The Effect of Hydroxyoxime Isomer Conformation on Metal Extraction in the LIX 63/Versatic 10 Synergistic System

LIX 63 contains an aliphatic α-hydroxyoxime as its active component, with two isomeric forms (anti and syn) being present in a 3:2 ratio in “as supplied” reagent. In the present work, > 90% pure syn hydroxyoxime was isolated from LIX 63. Examination of metal extraction properties in systems containing Versatic 10 with anti and/or syn hydroxyoxime established unequivocally that the syn isomer plays no beneficial role in metal extraction in this synergistic solvent extraction system, thereby excluding the possibility of monodentate coordination of hydroxyoxime. Economic consequences arising from this outcome and the opportunity to maximize reagent utilisation are briefly discussed.     

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.     

TBP对LIX84由Cu2+-NH3-Cl——H2O系萃取铜及氨的影响

以Cu2+-NH3-Cl--H2O氨性溶液为被萃水相,在LIX84中添加磷酸三丁酯(TBP),考察了有机相中TBP浓度、被萃水相铜离子浓度、总氨浓度和pH值及相比、LIX84浓度对铜萃取率、共萃氨量的影响. 结果表明,随LIX84中TBP浓度升高,铜萃取率变化不大,负载有机相的共萃氨量明显降低. 有机相中TBP浓度为0.1 mol/L、LIX84浓度为40%、被萃水相铜离子浓度25 g/L、总氨浓度3 mol/L及pH值9.1、相比1:1、萃取时间30 min时,铜萃取率约为81%,与未添加TBP时基本一致,而负载有机相的共萃氨量由未添加TBP时的260 mg/L降至添加TBP后的85 mg/L.     

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.     

Separation of Cadmium,Cobalt, and Nickel by Solvent Extraction using the Nickel Salts of the Extractants

A new solvent‐extraction process for the separation of cadmium, cobalt, and nickel in sulphate solutions coming from the hydrometallurgical processing of spent Ni‐Cd batteries is proposed. The main innovation is to use nickel salts of the extractants, thus avoiding external pH control in the extraction operation. The extractants are first loaded with nickel in conditioning steps, using a neutralizer for pH control, and afterwards contacted with the aqueous processing solutions for extraction of interested metals with no further need of neutralization. This process is an alternative to the usual approach, which uses the sodium or ammonium salts of the extractants, avoiding introducing these cations in the process stream. Using this approach, the extraction of cadmium with nickel salt of 1 M DEHPA was performed at resulting pH values of 3.8–4.3 producing an organic phase loaded with 35 g/L Cd. Cobalt extraction with the nickel salt of Cyanex 272 was further achieved at resulting pH of 5.1–5.7 obtaining a organic loaded with 6.5 g/L Co.     

Recovery of Copper from a Waste Heat Boiler Dust Leach Liquor using LIX 84I and LIX 622N

The dust collected from the waste heat boiler of a copper plant was leached with sulfuric acid and the leach liquor contained 31.63 kg/m³ Cu, 14.78 kg/m³ Fe, 2.21 kg/m³ Zn, 0.26 kg/m³ Co, 0.09 kg/m³ Ni, and 0.23 kg/m³ Cd. The iron content in the leach liquor was precipitated out using Ca(OH)₂ and from the filtrate copper was extracted with the extractants LIX 84I and LIX 622N in kerosene. Extraction of copper with either extractant increased with increasing equilibrium pH and extractant concentration. The McCabe-Thiele plots for quantitative extraction of copper indicated 3-stages at O:A ratio of 3:2 with 30% extractants. The counter-current extraction study showed 0.21 kg/m³ and 6.77 g/m³ copper in the third stage raffinates of LIX 84I and LIX 622N indicating 98.64% and 99.95% extraction, respectively. For extraction of a mole of copper ion, two moles of the extractant was required to release two moles of hydrogen ion to the aqueous phase. The quantitative stripping of copper from the loaded organic phases of LIX 84I and LIX 622N with 180 kg/m³ H₂SO₄ was possible in 3-stages at O:A ratio of 3:1 and 3:2, respectively. The thermodynamic parameters such as ΔH, ΔG, and ΔS were calculated for both the systems. The enthalpy change (ΔH) values were positive for extraction of Cu with either extractant indicating the processes to be endothermic. The IR spectra indicated the association of phenolic-OH group of oxime molecules in the formation of copper complexes.     

