Recycling of Critical Metals from Light-Emitting Diodes

Light-emitting diodes (LED) are widely used for energy savings. A lot of different materials and especially metals are needed to produce LED. End-of-life LED contain critical metals like indium or rare earth elements. In this study, first a thermochemical step is used to recover the critical metal indium from LED with hydrochloric acid-containing vapor from polyvinyl chloride as chlorine source. Then, the LED residue is leached with sulfuric acid and hydrogen peroxide. From the leachate, the heavy rare earth element lutetium can be extracted with n-octanol and tributyl phosphate.