Cite this article as: |
Tai-qi Yin, Yun Xue, Yong-de Yan, Zhen-chao Ma, Fu-qiu Ma, Mi-lin Zhang, Gui-ling Wang, and Min Qiu, Recovery and separation of rare earth elements by molten salt electrolysis, Int. J. Miner. Metall. Mater., 28(2021), No. 6, pp. 899-914. https://doi.org/10.1007/s12613-020-2228-4 |
With the increasing demand of rare earth metals in functional materials, recovery of rare earth elements (REEs) from secondary resources has become important for the green economy transition. Molten salt electrolysis has the advantages of low water consumption and low hazardous waste during REE recovery. This review systematically summarizes the separation and electroextraction of REEs on various reactive electrodes in different molten salts. It also highlights the relationship between the formed alloy phases and electrodeposition parameters, including applied potential, current, and ion concentration. Moreover, the feasibility of using LiF–NaF–KF electrolyte to recover REEs is evaluated through thermodynamic analysis. Problems related to REE separation/recovery the choice of electrolyte are discussed in detail to realize the low-energy and high current efficiency of practical applications.
[1] |
Y.X. Yang, A. Walton, R. Sheridan, K. Güth, R. Gauß, O. Gutfleisch, M. Buchert, B.M. Steenari, T. Van Gerven, P.T. Jones, and K. Binnemans, REE recovery from end-of-life NdFeB permanent magnet scrap: A critical review, J. Sustainable Metall., 3(2017), No. 1, p. 122. doi: 10.1007/s40831-016-0090-4
|
[2] |
M. Tanaka, T. Oki, K. Koyama, H. Narita, and T. Oishi, Recycling of rare earths from scrap, Handb. Phys. Chem. Rare Earths, 43(2013), p. 159.
|
[3] |
K.M. Goodenough, F. Wall, and D. Merriman, The rare earth elements: demand, global resources, and challenges for resourcing future generations, Nat. Resour. Res., 27(2018), No. 2, p. 201. doi: 10.1007/s11053-017-9336-5
|
[4] |
J.P. Rabatho, W. Tongamp, Y. Takasaki, K. Haga, and A. Shibayama, Recovery of Nd and Dy from rare earth magnetic waste sludge by hydrometallurgical process, J. Mater. Cycles Waste Manage., 15(2013), No. 2, p. 171. doi: 10.1007/s10163-012-0105-6
|
[5] |
M. Firdaus, M.A. Rhamdhani, Y. Durandet, W.J. Rankin, and K. McGregor, Review of high-temperature recovery of rare earth (Nd/Dy) from magnet waste, J. Sustain. Metall., 2(2016), No. 4, p. 276. doi: 10.1007/s40831-016-0045-9
|
[6] |
K. Murase, K. Machida, and G. Adachi, Recovery of rare metals from scrap of rare earth intermetallic material by chemical vapour transport, J. Alloys Compd., 217(1995), No. 2, p. 218. doi: 10.1016/0925-8388(94)01316-A
|
[7] |
T. Uda, K.T. Jacob, and M. Hirasawa, Technique for enhanced rare earth separation, Science, 289(2000), No. 5488, p. 2326. doi: 10.1126/science.289.5488.2326
|
[8] |
T. Uda, Recovery of rare earths from magnet sludge by FeCl2, Mater. Trans., 43(2002), No. 1, p. 55. doi: 10.2320/matertrans.43.55
|
[9] |
Y.C. Xu, L.S. Chumbley, and F.C. Laabs, Liquid metal extraction of Nd from NdFeB magnet scrap, J. Mater. Res., 15(2000), No. 11, p. 2296. doi: 10.1557/JMR.2000.0330
|
[10] |
H. Konishi, T. Nohira, and Y. Ito, Formation and phase control of Dy alloy films by electrochemical implantation and displantation, J. Electrochem. Soc., 148(2001), No. 7, p. C506. doi: 10.1149/1.1379031
|
[11] |
T. Oishi, H. Konishi, T. Nohira, M. Tanaka, and T. Usui, Separation and recovery of rare earth metals by molten salt electrolysis using alloy diaphragm, Kagaku Kogaku Ronbunshu, 36(2010), No. 4, p. 299. doi: 10.1252/kakoronbunshu.36.299
|
[12] |
S. Kobayashi, K. Kobayashi, T. Nohira, R. Hagiwara, T. Oishi, and H. Konishi, Electrochemical formation of Nd−Ni alloys in molten LiF−CaF2−NdF3, J. Electrochem. Soc., 158(2011), No. 12, p. E142. doi: 10.1149/2.072112jes
|
[13] |
D.H. Tian, Z.C. Han, M.Y. Wang, and S.Q. Jiao, Direct electrochemical N-doping to carbon paper in molten LiCl−KCl−Li3N, Int. J. Miner. Metall. Mater., 27(2020), No. 12, p. 1687. doi: 10.1007/s12613-020-2026-z
|
[14] |
Y.H. Liu, M. Tang, S. Zhang, Y.L. Lin, Y.C. Wang, Y.Q. Wang, Y. Dai, X.H. Cao, Z.B. Zhang, and Y.H. Liu, Insights into U(VI) adsorption behavior onto polypyrrole coated 3R-MoS2 nanosheets prepared with the molten salt electrolysis method, Int. J. Miner. Metall. Mater, (2020). DOI: 10.1007/s12613-020-2154-5
|
[15] |
