HA和HNAPO萃取锌的密度泛函分析

为从微观层面分析从锌氨溶液中萃取Zn(II)的反应机理,采用密度泛函(DFT) B3LYP/6-31G+(d, p)理论对萃取剂1-苯基-1,3癸二酮(Mextral54-100,HA)和2-羟基-5-壬酰基苯甲酮肟(Lix84I,HNAPO)及Zn(II)萃合物的几何结构、红外光谱、原子轨道贡献率和电荷分布等进行研究。结果表明,在HA与锌形成萃合物的过程中,HA烯醇式上的O和C原子、HNAPO肟基上的C和N原子及苯酚上的O原子对分子轨道的贡献率最高;HA上的C=C双键的伸缩振动峰在萃取反应后发生红移,HNAPO肟基上的C=N双键的伸缩振动峰强度发生改变,酚羟基的摇摆振动峰消失,表明烯醇式、肟基和酚羟基为萃取反应的活性中心,键长和键角均发生了改变;Zn(II)取代烯醇式上的氢与氧原子形成配位键,C=O双键在形成萃合物后键长增大。HNAPO与锌形成萃合物的过程中,Zn(II)取代酚羟基上的氢与氧和氮原子形成配位键,且苯环和锌离子处于一个平面上;萃取剂HA的分子轨道差值和电负性均低于HNAPO,化学势高于HNAPO,理论预测HA萃取锌的反应活性大于HNAPO,与实验结果吻合。     

PC-88A萃取镍离子的工艺条件探究与优化

研究了酸性萃取剂2-乙基己基磷酸单2-乙基己基酯(PC-88A)萃取镍离子的萃取条件,反萃相硫酸含量对反萃效率的影响,并进行了优化。结果表明,优化萃取条件为:萃取反应温度40℃,萃取剂的体积分数80%,原料液初始pH为6.5,萃取剂皂化率为10%,此时PC-88A对Ni(II)的萃取率高达98.0%。在此优化条件下获得的负载有机相,采用0.8 mol/L的硫酸进行反萃,反萃率达到93.6%。     

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.     

用硫脲从季铵盐萃取液中反萃金,银,铜的探索

本文叙述了硫脲和季镀盐的基本物化性质,分析并论证了硫脲盐酸漓液反萃取季铵盐负载有机相中金、银、铜的可能性及其机理。理论分析和实验结果均表明,在酸性条件下,硫脲具有取代季铵盐萃取金、银、铜的萃合物中CN~-配位体的能力。CN~-配位体被中性硫脲SC(NH_2)_2取代后,使原来带负电的络阴离子M(CN)_2~-变成带正电的络阳离子M(SC(NH_2)_2)_2~+,带相同电荷的两离子(R_3CH_3N)和M(SC(NH_2)_2)_2~+互相排斥,迫使萃合物解离并分别进入有机相和水相,由此达到比较完全的反萃目的。反萃后的金、银、铜硫脲络合物和对应氰离子络合物比较其稳定常数大为降低,故易于被还原成金属元素。同时,通过控制反萃液的酸度,可将金与银、铜大致分离。     

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。     

Mextral V10–Mextral 973H体系脱除酸性矿山废水中重金属的研究

矿山选、冶废水成分复杂、水量大,目前所用方法对重金属的脱除效果不理想、成本高,为解决矿山废水重金属污染问题,开发适用于酸度较高、重金属浓度较低、对钙、镁离子有抑萃作用的协同萃取法脱除并回收废水中的重金属。通过绘制萃取等温线、FT-IR及紫外吸收光谱对Mextral V10–Mextral 973H协同萃取体系进行分析,研究了萃取剂浓度、有机相和水相体积比(简称相比,O/A)和Mextral V10皂化率对废水中重金属分离影响。结果表明,Mextral V10–Mextral 973H协同萃取体系能有效脱除酸性废水中Cu2+, Pb2+, Cd2+和Zn2+。在10vol% (Mextral V10+Mextral 973H)+90vol% Mextral DT100,Mextral V10:Mextral 973H=1:1的最佳实验条件下连续萃取六次,萃后废水中Cu2+, Cd2+, Zn2+, Pb2+, Mg2+和Ca2+的萃取率分别为99.1%±0.1%, 99.9%±0.02% 99.5%±0.05%, 97.6%±0.03%, 10.11%±0.1%和18.3%±0.05%,废水中残留Cu2+, Zn2+, Cd2+和Pb2+浓度分别为1.720±0.10, 0.256±0.03, 0.054±0.01和0.929±0.01 mg/L,低于GB8978-1996中第一类污染物最高允许排放标准值。     

