【作者】 郭攀峰；

【导师】 姚秉华；

【作者基本信息】 西安理工大学 ， 应用化学， 2008， 硕士

【摘要】 贵金属因具有独特的物理和化学性质而逐渐受到人们的青睐,被广泛应用于各个领域。但是由于贵金属的物理、化学性质极为相似,并且价态多变,不同价态之间差别很大,因此贵金属分离一直是一个难题。液膜分离技术集萃取与反萃取于一体,具有较高的传质速率和通量,高的选择性,良好的分离效率和浓缩倍数,以及操作简单等特点,是近年来研究较为广泛的新型分离技术。为了提高贵金属分离的选择性和实用性,许多研究者将液膜技术应用于贵金属的分离研究,取得了良好的进展。然而研究报道较多的是乳化液膜,利用支撑液膜（SLM）进行贵金属的分离研究报道较少。因此本文选择贵金属铂和钯为分离对象,在溶剂萃取实验基础上,较为系统的研究了Pt（Ⅳ）和Pd（Ⅱ）的支撑液膜迁移规律,取得了以下实验结果:1、Pt（Ⅳ）和Pd（Ⅱ）的萃取平衡使用不同萃取剂,分别对Pt（Ⅳ）和Pd（Ⅱ）的萃取和反萃取条件进行了探讨,获得了最佳实验条件。（1）Pt（Ⅳ）的萃取平衡实验在Pt（Ⅳ）初始浓度为5.0μg/mL的水相中,当氯化亚锡浓度为0.05mol/L,盐酸浓度为0.50mol/L,有机相选择煤油作为稀释剂,萃取剂2-乙基己基膦酸-单-2-乙基己基酯(P₅₀₇)浓度为5.0%（w/V）,水相和有机相体积比为1:1时,振荡30min,Pt（Ⅳ）的萃取率可达100%。选择等体积的4mol/L盐酸作为反萃剂,反萃率达99%以上。（2）Pd（Ⅱ）的萃取平衡实验在Pd（Ⅱ）初始浓度为6.754μg/mL的水相中,当盐酸浓度为0.10mol/L,有机相选择煤油作为稀释剂,萃取剂N,N-二甲庚基乙酰胺(N₅₀₃)浓度为10.0%（w/V）,水相和有机相体积比为1:1时,振荡30min,Pd（Ⅱ）的萃取率可达99.2%。选择等体积的0.2mol/L硫氰酸钾溶液作为反萃剂,反萃率达95%以上。2、支撑液膜分离实验以疏水性多孔聚偏氟乙烯膜为支撑体,P₅₀₇和N₅₀₃为流动载体,煤油为膜溶剂,分别研究了Pt（Ⅳ）和Pd（Ⅱ）在支撑液膜中的迁移规律。（1）Pt（Ⅳ）的迁移实验选择Pt（Ⅳ）初始浓度为1.0μg/mL,分别考察了料液相盐酸浓度、氯化亚锡浓度、载体浓度、反萃相盐酸浓度等因素对Pt（Ⅳ）迁移的影响,确定了Pt（Ⅳ）的最佳迁移条件:当料液相中Pt（Ⅳ）浓度为1.0μg/mL时,盐酸浓度为1.0mol/L,氯化亚锡的浓度为0.05mol/L,膜相中P₅₀₇浓度为5.0%（w/V）,反萃相盐酸浓度为6.0mol/L,迁移3h,Pt（Ⅳ）的迁移率可达100%。（2）Pd（Ⅱ）的迁移实验选择Pt（Ⅳ）初始浓度为3.0μg/mL,分别考察了料液相盐酸浓度、载体浓度和反萃相硫氰酸钾浓度对Pd（Ⅱ）迁移的影响,确定了Pd（Ⅱ）的最佳迁移条件:当料液相中Pd（Ⅱ）浓度为3.0μg/mL时,盐酸浓度为0.2mol/L,膜相中N₅₀₃浓度为10.0%（w/V）,反萃相中硫氰酸钾浓度为0.2mol/L,迁移4h,Pd（Ⅱ）的迁移率可达93%。3、模拟实验在Pt（Ⅳ）支撑液膜迁移研究的基础上,使用P₅₀₇/煤油支撑液膜体系,研究了Pt（Ⅳ）与部分过渡金属离子的分离情况。（1）两种金属离子的分离实验在Pt（Ⅳ）的最佳迁移条件下,1.0μg/mL的Pt（Ⅳ）能有效的分别从50μg/mL的Ni（Ⅱ）、100μg/mL的Co（Ⅱ）、100μg/mL的Cu（Ⅱ）、150μg/mL的Zn（Ⅱ）中分离出来,迁移3h,Pt（Ⅳ）的迁移率分别为89%、86%、81%、87%,基本实现了Pt（Ⅳ）与Ni（Ⅱ）、Pt（Ⅳ）与Co（Ⅱ）、Pt（Ⅳ）与Cu（Ⅱ）、Pt（Ⅳ）与Zn（Ⅱ）的相互分离。（2）模拟电镀废液的分离实验模拟配制了某车间镀铂废水,其组成为Pt（Ⅳ）（0.8μg/mL）,Cu（Ⅱ）（75μg/mL）,Zn（Ⅱ）（75μg/mL）,Co（Ⅱ）（75μg/mL）,Ni（Ⅱ）（75μg/mL）,SO₄^2-（75μg/mL）。在Pt（Ⅳ）的最佳迁移条件下,迁移3h,迁移率达87.8%,其他离子均未发生迁移,说明本文建立的Pt（Ⅳ）的SLM分离方法具有一定的应用参考价值。更多还原

