电子类化工废水中铟锡的回收利用

发布时间：2018-03-29 10:18

  本文选题：ITO刻蚀废液　切入点：沉淀法　出处：《合肥工业大学》2017年硕士论文

【摘要】：氧化铟锡(ITO)的主要应用领域是生产液晶显示器,而其主要成分金属铟在地壳上含量稀少,属于稀散金属。随着电子行业的发展、含铟原生资源的过渡开采以及铟的需求量进一步增加,很多国家将其列为战略资源,因此,开发铟的二次资源显得尤为重要。ITO刻蚀废液产生于液晶显示器的生产过程中。这种废液的特点为含酸高且含高回收价值的金属离子,若是采用的是直排方式,既会使环境受到污染,又会使宝贵的资源被浪费。鉴于铟的需求量扩大,回收ITO刻蚀废液中的铟显得十分必要。本文以ITO刻蚀废液为研究对象,研究刻蚀废液中铟锡的回收利用技术。首先,通过沉淀法对ITO刻蚀废液进行处理,介绍了沉淀法的优缺点,并叙述了实验现象。实验结果表明,通过沉淀法处理ITO刻蚀废液,其回收率较高,其中铟离子的回收率为99.9%,锡离子的回收效率为96.6%。其次,通过萃取法对ITO刻蚀废液进行处理,介绍了萃取法的优缺点,选择了三种常见的应用于铟锡萃取的萃取剂,即,P204,P507和TBP,并通过定性的角度确定了适合用于ITO刻蚀废液的萃取剂为P204,并做了P204的反萃实验。实验结果表明,通过对P204进行单因素实验及正交实验得出萃取法在处理ITO刻蚀废液的最佳工艺为萃取剂/稀释剂为3/7;搅拌时间为5分钟;油水比(A/O)为7/1,温度为30℃。最佳工艺条件下,铟离子的萃取率为99.14%,锡离子的萃取率为76.68%。但是由于反萃效率不高,经估算,该方法铟的总回收率在85%左右,锡的回收率仅为15%左右。最后,通过螯合树脂法对ITO刻蚀废液进行处理,介绍了螯合树脂法的优缺点,并通过对三类应用于金属离子吸附的螯合树脂进行比选,选出了适用于吸附铟锡离子的螯合树脂。实验结果表明,通过螯合树脂法处理ITO刻蚀废液,其回收率较高,其中对铟的平均去除率高达99.5%,对锡的平均去除率高达96.2%。通过解吸,能将废液中的铟锡进行回收利用,且解吸效率较高,该方法对铟锡的总回收率均在95%以上,且产废较少,后续处理成本不大。
[Abstract]:The main application field of indium tin oxide (ITO) is the production of liquid crystal display (LCD), and its main component, indium, is rare in the crust and belongs to dilute metal. The overexploitation of indium-containing primary resources and the further increase in demand for indium have been listed as strategic resources in many countries. It is particularly important to develop indium secondary resources. ITO etching waste liquid is produced in the production process of liquid crystal display. The waste liquid is characterized by high acid content and high recovery value of metal ions. In view of the increasing demand for indium, it is very necessary to recover indium from the waste liquid of ITO etch. In this paper, the ITO etching waste liquid is taken as the research object. The recovery and utilization technology of indium tin in etching waste liquid is studied. Firstly, the ITO etching waste liquid is treated by precipitation method, the advantages and disadvantages of precipitation method are introduced, and the experimental phenomena are described. The experimental results show that the ITO etching waste liquid is treated by precipitation method. The recovery rate of indium ion is 99.9 and the recovery efficiency of tin ion is 96.6. secondly, the ITO etching waste liquid is treated by extraction, and the advantages and disadvantages of the extraction method are introduced. Three common extractants used in indium tin extraction, namely P204P507 and TBP, were selected. The extractant P204was determined to be suitable for ITO etching waste liquid by qualitative analysis, and the back extraction experiment of P204 was carried out. Through the single factor experiment and orthogonal experiment of P204, it is concluded that the optimum process of extraction in treating ITO etching waste liquid is that the extractant / diluent is 3 / 7; the stirring time is 5 minutes; the ratio of oil to water is 7 / 1; the temperature is 30 鈩，

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