Recycling Indium from Scraped Glass of Liquid Crystal Display: Process Optimizing and Mechanism Exploring

Abstract

With rapid growth in the use of liquid crystal display (LCD) and increasing concerns for environmental protection as well as conservation of scarce metals such as indium, the recycling of indium from waste LCDs is becoming a hot issue for current society. In this study, the leaching process for indium and exploration of its mechanism were carried out with full consideration of potential theory and experiments. The optimal parameters for the leaching process is controlled at a <75 μm sample size, 180 min retention time, 50 °C temperature, H2SO4 for the leaching agent, 100 g/L initial concentration, and 1:1 liquid–solid ratio. The initial samples and leaching yields were examined with the necessary analytical techniques including SEM, XRF, EDS, XRD, FTIR, and ICP. We also found that the leaching process could largely modify raw material and enhance its activation for further recovery. All the obtained results and findings could contribute to affording a closed-loop recycling process for waste LCDs and sustainable development of indium industries.