X.X. Liang, J.X. Xiao, W. Weng, and W. Xiao, Electrochemical reduction of carbon dioxide and iron oxide in molten salts to Fe/Fe3C modified carbon for electrocatalytic oxygen evolution, Angew. Chem. Int. Ed., 60(2021), No. 4, p. 2120. doi: 10.1002/anie.202013257
|
[16] |
T. Lv, J.X. Xiao, W. Weng, and W. Xiao, Electrochemical fixation of carbon dioxide in molten salts on liquid zinc cathode to zinc@graphitic carbon spheres for enhanced energy storage, Adv. Energy Mater., 10(2020), No. 39, p. 2002241. doi: 10.1002/aenm.202002241
|
[17] |
W. Weng, S.B. Wang, W. Xiao, and X.W. Lou, Direct conversion of rice husks to nanostructured SiC/C for CO2 photoreduction, Adv. Mater., 32(2020), No. 29, p. 2001560. doi: 10.1002/adma.202001560
|
[18] |
W. Weng, B. Jiang, Z. Wang, and W. Xiao, In situ electrochemical conversion of CO2 in molten salts to advanced energy materials with reduced carbon emissions, Sci. Adv., 6(2020), No. 9, p. 9278. doi: 10.1126/sciadv.aay9278
|
[19] |
S.Q. Jiao, H.D. Jiao, W.L. Song, M.Y. Wang, and J.G. Tu, A review on liquid metals as cathodes for molten salt/oxide electrolysis, Int. J. Miner. Metall. Mater., 27(2020), No. 12, p. 1588. doi: 10.1007/s12613-020-1971-x
|
[20] |
S.M. Chen, C.F. Liao, J.Y. Lin, B.Q. Cai, X. Wang, and Y.F. Jiao, Electrical conductivity of molten LiF–DyF3–Dy2O3–Cu2O system for Dy–Cu intermediate alloy production, Int. J. Miner. Metall. Mater., 26(2019), No. 6, p. 701. doi: 10.1007/s12613-019-1775-z
|
[21] |
Y.K. Zhong, K. Liu, Y.L. Liu, Y.X. Lu, T.Q. Yin, L. Wang, Z.F. Chai, and W.Q. Shi, Preparation of γ-uranium-molybdenum alloys by electrochemical reduction of solid oxides in LiCl molten salt, J. Electrochem. Soc., 166(2019), No. 8, p. 276. doi: 10.1149/2.0201908jes
|
[22] |
D.Y. Zhang, X. Ma, H.W. Xie, X. Chen, J.K. Qu, Q.S. Song, and H.Y. Yin, Electrochemical derusting in molten Na2CO3–K2CO3, Int. J. Miner. Metall. Mater., 28(2021), No. 4, p. 637. doi: 10.1007/s12613-020-2068-2
|
[23] |
K.L. Nash, and M. Nilsson, Introduction to the reprocessing and recycling of spent nuclear fuels, [in] R. Taylor, ed., Reprocessing and Recycling of Spent Nuclear Fuel, Woodhead Publishing, Oxford, 2015, p. 3.
|
[24] |
J.J. Laidler, J.E. Battles, W.E. Miller, J.P. Ackerman, and E.L. Carls, Development of pyroprocessing technology, Prog. Nucl. Energy, 31(1997), No. 1-2, p. 131. doi: 10.1016/0149-1970(96)00007-8
|
[25] |
T. Koyama, Y. Sakamura, M. Iizuka, T. Kato, T. Murakami, and J.P. Glatz, Development of pyro-processing fuel cycle technology for closing actinide cycle, Procedia Chem., 7(2012), p. 772. doi: 10.1016/j.proche.2012.10.117
|
[26] |
A. Novoselova, and V. Smolenski, The influence of the temperature and Ga−In alloy composition on the separation of uranium from neodymium in molten Ga−In/3LiCl−2KCl system during the recycling of high-level waste, J. Nucl. Mater., 509(2018), p. 313. doi: 10.1016/j.jnucmat.2018.06.040
|
[27] |
J.H. Lan, S.L. Jiang, Y.L. Liu, X.M. Yin, Y.X. Wang, T.Q. Yin, S.A. Wang, C.Z. Wang, W.Q. Shi, and Z.F. Chai, Separation of actinides from lanthanides associated with spent nuclear fuel reprocessing in China: current status and future perspectives, Radiochim. Acta, 107(2019), No. 9-11, p. 951. doi: 10.1515/ract-2019-3110
|
[28] |
H. Konishi, H. Ono, E. Takeuchi, T. Nohira, and T. Oishi, Electrochemical formation of RE−Zn (RE = Dy, Nd) alloys in a molten LiCl−KCl system, ECS Trans., 61(2014), No. 28, p. 19. doi: 10.1149/06128.0019ecst
|
[29] |
A. Kuriyama, K. Hosokawa, H. Konishi, H. Ono, E. Takeuchi, T. Nohira, and T. Oishi, Electrochemical formation of RE−Sn (RE = Dy, Nd) alloys using liquid Sn electrodes in a molten LiCl-KCl system, ECS Trans., 75(2016), No. 15, p. 341. doi: 10.1149/07515.0341ecst
|
[30] |
P. Souček and R. Malmbeck, Pyrochemical processes for recovery of actinides from spent nuclear fuels, [in] R. Taylor, ed., Reprocessing and Recycling of Spent Nuclear Fuel, Woodhead Publishing, Oxford, 2015, p. 437.
|
[31] |
P. Taxil, L. Massot, C. Nourry, M. Gibilaro, P. Chamelot, and L. Cassayre, Lanthanides extraction processes in molten fluoride media: Application to nuclear spent fuel reprocessing, J. Fluorine Chem., 130(2009), No. 1, p. 94. doi: 10.1016/j.jfluchem.2008.07.004
|
[32] |
G. Xie, K. Ema, Y. Ito, and M.S. Zhao, Electrochemical formation of Ni−Y intermetallic compound layer in molten chloride, J. Appl. Electrochem., 23(1993), p. 753.
