Recovering Indium from the Liquid Crystal Display of Discarded Cellular Phones by Means of Chloride-Induced Vaporization at Relatively Low Temperature

Broadly speaking, indium (In) is extensively being used in the production of liquid crystal displays (LCDs). Nevertheless, LCDs, included in various types of end-of-life electronic devices (for example, discarded cellular phones), are generally discarded without recovering indium. Thus, the objective of this work is to recover indium from the LCD of the discarded cellular phone. The authors are putting forward a novel process in order to recover indium from the LCD of discarded cellular phones by means of chloride-induced vaporization at relatively low temperature. The samples are first treated with an aqueous solution of hydrochloric acid (HCl) to alter the structure of the indium(III) oxide found in LCDs into a chloride-induced indium compound and, therefore, enabling the vaporization of indium at relatively low temperature. The chloride-induced indium compound is then vaporized. Finally, the vaporized indium compound is condensed on a cooled surface of the apparatus and then recovered. The experimental results indicated that by using this process 84.3 pct of indium can be recovered from LCDs of discarded cellular phones.