溶剂萃取法分离锌锰金属离子的实验研究

以软锰矿和锌精矿同槽酸浸取得到硫酸锌、硫酸锰混合液,研究了从混合溶液中萃取分离锌离子、锰离子的萃取剂的选择以及适宜的萃取条件.实验结果表明,磷酸二(2-乙基己基)酯(P204)萃取锌的能力优于磷酸三丁酯(TBP),在室温、相比A/O=2∶ 1、萃取时间10 min、萃取级数5级、溶液pH为4.0,P204的体积分数为40%时,萃取率达到95%,萃取相锌质量浓度为27.15 g/L.反萃液为0.8 mol/L的稀硫酸,4级反萃,反萃液锌质量浓度可达到89.9 g/L,在此基础上提出了从软锰矿和锌精矿同槽酸浸取液中用P204萃取锌的工艺.     

三辛胺-磷酸三丁酯从硫酸亚铁与氯化钾溶液中萃取盐酸的机理研究

研究了三辛胺 磷酸三丁酯 (TOA TBP)从硫酸亚铁与氯化钾溶液中萃取盐酸的特性及规律。研究表明三辛胺从FeSO4与KCl水溶液中萃取盐酸的机理主要属于离子缔合成盐过程 ,还存在阴离子交换机理。磷酸三丁酯 (TBP)在此过程中主要起协萃作用。通过斜率法、饱和法、红外光谱等对萃合物组成的研究 ,提出三辛胺从硫酸亚铁与氯化钾溶液中萃取盐酸的机理是 :2R3 N +2HCl+TBP =(R3 NHCl) 2 TBP。     

撞击流旋转填料床内磷酸三丁酯对苯酚的络合萃取

在撞击流-旋转填料床(IS—RPB)内进行了磷酸三丁酯(TBP)对苯酚稀溶液的络合萃取实验研究。在研究IS—RPB转速和撞击流初速对萃取级效率影响的基础上,确定了最适宜操作条件。在最适宜操作条件下,应用不同体积组成的TBP 煤油萃取剂对苯酚稀溶液进行萃取,得到了95％以上的除酚率。动力学分析表明,TBP与苯酚的络合反应是一个快速过程,IS—RPB作为萃取器使用可以对扩散类型的萃取过程提供很高的萃取级效率。     

磷酸三丁酯从盐湖卤水中萃取锂的机理研究

以磷酸三丁酯（TBP）为萃取剂,磺化煤油为稀释剂,在六水合三氯化铁存在的条件下,从盐湖卤水中萃取锂。研究了TBP浓度对萃取率的影响,得到TBP最佳浓度为80%TBP+20%磺化煤油。通过斜率法、化学分析法、紫外光谱与红外光谱法,证实了锂离子（Li+）在溶液中与铁络阴离子（FeCl4-）形成铁氯络酸盐（LiFeCl4）,LiFeCl4与TBＰ中的PO键作用配位形成二溶剂化物LiFeCl4·2TBP,从而达到与其他组分分离的目的。利用空腔理论阐述了萃取过程。     

磷酸三丁酯萃取分离钛铁矿亚熔盐反应产物酸解液中Fe3+及金红石型TiO2的制备

在盐酸介质中以磷酸三丁酯(TBP)为萃取剂、磺化煤油为稀释剂,从钛铁矿与氢氧化钾亚熔盐反应产物的酸解液中萃取分离Fe3+,并利用萃取后的含钛液水解制备二氧化钛. 考察了萃取剂浓度、盐酸浓度、有机相和水相体积比(O/A)和萃取时间对铁萃取率的影响. 结果表明,钾系亚熔盐法分解钛铁矿的分解率在96%以上. 萃取率随着TBP浓度及盐酸浓度的增加和O/A值的减小而增大;通过调节萃取条件,萃取率可以达到99%以上. 用1.0 mol/L的NaCl溶液进行反萃,反萃率可达98%以上. 萃取后含钛液经水解可以制得纯度高于98%的金红石型TiO2球状颗粒.     