二(2—乙基已基)磷酸萃取钆的研究

本文研究了采用二(2—乙基己基)磷酸(D_2EHPA)从盐酸体系中萃取钆的机理,确定了萃合物的组成为GdA_3·3HA,测定出萃取平衡常数K_e=10~(0·54)(20±0.5℃)。实验表明当起始水相酸度为0.1213M时,萃取率可高达99.89％将采用4M盐酸进行反萃,反萃率达99.96％。     

β-二酮和5-壬基水杨醛肟从氨性溶液萃取铜的研究

对β-二酮,5-壬基水杨醛肟和它们的混和物萃取氨性溶液中的铜的性能做了研究,结果表明:在铜离子初始浓度为2.5g/L,氨浓度为56g/L,β-二酮与5-壬基水杨醛肟的体积比为1∶2时,铜回收率达到85.10%,饱和萃铜容量为6.0g/L。最佳萃取和反萃条件为:初始水相pH10,温度30℃,硫酸浓度为180g/L。并把β-二酮和5-壬基水杨醛肟与β-二酮的体积比为1∶2的混和物应用于模拟印制电路板蚀刻废液中铜的回收,经过单级萃取,混合物的铜回收率比β-二酮提高2.7%。     

希夫碱配体结构的改变对Cu（Ⅱ）SOD模拟物的抗氧

在希夫碱Cu(II)配合物1 (Cu(II)双香草醛缩乙二胺)、4 (Cu(II)双香草醛缩邻苯二胺)的基础上,对配体结构进行了设计,将重原子效应、共轭效应、空间位阻效应等结构影响因素引入到SOD(超氧化物歧化酶)模拟物的结构设计中,合成了4种希夫碱类铜金属配合物,并用X 射线单晶衍射法测定了配合物2的晶体结构。运用改进的NBT还原法测定了这6种SOD模拟物的抗氧化活性,结果表明：结构改变后的SOD模拟物较原结构配合物的抗氧化活性均有明显的提高且各因素影响幅度有所不同。     

2,3-丁二酮缩苯甲酰肼Schiff碱的合成与抗肿瘤活性研究

合成了一种2,3-丁二酮缩苯甲酰肼Schiff碱配体及其过渡金属Cu(II)、Co(II)、Zn(II)、Mn(II)、Ni(II)的配合物,并用元素分析、红外光谱、~1H NMR、电子光谱、摩尔电导加以表征,表征结果表明所研究的结构与所预测的基本一致。配体及各配合物的体外抗肿瘤活性用四氮唑盐比色法进行测定,抗肿瘤活性结果表明,配体及与金属离子配位后,均有一定的抗肿瘤效果,其中,二价铜离子配合物的抑制肿瘤效果最佳。     

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 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.     

Solvent extraction with LIX 973N for the selective separation of copper and nickel

LIX 973N diluted with Iberfluid was used to co‐extract copper and nickel from ammoniacal/ammonium carbonate aqueous media. The influence of equilibration time, temperature, equilibrium pH and extractant concentration on the extraction of both metals has been studied. It was observed that neither copper nor nickel extraction is sensitive to temperature and equilibrium pH, however nickel extraction equilibrium is reached at a longer contact time (20 min) than that of copper (5 min), in addition nickel extraction depends greatly on the extractant concentration in the organic phase. For a solution containing 3 g dm⁻³ each of copper and nickel and 60 g dm⁻³ ammonium carbonate, conditions were established for the co‐extraction of both metals, ammonia scrubbing and selective stripping (with H₂SO₄) of nickel and copper. Using the appropriate extractant concentration the yield (extraction stage) for both metals is near 100%, whereas the percentage of nickel and copper stripping is also almost quantitative. © 1999 Society of Chemical Industry     

Recovery of copper from ammoniacal/ammonium sulfate medium by LIX 54

The extraction‐stripping reaction of Cu(II) by LIX 54 in Iberfluid from aqueous ammonium sulfate medium at pH 8.5 has been investigated. The effects of pH, metal ion, extractant concentration as well as the loading capacity of the reagent were studied. The extraction equilibrium constant for copper was determined numerically to be 7 × 10⁻⁷. Experimental data can be explained assuming the formation of CuR₂ species in the organic phase (R represents the extractant). Copper stripping was studied using typical spent copper electrowinning solutions as stripping medium. The number of stages required for the extraction and stripping of copper was also evaluated. The results were used to asses the conditions for purification of industrial waste solutions (eg spent etchants) containing copper through counter‐current extraction‐stripping. © 1999 Society of Chemical Industry     

Separation of Copper and Nickel from Ammoniacal/Ammonium Carbonate Solutions Using ACORGA PT5050

ABSTRACT

ACORGA PT5050 diluted with iberfluid (kerosene-type diluent, mostly aliphatic) was used to coextract copper and nickel from ammoniacal carbonate solutions. The influence of kinetics, temperature, equilibrium pH, and extractant concentration on the extraction of both metals has been studied. It was observed that nickel extraction is very sensitive to aqueous pH and that the extraction falls beyond an equilibrium pH of 9. For a typical solution containing near 3 g/L each of copper and nickel and 60 g/L ammonium carbonate, conditions were established for the coextraction and selective stripping of nickel and copper.     

