Rare earth elements recovery from secondary wastes by solid-state chlorination and selective organic leaching

Processing of end-of-life products (EoL) containing rare earth elements (REE) has gained increasing importance in recent years with the aim avoiding supply risks. In addition, circular economy renders complete recirculation technology metals mandatory. Fluorescent lamp wastes are an important source for REE recovery since they contain significant amounts, up to 55 wt%, Y and Eu red phosphors. For these purposes, solid-state chlorination (SSC) is economically attractive alternative wet acid leaching treatment, which profits from a considerable reduction chemicals consumption process costs. Chlorination takes place dry HCl(g) produced thermal decomposition NH4Cl(s), not only converting content Hg-free phosphor waste into water soluble metal chlorides, but also implications aqueous complex chemistry REE. To establish industrial viable on commercial scale, SSC been optimized by (i) using design experiment (DOE) varying temperature, residence time, gNH4Cl/gsolid ratio (ii) improved chlorinated organic mixture selective As result, 95.7% 92.2% were selectively recovered at 295.9 °C, 67 min 1.27 gNH4Cl/gsolid, followed quantitative Owed its low operation costs, current allows valorizing even when raw material prices low.