磁性流体固定床萃取分离低浓度金离子

采用一种全新的快速萃取方法--磁性流体固定床萃取分离技术,该方法是将磁性Fe₃O₄纳米颗粒表面包覆油酸,溶于有机溶剂中,加入萃取剂三苯基氧化膦TPPO,制成磁性萃取剂。借助于高梯度磁性分离装置,对目标离子进行萃取分离。萃取完成后通过原子吸收光谱仪测定萃取后金溶液中Au³⁺的浓度。通过对铁磁导线直径、初始金溶液pH值、萃取剂体积分数和协同萃取等影响因素的考察,得出了对Au³⁺浓度为19.128 mg·L^-1的氯金酸溶液进行萃取分离的最佳工艺：采用直径为2.34 mm的铁磁导线作为磁性填充介质时萃取率较其他优越。初始金溶液的pH值和萃取剂的体积分数对萃取率影响较大。在初始金溶液pH=1,萃取剂(TPPO)体积分数达到50%时萃取率最高。使用TPPO和TBP协同萃取也能提高萃取率。采用浓度为1 mol·L^-1的硫脲进行反萃实验,振荡10 min,反萃率在90%以上。     

溶剂萃取法处理苯酚稀溶液及其废水的研究

为探索工业含酚废水处理的适宜萃取剂,选用具有物理萃取和络合萃取作用的两类萃取剂正辛醇、甲基异丁基甲酮(MIBK)和磷酸三丁酯(TBP)(以煤油为稀释剂)进行了苯酚稀溶液萃取性能的实验研究。测定了不同溶液pH值、初始苯酚浓度和TBP浓度条件下的萃取平衡数据,分析了各萃取剂萃取平衡的规律及机理。结果表明,虽然各萃取剂的萃取机理不同,但在酸性和中性范围内都可获得较大的萃取平衡分配系数,所以,这三种萃取剂的适宜pH值操作条件为酸性和中性,且在稀溶液的范围内溶剂的萃取能力为TBP > MIBK >正辛醇,而在极稀的苯酚浓度条件下(<20mgL-1),则为正辛醇> TBP > MIBK。同时,正辛醇、TBP处理工业含酚废水的错流萃取实验表明,若考虑通过单一的萃取方法使得废水中苯酚的浓度达到国家排放标准(0.5mgL-1),正辛醇为适宜的萃取剂。     

磷酸三丁酯在碱中的降解研究

磷酸三丁酯(TBP)广泛应用于磷酸萃取,但重复用于萃取过程时会发生一定程度的降解,导致萃取剂损失。为更好地控制TBP的再生条件,减少TBP损失,降低生产成本,本文研究了在Na OH碱溶液体系下,不同温度和pH值对TBP降解率的影响。结果表明:当pH值为11,反应16h时,TBP在30、40、50℃下降解率分别为13.25%,18.51%和26.05%;当pH值为12,反应16h时,TBP在30、40、50℃下降解率分别为14.82%,32.76%和45.95%。由此可见,温度和pH值对TBP的降解均有显著影响,且温度越高,pH值越大,TBP降解越快。     

盐酸介质中磷酸三丁酯萃取分离铬(Ⅵ)

为了深入研究在盐酸介质中TBP萃取Cr(Ⅵ )的萃取行为 ,分别以煤油、四氯化碳、二甲苯为稀释剂 ,进行萃取平衡特性研究 ,考察了酸度、铬的初始浓度、有机相TBP含量以及温度对萃取平衡的影响。实验结果表明 :温度和稀释剂种类对萃取分配比的影响较小 ,酸度、TBP浓度和铬初始浓度对分配比影响较大。萃取过程所形成的萃合物为HCrO3 Cl·2TBP和HCrO3 Cl·3TBP。TBP在盐酸介质中萃取铬为吸热过程 ,其过程热为17.99kJ/mol。     

兰炭厂含酚废水的络合萃取研究

本文选用磷酸三丁酯(TBP)为萃取剂,煤油为稀释剂对高浓度含酚废水进行络合萃取,考察pH值、油/水相比(V/V)和TBP的含量(络合萃取剂中TBP的体积分数)等对酚萃取率的影响,并对酚进行反萃回收。实验结果表明:在pH值为6、温度为25℃、搅拌转速为625r·min-1、油/水相比为1∶3和TBP的含量为60%的最佳实验条件下,一级萃取率为94.7%,二级萃取率为98.12%,三级萃取率为99.5%。从经济效益考虑,选择一级萃取,其COD去除率为72.64%。用质量分数为10%的Na OH溶液作反萃取剂,反萃取温度为45℃,按油/碱比(V/V)为1∶1对一级萃取有机相进行两次反萃取,酚回收率可达97.24%。络合萃取剂在萃取-反萃取的过程中可多次循环使用。     

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.     

