Extraction of indium-tin oxide from end-of-life LCD panels using ultrasound assisted acid leaching

• Published in: Ultrasonics sonochemistry Vol. 40; no. Pt A; pp. 929 - 936
• Main Authors: Souada, Malika, Louage, Christophe, Doisy, Jean-Yves, Meunier, Ludivine, Benderrag, Abdelkader, Ouddane, Baghdad, Bellayer, Séverine, Nuns, Nicolas, Traisnel, Michel, Maschke, Ulrich
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.01.2018; Elsevier
• Subjects: Chemical Sciences; Indium; Indium tin oxide; LCD; or physical chemistry; Recycling; Theoretical and; Ultrasound; WEEE; Recycling; LCD; Indium; Indium tin oxide; Ultrasound; WEEE; indium; recycling; indium tin oxide; ultrasound
• ISSN: 1350-4177; 1873-2828
• DOI: 10.1016/j.ultsonch.2017.08.043

[Display omitted] •Fast recovery of indium-tin-oxide from end-of-life LCDs.•Efficient ultrasound-assisted sulfuric acid leaching process.•High extraction yield of indium and tin.•Controlled dissolution from the ITO-side of LCD panels.•Recyclability of the neat LCD glass substrates. In this report, indium-tin-oxide (ITO)-layer extraction from end-of-life (EOL) Liquid Crystal Displays (LCDs) was discussed by sulfuric acid leaching with simultaneous application of ultrasonication on the ITO-side of glass/ITO panels, exhibiting various dimensions. Applying this technique presents several advantages compared to the traditional leaching process such as fast and controllable kinetics, high extraction yield of indium and tin, selective recovery of these two metals possible, and the opportunity to recycle the neat glass separately avoiding additional separation processes. ITO-dissolution kinetics from EOL LCD panels were investigated as function of leaching time and acidity of sulfuric acid. At a temperature of 60°C, a nearly quantitative indium yield was obtained using an acid concentration of 18mol/L by simultaneous application of ultrasonication, whereas only 70% were recovered in the absence of ultrasound. Results from ICP-AES agreed well with SEM/BSE observations demonstrating the high efficiency of the ultrasound assisted process since only 3–4min were required to obtain maximum ITO recovery.