Separation of Copper and Zinc by Solvent Extraction During Reprocessing of Flotation Tailings

Results from the solvent extraction of copper and zinc from pregnant solutions after bioleaching of re-floated tailings from the Kipushi concentrator in DR of Congo are presented. LIX984N has been used as extractant for copper, while D2EHPA as such for zinc, following prior removal of the ferric iron via precipitation. The McCabe-Thiele diagrams constructed for Cu and Zn extraction have theoretically suggested the need for two stages for copper and one for zinc. Stripping these metals to the aqueous phase by sulphuric acid has yielded rich electrolytes with 48.5 g/L copper and 85.5 g/L zinc. Thus, copper and zinc could be further recovered from the stripped solutions by electrolysis.     

Solvent Extractive Separation of Zirconium and Hafnium from Hydrochloric Acid Solutions by Organophosphorous Extractants and Their Mixtures with Other Types of Extractants

From 1 to 4 M HCl medium, zirconium was selectively extracted over hafnium by organophosphorous extractants (D2EHPA, PC88A, Cyanex 272). In order to increase the separation factor Zr/Hf, mixtures of organophosphorous extractants with amines (Alamine 336, Aliquat 336) or cationic extractants (Versatic acid 10, LIX 63) were employed in 1–4 M HCl medium. Mixtures with Versatic acid 10 and LIX 63 led to depression in the extraction percentages. But the mixture with LIX 63 was found to be the most effective in separating the two metals among the extractant systems tested in this study. The highest separation factor of around 9.5 was obtained with a mixture of 0.01 M LIX 63 + 0.05 M Cyanex 272 at HCl concentration of 2–4 M. The Zr and Hf were effectively stripped from the loaded mixture of LIX 63 + Cyanex 272 by sulfuric acid solution.     

Selective Recovery of Copper,Cobalt, and Nickel from Aqueous Chloride Media using Solvent Impregnated Resins

Selective recovery of copper, cobalt, and nickel from acidic chloride media was investigated with solvent impregnated resins (SIRs) containing acidic organophosphorus extractants. The adsorption of each metal with the SIR proceeds via a cation exchange mechanism. An SIR containing 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (PC-88A) has high selectivity for Cu²⁺, and the order of selectivity is Cu²⁺ > Co²⁺ > Ni²⁺. Effective adsorption-elution can be achieved by chromatographic operation for the selective recovery of Cu²⁺ from a ternary metal solution. High selectivity for Co²⁺ was observed using a SIR comprising bis-2,4,4-trimethylpentylphosphinic acid (Cyanex 272) and can be effectively separated from a Co and Ni binary metal solution by column adsorption. A simple and effective process flow sheet is proposed for selective recovery of Cu²⁺, Co²⁺, and Ni²⁺ from aqueous chloride media using the two SIRs.     

溶剂萃取过滤分离油浆中的催化剂粉末

介绍了催化裂化油浆的用途及主要的净化技术,并重点对以糠醛作为溶剂萃取过滤分离催化裂化油浆中催化剂粉末工艺进行了考察.试验结果表明,在抽提温度为60 ℃,m(剂):m(油)为2.5:1.0,抽提时间为25 min的条件下,抽出油收率可以达到48.14%,同时可使油浆中95%以上的催化剂细粉末转移到抽余油中,抽出油中约5%...     

阴离子交换色谱法分离含钴溶液中锌、镉、铜等杂质

采用阴离子交换色谱法,研究了某锌厂冶炼废渣的硫酸化焙砂浸出液中钴与锌、镉、铜等杂质离子的分离工艺,确定了最佳工艺参数：将料液配制成含2 mol/L Cl–1和0.1 mol/L Na2SO3的溶液,调节pH值为 4.5,搅拌数分钟,料液pH值降低至 4.0后,用201?7阴离子交换色谱柱进行分离,柱后流出液中锌、镉、铜等杂质的含量达到钴冶金工艺要求,钴的损失为0.7%左右.     

P507与Cyanex272协同萃取分离溶液中钴镍离子

采用P507与Cyanex272协同萃取分离回收浸出液中的Ni2+, Co2+,考察了初始pH值、有机相复配比(P/C)和水油相比(A/O)的影响. 结果表明,协萃优化条件为：有机相皂化率50%,皂化时间30 min;有机相组成为10%复配萃取剂[P507:Cyanex272为3:2(j)]+85%磺化煤油+5% TBP;相比为3:1,水相pH值为2.5. 在此条件下,Co2+的一级萃取率为92.96%. 利用200 g/L硫酸反萃负载有机相,在相比2:3、振荡强度225 r/min、时间4 min的条件下,Co2+的反萃率为98.68%,实现了低pH值下Ni2+和Co2+的萃取分离.     