SYNERGISTIC EXTRACTION OF ZINC(II) BY MIXTURES OF PRIMARY AMINE N1923 AND CYANEX272

ABSTRACT

The extraction of zinc(II) and cadmium(II) from chloride solution by mixtures of primary amine N1923 and Cyanex272 (HA) was studied. The synergistic effect was observed for the extraction of zinc(II) while no synergistic effect for cadmium(II), which makes it possible to separate zinc(II) and cadmium(II) with the mixtures. The results showed that zinc(II) was extracted as (RNH₃Cl)₃·ZnClA instead of ZnA₂·2HA which was extracted by Cyanex272 alone. The extraction mechanism was discussed and the formation constants and thermodynamic functions were determined. The separation factors between zinc(II) and cadmium(II) were calculated.     

高温水解和水蒸气蒸馏样品处理法在氧化锌中氟和氯含量测定的比较

氧化锌中氟和氯的主要形态有NaCl,KCl,Zn_5(OH)_8Cl_2·H_2O、Pb(OH)Cl和PbClF。分别采用高温水解法和水蒸气蒸馏法提取了不同氟、氯存在形态的氧化锌样品,采用离子色谱法测定氟和氯含量,对两种提取方法的测定结果进行比较。实验结果表明两种方法的测定值一致,高温水解法较水蒸气蒸馏法处理样品检测结果精密度更高,操作简便,硫酸根离子残留少,离子色谱洗脱耗时短。     

Extraction of Vanadium(V) from Mixed Chloride/Thiocyanate Solutions with Two Commercial Solvating Extractants

Studies on the extraction and separation of vanadium(V) from mixed hydrochloric acid/ammonium thiocyanate solution with CYANEX 921 and CYANEX 925 in kerosene were carried out. The effects of various factors affecting the extraction process as well as temperature were investigated. Addition of thiocyanate to the chloride solution was found to enhance markedly the extraction of vanadium. HCl solution efficiently stripped V(V). The number of stages required for extraction and stripping of vanadium ions was determined from the McCabe–Thiele diagram. Based on the obtained results, the separation of V(V) from spent catalyst leach indicates the efficiency of the proposed process.     

Transport of zinc complexes through an anion exchange membrane

The transport of zinc complexes ions through an anion exchange membrane was evaluated by the treatment of solutions with and without cyanide. The ionic transport was analyzed as a function of the applied current density and of the cyanide and hydroxyl concentration. Experimental results showed that the ionic transfer in electrodialysis was mainly affected by concentration. There is an ideal molar relationship among the concentration of the cyanide ions, hydroxyl and zinc ions, in solution, in which the zinc transport is maximized. For values above or below this, the transport decreases. Zinc extraction from solution containing CN⁻ was more effective when the current density of 29 mA.cm⁻² was applied. The current–voltage curves (CVC) of the anion exchange membrane show that the electrical resistance of the AMV membrane increases with the presence of the zinc–cyanide complex in the solution.     

SOLVENT EXTRACTION OF PALLADIUM(II) WITH A SULFUR-CONTAINING CARBOXYLIC ACID

The mechanism of solvent extraction of palladium (II) from aqueous ammonium chloride solution with α-butylthiolauric acid( α-BTLA = S) in toluene was investigated in terms of extraction equilibrium and kinetics at 303 K. From the results of extraction equilibrium, it was found that α-BTLA behaves as a solvating extractant for palladium(II) and that the extracted species is a 1:2 metal:reagent complex, PdCl₂S₂ The extraction rate of palladium(II) was measured in a batch-type vigorously stirred cell. The effects of the concentrations of palladium(I I), hydrogen ion, chloride ion and extractant on the extraction rate were quantitatively interpreted by a reaction mechanism where the parallel reactions of α-BTLA with PdCl₃(H₂0)- and PdCl₄ ^2- are the rate-determining steps.     