|
[33] |
K. Hachiya and Y. Ito, Molecular dynamics simulations of the self-diffusion phenomena in Ni2Y intermetallic phase, J. Alloys Compd., 279(1998), No. 2, p. 171. doi: 10.1016/S0925-8388(98)00647-1
|
[34] |
W. Han, Q. Zhao, J. Wang, M. Li, W.K. Liu, M.L. Zhang, X.G. Yang, and Y. Sun, Electrochemical behavior of Y(III) and preparation of Y−Ni intermetallic compounds in molten LiCl−KCl salts, J. Rare Earths, 35(2017), No. 1, p. 90. doi: 10.1016/S1002-0721(16)60178-3
|
[35] |
T. Nohira, H. Kambara, K. Amezawa, and Y. Ito, Electrochemical formation and phase control of Pr−Ni alloys in a molten LiCl−KCl−PrCl3 system, J. Electrochem. Soc., 152(2005), No. 4, p. C183. doi: 10.1149/1.1864281
|
[36] |
T.Q. Yin, Y. Liang, J.M. Qu, P. Li, R.F. An, Y. Xue, M.L. Zhang, W. Han, G.L. Wang, and Y.D. Yan, Thermodynamic and electrochemical properties of praseodymium and the formation of Ni−Pr intermetallics in LiCl−KCl melts, J. Electrochem. Soc., 164(2017), No. 13, p. D835. doi: 10.1149/2.0901713jes
|
[37] |
T. Iida, T. Nohira, and Y. Ito, Electrochemical formation of Sm–Ni alloy films in a molten LiCl–KCl–SmCl3 system, Electrochim. Acta, 46(2001), No. 16, p. 2537. doi: 10.1016/S0013-4686(01)00470-4
|
[38] |
T.Q. Yin, L. Chen, Y. Xue, Y.H. Zheng, X.P. Wang, Y. Yongde, M.L. Zhang, G.L. Wang, F. Gao, and M. Qiu, Electrochemical behavior and underpotential deposition of Sm on reactive electrodes (Al, Ni, Cu, and Zn) in a LiCl–KCl melt, Int. J. Miner. Metall. Mater., 27(2020), No. 12, p. 1657. doi: 10.1007/s12613-020-2112-2
|
[39] |
H. Konishi, K. Mizuma, H. Ono, E. Takeuchi, T. Nohira, and T. Oishi, Electrochemical formation of Tb−Ni alloys in a molten LiCl−KCl−TbCl3 system, ECS Trans., 50(2013), No. 11, p. 561. doi: 10.1149/05011.0561ecst
|
[40] |
H. Konishi, T. Nohira, and Y. Ito, Kinetics of DyNi2 film growth by electrochemical implantation, Electrochim. Acta, 48(2003), No. 5, p. 563. doi: 10.1016/S0013-4686(02)00723-5
|
[41] |
T. Iida, T. Nohira, and Y. Ito, Electrochemical formation of Yb–Ni alloy films by Li codeposition method in a molten LiCl–KCl–YbCl3 system, Electrochim. Acta, 48(2003), No. 11, p. 1531. doi: 10.1016/S0013-4686(03)00031-8
|
[42] |
H. Konishi, H. Ono, T. Oishi, and T. Nohira, Electrochemical formation of Tb alloys in molten LiCl–KCl eutectic melts and separation of Tb, [in] Proceedings of the TMS Annual Meeting & Exhibition, 2018, p. 89.
|
[43] |
H. Konishi, H. Ono, T. Nohira, and T. Oishi, Separation of Dy and Nd (La) using molten salt and an alloy diaphragm, ECS Trans., 50(2013), No. 11, p. 463.
|
[44] |
H. Konishi, H. Ono, E. Takeuchi, T. Nohira, and T. Oishi, Separation of Dy from Nd−Fe−B magnet scraps using molten salt electrolysis, ECS Trans., 64(2014), No. 4, p. 593. doi: 10.1149/06404.0593ecst
|
[45] |
H. Konishi, T. Oishi, T. Nohira, H. Ono, and E. Takeuchi, Dy permeation through an alloy diaphragm using electrochemical implantation and displantation, ECS Trans., 75(2016), No. 15, p. 105. doi: 10.1149/07515.0105ecst
|
[46] |
K. Yasuda, S. Kobayashi, T. Nohira, and R. Hagiwara, Electrochemical formation of Dy–Ni alloys in molten NaCl–KCl–DyCl3, Electrochim. Acta, 106(2013), p. 293. doi: 10.1016/j.electacta.2013.05.095
|
[47] |
K. Yasuda, S. Kobayashi, T. Nohira, and R. Hagiwara, Electrochemical formation of Nd–Ni alloys in molten NaCl–KCl–NdCl3, Electrochim. Acta, 92(2013), p. 349. doi: 10.1016/j.electacta.2013.01.049
|
[48] |
K. Yasuda, K. Kondo, T. Nohira, and R. Hagiwara, Electrochemical formation of Pr–Ni alloys in LiF–CaF2–PrF3 and NaCl–KCl–PrCl3 melts, J. Electrochem. Soc., 161(2014), No. 7, p. D3097. doi: 10.1149/2.012407jes
|
[49] |
K. Yasuda, K. Kondo, S. Kobayashi, T. Nohira, and R. Hagiwara, Selective formation of rare-earth–nickel alloys via electrochemical reactions in NaCl–KCl molten salt, J. Electrochem. Soc., 163(2016), No. 5, p. D140. doi: 10.1149/2.0501605jes
|
[50] |
S. Kobayashi, T. Nohira, K. Kobayashi, K. Yasuda, R. Hagiwara, T. Oishi, and H. Konishi, Electrochemical formation of Dy-Ni alloys in molten LiF–CaF2–DyF3, J. Electrochem. Soc., 159(2012), No. 12, p. E193. doi: 10.1149/2.053212jes
|
[51] |
C. Nourry, L. Massot, P. Chamelot, and P. Taxil, Formation of Ni−Nd alloys by Nd(III) electrochemical reduction in molten fluoride, J. New Mater. Electrochem. Syst., 10(2007), No. 2, p. 117.
