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Title: Recovery of valuable materials from waste liquid crystal display panel

Abstract

Associated with the rapid development of the information and electronic industry, liquid crystal displays (LCDs) have been increasingly sold as displays. However, during the discarding at their end-of-life stage, significant environmental hazards, impacts on health and a loss of resources may occur, if the scraps are not managed in an appropriate way. In order to improve the efficiency of the recovery of valuable materials from waste LCDs panel in an environmentally sound manner, this study presents a combined recycling technology process on the basis of manual dismantling and chemical treatment of LCDs. Three key processes of this technology have been studied, including the separation of LCD polarizing film by thermal shock method the removal of liquid crystals between the glass substrates by the ultrasonic cleaning, and the recovery of indium metal from glass by dissolution. The results show that valuable materials (e.g. indium) and harmful substances (e.g. liquid crystals) could be efficiently recovered or separated through above-mentioned combined technology. The optimal conditions are: (1) the peak temperature of thermal shock to separate polarizing film, ranges from 230 to 240 deg. C, where pyrolysis could be avoided; (2) the ultrasonic-assisted cleaning was most efficient at a frequency of 40 KHz (Pmore » = 40 W) and the exposure of the substrate to industrial detergents for 10 min; and (3) indium separation from glass in a mix of concentrated hydrochloric acid at 38% and nitric acid at 69% (HCl:HNO{sub 3}:H{sub 2}O = 45:5:50, volume ratio). The indium separation process was conducted with an exposure time of 30 min at a constant temperature of 60 deg. C.« less

Authors:
 [1]; ; ;  [1]
  1. Department of Environmental Science and Engineering, Tsinghua University (China)
Publication Date:
OSTI Identifier:
21269339
Resource Type:
Journal Article
Journal Name:
Waste Management
Additional Journal Information:
Journal Volume: 29; Journal Issue: 7; Other Information: DOI: 10.1016/j.wasman.2008.12.013; PII: S0956-053X(08)00431-5; Copyright (c) 2008 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0956-053X
Country of Publication:
United States
Language:
English
Subject:
12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; CLEANING; DETERGENTS; GLASS; HYDROCHLORIC ACID; INDIUM; LIQUID CRYSTALS; MATERIALS RECOVERY; NITRIC ACID; PYROLYSIS; SEPARATION PROCESSES; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; THERMAL SHOCK; WASTES

Citation Formats

Jinhui, Li, Sino-Italia Environmental Energy Building, Room 804, Haidian District, Beijing 100084, Song, Gao, Huabo, Duan, and Lili, Liu. Recovery of valuable materials from waste liquid crystal display panel. United States: N. p., 2009. Web.
Jinhui, Li, Sino-Italia Environmental Energy Building, Room 804, Haidian District, Beijing 100084, Song, Gao, Huabo, Duan, & Lili, Liu. Recovery of valuable materials from waste liquid crystal display panel. United States.
Jinhui, Li, Sino-Italia Environmental Energy Building, Room 804, Haidian District, Beijing 100084, Song, Gao, Huabo, Duan, and Lili, Liu. 2009. "Recovery of valuable materials from waste liquid crystal display panel". United States.
@article{osti_21269339,
title = {Recovery of valuable materials from waste liquid crystal display panel},
author = {Jinhui, Li and Sino-Italia Environmental Energy Building, Room 804, Haidian District, Beijing 100084 and Song, Gao and Huabo, Duan and Lili, Liu},
abstractNote = {Associated with the rapid development of the information and electronic industry, liquid crystal displays (LCDs) have been increasingly sold as displays. However, during the discarding at their end-of-life stage, significant environmental hazards, impacts on health and a loss of resources may occur, if the scraps are not managed in an appropriate way. In order to improve the efficiency of the recovery of valuable materials from waste LCDs panel in an environmentally sound manner, this study presents a combined recycling technology process on the basis of manual dismantling and chemical treatment of LCDs. Three key processes of this technology have been studied, including the separation of LCD polarizing film by thermal shock method the removal of liquid crystals between the glass substrates by the ultrasonic cleaning, and the recovery of indium metal from glass by dissolution. The results show that valuable materials (e.g. indium) and harmful substances (e.g. liquid crystals) could be efficiently recovered or separated through above-mentioned combined technology. The optimal conditions are: (1) the peak temperature of thermal shock to separate polarizing film, ranges from 230 to 240 deg. C, where pyrolysis could be avoided; (2) the ultrasonic-assisted cleaning was most efficient at a frequency of 40 KHz (P = 40 W) and the exposure of the substrate to industrial detergents for 10 min; and (3) indium separation from glass in a mix of concentrated hydrochloric acid at 38% and nitric acid at 69% (HCl:HNO{sub 3}:H{sub 2}O = 45:5:50, volume ratio). The indium separation process was conducted with an exposure time of 30 min at a constant temperature of 60 deg. C.},
doi = {},
url = {https://www.osti.gov/biblio/21269339}, journal = {Waste Management},
issn = {0956-053X},
number = 7,
volume = 29,
place = {United States},
year = {2009},
month = {7}
}