从电镀污泥浸出液中选择性萃取铜的研究

采用M5640-磺化煤油作为萃取剂,H2SO4为反萃剂,对电镀污泥浸出液中的铜进行选择性萃取实验,确定了萃取铜及反萃的最佳工艺参数。结果表明,实验采用二级萃取,萃取剂浓度为5％,VO/VA=1：1,混合时间为2min时,铜的萃取率可达到9996以上,另外采用已优化的反萃工艺参数,铜的反萃率可达99％以上。同时,萃取剂对Ni、Zn的共萃率较低,表明M5640-磺化煤油体系对电镀污泥液中铜的萃取选择能力较高,可以达到与溶液中Ni、Zn有较好的分离效果。     

汽油硫醚的结构和萃取性能的研究

本文利用合成硫醚和色质联用方法分析了江汉汽油硫醚的结构,研究了硫醚作为萃取剂进行萃铜实验,并利用氨水作为反萃试剂解决了硫醚-铜络合物的反萃问题。     

浊点萃取-高效液相色谱法测定某些中草药中铜的研究

基于浊点现象,建立了以双硫腙为配位剂、TritonX-114为表面活性剂的浊点萃取-高效液相色谱法测定中草药中痕量铜的新方法。研究了溶液pH值、配位剂的浓度、表面活性剂的浓度、平衡温度和平衡时间、流动相类型等实验条件对浊点萃取及铜测定的影响。在最佳试验条件下,该方法的线性范围为0．1—120μg·L^-1,相关系数达0．997-0．999,铜的检出限达到0．1μg·L^-1。相对于传统的液相色谱分析法灵敏度提高了18倍。该方法成功用于中草药样品中铜的测定并获得了满意的结果。     

生长液滴法Lix54-100萃铜的动力学

采用改进的生长液滴法,研究氨性条件下Lix54-100萃铜的动力学,考察了萃取剂浓度、水相铜离子浓度、pH值等对萃取初速的影响,Lix54-100萃铜的动力学方程为:R0=k[HL]o. 萃取剂进入水相发生构型改变,速度较慢,是整个萃取过程的控制步骤.     

盐湖提锂萃取剂及萃取体系研究进展

中国盐湖中蕴藏着丰富的锂资源,溶剂萃取法提锂是目前研究较多且较深入的方法之一。大量研究表明,萃取剂分子的结构是决定萃取效率的关键因素。对近年来盐湖卤水提锂萃取剂及萃取体系的研究进展做了综述,着重综述了醇+酮、有机磷、季胺盐-偶氮离子螯合-缔合、冠醚和离子液体等不同类型萃取剂及萃取体系的研究现状,分析了各类萃取剂在提锂过程中的机理、特点及存在的问题,并在此基础上对溶剂萃取法盐湖提锂萃取剂的发展方向做了展望。     

从电镀污泥中回收铜和镍

本文研究了从铜镍电镀污泥中回收铜和镍的工艺,确定了萃取分离铜和镍的最佳工艺条件。实验结果表明,以M5640为萃取剂,硫酸溶液为反萃取剂,经萃取分离后．铜的回收率大于90％,镍的回收率大于95％。     

铜萃取剂Mac12萃取性能的研究

采用国产化工原料合成了Mac12铜萃取剂，用Mac12萃取剂进行了萃取剂用量、有机相与无机相相比、pH值试验、萃取动力学试验、萃取热力学试验、反萃动力学试验、反萃剂酸度试验，得到了较好的萃取效果，萃取率≥93％，反萃取率≥96％。     

LIX84-I从氨性溶液中提纯铜的研究

研究了LIX84-I对氨性溶液中铜的萃取和反萃取过程,考察了相比、萃取剂体积浓度、振荡时间及萃取次数对萃取过程的影响,并优化萃取试验条件:萃取相比为1:3;萃取剂体积分数为32%;振荡时间为30 s;经过一次萃取,铜萃取率可达98.72%。用硫酸反萃,主要研究了反萃硫酸浓度、振荡时间、相比、反萃次数对反萃的影响,并优化反萃试验条件:反萃取硫酸浓度140g/L;振荡时间为30 s,相比为1:1,经过两次反萃后有机相中铜浓度达到99%以上。     

Lix984萃取分离碘量法测定电镀污泥中铜

建立了铜与LIX984的萃取体系,测定电镀污泥浸出液中铜,当萃取剂为3%时对铜的萃取达到99.5%。相比1∶1萃铜效果最佳铁镍锌的萃取很少。本方法就是运用其好的选择性检测酸性浸出液中的铜含量。结果相对标准偏差为0.04%,回收率为101.3%102.5%。     