|
[52] |
C. Nourry, L. Massot, P. Chamelot, and P. Taxil, Electrochemical reduction of Gd(III) and Nd(III) on reactive cathode material in molten fluoride media, J. Appl. Electrochem., 39(2009), No. 6, p. 927. doi: 10.1007/s10800-008-9740-y
|
[53] |
C. Nourry, L. Massot, P. Chamelot, and P. Taxil, Neodymium and gadolinium extraction from molten fluorides by reduction on a reactive electrode, J. Appl. Electrochem., 39(2009), No. 12, p. 2359. doi: 10.1007/s10800-009-9922-2
|
[54] |
A. Saïla, M. Gibilaro, L. Massot, P. Chamelot, P. Taxil, and A.M. Affoune, Electrochemical behaviour of dysprosium(III) in LiF–CaF2 on Mo, Ni and Cu electrodes, J. Electroanal. Chem., 642(2010), No. 2, p. 150. doi: 10.1016/j.jelechem.2010.03.002
|
[55] |
T. Nohira, S. Kobayashi, K. Kondo, K. Yasuda, R. Hagiwara, T. Oishi, and H. Konishi, Electrochemical formation of RE−Ni (RE = Pr, Nd, Dy) alloys in molten halides, ECS Trans., 50(2013), No. 11, p. 473. doi: 10.1149/05011.0473ecst
|
[56] |
Y.S. Yang, M.L. Zhang, W. Han, P.Y. Sun, B. Liu, H.L. Jiang, T. Jiang, S.M. Peng, M. Li, K. Ye, and Y.D. Yan, Selective electrodeposition of dysprosium in LiCl–KCl–GdCl3–DyCl3 melts at magnesium electrodes: Application to separation of nuclear wastes, Electrochim. Acta, 118(2014), p. 150. doi: 10.1016/j.electacta.2013.11.145
|
[57] |
Y.C. Wang, M. Li, W. Han, M.L. Zhang, Y.S. Yang, Y. Sun, Y.C. Zhao, and Y.D. Yan, Electrochemical extraction and separation of praseodymium and erbium on reactive magnesium electrode in molten salts, J. Solid State Electrochem., 19(2015), No. 12, p. 3629. doi: 10.1007/s10008-015-2989-2
|
[58] |
D.B. Ji, T.Q. Yin, Y.D. Yan, M.L. Zhang, P. Wang, Y.H. Liu, J.N. Zheng, Y. Xue, X.Y. Jing, and W. Han, Electrochemical reduction La(III) on W and Mg electrodes: application to prepare Mg–La and Mg–Li–La alloys in LiCl–KCl melts, RSC Adv., 6(2016), No. 35, p. 29353. doi: 10.1039/C6RA01404F
|
[59] |
X. Li, Y.D. Yan, M.L. Zhang, H. Tang, D.B. Ji, W. Han, Y. Xue, and Z.J. Zhang, Electrochemical reduction of Tm on Mg electrodes and co-reduction of Mg, Li and Tm on W electrodes, Electrochim. Acta, 135(2014), p. 327. doi: 10.1016/j.electacta.2014.05.030
|
[60] |
Y. Chen, K. Ye, and M.L. Zhang, Preparation of Mg−Yb alloy film by electrolysis in the molten LiCl−KCl−YbCl3 system at low temperature, J. Rare Earths, 28(2010), No. 1, p. 128. doi: 10.1016/S1002-0721(09)60065-X
|
[61] |
Z.S. Hua, J. Wang, L. Wang, Z. Zhao, X.L. Li, Y.P. Xiao, and Y.X. Yang, Selective extraction of rare earth elements from NdFeB scrap by molten chlorides, ACS Sustain. Chem. Eng., 2(2014), No. 11, p. 2536. doi: 10.1021/sc5004456
|
[62] |
D.B. Ji, Y.D. Yan, M.L. Zhang, X. Li, X.Y. Jing, W. Han, Y. Xue, and Z.J. Zhang, Separation of lanthanum from samarium on solid aluminum electrode in LiCl–KCl eutectic melts, J. Radioanal. Nucl. Chem., 304(2015), No. 3, p. 1123. doi: 10.1007/s10967-015-3978-8
|
[63] |
K. Liu, Y.L. Liu, L.Y. Yuan, H. He, Z.Y. Yang, X.L. Zhao, Z.F. Chai, and W.Q. Shi, Electroextraction of samarium from Sm2O3 in chloride melts, Electrochim. Acta, 129(2014), p. 401. doi: 10.1016/j.electacta.2014.02.136
|
[64] |
K. Liu, Y.L. Liu, L.Y. Yuan, X.L. Zhao, Z.F. Chai, and W.Q. Shi, Electroextraction of gadolinium from Gd2O3 in LiCl–KCl–AlCl3 molten salts, Electrochim. Acta, 109(2013), p. 732. doi: 10.1016/j.electacta.2013.07.084
|
[65] |
Y. Castrillejo, A. Vega, M. Vega, P. Hernández, J.A. Rodriguez, and E. Barrado, Electrochemical formation of Sc−Al intermetallic compounds in the eutectic LiCl–KCl. Determination of thermodynamic properties, Electrochim. Acta, 118(2014), p. 58. doi: 10.1016/j.electacta.2013.11.163
|
[66] |
Y.L. Liu, L.Y. Yuan, G.A. Ye, L. Zhu, M.L. Zhang, Z.F. Chai, and W.Q. Shi, Co-reduction behaviors of lanthanum and aluminium ions in LiCl–KCl eutectic, Electrochim. Acta, 147(2014), p. 104. doi: 10.1016/j.electacta.2014.08.114
