Exploiting end-of-life lamps fluorescent powder e-waste as a secondary resource for critical rare earth metals

The consensus is growing for the UN sustainable development goals regarding responsible consumption, production, and climate actions. Because of growth towards a digital society (“industry 4.0 revolution”), it is needed to have our resources and economies to be circular. The success also depends on appropriate management of critical raw materials, such as Rare Earth Elements (REEs). Here, a cost-effective recycling method for the recovery of single REEs from fluorescent powder (FP) with end-of-life lamp e-waste is presented with the additional benefit of having a much less environmental impact than mining. The recycling method involves a carefully designed sequential digestion of two phosphor components (YOX and LAP) and treating their leachates separately under specific hydrometallurgical conditions. The phosphors were targeted for Yttrium (Y), Europium (Eu), Terbium (Tb), Lanthanum (La), Cerium (Ce), and Gadolinium (Gd). On trace REEs basis, the leaching process with the FP showed >95% recovery for Eu, La, Ce, Y and Tb. The effective recycling was achieved to >99% purity for Y, Eu, and Tb in 1, 25, and 55 liquid-liquid extraction stages, respectively. To our knowledge, this is one of the first methods to leach and separate Tb from FP e-waste with near quantitative leaching efficiency and >99% purity.