萃取光度法测定微量铜

以三氯甲烷作萃取剂，PAN作显色剂，通过光度法测定镀铜废水中的微量铜，选择了适合的测量波长，讨论了酸度，萃取剂用量及振荡时间对萃取率的影响，分析了干扰元素的影响及消除，该方法准确度高，可测量0．01－1．00μg/mL的微量铜。     

Solvent Extraction of Copper from Nitrate Media with Chelating LIX‐Reagents: Comparative Equilibrium Study

Abstract

Comparative experimental studies were carried out on extraction of copper(II) cations from aqueous acid nitrate media using four LIX‐reagents, representatives of different extractant classes: LIX 984N‐I, LIX 860N, LIX 84‐I and LIX 65N. As a diluent, liquid hydrocarbon undecane was used. The extraction behavior of the LIX‐reagents was compared based on an analysis of the influence of the main factors on the two‐phase mass transfer process: aqueous pH‐value, initial copper and extractant concentrations, and temperature. The experimental data received were used in the calculation of important parameters characterizing the efficiency of copper extraction from nitrate media with different LIX reagents: distribution ratios D, concentration extraction constants K _ex, pH_0.5‐values, and thermodynamic parameters such as enthalpy, entropy, and free energy changes (ΔH ⁰, ΔS ⁰, ΔG ⁰‐values).     

Hollow-Fiber Membrane Extraction of Copper from Aqueous Nitrate Media by LIX® Reagents: Comparison of Extraction Efficiency and Fractional Resistances

Abstract

Extraction of copper from nitrate/nitric acid aqueous solutions was studied using a HF Membrane Module and four LIX reagents (LIX® 860N-I, LIX® 984N, LIX® 84-I, and LIX® 65N) containing different active compounds (ketoximes and/or salicylaldoximes). Kinetic experiments varying the flow rates of both phases, aqueous and organic, and the extractant concentration were carried out to compare the extraction rate and efficiency from nitrate-aqueous media. A mathematical model based on the “aqueous extraction mechanism” in which the chemical reaction takes place in an aqueous-reaction zone was applied to determine the individual resistances of the copper mass-transfer process. It was found that the fractional resistance due to chemical reaction in the aqueous reaction zone, which varied from 92.5% to 95.8% in the order LIX® 860N-I < LIX® 984N < LIX® 84-I < LIX® 65N, controlled the total rate of the hollow-fiber copper extraction from nitrate aqueous media.     

Stepwise addition of chemical reagents for enhancing electrokinetic removal of cu from real site contaminated soils

In this study, a circulation-enhanced electrokinetics (CEEK) system integrated with the stepwise addition of chemical reagents was used to remediate copper-contaminated soils collected from a real site. At first, an optimal extraction process of different chemical reagents was found to obtain the highest copper removal efficiency by conducting batch extraction experiments. The chemical reagents served as extracts including EDTA, NaOH, and sodium dithionite + sodium citrate. Then, CEEK integrated this optimal extraction, that is, the treatment of 6-day EDTA, NaOH, EDTA, sodium dithionite + sodium citrate, and EDTA in a series. According to experimental results, the NaOH and sodium dithionite + sodium citrate could effectively facilitate the copper removal during the extraction and electrokinetics (EK) processes. The optimal extraction process for this real contaminated soil (94% copper removal efficiency) was the alternative extraction of EDTA, NaOH, and sodium dithionite + sodium citrate. The copper removal efficiency of the real contaminated soil could reach around 55% after 30-day CEEK treatment. The continuous decline of soil copper concentration of this integrated EK technique could be achieved as the remediation time was extended sufficiently.     

Copper Solvent Extraction from Waste Cyanide Solution with LIX 7820

The use of a solvent mixture of a quaternary amine and nonylphenol (LIX 7820) to extract copper cyanide from waste cyanide solution has been studied. Copper extraction is favorable at low pH, whereas a high cyanide‐to‐copper ratio tends to suppress copper loading. The preferential extraction of Cu(CN)₃ ^2? over Cu(CN)₄ ^3? and CN^? has been confirmed by the examination of both the extraction of copper and cyanide by the solvent mixture under different experimental conditions. The solvent mixture also strongly extracted zinc and nickel from the cyanide solution, but it exhibits weak affinity for iron cyanide complex and free cyanide. The important findings suggested the potential application of the solvent mixture for the recovery of copper and cyanide from waste cyanide solutions, by which copper can be extracted and concentrated into a small volume of solution and the barren cyanide solution recycled to the cyanidation process.     

