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Scientific Article details

Title Sequential Selective Dissolution of Coinage Metals in Recyclable Ionic Media
ID_Doc 13282
Authors Zupanc, A; Install, J; Weckman, T; Melander, MM; Heikkilae, MJ; Kemell, M; Honkala, K; Repo, T
Title Sequential Selective Dissolution of Coinage Metals in Recyclable Ionic Media
Year 2024
Published Angewandte Chemie-International Edition, 63, 31
DOI 10.1002/anie.202407147
Abstract Coinage metals Cu, Ag, and Au are essential for modern electronics and their recycling from waste materials is becoming increasingly important to guarantee the security of their supply. Designing new sustainable and selective procedures that would substitute currently used processes is crucial. Here, we describe an unprecedented approach for the sequential dissolution of single metals from Cu, Ag, and Au mixtures using biomass-derived ionic solvents and green oxidants. First, Cu can be selectively dissolved in the presence of Ag and Au with a choline chloride/urea/H2O2 mixture, followed by the dissolution of Ag in lactic acid/H2O2. Finally, the metallic Au, which is not soluble in either solution above, is dissolved in choline chloride/urea/Oxone. Subsequently, the metals were simply and quantitatively recovered from dissolutions, and the solvents were recycled and reused. The applicability of the developed approach was demonstrated by recovering metals from electronic waste substrates such as printed circuit boards, gold fingers, and solar panels. The dissolution reactions and selectivity were explored with different analytical techniques and DFT calculations. We anticipate our approach will pave a new way for the contemporary and sustainable recycling of multi-metal waste substrates. Coinage metals Cu, Ag, and Au can be sequentially dissolved from waste electrical and electronic equipment using green oxidants: aqueous H2O2 and Oxone in biomass-derived sustainable and recyclable ionic media: lactic acid and deep eutectic solvent made of choline chloride and urea. This sequential one metal - one method recycling approach closely follows efforts for the security of supply and objectives of circular economy and sustainable development. image
Author Keywords copper; silver; gold; noble metals; recycling
Index Keywords Index Keywords
Document Type Other
Open Access Open Access
Source Science Citation Index Expanded (SCI-EXPANDED)
EID WOS:001250518800001
WoS Category Chemistry, Multidisciplinary
Research Area Chemistry
PDF https://doi.org/10.1002/anie.202407147
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