Expectation for Center for Mineral Processing and Metallurgy

[1111-17-07] Selective Extraction of Platinum Group Metal Ions from Aqueous Solutions by Functional Ionic Liquids

○Kiyoshi Kanie¹, Atsushi Muramatsu¹ (1. Tohoku University)

Chairman: Itaru HONMA (Tohoku University)

Keywords:Ionic Liquid, Platinum Group Metal, Sovent Extraction, Back-Extraction, Rhodium

Platinum group metals (PGMs) are of significant importance for modern technologies and advanced materials. However, the continuous high demand for and scarcity of PGMs are critical issues that correspondingly challenge recycling technologies to fill the gap between demand and supply. To date, organic solvent extraction consisting of extractants and/or organic solvents is a widely applied practical method for the recovery of PGM ions. Recently, ionic liquids (ILs) are considered to be alternative green solvents for PGM extraction. In our previous study, we reported a metal-selective deprotection-mediated Pd(II) extraction utilizing ILs with tetrahydropyran-2H-yl-protected thiol moieties (Chem. Lett., 46, 434 (217)). The result suggested that functionalization of ILs, regarded as task-specific ILs (TSILs), is a promising technique to introduce PGM extraction ability into ILs. In the present research, we have designed and synthesized novel ILs with amino moieties for the recovery of Pt, Pd, and Rh ions. The resulting ILs exhibited excellent extractability (> 8%) towards Pt(IV) and Pd(II) ions with an HCl concentration ranging from .3 to 4. M. The extraction/back-extraction abilities of the ILs were also investigated.