|About this Abstract
||2022 TMS Annual Meeting & Exhibition
||REWAS 2022: Recovering the Unrecoverable
||Recovery of Terbium, Europium, and Yttrium from Waste Fluorescent Lamp Using Supercritical Fluid Extraction
||Jiakai Zhang, John Anawati, Gisele Azimi
|On-Site Speaker (Planned)
Recycling of waste electrical and electronic equipment (WEEE) has been receiving significant attention around the world. Here, we develop an environmentally sustainable process that uses supercritical carbon dioxide as the solvent along with a small volume of tributyl-phosphate (TBP) nitric acid adduct as the chelating agent to recover rare earth elements (REEs) from fluorescent lamp waste. We show that mechanical activation using oscillation milling increases extraction efficiency. We elucidate the process mechanism by characterizing the solids before and after the process using transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). We show that Al3+ and Ca2+ cations from the Al2O3 and Ca5(PO4)3OH (hydroxyapatite) present in the fluorescent lamp waste result in competing reactions with REEs with TBP-HNO3 adduct; thus, REE extractions from real fluorescent lamp waste is less than what has been reported from synthetic feeds. Management of fluorescent lamp waste leads to sustainability of biosphere and circular economy.