|
[67] |
L. Wang, Y.L. Liu, K. Liu, S.L. Tang, L.Y. Yuan, L.L. Su, Z.F. Chai, and W.Q. Shi, Electrochemical extraction of cerium from CeO2 assisted by AlCl3 in molten LiCl–KCl, Electrochim. Acta, 147(2014), p. 385. doi: 10.1016/j.electacta.2014.08.113
|
[68] |
M. Zhang, H.Y. Wang, W. Han, M.L. Zhang, Y.N. Li, Y.L. Wang, Y. Xue, F.Q. Ma, and X.M. Zhang, Electrochemical extraction of cerium and formation of Al–Ce alloy from CeO2 assisted by AlCl3 in LiCl–KCl melts, Sci. China Chem., 57(2014), No. 11, p. 1477. doi: 10.1007/s11426-014-5214-8
|
[69] |
H. Tang, H. Deng, Q.B. Ren, D.Z. Cai, Y.M. Ren, L. Shao, Y.D. Yan, and M.L. Zhang, Electrochemical behavior of praseodymium and Pr−Al intermetallics in LiCl−KCl−AlCl3−PrCl3 melts, J. Rare Earths, 34(2016), No. 4, p. 428. doi: 10.1016/S1002-0721(16)60044-3
|
[70] |
Y. Castrillejo, M. Bermejo, P.D. Arocas, A. Martínez, and E. Barrado, Electrochemical behaviour of praseodymium(III) in molten chlorides, J. Electroanal. Chem., 575(2005), No. 1, p. 61. doi: 10.1016/j.jelechem.2004.08.020
|
[71] |
Y. Castrillejo, P. Fernández, J. Medina, P. Hernández, and E. Barrado, Electrochemical extraction of samarium from molten chlorides in pyrochemical processes, Electrochim. Acta, 56(2011), No. 24, p. 8638. doi: 10.1016/j.electacta.2011.07.059
|
[72] |
D.B. Ji, Y.D. Yan, M.L. Zhang, X. Li, X.Y. Jing, W. Han, Y. Xue, Z.J. Zhang, and T. Hartmann, Electrochemical preparation of Al–Sm intermetallic compound whisker in LiCl–KCl Eutectic Melts, Electrochim. Acta, 165(2015), p. 211. doi: 10.1016/j.electacta.2015.02.227
|
[73] |
M.R. Bermejo, F. De la Rosa, E. Barrado, and Y. Castrillejo, Cathodic behaviour of europium(III) on glassy carbon, electrochemical formation of Al4Eu, and oxoacidity reactions in the eutectic LiCl–KCl, J. Electroanal. Chem., 603(2007), No. 1, p. 81. doi: 10.1016/j.jelechem.2007.01.018
|
[74] |
M.R. Bermejo, J. Gómez, J. Medina, A.M. Martínez, and Y. Castrillejo, The electrochemistry of gadolinium in the eutectic LiCl–KCl on W and Al electrodes, J. Electroanal. Chem., 588(2006), No. 2, p. 253. doi: 10.1016/j.jelechem.2005.12.031
|
[75] |
M. Li, Q.Q. Gu, W. Han, Y.D. Yan, M.L. Zhang, Y. Sun, and W.Q. Shi, Electrodeposition of Tb on Mo and Al electrodes: Thermodynamic properties of TbCl3 and TbAl2 in the LiCl−KCl eutectic melts, Electrochim. Acta, 167(2015), p. 139. doi: 10.1016/j.electacta.2015.03.145
|
[76] |
Y. Castrillejo, M.R. Bermejo, A.I. Barrado, R. Pardo, E. Barrado, and A.M. Martinez, Electrochemical behaviour of dysprosium in the eutectic LiCl–KCl at W and Al electrodes, Electrochim. Acta, 50(2005), No. 10, p. 2047. doi: 10.1016/j.electacta.2004.09.013
|
[77] |
L.L. Su, K. Liu, Y.L. Liu, L. Wang, L.Y. Yuan, L. Wang, Z.J. Li, X.L. Zhao, Z.F. Chai, and W.Q. Shi, Electrochemical behaviors of Dy(III) and its co-reduction with Al(III) in molten LiCl−KCl salts, Electrochim. Acta, 147(2014), p. 87. doi: 10.1016/j.electacta.2014.09.095
|
[78] |
Y. Castrillejo, M.R. Bermejo, E. Barrado, J. Medina, and A.M. Martínez, Electrodeposition of Ho and electrochemical formation of Ho–Al alloys from the eutectic LiCl–KCl, J. Electrochem. Soc., 153(2006), No. 10, p. C713. doi: 10.1149/1.2257971
|
[79] |
K. Liu, Y.L. Liu, L.Y. Yuan, L. Wang, L. Wang, Z.J. Li, Z.F. Chai, and W.Q. Shi, Thermodynamic and electrochemical properties of holmium and HoxAly intermetallic compounds in the LiCl−KCl eutectic, Electrochim. Acta, 174(2015), p. 15. doi: 10.1016/j.electacta.2015.05.161
|
[80] |
Y. Castrillejo, M.R. Bermejo, E. Barrado, and A.M. Martínez, Electrochemical behaviour of erbium in the eutectic LiCl–KCl at W and Al electrodes, Electrochim. Acta, 51(2006), No. 10, p. 1941. doi: 10.1016/j.electacta.2005.07.004
|
[81] |
