离子液体膜分离富集废旧镍镉电池中镉的资源化研究

发布时间：2018-04-23 16:00

  本文选题：[Bmim]PF6/[Beim]PF6 + 液膜分离　； 参考：《西安工程大学》2015年硕士论文

【摘要】：随着通讯与家电业的高速发展,镍镉电池的需求量也日渐增大,但随之而来的环境污染问题也越来越严重。镉是稀有贵重金属,也是有毒金属,镍镉电池中的镉含量较大,废旧镍镉电池带来的环境污染问题主要是由镉的污染造成的,所以无论是从资源回收再利用的角度,还是从保护环境的角度,富集回收废旧镍镉电池中的镉都具有重要的现实意义。本实验中合成离子液体1-丁基-3-甲基咪唑六氟磷酸盐([Bmim]PF6)和1-丁基-3-乙基咪唑六氟磷酸盐([Beim]PF6),并考察了反应时间、反应温度、反应物配比、溶剂用量等因素的影响。将此离子液体与液膜分离技术联用,以三正辛胺为载体,硫酸作反萃取剂,研究了此项技术对硝酸镉模拟废水溶液中镉的分离富集效果,考察了反应时间、载体的浓度、溶液p H值和硫酸浓度等影响因素。最后研究了将此项技术应用于废旧镍镉电池预处理液,检测了其对镉的分离富集效果,实验取得的结果如下:1.合成中间体[Bmim]Br和[Beim]Br的最佳参数条件为:0.1mol N-甲基咪唑/N-乙基咪唑、0.12mol溴代正丁烷、反应时间24h、反应温度60℃;合成[Bmim]PF6和[Beim]PF6的最佳条件是:0.1mol[Bmim]Br/[Beim]Br、0.11mol KPF6、反应温度50℃,反应时间24h,[Bmim]PF6和[Beim]PF6的合成率分别为88.2%和90.6%,并对产物进行了表征;2.离子液体与液膜分离技术联用处理5×10-4mol/L硝酸镉模拟废水溶液,最佳反应条件分别为:选择离子液体[Bmim]PF6、载体的浓度为9×10-4mol/L、溶液p H值为5、萃取时间为80min、硫酸浓度为1.5mol/L、反萃取时间为60min,最终镉的分离富集效率为91.9%,干扰离子镍钴的加入对镉的分离富集效率的影响极小。离子液体经纯化处理后可实现循环利用;3.将此技术应用于分离富集废旧镍镉电池预处理液中的镉,实验在最佳参数条件下进行,达到了预期的处理效果,镉、镍和钴的分离富集效率为91.2%、3.5%和2.1%,实现了镉的分离富集。利用离子液体与液膜分离技术联用的方法分离富集废旧镍镉电池中的镉,反应操作简单、反应过程绿色安全无污染,可以很好地分离富集出其中的镉,达到了预期的效果。
[Abstract]:With the rapid development of communication and home appliances, the demand for Ni-CD batteries is increasing, but the environmental pollution is becoming more and more serious. Cadmium is a rare and precious metal, but also a toxic metal. The cadmium content in Ni-CD batteries is large. The environmental pollution caused by waste Ni-CD batteries is mainly caused by cadmium pollution, so whether from the perspective of resource recovery and reuse, It is also of practical significance to enrich and recover cadmium from waste nickel-cadmium batteries from the point of view of environmental protection. Ionic liquids 1 Ding Ji 3 methyl imidazolium hexafluorophosphate ([Bmim] PF6) and 1 Ding Ji 3 ethyl imidazolium hexafluorophosphate ([Beim] PF 6) were synthesized in this experiment. The effects of reaction time, reaction temperature, reactant ratio and solvent dosage were investigated. The separation and enrichment of cadmium in the simulated wastewater solution of cadmium nitrate was studied by using this ionic liquid and liquid membrane separation technology, with trioctylamine as the carrier and sulfuric acid as the stripping agent. The reaction time and the concentration of the carrier were investigated. The pH value of solution and the concentration of sulfuric acid were affected. Finally, the application of this technology to the pretreatment solution of waste Ni-CD battery was studied, and the separation and enrichment of cadmium was detected. The experimental results were as follows: 1. The optimum conditions for the synthesis of [Bmim] Br and [Beim] Br are as follows: 0.1 mol N-methylimidazole / N-ethylimidazolium 0.12 mol bromo-n-butane, reaction time 24 h, reaction temperature 60 鈩，

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