The Use of Deep Eutectic Solvents Ionic Liquids for Selective Dissolution and Recovery of Sn, Pb and Zn from Electric and Electronic Waste (WEEE)

Abstract

The recovery of metals from a multi-component alloy obtained by crushing, melting and anodic dissolution of waste electric and electronic equipment (WEEE) has been investigated. The aim of this paper is to selective recover of Sn, Pb and Zn by a novel ecological technology using ionic liquids. Metallic Sn, Pn and Zn were electrochemically recovered from the WEEE dissolved in choline chloride-ethylene glycol-iodine ionic liquid. Cyclic voltammetry was used in order to determine the deposition potentials of the studied metals. XRD and SEM/EDX analysis methods were used to characterize the structure and morphology of the metallic deposits. Evolution of the cathodic deposition and of the chemical composition of the anode during the anodic dissolution process for Sn, Pb and Zn was also studied. This study has demonstrated the possibility of selective recovery of Sn, Pb and Zn from the multi-component alloy (which resulted from consecutive anodic dissolution of WEEE) by anodic dissolution/deposition in ionic liquids.

Status and advances of deep eutectic solvents for metal separation and recovery

“…Additionally, the hydrophilic DESs have also been applied as electrolytes for electrochemical dessolution of metals (e.g., Sn, Pb, Zn, Cu, Co, etc. ), such as anodic dissolution 109,118 and electrodeposition. [119][120][121][122] The advantages of hydrophilic DESs as electrolytes for the electrochemical process include nonacidic formulation, the improved surface finish on cast pieces, and enhanced current efficiency.…”

“…212 Furthermore, green leaching processes using DESs were approached to selective extraction of various metal ions from other e-waste, including end-of-life permanent magnets, 130,214 lamp phosphor waste, 215 and printed circuit boards (PCB). 96,118 Specifically, the guanidine hydrochloride-lactic acid (GUC-LAC) combined DES was screened from nine kinds of guanidine-based DESs as the best leachant to selectively extract the rare earth elements, neodymium (Nd), from the end-of-life permanent magnets with a high separation factor (>1300) between Nd and Fe through a simple selective dissolution step followed by precipitation process with oxalic acid. 130 The ChCl : levulinic acid DES was demonstrated to have high extraction efficiency (>70%) to the red phosphor Y 2 O 3 :Eu 3+ (YOX), and thus could be used as a more costeffective alternative to IL for the selective leaching of rare earth elements (i.e., yttrium (Y) and europium (Eu)) from lamp phosphor waste.…”

“…215 The integrated process of ultrasonic-assisted leaching in ethaline and subsequent electrodeposition showed good performance in terms of high selectivity and extraction efficiency for Sn, Pb, Zn and Cu ions from PCB. 96,118…”

Iodine speciation in deep eutectic solvents

“…Iodine is a very efficient oxidising agent which has been used for metal and mineral digestion, as it is strong enough to dissolve gold in both aqueous [20][21][22] and DES systems 19,[23][24][25][26] under mild conditions, along with other metals found in printed circuit boards 27 and minerals. [28][29][30] Phosphonium halide and trihalide ionic liquids have also been successfully used to digest metals.…”

Corrosion Behavior of Some Steels in Ionic Liquids Based on Choline Chloride

“…Ionic liquids (ILs) are a new class of electrolytes with special properties and with many applications in various fields: media for electrodeposition of metals [9][10][11], fluids for thermal storage and exchange in solar concentrating power plants [12], use as solvents for chemical synthesis [13,14], supercapacitors [15,16], electrolyte for electrochemical devices such as battery [17]. ILs are ideal solvents for green chemistry, metals electrodeposition and recovery from electric and electronic waste [18][19][20]. The ILs involvement will minimize the environmental pollution, and synchronizes with the international technological development.…”