Electrochemical analysis of diffusion behavior and nucleation mechanism for Dy(II) and Dy(III) in phosphonium-based ionic liquids

Solvation and electrochemical analyses of neodymium complexes in TFSA-based ionic liquids dissolving the nitrates synthesized from spent Nd–Fe–B magnets

“…The hardness of a metal ion as the Lewis acid was evaluated by the absolute hardness, g [30]. The g value of 12 14 16 18 20…”

“…The solubility of the RE nitrate salts in [N 1116 ] [TFSA] was evaluated from the calibration curve. The mea- 3 ] was performed at 423 K by a UV-Vis spectrometer (ADC1000-USB, Ocean Optics Inc.) with a heating system [12] because the [N 1116 ][NO 3 ] sample was in the liquid state above the melting point (389 K). Raman samples were prepared under Ar atmosphere in a glovebox (DPO-1KP-YUMO1, MIWA Inc.).…”

“…There are some reports about the electrochemical behavior and electrodeposition of RE elements such as La, Sm, Eu and Yb [7,8] in ILs. We have already demonstrated that the recovery process of Nd [9][10][11] and Dy [12,13] metals by electrodeposition using quaternary phosphonium and ammonium-based ILs, such as triethyl-pentyl-phosphonium bis(trifluoromethyl-sulfonyl)amide, [P 2225 ] [TFSA], and 2-hydroxy ethyl-trimethyl-ammonium bis(trifluoromethyl-sulfonyl)amide, [N 1112OH ] [TFSA]. In addition to the electrodeposition process using ILs, the wet separation process has been recently indispensable for the recycling of spent Nd-Fe-B magnets.…”

“…Especially, solvent extraction and precipitation separation are effective wet separation processes. Therefore, we have proposed the combination process constituting a wet separation, such as solvent extraction [14][15][16] or precipitation separation [17,18], with electrodeposition [9][10][11][12][13]. Moreover, it is also important to develop recycling processes from the viewpoint of low cost.…”

Extraction of Rare Earth Ions from Nd-Fe-B Magnet Wastes with TBP in Tricaprylmethylammonium Nitrate

“…Therefore, in order to develop an efficient recovery process, we have proposed the recovery of metallic REs by direct electrodeposition from an IL phase after the extraction process. We have already demonstrated that Nd [9][10][11] and Dy [12,13] metals can be recovered by electrodeposition using an IL as an electrolyte. In the case of recovering RE metals from the wastes such as spent Nd-Fe-B magnets, the combined processes for extraction and electrodeposition are expected to purify RE metals from trace elements and simplify the total recycling process.…”