2016-Sustainable Industrial Processing Summit
SIPS 2016 Volume 3: Oye Intl. Symp. / Ionic Liquid and Aluminum
| Editors: | Kongoli F, Feng N, Polyakov P, Gaune-Escard M |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2016 |
| Pages: | 180 pages |
| ISBN: | 978-1-987820-40-9 |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
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The application of deep eutectic solvents ionic liquids for environmentaly-friendly dissolution and recovery of metals fom electronic waste
Ana-Maria Julieta Popescu1; Cristina Donath1; Elena Ionela Neacsu2; Vasile Soare3; Marian Burada4; Virgil Constantin2; Marcelle Gaune-Escard5;1ILIE MURGULESCU INSTITUTE OF PHYSICAL CHEMISTRY, LABORATORY OF MOLTEN SALTS, Bucharest, Romania; 2ILIE MURGULESCU INSTITUTE OF PHYSICAL CHEMISTRY, Bucharest, Romania; 3NATIONAL R&D INSTITUTE FOR NONFERROUS AND RARE METALS - IMNR, Pantelimon, Romania; 4NATIONAL R&D INSTITUTE FOR NONFERROUS AND RARE METALS – IMNR, Pantelimon, Romania; 5AIX-MARSEILLE UNIVERSITE/POLYTECH, CNRS/IUSTI UMR7343, Marseille, France;
Type of Paper: Regular
Id Paper: 133
Topic: 37
Abstract:
The treatment of Waste Electrical and Electronic Equipment (WEEE) includes several subsequent steps. The aim of this paper is to obtain a new ecological route for recycling of different metals (Al, Zn, Pb, Ag, and Au) from WEEE by using deep eutectic solvents (DES). DES is a form of ionic liquids that are mixtures of salts such as choline chloride with hydrogen-bond donors such as urea. DESs are environmentally benign, yet chemically stable and, furthermore, the components are already produced in large quantities at comparable costs to conventional reagents. The dissolution of different metals or of the multicomponent alloy obtained by pyro metallurgical technology from WEEE was found to be soluble in Choline chloride-X (X=Urea, Ethylene glycol, Malonic acid, 0,2MCuCl22H2O +30% ChCl) through an oxidative/non-oxidative leach at 45–80C. A remarkable difference between genuine DES and ILs with the solutions used in this paper is the addition of rather large quantities of water, which was shown to have a lot of advantages on the leaching of metals, while the properties typical for DES still remain. The dissolution of some metals was studied with or without oxidizing agents. In the experiments on ChCl-(CuCl22H2O+ChCl) it was observed that Al dissolved fast at 80ºC, while at room temperature the leaching stopped after 10 minutes presumably because of a protective layer formed on the Al surface. For Zn and Pb this is ascribed to the impossibility of forming a protective layer at a higher temperature. For Au and Ag this solution was not efficient. It seems that the presence of water is not advantageous in this case, but good results were obtained in ChCl-X (X=Urea, Ethylene glycol). Metals were electrodeposited on Cu/Pt from the studied ionic liquids and submitted to XRD and SEM experiments. Finally, the metals electrodeposition mechanism was studied by cyclic voltammetry and a two steps mechanism was found for Al, Pb and one step for Zn, Ag, Au.
Keywords: metals recovery from WEEE, ionic liquids, electrodeposition, cyclic voltammetry