热还原—真空蒸馏法回收ITO废料中金属铟的研究
发布时间:2018-01-16 04:25
本文关键词:热还原—真空蒸馏法回收ITO废料中金属铟的研究 出处:《昆明理工大学》2017年硕士论文 论文类型:学位论文
更多相关文章: ITO废料 热还原 响应曲面法 真空蒸馏法 铟
【摘要】:随着电子信息技术的发展,ITO靶材主要用于生产液晶显示屏的透明电极。每年用于ITO靶材方面的铟在560t以上,占铟总消耗量的80%以上。但在ITO靶材磁控溅射方法制备ITO薄膜中,靶材的利用率低,并且ITO靶材加工过程中会产生大量的边角料与切削粉末,使得ITO靶材的利用率仅有30%。且废料中含铟在80%以上,因此研究从ITO废靶中回收金属铟具有重要意义,本文研究了CO还原-真空蒸馏分离的方法处理ITO废料还原铟、锡。本文首先对CO还原氧化铟和氧化锡进行了热力学分析与动力学分析探讨,得到还原反应发生的温度范围和可能存在的控制步骤。通过单因素实验研究表明:最佳的反应条件为温度950℃,CO流量为40ml/min,还原时间为50min,此时铟锡合金的还原率大于97%,合金中铟的还原率大于99%锡的还原率大于98%,在实验研究的基础上,利用响应曲面法对实验条件进行了优化。动力学实验研究表明:在750℃~950℃温度段还原反应处于扩散传质控制阶段,其表观扩散活化能为52.85kJ/mol。经过氧化铟与氧化锡混合物CO还原反应实验研究知道,氧化铟与氧化锡CO还原法制备铟锡合金是可行的。ITO废靶材CO还原实验研究表明:在还原温度为950℃,CO流量为40ml/min,还原时间为50min,粒度为200目以上时,产物铟锡合金中铟的含量为90.43%,锡的含量为9.5%;铟的还原率大于99%,锡的还原率大于98%。真空蒸馏多级冷凝实验表明:在温度1400 ℃,保温1h,压强为10~15 Pa的冷凝条件下,铟主要分布在中间3级至6级冷凝盘中,其中杂质元素Cu、Cd、Fe、A1、Sn主要分布在1级和2级,Pb、T1主要分布在8级至10级冷凝盘,其中3级和4级冷凝盘中铟纯度为99.9%,直收率为53.87%,5级和6级冷凝盘的铟纯度为99.99%,直收率为36.7%,因此通过一次真空蒸馏多级冷凝,可产出99.9%~99.99%的精铟,直收率达到90.57%,杂质可以达到4N铟的国家标准要求。综上所述采用热还原-真空蒸馏法处理ITO废料,具有铟锡回收率高,能耗低,流程简单,有利于环保等优点。
[Abstract]:With the development of electronic information technology, ITO targets are mainly used to produce transparent electrodes for liquid crystal display screen. The indium used in ITO targets is 560t / year. The total consumption of indium is more than 80%. However, in the preparation of ITO thin films by ITO target magnetron sputtering, the utilization ratio of target is low, and a large number of side materials and cutting powder will be produced in the process of ITO target processing. The utilization ratio of ITO target is only 30%, and the content of indium in waste material is more than 80%. Therefore, it is of great significance to study the recovery of metal indium from the waste target of ITO. In this paper, the reduction of indium and tin from ITO waste by CO reduction-vacuum distillation method was studied. Firstly, the thermodynamic analysis and kinetic analysis of indium oxide and tin oxide by CO reduction were carried out. The temperature range of the reduction reaction and the possible control steps are obtained. The results of single factor experiment show that the optimum reaction condition is that the CO flow rate is 40 ml / min at 950 鈩,
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