Optimisation of metallic pigments in coatings by an electrochemical technique and an investigation of manganese powder as pigment for metal rich primers

Zinc dust and manganese powder as pigments were incorporated in epoxy-polyamide and butyl titanate medium, with different pigment volume concentration (PVC) ranging from 20 to 74. These protective coatings were coated on sand blasted mild steel substrates and immersed in 3 wt.% sodium chloride solution and the corrosion current was measured by the Tafel extrapolation method. From the corrosion current produced by these primers, the optimum level of the pigments in these binders was identified. Thus the protective performance of optimised primers was evaluated on a sand blasted mild steel surface by the Tafel polarisation method in 3 wt.% sodium chloride solution, over different periods of time. The results were found to be comparable with the salt spray test and galvanic current measurements. The manganese powder used for this investigation showed that it could be used as an alternative to zinc powder for metal rich primers.     

Solvent Extraction of Uranium (VI) from Chloride Solutions using Cyphos IL-101

The solvent extraction of uranium (VI) from chloride solutions by Cyphos IL-101 in xylene has been studied. Distribution coefficients were found to increase with aqueous chloride concentration and extractant concentration. The enthalpy of extraction is endothermic with ΔH = +24 ± 2 kJ·mol^?1. Based upon slope analysis, an anion exchange extraction mechanism is proposed, with formation of a UO₂Cl₄ ^2- complex in association with 4 Cyphos IL-101 ligands. The extraction kinetics were fast, with complete equilibration occurring within 30 seconds. An isotherm for uranium extraction from 1.0 mol·L^?1 chloride solution by 0.1 mol·L^?1 Cyphos IL-101 in xylene shows that 45 mmol·L^?1 uranium can be loaded into the organic phase in equilibrium with 2.1 mmol·L^?1 in the aqueous phase. The absorption spectrum of the uranium loaded solvent between 350 and 550 nm is indicative of the UO₂Cl₄ ^2- complex with only chlorides present in the inner coordination sphere, unlike the more strongly hydrogen bonded Alamine 336 extracted uranium complex. Subject to the same experimental conditions, distribution coefficients for Cyphos IL-101 were significantly greater than for Alamine 336 or Aliquat 336.     

Recovery of nickel,cobalt, copper and zinc in sulphate and chloride solutions using synergistic solvent extraction

A number of synergistic solvent extraction (SSX) systems have been developed to recover nickel, cobalt, zinc and copper from sulphuric and chloride leach solutions by the solvent extraction team of CSIRO, Australia. These in-clude (1) Versatic 10/CLX50 system for the separation of Ni from Ca in sulphate solutions, (2) Versatic 10/4PC system for the separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, (3) Cyanex 471X/HRJ-4277 system for the separation of Zn from Cd in sulphate solutions, (4) Versatic 10/LIX63 system for the separation of Co from Mn/Mg/Ca in sulphate solutions, (5) Versatic 10/LIX63/TBP system for separation of Ni and Co from Mn/Mg/Ca in sulphate solutions, (6) Versatic 10/LIX63 system for the separation of cobalt from nickel in sulphate solutions by difference in kinetics, (7) Cyanex 272/LIX84 system for the separation of Cu/Fe/Zn from Ni/Co in sulphate solutions, (8) Versatic 10/LIX63/TBP system to recover Cu/Ni from strong chloride solutions, and (9) Versatic 10/LIX63 system to separate Cu from Fe in strong chloride solutions. The synergistic effect on metal separation and efficiency is presented and possible industrial applications are demonstrated. The chemical stability of selected SSX systems is also reported.     

高锌烟灰中提取锌及富集铟工艺研究

本文研究了从高锌烟灰中提取锌及有价金属铟的富集,考察了在不同工艺参数对浸出的影响,得到优化的浸出条件。同时在回收铟等有价金属时,还注意到环保问题,有效地提高酸的使用率,减少污染。整个工艺过程基本不产生废渣、废液、和废气。试验表明：pH=5．2时,Zn的浸出率达81％,铟在终酸度为53．65g／1,浸出率达92％。