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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.

The cathodic reduction processes of cobalt (II), tungsten (VI) and molybdenum (VI) in Na2WO4 melts are discussed. Electrochemical behavior of cobalt in a tungstate melt, as well as the effect of electrolysis conditions on the composition and structure of Co-W and Co-Mo alloys deposits from tungstate-molybdate melts is also studied. With a decrease in the concentration of cobalt ions and an increase in the concentration of molybdenum (tungsten) ions in the melt, the phase composition of cathodic deposits is shown to change from individual cobalt to individual molybdenum (tungsten) via a series of cobalt-molybdenum (tungsten) compounds of various compositions.

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.

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