https://sj.jst.go.jp/news/202602/n0206-01k.html

https://www.sciencedirect.com/science/article/abs/pii/S0167732225021919?via%3Dihub

A research group Nuclear Science Research Institute, Japan Atomic Energy Agency (JAEA) and Yokohama and Osaka National Universities has developed technology for the efficient solvent extraction of palladium (Pd), ruthenium (Ru), and rhodium (Rh) from waste materials. Notably, it achieves a 10-fold increase in efficiency compared with conventional methods for ruthenium, which has been difficult to selectively extract and separate.

Among platinum group elements, Ru is used in computer HDDs, while Pd and Rh are employed in automotive exhaust gas purification catalysts. In this study, the research group established that by using extractants which become cations under acidic conditions, “ion-pair extraction” occurs. Within this, the extractants pair with anions formed by platinum group elements and hydrochloric acid, enabling their extraction.