Recycling indium from waste LCDs: A review

As one of the most widely used scarce metals located at the column of IIIA in the periodic table, indium has drawn more and more attention due to its semiconductor and optoelectronic performance. While the reduction of indium minerals, as one of secondary resources, the amount of waste liquid crystal display (LCD) has been accumulated considerably. Indium tin oxide (ITO) film which is the main functional fraction of LCD has consumed more than 70% of the indium production worldwide. Therefore, it is necessary to recycle indium from waste LCDs. Some researches have been done for proper treatment to recycle indium from waste LCD which is a primary part of waste electric and electronic equipment (WEEE). In this paper, the main characteristics of indium and the waste management status of end-of-life LCDs are introduced. And we mainly focus on the highly developed single recycling and reusing techniques. In addition, several combined recycling processes are evaluated. Furthermore, on the foundation of techniques and processes mentioned above, the promising related single techniques and the improvements on whole treatment process of waste LCDs are suggested. (C) 2015 Elsevier B.V. All rights reserved.