K. Liu, Y.L. Liu, L.Y. Yuan, X.L. Zhao, H. He, G.A. Ye, Z.F. Chai, and W.Q. Shi, Electrochemical formation of erbium-aluminum alloys from erbia in the chloride melts, Electrochim. Acta, 116(2014), p. 434. doi: 10.1016/j.electacta.2013.11.093
|
[82] |
Y. Castrillejo, P. Fernández, M.R. Bermejo, E. Barrado, and A.M. Martínez, Electrochemistry of thulium on inert electrodes and electrochemical formation of a Tm–Al alloy from molten chlorides, Electrochim. Acta, 54(2009), No. 26, p. 6212. doi: 10.1016/j.electacta.2009.05.095
|
[83] |
X. Li, Y.D. Yan, M.L. Zhang, H. Tang, D.B. Ji, W. Han, Y. Xue, and Z.J. Zhang, Electrochemical formation of Al–Tm intermetallics in eutectic LiCl–KCl melt containing Tm and Al ions, J. Nucl. Mater., 452(2014), No. 1-3, p. 197. doi: 10.1016/j.jnucmat.2014.05.015
|
[84] |
Y. Castrillejo, P. Fernández, J. Medina, M. Vega, and E. Barrado, Chemical and electrochemical extraction of ytterbium from molten chlorides in pyrochemical processes, Electroanalysis, 23(2011), No. 1, p. 222. doi: 10.1002/elan.201000421
|
[85] |
Y.D. Yan, X. Li, M.L. Zhang, Y. Xue, H. Tang, W. Han, and Z.J. Zhang, Electrochemical extraction of ytterbium and formation of Al–Yb alloy from Yb2O3 assisted by AlCl3 in LiCl–KCl melt, J. Electrochem. Soc., 159(2012), No. 11, p. 649. doi: 10.1149/2.049211jes
|
[86] |
M.R. Bermejo, E. Barrado, A.M. Martínez, and Y. Castrillejo, Electrodeposition of Lu on W and Al electrodes: electrochemical formation of Lu–Al alloys and oxoacidity reactions of Lu(III) in the eutectic LiCl–KCl, J. Electroanal. Chem., 617(2008), No. 1, p. 85. doi: 10.1016/j.jelechem.2008.01.017
|
[87] |
X. Li, Y.D. Yan, M.L. Zhang, Y. Xue, H. Tang, D.B. Ji, and Z.J. Zhang, AlCl3 and liquid Al assisted extraction of Nd from NaCl–KCl melts via intermittent galvanostatic electrolysis, RSC Adv., 4(2014), No. 76, p. 40352. doi: 10.1039/C4RA06864E
|
[88] |
Y. Ito and T. Nohira, Non-conventional electrolytes for electrochemical applications, Electrochim. Acta, 45(2000), No. 15, p. 2611.
|
[89] |
D.C. Jiles, The development of highly magnetostrictive rare earth-iron alloys, J. Phys. D: Appl. Phys., 27(1994), No. 1, p. 1. doi: 10.1088/0022-3727/27/1/001
|
[90] |
H. Konishi, T. Nohira, and Y. Ito, Formation of Dy–Fe alloy films by molten salt electrochemical process, Electrochim. Acta, 47(2002), No. 21, p. 3533. doi: 10.1016/S0013-4686(02)00323-7
|
[91] |
H. Konishi, H. Hua, H. Ono, Y. Koizumi, T. Oishi, and T. Nohira, Electrochemical formation of Dy−Fe and Nd−Fe alloys in molten CaCl2−LiCl systems, ECS Trans., 86(2018), No. 14, p. 321. doi: 10.1149/08614.0321ecst
|
[92] |
T. Iida, T. Nohira, and Y. Ito, Electrochemical formation of Sm–Co alloy films by Li codeposition method in a molten LiCl–KCl–SmCl3 system, Electrochim. Acta, 48(2003), No. 7, p. 901. doi: 10.1016/S0013-4686(02)00786-7
|
[93] |
T. Kubota, T. Iida, T. Nohira, and Y. Ito, Formation and phase control of Co–Gd alloy films by molten salt electrochemical process, J. Alloys Compd., 379(2004), No. 1-2, p. 256. doi: 10.1016/j.jallcom.2004.02.041
|
[94] |
H. Konishi, H. Ono, E. Takeuchi, T. Nohira, and T. Oishi, Electrochemical formation of RE−Cu (RE = Dy, Nd) alloys in a molten LiCl-KCl system, ECS Trans., 53(2013), No. 11, p. 37. doi: 10.1149/05311.0037ecst
|
[95] |
M. Li, B. Liu, N. Ji, Y. Sun, W. Han, T. Jiang, S.M. Peng, Y.D. Yan, and M.L. Zhang, Electrochemical extracting variable valence ytterbium from LiCl–KCl–YbCl3 melt on Cu electrode, Electrochim. Acta, 193(2016), p. 54. doi: 10.1016/j.electacta.2016.02.020
|
[96] |
W. Han, Z.Y. Li, M. Li, X. Hu, X.G. Yang, M.L. Zhang, and Y. Sun, Electrochemical behavior and extraction of holmium on Cu electrode in LiCl−KCl molten salt, J. Electrochem. Soc., 164(2017), No. 13, p. D934. doi: 10.1149/2.0101714jes
|
[97] |
Y.C. Wang, M. Li, W. Han, M.L. Zhang, T. Jiang, S.M. Peng, and Y.D. Yan, Electrochemical behaviour of erbium(III) and its extraction on Cu electrode in LiCl−KCl melts, J. Alloys Compd., 695(2017), p. 3484. doi: 10.1016/j.jallcom.2016.12.008