Extraction of Copper,Nickel and Cobalt from Indian Ocean Polymetallic Nodules

Various processes used for the recovery of valuable metals such as copper, nickel and cobalt from marine manganese nodules has been reviewed and an effective process for their extraction has been described.     

Separation and Recovery of Cadmium from Acidic Leach Liquors of Spent Ni-Cd Batteries using Molten Paraffin Wax Solvent Extraction

Separation and recovery of cadmium from sulphate leach liquors of spent Ni-Cd batteries using TBP, HDEHP (D2EHPA), EHEHPA (PC 88A or Ionquest 801 or P507) have been investigated in a laboratory scale. Cadmium can be extracted into paraffin waxes from acidic solutions in the temperature range of 55–75°C using different extractants. The influence of various parameters on extraction and stripping were studied in detail. The feasibility of separation of cadmium from nickel using these extractants and their combination was studied. The mixture extractant of EHEHPA and TBP was found to be the best for the separation of Cd and Ni. A three-stage counter-current extraction simulation test for cadmium extraction was carried out at an A/O phase ratio of 4:1 and pH 2.5. More than 99.97% Cd²⁺ was extracted with the organic phase containing 0.7 mol L^?1 EHEHPA and 0.5 mol L^?1 TBP, while more than 99.97% nickel was left in the raffinate. The cadmium loaded organic phase was stripped with 2 mol L^?1 hydrochloric acid in the stripping stage. The present method can be applied to the separation and recovery of cadmium from acidic leach liquor of spent Ni-Cd batteries or related waste liquor.     

Solvent Extraction and Separation of Gallium(III) using Hexaacetato Calix(6)Arene

Gallium(III) was extracted at pH 3.5 by equilibrating eight min with 10 mL of 0.0001 M acetyl derivative of calix(6)arene in xylene. Gallium(III) was stripped quantitatively with 0.1 N hydrochloric acid and determined spectrophotometrically with 0.01% PAR at 510 nm. The nature of the extracted species was determined from the log-log plots and its stoichiometry was confirmed by numerical treatment to experimental data. The IR analysis of Ga(III) loaded organic phase was also studied. The conformational change of reagent during complex formation was studied from the ¹H NMR treatment. The temperature dependence of the extraction equilibrium and metal loading capacity of the reagent was also evaluated. The proposed method was successfully applied for the extraction and separation of multicomponent mixtures, synthetic mixtures, and binary and ternary separation of gallium from the associated elements. The results obtained were reproducible and accurate.     

含钴废渣硫酸化焙砂浸出液中钴、铁、锰分离研究

对某锌厂含钴废渣硫酸化焙砂浸出液进行了钴与铁、锰分离工艺研究。研究表明 ,焙砂用水浸出时延长时间为 3.5h,可使大量铁以黄铁矾的形式除去 ,再控制溶液 p H3～ 3.5,温度 1 0 0°C,时间 1 h的条件下 ,采用针铁矿法除铁 ,铁的去除率可达 99.5% ,然后控制溶液 p H4～ 4.5,温度1 0 0°C,用 1 0 % ( NH4 ) 2 S2 O8溶液氧化 Mn2 + 为沉淀而除去 ,锰的去除率为 99.8% ,同时还可氧化Fe2 +达到深度除铁的目的 ,铁的总去除率达 99.9%。在此过程中 ,钴的损失率仅为 2 .5% ,取得了令人满意的结果     

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.     

Extraction of uranium(VI) from nitric acid solutions using N,N-dihexyloctanamide in ionic liquids: Solvent extraction and spectroscopic studies

Liquid-liquid extraction studies of uranium(VI) were carried out from nitric acid medium using di-n-hexyloctanamide (DHOA) in several room-temperature ionic liquids (RTIL). The extraction of the metal ion as a function of nitric acid concentration showed different trends based on the alkyl substituents of the RTIL. While the D_U values decreased with increasing HNO₃ concentration (up to ca. 0.5 M) with [C₄mim][NTf₂] and [C₆mim][NTf₂], almost no change was seen with [C₈mim][NTf₂]. This suggested that while a cation-exchange mechanism is operative with the former diluents, which was to a much lower extent for the latter. The extracted species were found to contain about 2 molecules of DHOA from the feed solutions containing either 0.01 M and 4 M HNO₃, which was arrived at from the ligand-concentration-variation experiments. Recycling studies were also performed by carrying out stripping and radiolytic stability studies. The nature of the extracted species as ascertained from the UV-visible spectrophotometry studies indicated similarity between the extracts obtained in RTIL medium, which were entirely different from that observed with n-dodecane as the diluent.     

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.