A conceptual chemical process for the recycling of Ce, Eu, and Y from LED flat panel displays

Abstract

The popularity and rapid obsolescence of electronic devices and products leads to many of these items eventually ending up in various waste streams. Understanding the tradeoffs in processing end-of-life E-waste materials for reuse is an important part of informing decision-makers who are considering recovery and recycle of these materials. An example study presented here is the recovery and recycle of rare earth metals in the light emitting diodes (LED) found in the backlighting unit for liquid crystal displays (LCD) of flat panel televisions. A conceptual and defined commercial-scale process for recycling E-waste is described, including the recycle of rare earth elements from the LED module. Synthesis of a full process, from display dismantling to rare earth separation, is proposed based on engineering principles and fragmented literature. The synthesis defines a process flow diagram, complete with mass and energy transfer modeling. Such a detailed commercial scale process model for recycling rare earth elements provides an advance to the science. Rare earth elements are critically important, but are low-quantity materials in many electronic items. Providing a process model for their recycle is an essential first step towards a sustainability analysis, with social, economic, and environmental implications.