|
[98] |
W. Han, Z.Y. Li, M. Li, Y.Y. Gao, X.G. Yang, M.L. Zhang, and Y. Sun, Electrolytic extraction of dysprosium and thermodynamic evaluation of Cu–Dy intermetallic compound in eutectic LiCl–KCl, RSC adv., 8(2018), No. 15, p. 8118. doi: 10.1039/C7RA13423A
|
[99] |
M. Li, J. Wang, W. Han, Y.C. Dong, W. Wang, M.L. Zhang, X.G. Yang, and Y. Sun, Recovery of terbium from LiCl−KCl−TbCl3 system by electrodeposition using different electrodes, J. Electrochem. Soc., 165(2018), No. 14, p. D704. doi: 10.1149/2.0551814jes
|
[100] |
Y.C. Wang, M. Li, M.L. Zhang, W. Han, T. Jiang, and Y.D. Yan, Electrochemical deposition of praseodymium(III) and copper(II) and extraction of praseodymium on copper electrode in LiCl−KCl melts, J. Solid State Electrochem., 22(2018), No. 12, p. 3689. doi: 10.1007/s10008-018-4080-2
|
[101] |
Y.C. Wang, Y.H. Liu, M. Li, W. Han, Y.B. Liu, and Y.H. Liu, Extraction of gadolinium on Cu electrode from LiCl−KCl melts by formation of Cu−Gd alloys, Ionics, 25(2019), No. 4, p. 1897. doi: 10.1007/s11581-018-2762-5
|
[102] |
Y. Kamimoto, T. Itoh, K. Kuroda, and R. Ichino, Recovery of rare-earth elements from neodymium magnets using molten salt electrolysis, J. Mater. Cycles Waste Manage., 19(2017), No. 3, p. 1017. doi: 10.1007/s10163-016-0563-3
|
[103] |
Y. Kamimoto, T. Itoh, G. Yoshimura, K. Kuroda, T. Hagio, and R. Ichino, Electrodeposition of rare-earth elements from neodymium magnets using molten salt electrolysis, J. Mater. Cycles Waste Manage., 20(2018), No. 4, p. 1918. doi: 10.1007/s10163-017-0682-5
|
[104] |
Y. Kamimoto, G. Yoshimura, T. Itoh, K. Kuroda, and R. Ichino, Leaching of rare earth elements from neodymium magnet using electrochemical method, Trans. Mater. Res. Soc. Jpn., 40(2015), No. 4, p. 343. doi: 10.14723/tmrsj.40.343
|
[105] |
W. Han, W.L. Li, M. Li, Z.Y. Li, Y. Sun, X.G. Yang, and M.L. Zhang, Electrochemical co-reduction of Y(III) and Zn(II) and extraction of yttrium on Zn electrode in LiCl−KCl eutectic melts, J. Solid State Electrochem., 22(2018), No. 8, p. 2435. doi: 10.1007/s10008-018-3956-5
|
[106] |
Y.L. Liu, L.Y. Yuan, K. Liu, G.A. Ye, M.L. Zhang, H. He, H.B. Tang, R.S. Lin, Z.F. Chai, and W.Q. Shi, Electrochemical extraction of samarium from LiCl−KCl melt by forming Sm-Zn alloys, Electrochim. Acta, 120(2014), p. 369. doi: 10.1016/j.electacta.2013.12.081
|
[107] |
L. Wang, Y.L. Liu, K. Liu, S.L. Tang, L.Y. Yuan, T. Lu, Z.F. Chai, and W.Q. Shi, Electrochemical extraction of cerium by forming Ce−Zn alloys in LiCl−KCl eutectic on W and liquid Zn electrodes, J. Electrochem. Soc., 162(2015), No. 9, p. E179. doi: 10.1149/2.1141509jes
|
[108] |
M. Li, J. Wang, W. Han, X.G. Yang, M. Zhang, Y. Sun, M.L. Zhang, and Y.D. Yan, Electrochemical formation and thermodynamic evaluation of Pr−Zn intermetallic compounds in LiCl−KCl eutectic melts, Electrochim. Acta, 228(2017), p. 299. doi: 10.1016/j.electacta.2017.01.070
|
[109] |
L.X. Luo, Y.L. Liu, N. Liu, L. Wang, L.Y. Yuan, Z.F. Chai, and W.Q. Shi, Electrochemical and thermodynamic properties of Nd(III)/Nd(0) couple at liquid Zn electrode in LiCl−KCl melt, Electrochim. Acta, 191(2016), p. 1026. doi: 10.1016/j.electacta.2016.01.115
|
[110] |
W. Zhou, Y.L. Liu, K. Liu, Z.R. Liu, L.Y. Yuan, L. Wang, Y.X. Feng, Z.F. Chai, and W.Q. Shi, Electroreduction of Gd3+ on W and Zn electrodes in LiCl–KCl eutectic: A comparison study, J. Electrochem. Soc., 162(2015), No. 10, p. D531. doi: 10.1149/2.0541510jes
|
[111] |
Y.L. Liu, W. Zhou, H.B. Tang, Z.R. Liu, K. Liu, L.Y. Yuan, Y.X. Feng, Z.F. Chai, and W.Q. Shi, Diffusion coefficient of Ho3+ at liquid zinc electrode and co-reduction behaviors of Ho3+ and Zn2+ on W electrode in the LiCl−KCl eutectic, Electrochim. Acta, 211(2016), p. 313. doi: 10.1016/j.electacta.2016.06.061
|
[112] |