含金属氨络合离子的高浓度氨氮废水处理

对氨氮的质量浓度高达10 g/L以上的球镍废水采用空气吹脱技术进行处理,由于废水中氨氮浓度过高,且存在一定量的金属离子与氨形成金属氨络合离子,影响氨氮去除效果。采用延长吹脱时间和加入硫化钠破坏络合作用的方法,提高吹脱效率。试验证明,在反应进行至8～10 h后,加入适量硫化钠,可提高氨氮去除效果,并且对废水中的金属络合离子具有一定的去除作用。反应进行到34 h后,氨氮去除率达到99.1%;进行至46h后,氨氮去除率达到99.98%,氨氮的质量浓度由初始的12 870 mg/L降至3 mg/L。处理后的出水氨氮和铜离子分别达到《污水综合排放标准》(GB8978-1996)的一级和二级排放标准。     

Purification of nickel sulphate solutions containing iron,copper, cobalt,zinc and manganese

Acidic nickel-bearing solution containing iron, cobalt, manganese, zinc and copper was processed through a solvent extraction and precipitation technique to obtain a pure nickel sulphate solution. Iron was extracted using 0.2M Cyanex-272 (partially neutralised) as the extractant. Stripping of iron from the loaded organic has also been studied. After iron recovery through solvent extraction the raffinate still contained 0·25 g dm^?3 of iron which was quantitatively separated by a lime precipitation technique. During this iron precipitation there was no loss of cobalt and nickel but copper, manganese and zinc were coprecipitated to some extent. From the iron-free nickel sulphate solution the other impurities were extracted using the same extractant (Cyanex-272) in a single stage. The metal ions from the loaded organic were stripped using a 0·5% (v/v) H₂SO₄ solution in a single stage. The entire operation needs only seven stages: two stages for iron extraction, three stages for iron stripping from the loaded organic, and one stage each for extraction and stripping of other impurities. In the entire operation the loss of nickel was less than 0·5%.     

硫杂冠醚对Ag(I)和Tl(I)的萃取

基于冠醚的配位化学及软硬酸碱理论,设计并合成了五种硫杂冠醚,系统研究了其对Ag(I)和Tl(I)两种软酸离子的络合能力.模拟计算结果表明,五种冠醚与Ag(I)和Tl(I)络合后构型均发生了转变,且结构优化后的五种冠醚与Ag(I)络合过程的ΔG和ΔU均较负,表现出了一定的配位能力,而与Tl(I)络合过程的ΔG和ΔU均接近...     

溶剂萃取法回收不锈钢酸洗废液中再生H2SO4的研究

随着我国不锈钢粗钢产量逐年增大,对不锈钢进行酸洗而产生的酸洗废酸也在逐年增多。不锈钢酸洗排放的废硫酸溶液中含大量游离酸,根据本课题组开发的酸再生循环工艺,在有效回收废酸中有价金属离子的同时,使酸洗废酸中游离酸浓度增大得到再生硫酸。针对不锈钢酸洗废液中再生硫酸浓度较高、中和处理试剂消耗高、废渣产生量大的问题,研究了溶剂萃取法回收不锈钢酸洗废液中硫酸的工艺。研究发现,有机体系40%(体积分数)三(2-乙基己基)胺(TEHA)+50%异构十三醇+10% Exxsol D110为最优化组成,硫酸萃取率随TEHA浓度增加而升高,随温度升高萃取率降低,表明萃取反应为放热反应,计算所得萃取反应的ΔH=?7.5708 kJ/mol。根据萃取和反萃分配曲线分别绘制了McCabe-Thiele图,在30℃、相比A/O=1:2条件下,经过3级(理论)萃取,硫酸的萃取率可达79.8%以上;采用水作反萃剂,在30℃、相比A/O=1:1条件下,经过3级(理论)反萃,硫酸的反萃率可达85.5%。萃取、反萃动力学快,分相迅速,可满足工业连续生产要求。