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.     

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。     

Mextral 984H从页岩提钒浸出液中萃取V(V)的研究

考察Mextral 984H螯合萃取体系下料液相pH、相比、萃取剂浓度、萃取时间对钒和杂质离子铁、铝、镁、钾、磷的萃取率的影响。结果表明:在料液pH=1.0、萃取时间20min、相比O/A=1/2、萃取剂浓度20%、稀释剂为磺化煤油的条件下,酸浸液中钒一级萃取率为79.43%,二级萃取率达到99.06%,且杂质铁、铝、镁、钾和磷的萃取率均低于2%。Mextral 984H通过羟基和肟基共同作用螯合萃取V(Ⅴ),实现了高酸多杂页岩提钒浸出液中钒的高效分离提取。     

TXIB对Mextral973H从铜氨溶液中萃取铜及氨的影响研究

以Cu-NH_3-NH_4Cl-H_2O体系为研究对象,TXIB(2,2,4-三甲基-1,3-戊二醇双异丁酸酯)为改质剂,考察TXIB用量、萃取剂浓度、萃取相比、水相铜浓度、氨浓度等对萃取剂Mextral973H从铜氨溶液中萃取铜及氨的影响。结果表明,TXIB的使用可以显著降低氨的共萃而不影响铜的萃取。在萃取相比O/A=1/1、有机相浓度20%、铜浓度18.0g/L、氨浓度84.0g/L的条件下,向有机相中添加10%的TXIB后,铜萃取率由60.44%变化为60.20%,有机相共萃氨量从410.2mg/L降至154.8mg/L。     

金属萃取剂Mextral 84H萃取铜的性能研究

研究了Mextral 84H萃取剂萃取铜的性能及影响因素。结果表明:Mextral 84H萃取剂具有萃取效率高、分相速度快、使用寿命长等特点,可用于从矿石浸出液或印刷线路板蚀刻液中萃取铜。     

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.     

Mextral204P和Mextral336A混合萃取稀土元素的研究

向萃取剂Mextral204P中加入萃取剂Mextral336A构成混合萃取剂来萃取稀土元素,考察了混合萃取剂的配比、萃取时间、萃取相比、水相pH以及料液中稀土的浓度对萃取的影响。结果表明,当混合萃取剂中Mextral204P的摩尔分数为0.74时,混合萃取剂之间具有最大正协同作用,并且在萃取时间为4min、相比1∶1、料液pH=4时,萃取效果最好,最大钐负载高达23g/L。     

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。