@article{oai:ynu.repo.nii.ac.jp:00009419,
 author = {Yueqi, Song and Tsuchida, Yusuke and Matsumiya, Masahiko and Tsunashima, Katsuhiko},
 journal = {Hydrometallurgy},
 month = {Nov},
 note = {It is important to recover Ru metal from spent target materials including Pt, Co and Cr. The extraction behavior using di-(2-hylhexyl)phosphoric acid (HDEHP) and ionic liquid (IL), triethyl-n-pentyl phosphonium bis(trifluoromethyl-sulfonyl)amide; [P2225][TFSA] diluent was investigated with pH dependence. Co(II) and Cr(II) were selectively extracted into the organic phase because the extraction of Co(II) and Cr(II) proceeded by cation exchange. As a result, Pt(IV) and Ru(III) can be separated from Co(II) and Cr(II) by controlling the pH. Moreover, the extraction mechanism of Ru(III) with the Alamine336 (A336)/[P2225][TFSA] system was based on the following anion exchange reaction; [R3NH+Cl−]org + [RuCl4(H2O)2−]aq ⇔ [R3NH+RuCl4(H2O)2−]org + [Cl−]aq, (R = CH3(CH2)7-/CH3(CH2)9-).The electrochemical behavior for Ru(III) in the [P2225][TFSA] was investigated by cyclic voltammetry at 373 K. It was revealed that two step cathodic reactions: Ru(III) + e− → Ru(II) and Ru(II) + 2e− → Ru(0) were proceeded in the [P2225][TFSA] system. Moreover, the potentiostatic electrodeposition allowed us to recover the blackish electrodeposits, which were identified as most of Ru metal by EDX analysis. Finally, we investigated the reuse of the Ru(III) in A336/IL solvent for continuous extraction and lectrodeposition. The extraction percentage of Ru(III) using A336/IL remained relatively high (81.5–96.1%) for the 1st − 5th cycles. This series of experimental results enabled us to demonstrate that Ru metal can be obtained from direct electrodeposition of the extracted [R3NH+RuCl4(H2O)2−] in the A336/[P2225][TFSA] system},
 pages = {164--168},
 title = {Recovery of ruthenium by solvent extraction and direct electrodeposition using ionic liquid solution},
 volume = {181},
 year = {2018}
}