离子液体的制备及萃取电镀污泥中金属的研究

发布时间：2019-03-17 19:22

【摘要】：电镀行业作为基础产业之一,为我国经济快速发展做出了巨大贡献。但与此同时,电镀行业会产生大量的电镀污泥,其中含有大量有毒有害的金属,若得不到有效的处理,将会对环境造成巨大的影响。离子液体作为新型绿色溶剂,广泛应用于各个行业中,本文主要利用离子液体的萃取金属特性,将其应用于回收电镀污泥中金属,使电镀污泥达到变废为宝的目的。1、本文主要采用微波辅助两步法合成1-丁基-3-甲基咪唑六氟磷酸盐([BMIM][PF_6])、1-己基-3-甲基咪唑六氟磷酸盐([HMIM][PF_6])、1-辛基-3-甲基咪唑六氟磷酸盐([OMIM][PF_6])3种咪唑类离子液体,并对其粘度进行测定。利用合成的3种离子液体对Pb~(2+)、Zn~(2+)、Ni~(2+)、Cd~(2+)、Co~(2+)5种金属离子进行萃取实验,结果表明[BMIM][PF_6]对5种金属的萃取量最大。利用FT-IR、1HNMR、HPLC表征手段对[BMIM][PF_6]的结构和含量进行了测定。2、采用[BMIM][PF_6]、[BMIM][PF_6]-双硫腙两种体系分别对Pb~(2+)、Zn~(2+)、Ni~(2+)、Cd~(2+)、Co~(2+)5种金属离子的萃取性能进行了研究。在最佳萃取体系[BMIM][PF_6]-双硫腙条件下,研究了温度、时间、p H、金属离子初始浓度等因素对萃取性能的影响,并对Pb~(2+)、Zn~(2+)、Ni~(2+)3种金属离子做了正交实验,得到最佳萃取条件。3、以实际电镀污泥为原料,优化酸浸出时的工艺条件,探究固液比、时间、温度对金属浸出的影响,最终得到最佳工艺条件为:固液比为1:10,搅拌时间为100min,温度40℃。4、以硫酸浸出液为原料,采用分步沉淀法和溶剂萃取法对溶液中金属进行分离。铜的萃取剂和反萃剂分别为LIX984N和硫酸,萃取的最佳条件为:萃取剂和金属溶液体积之比为1:3,p H=1.5,搅拌时间为3min,萃取温度为45℃,萃取率可达96.7%;反萃硫酸最佳浓度为5mol/L,反萃率可达84.2%。锌的萃取剂和反萃剂分为为[BMIM][PF_6]-双硫腙和硫酸,锌采用4级萃取,萃取率可达95.5%;反萃使用3mol/L的硫酸,反萃级数为3级,反萃率为81.7%。在最优的工艺条件下,对电镀污泥进行放大处理,经酸浸、分步沉淀、萃取等步骤之后,分别得到硫酸铜、硫酸镍、硫酸锌。Cu回收率为77.37%,Ni回收率为78%,Zn回收率为73.9%。
[Abstract]:As one of the basic industries, electroplating industry has made great contribution to the rapid development of China's economy. But at the same time, electroplating industry will produce a large number of electroplating sludge, which contains a large number of toxic and harmful metals, if not treated effectively, it will have a great impact on the environment. Ionic liquids, as a new green solvent, are widely used in various industries. In this paper, the metal extraction properties of ionic liquids are mainly used to recover metal from electroplating sludge, and the electroplating sludge is used to turn waste into treasure. In this paper, 1-Ding Ji-3-methylimidazole hexafluorophosphate ([BMIM] [PF_6]) and 1-hexyl-3-methylimidazole hexafluorophosphate ([HMIM] [PF_6]) were synthesized by microwave assisted two-step method. Three kinds of imidazole ionic liquids, 1-octyl-3-methylimidazole hexafluorophosphate ([OMIM] [PF_6]), and their viscosity were determined. Five metal ions (Pb~ (2), Zn~ (2), Ni~ (2), Cd~ (2), Co~ (2) were extracted with three synthetic ionic liquids. The results showed that [BMIM] [PF_6] had the highest extraction amount of five metals. The structure and content of [BMIM] [PF_6] were determined by FT-IR,1HNMR,HPLC. 2. Pb~ (2) and Zn~ (2) were determined by [BMIM] [PF_6], [BMIM] [PF_6]-dithizone, respectively. The extraction properties of Ni~ (2), Cd~ (2) and Co~ (2) were studied. Under the optimum extraction system [BMIM] [PF_6]-dithizone, the effects of temperature and time, p H, initial concentration of metal ions on the extraction performance were studied, and Pb~ (2), Zn~ (2), etc. The orthogonal experiment of Ni~ (2) three kinds of metal ions was carried out, and the optimum extraction conditions were obtained. 3. The effect of solid-liquid ratio, time and temperature on the leaching of metal was studied by optimizing the technological conditions of acid leaching with the actual electroplating sludge as the raw material, and the effects of solid-liquid ratio, time and temperature on the leaching of metal were studied. The optimum technological conditions are as follows: the ratio of solid to liquid is 10, stirring time is 100min, temperature is 40 鈩，

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