Elena Maria Iannicelli Zubiani
Politecnico di Milano, Italy
Title: Solid sorbents for rare earths recovery from electronic waste
Biography
Biography: Elena Maria Iannicelli Zubiani
Abstract
Today there is an increasing need for Rare Earths (REs) due to their usage in numerous high-technology applications. Currently each EU citizen produces about 17 kg of Waste Electrical and Electronic Equipment (WEEE) per year. These wastes are rich in precious and strategic metals and, in many cases, are characterized by higher REs contents than those of natural minerals. Accordingly, recycling can be considered a valuable opportunity: This perspective is known as "urban miningâ€. For these reasons, the study of a targeted and efficient REs recovery from WEEE can only lead to undeniable both socio-economic and environmental benefits. Activated carbon (AC) and modified AC were tested as solid sorbents at the purpose. The modified AC was synthesized by loading pentaethylenehexamine and the amount of loaded amine was estimated by COD analysis of the residual amount in solution. The AC and the modified AC were contacted with lanthanum solutions (chosen as representing element of REs family) and the lanthanum adsorbed by the solids was analyzed by ICP-OES of the contacted solution. Finally, release tests were performed on the different samples in order to verify the solids capability not only to capture but also to recover metal ions. The obtained results showed that the experimental procedure was appropriate to load the amine onto the AC and that the modification of the AC improved both adsorption (from 44% to 100%) and release (from 65% to 91%) with respect to natural AC, ensuring a global recovery efficiency of 90%.