Developing Feasible Processes for the Total Recycling of WEEE to Recover Rare Metals

Abstract

The present paper reports several application-oriented processes developed for the recovery of various non-ferrous (Cu, Ni, Al, Pb, Sn), rare (Li, Co, In), precious (Au, Ag, Pt, and Pd), and rare earth metals (Nd, Ce, La, Y, Eu) from various urban ores, i.e., waste electrical and electronic equipment (WEEE), liquid crystal displays (LCD), batteries, magnets, fluorescent tubes, etc. Initially, the WEEE and various wastes were classified and dismantled. Further, the materials were pretreated to separate plastics, epoxy, ceramics, rubber, iron covers, and metallic concentrates. Based on their properties, plastic, epoxy, and rubber could be either pyrolysed for production of marketable low-density oil and saleable activated carbon or directly recycled. The pre-treated metallic concentrates were processed by hydrometallurgical techniques, i.e., leaching, solvent extraction, ion exchange, and electro-winning for maximum recovery of metals. Various flow sheets discussed for rare metal extraction and processing strictly comply with environmental regulations.