Diallo, Salmata; Tran, Lan Huong; Larivière, Dominic et Blais, Jean-François 
ORCID: https://orcid.org/0000-0003-3087-4318
(2025).
Leaching and recovery of rare earth elements, copper, nickel, silver and gold from used smartphone circuit boards.
Minerals Engineering
, vol. 222
.
p. 109157.
DOI: 10.1016/j.mineng.2024.109157.
Résumé
Printed circuit board (PCB) assemblies constitute a concentrated source of valuable metals. This study evaluates the performance of a complete hydrometallurgical process for extracting and recovering rare earth elements (REE), Cu, Ni, Ag and Au from leachates produced from PCB found in smartphones via four selective leaching steps. In a REE leachate ([Dy] = 43 mg/L, [Gd] = 5 mg/L, [Nd] = 266 mg/L, [Sm] = 35 mg/L, [Tb] = 8 mg/L, [Ho] = 2 mg/L), 92 % of REE was precipitated at room temperature with H2C2O4/REE molar ratio of 2/1. Calcination of the REE-oxalate precipitates at 800 °C resulted in a mixture of rare earth oxides (REO) with a 91 % purity. From the base metal leachate ([Cu] = 19,376 mg/L and [Ni] = 1,264 mg/L), Cu was electrodeposited during 120 min (pH = 3, current 270 A/m2) while Ni was precipitated by addition of oxalic acid (H2C2O4/Ni molar ratio of 2/1, pH 4.4, T = 60 °C, t = 60 min), followed by calcination at 600 °C for 4 h to form NiO (93 % purity). Three oxidative leaching steps (10 % w/v solids, T = 80 °C, t = 180 min, 1.0 M H2SO4, 67 g H2O2/L, T = 80 °C, t = 180 min) solubilized 97 % of Ag. Subsequently, with the addition of Cu (Cu/Ag mass ratio of 2), at room temperature and 120 min, Ag was precipitated 99.4 % in the first leachate ([Ag] = 488 mg/L). A Zn/Au mass ratio of 30 precipitated 99.1 % of gold at the room-temperature from the gold leachate ([Au] = 107 mg/L).
| Type de document: | Article |
|---|---|
| Mots-clés libres: | smartphone; leaching; metal; solvent; electrodeposition; precipitation; rare earth |
| Centre: | Centre Eau Terre Environnement |
| Date de dépôt: | 06 mars 2025 16:09 |
| Dernière modification: | 06 mars 2025 16:09 |
| URI: | https://espace.inrs.ca/id/eprint/16246 |
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