Extraction of Copper(II) Ions from Chloride and Sulphate Solutions Using Hydrophobic Pyridyl Ketoximes

Hydrophobic pyridyl ketoximes: 1-(2-pyridyl)tridecan-1-one oxime, 1-(3-pyridyl)tridecan-1-one oxime and 1-(4-pyridyl)tridecan-1-one oxime have been synthesized and investigated as extractants of copper(II) ions. Removal of metal ions was conducted from chloride, sulphate, and sulphate/chloride solutions. The influence of pH of aqueous solutions, copper(II), chloride, and sulphate ions and ligand concentration for extraction process were studied. Copper(II) extraction by hydrophobic 2-, 3-, and 4-pyridyl ketoximes from sulphate solutions is not possible. However, addition of chloride ions to initial sulphate media enables metal removal. The oxime of 1-(2-pyridyl)tridecane-1-one was determined as the strongest extractant of the tested oximes, but metal stripping was impossible. For the rest of the studied extractants the stripping process could be done using water or diluted mineral acid.     

PART 3. THE EXTRACTION OF Co2+, Ni2+, Cu2+ AND Zn2+ USING NOVEL DITERTIARY-AMINEEXTRACTANTS

The syntheses of N-N-octyl-2-2'-pyridylimidazole and N,N'-di-n-octyl-(a)-aminopicoline are presented. Their extraction properties are compared with that of an aliphatic diamine N,N,N',N'-tetraoctylethylene-diamine. The reagents, dissolved in chloroform, were used to extract divalent cobalt, nickel, copper and zinc from aqueous chloride medium. Two extraction mechanisms are postulated for the extraction of these metals, and extraction data are discussed in terms of these postulates.

Extraction of the copper(II) ion at low pH values with amines is best effected by the inclusion of aromatic nitrogen atoms into a diamine extractant.     

N910萃取碱性蚀刻废液中Cu(Ⅱ)的工艺研究

采用萃取剂N910为萃取剂,磺化煤油为稀释剂,研究了从碱性蚀刻废液中萃取回收铜的单级及多级萃取工艺。结果表明,在Cu2+含量为112 g/L,总氨浓度为5.7 mol/L的蚀刻废液中,单级萃取优化的工艺条件为:N910体积浓度为60%,有机相和水相的相比O/A=2∶1,T=30℃。碱性蚀刻液不需进行酸碱度的调整,萃取时间为3 min即可达到平衡,Cu2+的萃取率为56.73%,N910萃取Cu2+的饱和萃取量为64.03 g/L。萃取热效应△H=8.95 kJ/mol,萃取过程为吸热反应。在此条件下,PCB碱性蚀刻液中Cu2+的四级错流和三级逆流萃取率分别为94.78%和76.01%,蚀刻液中Cu2+浓度降低至37.98 g/L。     

镍电解一次铁渣浸出的研究

控制不同工艺条件浸出镍电解一次铁渣研究表明,升高温度有利于铁渣中铁、镍、铜元素的浸出;当反应体系温度≥60℃时,采用浓度为20%的硫酸浸出镍电解一次铁渣,反应1.5 h,可以将铁渣中的绝大多数铁、镍、铜元素浸出;正交实验表明,当控制反应时间为1.5 h时,镍电解一次铁渣浸出的最佳工艺条件为:硫酸浓度20%,反应液固比10∶4,反应温度90℃。     

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.     

Metral54-100萃取分离铜、镍的密度泛函研究

采用密度泛函理论DFT/B3LYP/6-31G+(d, p)方法计算不同配位形态的铜、镍萃合物的结合能、全局活性指数、局部活性指数和红外光谱,探讨了1-苯基-1,3癸二酮(Mextral54-100)萃取Cu(II), Ni(II)的行为及机理。结果表明,Mextral54-100对Cu(II)的萃取能力大于Ni(II)。在反萃过程中,铜的萃合物更易被反萃。萃合物羰基表现出最高的反应活性,为活性中心。萃合物中氨分子的取代数越多,萃合物构型近似于稳定的八面体结构。配体氨逐一被萃取剂的羰基取代,有效避免共萃氨。Mextral54-100从铜、镍氨混合溶液中萃取–反萃Cu(II)和Ni(II)的实验结果与理论预测结果吻合,进一步通过FT-IR证实了理论计算结果的准确性,密度泛函理论有望成为一种研究萃取分离性能的新方法。