School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai, 200240, People's Republic of China.
J Hazard Mater. 2017 Apr 5;327:55-63. doi: 10.1016/j.jhazmat.2016.12.026. Epub 2016 Dec 19.
Recycling of waste liquid crystal display (LCD) panels is an urgent task with the rapid expanding LCD market. However, as important composition of LCD panels, the treatment of liquid crystal is seldom concerned for its low concentration. In present study, a stripping product enriched liquid crystal and indium is gained by mechanical stripping process, in which liquid crystal is enriched from 0.3wt.% to 53wt.% and indium is enriched from 0.02wt.% to 7.95wt.%. For the stripping product, liquid crystal should be removed before indium recovery because (a) liquid crystal will hinder indium recycling; (b) liquid crystal is hazardous waste. Hence, an effective and green approach by vacuum pyrolysis is proposed to treat liquid crystal in the stripping product. The results are summarized as: (i) From the perspective of apparent activation energy, the advantages of vacuum pyrolysis is expounded according to kinetic analysis. (ii) 89.10wt.% of liquid crystal is converted and the content of indium in residue reaches 14.18wt.% under 773K, 15min and system pressure of 20Pa. This study provides reliable information for further industrial application and an essential pretreatment for the next step of indium recycling.
回收废弃液晶显示屏 (LCD) 面板是当务之急，随着 LCD 市场的迅速扩大。然而，作为 LCD 面板的重要组成部分，由于液晶浓度低，其处理方法很少受到关注。在本研究中，通过机械剥离工艺获得了富含液晶和铟的剥离产物，其中液晶从 0.3wt.%富集到 53wt.%，铟从 0.02wt.%富集到 7.95wt.%。对于剥离产物，在回收铟之前应该去除液晶，因为 (a) 液晶会阻碍铟的回收；(b) 液晶是危险废物。因此，提出了一种通过真空热解处理剥离产物中液晶的有效且绿色的方法。结果总结如下：(i) 从表观活化能的角度出发，通过动力学分析阐述了真空热解的优势。(ii) 在 773K、15min 和系统压力为 20Pa 的条件下，89.10wt.%的液晶转化，残留物中铟的含量达到 14.18wt.%。本研究为进一步的工业应用提供了可靠的信息，也为下一步回收铟提供了必要的预处理。
