistic shifts were obtained for cobalt (max. ΔpH₅₀ 4.24) and zinc (max. ΔpH₅₀ 1.62). After a single contact at pH 4.5, the extraction of cobalt was almost complete and that of zinc 80%. The extraction of manganese was 1.55%, and almost no magnesium and calcium were extracted, indicating excellent separation of cobalt and good separation of zinc from manganese, magnesium, and calcium. The SSX system was further optimized to reduce the co-extraction of manganese with the synthetic Boleo demonstration plant solution. It was found that with 0.33 M Versatic 10 and 0.30 M LIX 63, the SSX system composition approached optimum. After a single contact at pH 5.5, the extractions of cobalt and zinc were 93% and 70%, respectively, while the manganese concentration in the loaded organic solution was only 0.28 g/L. The extraction and stripping kinetics of cobalt and zinc were rapid. The SSX system was tested in two integrated pilot-plant trials with excellent results. Baja Mining has planned to implement the SSX circuit in their future Boleo plant.     

Solvent Extraction Studies for Separation of Zn(II) and Mn(II) from Spent Batteries Leach Solutions

This study aims at assessing the possibility of using solvent extraction processes for separating Zn(II) and Mn(II) dissolved in aqueous solutions obtained by acid bioleaching of spent alkaline and Zn-C batteries. In this context, Cyanex 272 and DEHPA were tested as extractant agents, and the former was shown to have better performance. Hence, the effect of four factors (equilibrium pH, extractant concentration, A/O ratio, and temperature) into three response variables (extraction efficiency of Zn, Y_Zn; extraction efficiency of Mn, Y_Mn; separation factor, β) were tested according to a full factorial design (2⁴) with two replicated center points. Our study revealed that Y_Zn depends mainly on the extractant concentration, Y_Mn on the equilibrium pH and β on the equilibrium pH, extractant concentration, and A/O ratio as well as on second and third order interactions. One extraction step is sufficient to reach high extraction of zinc in synthetic solutions, but two stages were required for real leaching liquor. The extraction kinetics is fast (less than 15 min) for both metals, even when real liquor was tested. The organic solvent can be efficiently recovered using a stripping solution of H₂SO₄ 1 M and thus the process can be considered environmentally sustainable.     

Recovery of Zinc by LIX 984N‐C from Electroplating Rinse Bath Solution

The development of a complete solvent extraction process at the laboratory scale for recovering zinc from the zinc electroplating first rinse bath solution (alkali solution) containing ～1.9 g/L zinc (ZEFRBS) by a solvent extraction route using LIX 984N‐C, which is a new SX reagent developed by Cognis, and dissolved in commercial kerosene was investigated. By using LIX 984N‐C, an electrolyte from ZEFRBS with ～12 g/L zinc content, which was addable to the alkali zinc electroplating bath, was generated by 10 vol.% LIX 984N‐C in commercial kerosene at the O/A ratio of 1/4 and equilibrium pH value of 8.00 ± 0.05 with a two‐stage countercurrent extraction, and stripping of the loaded organic by a strip solution with 150 g/L sulfuric acid and with the O/A ratio of 1.5 at a two‐stage countercurrent stripping process. A new complete flow sheet of 10 vol.% LIX 984N‐C process for the recovery of zinc from ZEFRBS has been demonstrated.     

用M5640从锌氨溶液中萃取锌

以M5640为萃取剂,在CO2协同作用下,从氨?硫酸铵溶液中萃取锌,考察了萃取剂浓度、总氨浓度、相比、温度、加入CO2等因素对锌萃取率的影响. 结果表明,M5640在氨性溶液中对锌有一定的萃取能力,溶液pH值和总氨浓度对锌的萃取率影响较大,向溶液中加入CO2可明显提高M5640对锌离子的萃取能力. 在温度25℃及M5640加入量35vol%、相比O/A=2、锌离子浓度18.02 g/L、总氨浓度3 mol/L、加入CO2的条件下,锌的单级萃取率由不加CO2时的65.1%提升至97%以上,两级错流萃取锌萃取率达99.9%. 萃取得到的有机相不含氨,表明加入CO2可避免氨的共萃.     

氢氧化钠浸取-浸取渣熔融法从炼钢厂烟尘中提取锌的研究

Extractability of zinc from two types of electric arc furnace (EAF) dusts containing 24.8% and 16.8% of zinc respectively (denoted as Sample A and Sample B) were tested using direct alkaline leaching followed by fusion of the resulting leaching residues with caustic soda. The experimental results show that the extraction of zinc is heavily dependent on the contents of iron in the dusts. The higher iron content, the lower extraction of zinc is obtained. 53% and 38% of zinc can be extracted when both dusts were directly contacted with 5 mol.L-1 NaOH solution for 42 h. The remaining zinc left in the leaching residues, which supposed to be present as zinc ferrites, can be further leached when the residues were fused with caustic soda. Quantitative extraction of zinc can be obtained from the leaching residue of Sample A while only 85% from Sample B. The extractability of zinc from dusts with various contents of iron is compared. The production flowsheet for zinc from the dusts using the process proposed is d     

Separation of Zinc by a Non‐dispersion Solvent Extraction Process in a Hollow Fiber Contactor

Abstract

A process for recovery of zinc from acid solution with di(2‐ethyl hexyl phosphoric acid) (D2EHPA) dissolved in iso‐dodecane was carried out at 20°C in a countercurrent tubular membrane extractor using a hollow fiber as solid support. Experiments were performed at different aqueous metal concentrations (0.1–1.0 g/L), pH 0.1–2.1, and D2EHPA concentrations (2–8 v%). It was found that both the flux of metal and the extraction extent was highly influenced by the extractant concentration and the pH of the feed solution. Overall mass transfer coefficients were determined and related to the tube side, the membrane, and the shell side mass transfer by varying the aqueous flow rate (0.38–0.80 L/min) and organic flow rate (0.22–0.57 L/min) in countercurrent flow. The overall mass transfer coefficient for zinc extraction ranged from 6.2×10^?6 m/s to 25.3×10^?6 m/s. It was concluded that extraction kinetics were a major contributor to the overall resistance to mass transfer.     

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.     

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.