Recovery of Silver and Gold From Electronic Waste by Electrodeposition in Ethaline Ionic Liquid

Abstract

The recycling of metals from electronic equipment waste (e-waste) is of great concern today. The work described in the article focuses on the application of ionic liquids (ILs) to selectively recover of precious metals (Ag and Au) from the anodic slime obtained at the anodic dissolution of cast ewaste. The ingots obtained from molten and cast anodic slime were selectively dissolved in ILs. Silver and gold compositions of the ingots: 39.7 wt.% and respectively 18.9 wt.%. The IL used was an eutectic mixture of choline chloride with ethylene glycol in a 1:2 molar ratio. As catalytic/oxidizing agent, there was used pure iodine in a concentration of 0.1-0.2 moldm -3 at 298-303 K. Cyclic voltammetry was employed for the determination of the electrochemical windows of ILs as well as of the dissolution and electrodeposition potentials of principal metals present in the ingot (anode). For Ag and Au, the deposition potentials determined were 0.074 V and respectively 0.696 V. The XRD and SEM-EDX analyses revealed that the content of precious metals in the cathodic deposits was 99 wt.% for Ag and respectively >70 wt.% for Au. We demonstrated that ILs electrolytes could be a solution to selective recovery of precious metals from e-waste.

Plasmonic Au‐Metal Oxide Nanocomposites for High‐Temperature and Harsh Environment Sensing Applications

“…[223] AuNPs recovery by anodic dissolution without prior chemical dissolution is a promising method that is energy efficient and environmentally compatible, and can be used to selectively dissolve and recover precious metals like Au, Ag, Pt, Pd etc. [224] Such processes of Au recovery in part drive the substantial and increasing demand for AuNPs, wherein their applications cover five major market sectors viz., (a) pollution and emission control technologies including fuel cells and sensors, (b) advanced electronics and devices (c) chemical processing using gold based catalysts (d) advanced coating technologies (e) Reproduced with permission from. [219] biomedical uses including drug delivery, implants, sensor and devices.…”

Recent Studies on Ionic Liquids in Metal Recovery from E-Waste and Secondary Sources by Liquid-Liquid Extraction and Electrodeposition: a Review

“…6-Iodine was used as electrocatalytic oxidizing agent for Au and Ag recovery. (Popescu et al 2020) Choline AgCl/Ag/ In T = RT/ no stirring/telectrodeposition = 2 h 1-IL was used as the electrolyte 2-This IL was chosen because of low viscosity, high cathodic stability, low hygroscopy, and relatively high electrochemical window.…”

“…To solve this problem, low viscosity ILs are used or a combination of different ILs is used with each other and or a wide range of diluents can be used to reduce viscosity and with a variety of diluents can even make changes in the oxidation and conductivity properties and control the deposited layer (Leclerc et al 2018;Matsumiya et al 2020). In the extraction of metals in this way, in the face of multi-compounds, the use of potential controlling reagents such as the effect of salts and some different diluents and electrodeposition in several stages can be effective (Popescu et al 2018;Matsumiya et al 2020;Popescu et al 2020).…”

Comparative Leaching Tests of Gold from Unroasted and Roasted Pyrite Using Microwave Radiation

“…Popescu et al [9] have recently investigated the application of ionic liquids (ILs) to selectively recover of precious metals (Ag and Au) from the anodic slime obtained at the anodic dissolution of cast e-waste.…”