Comparison of two acid leaching processes toward indium recovery obtained from end-of-life In-Cell Touch smartphone displays

In this work, leaching processes of thin-film-transistor (TFT) displays using nitric and sulfuric acid, respectively, for the purpose of indium recovery are studied. The substrates are extracted from end-of-life In-Cell Touch smartphone displays. Using EDS-SEM chemical mapping we have found that both acids can lead to the extraction of indium from the TFT matrixes. However, it is observed that sulfuric acid can remove almost 4% more indium than nitric acid under the same lixiviation conditions.