【Abstract】 Noble metals have unique physical and chemical properties,so they have a wide range of industrial applications.But because their physical and chemical properties are very similar,also their valences are changeful and the same noble metal ion with different valences have different properties,so it’s a challenging task to separate the noble metals.The liquid membrane separation technology has the advantages of combination of extraction and back extraction,higher mass transportation speed and throughput,higher selectivity,better separation efficiency and concentration ratio,easy to operate.It’s a new separation technology studied extensively in recent years.In order to improve the selectivity and practicability of separation of noble metals,the application of liquid membrane technology to separate noble metals has been studied and good progress has been made by a lot of researchers.however,the separation of noble metals through emulsion liquid membrane has been reported more than that of supported liquid membrane.Therefore,on the basis of solvent extraction,the transfer behaviors of Pt（Ⅳ） and Pd（Ⅱ）through supported liquid membrane have been studied systemically in the paper.The results are as follows:1.The extraction equilibrium of Pt（Ⅳ）and Pd（Ⅱ）The experiments have been carried out with various extractants.The conditions of extraction and back extraction have been discussed,and the optimum extraction conditions are obtained.（1）The extraction equilibrium experiment of Pt（Ⅳ）When the initial concentration of Pt（Ⅳ）in the aqueous phase is 5.0μg/mL,SnCl₂ concentration is 0.05mol/L,HCl concentration is 0.50mol/L,kerosene as diluent in the organic phase,2-ethylhexylphosphonic acid mono-2-ethylhexyl ester(P₅₀₇)concentration is 5.0%（w/V）,the volume ratio of aquous phase and organic phase is 1:1,oscillation 30 minutes,the extraction rate of Pt（Ⅳ）is nearly 100%,the stripping agent is the same volume of 4mol/L HCl,the strip percentage is above 99%.（2）The extraction equilibrium experiment of Pd（Ⅱ）When the initial concentration of Pd（Ⅱ）in the aqueous phase is 6.754μg/mL,HCl concentration is 0.50mol/L,kerosene as diluent in the organic phase,N,N-di（methyl-heptyl）acetaminde(N₅₀₃)concentration is 10.0%（w/V）,the volume ratio of aquous phase and organic phase is 1:1,oscillation 30 minutes,the extraction rate of Pd（Ⅱ）is 99.2%,the stripping agent is the same volume of 0.2mol/L KSCN,the strip percentage is above 95%.2.The transport of Pt（Ⅳ）and Pd（Ⅱ）through supported liquid membraneThe transfer behaviors of Pt（Ⅳ）and Pd（Ⅱ）through a supported liquid membrane consisting of P₅₀₇or N₅₀₃solution in kerosene,adsorbed on a hydrophobic Polyvinylidene Fluoride microporous film have been studied respectively.（1）The transport experiment of Pt（Ⅳ）The concentration ofPt（Ⅳ）1.0μg/mL has been chosen as initial concentration,the effects of HCl and SnCl₂ concentration in the feed phase,P₅₀₇concentration in the membrane phase,HCl concentration in the strip phase on the transport of Pt（Ⅳ）have been discussed,and the best transport conditions of Pt（Ⅳ）are obtained:When initial concentration of Pt（Ⅳ）is 1.0μg/mL,SnCl₂ concentration is 0.05mol/L and HCl concentration is 1.0mol/L in the feed phase,P₅₀₇concentration in the membrane phase is 5.0%（w/V）,HCl concentration in the strip phase is 6.0mol/L,the transport rate is nearly 100%in three hours.（2）The transport experiment of Pd（Ⅱ）The concentration of Pd（Ⅱ）3.0μg/mL has been chosen as initial concentration,the effects of HCl concentration in the feed phase,N₅₀₃concentration in the membrane phase,KSCN concentration in the strip phase on the transport of Pd（Ⅱ）have been discussed,and the best transport conditions of Pd（Ⅱ）are obtained:When initial concentration of Pd（Ⅱ）is 3.0μg/mL and HCl concentration is 0.2mol/L in the feed phase,N₅₀₃concentration in the membrane phase is 10.0%（w/V）,KSCN concentration in the strip phase is 0.2mol/L,the transport rate is above 93%in four hours.3.Simulation experimentsOn the basis of Pt（Ⅳ）transport through the supported liquid membrane using P₅₀₇as a mobile carrier,the separation of Pt（Ⅳ）and several transition metal ions have been studied.（1）Separation experiments of two metal ionsUnder the best conditions of transport Pt（Ⅳ）,1.0μg/mL Pt（Ⅳ）can separate from 50μg/mLNi（Ⅱ）,100μg/mLCo（Ⅱ）,100μg/mL Cu（Ⅱ）and 150μg/mLZn（Ⅱ）respectively.The transport rates of Pt（Ⅳ）are 89%,86%,81%and 87%,respectively in three hours.The mutual separation of Pt（Ⅳ）and Ni（Ⅱ）,Pt（Ⅳ）and Co（Ⅱ）,Pt（Ⅳ）and Cu（Ⅱ）,Pt（Ⅳ）and Zn（Ⅱ）,has been basically achieved.（2）The separation experiment of simulated platinum plating solutionSimulated platinum plating solution consisting of 0.8μg/mLPt（Ⅳ）,75μg/mLCu（Ⅱ）, 75μg/mLZn（Ⅱ）,75μg/mL Co（Ⅱ）,75μg/mLNi（Ⅱ）,75μg/mLSO₄^2-is treated through the supported liquid membrane system which has been established above,the transport rate of Pt（Ⅳ） is 87.8%in three hours,other metal ions do not transport.The results showed that the separation method of Pt（Ⅳ）through SLM established in this paper has certain value of reference and application.更多还原