X. Li, Y.D. Yan, M.L. Zhang, Y. Xue, H. Tang, Z.P. Zhou, X.N. Yang, and Z.J. Zhang, ZnCl2 and liquid zinc assisted electrochemical extraction of thulium from LiCl−KCl melt, J. Electrochem. Soc., 161(2014), No. 5, p. D248. doi: 10.1149/2.061405jes
|
[113] |
P. Wang, D.B. Ji, D.Q. Ji, J.N. Zheng, Y.D. Yan, M.L. Zhang, W. Han, and H.J. Wu, Electrochemical and thermodynamic properties of ytterbium and formation of Zn−Yb alloy on liquid Zn electrode, J. Nucl. Mater., 517(2019), p. 157. doi: 10.1016/j.jnucmat.2019.02.003
|
[114] |
J.W. Pang, K. Liu, Y.L. Liu, C.M. Nie, L.X. Luo, L.Y. Yuan, Z.F. Chai, and W.Q. Shi, Electrochemical properties of lanthanum on the liquid gallium electrode in LiCl−KCl eutectic, J. Electrochem. Soc., 163(2016), No. 14, p. D750. doi: 10.1149/2.0611614jes
|
[115] |
K. Liu, Y.L. Liu, Z.F. Chai, and W.Q. Shi, Evaluation of the electroextractions of Ce and Nd from LiCl−KCl molten salt using liquid Ga electrode, J. Electrochem. Soc., 164(2017), No. 4, p. D169. doi: 10.1149/2.0511704jes
|
[116] |
B. Li, K. Liu, J.W. Pang, L.Y. Yuan, Y.L. Liu, and M.Z. Lin, Electrochemical properties of gadolinium on liquid gallium electrode in LiCl−KCl eutectic, J. Rare Earths, 36(2018), No. 6, p. 656. doi: 10.1016/j.jre.2017.11.014
|
[117] |
M. Li, Y.C. Liu, Z.X. Sun, W. Han, M.L. Zhang, X.G. Yang, and Y. Sun, Electrochemical co-reduction of Bi(III) and Y(III) and extracting yttrium from molten LiCl−KCl using liquid Bi as cathode, Chem. Res. Chin. Univ., 35(2019), No. 1, p. 60. doi: 10.1007/s40242-018-8252-5
|
[118] |
M. Li, Q.Q. Gu, W. Han, X.M. Zhang, Y. Sun, M.L. Zhang, and Y.D. Yan, Electrochemical behavior of La(III) on liquid Bi electrode in LiCl–KCl melts. Determination of thermodynamic properties of La–Bi and Li–Bi intermetallic compounds, RSC Adv., 5(2015), No. 100, p. 82471. doi: 10.1039/C5RA12723H
|
[119] |
W. Han, Z.Y. Li, M. Li, W.L. Li, X.M. Zhang, X.G. Yang, M.L. Zhang, and Y. Sun, Electrochemical extraction of holmium and thermodynamic properties of Ho-Bi alloys in LiCl−KCl eutectic, J. Electrochem. Soc., 164(2017), No. 4, p. E62. doi: 10.1149/2.0741704jes
|
[120] |
W. Han, N. Ji, J. Wang, M. Li, X.G. Yang, Y. Sun, and M.L. Zhang, Electrochemical formation and thermodynamic properties of Tb–Bi intermetallic compounds in eutectic LiCl–KCl, RSC Adv., 7(2017), No. 50, p. 31682. doi: 10.1039/C7RA04448H
|
[121] |
S.S. Wang, B.C. Wei, M. Li, W. Han, M.L. Zhang, X.G. Yang, and Y. Sun, Electrochemical behavior of Dy(III) on bismuth film electrode in eutectic LiCl-KCl melts, J. Rare Earths, 36(2018), No. 9, p. 1007. doi: 10.1016/j.jre.2018.03.010
|
[122] |
Y. Ito, T. Nishikiori, and H. Tsujimura, Novel molten salt electrochemical processes for industrial applications, Electrochemistry, 86(2018), No. 2, p. 21. doi: 10.5796/electrochemistry.18-H0001
|
[123] |
T. Oishi, M. Yaguchi, Y. Katasho, and T. Nohira, Separation of neodymium and dysprosium by molten salt electrolysis using an alloy diaphragm, [in] Azimi, K. Forsberg, T. ouchi, H. Kim, S. Alam, and A. Baba, eds., Rare Metal Technology 2020, Springer, Cham, 2020, p. 151.
|
[124] |
M. Itoh, K. Miura, and K. Machida, Novel rare earth recovery process on Nd–Fe–B magnet scrap by selective chlorination using NH4Cl, J. Alloys Compd., 477(2009), No. 1-2, p. 484. doi: 10.1016/j.jallcom.2008.10.036
|
[125] |
S. Shirayama and T.H. Okabe, Selective extraction and recovery of Nd and Dy from Nd–Fe–B magnet scrap by utilizing molten MgCl2, Metall. Mater. Trans. B, 49(2018), p. 1067. doi: 10.1007/s11663-018-1176-0
|
[126] |
Y.X. Chen, Research progress of preparation of rare earth metals by electrolysis in fluoride salt system, Chin. Rare Earths, 35(2014), No. 2, p. 99.
|
[127] |
A. Abbasalizadeh, A. Malfliet, S. Seetharaman, J. Sietsma, and Y. Yang, Electrochemical recovery of rare earth elements from magnets: conversion of rare earth based metals into rare earth fluorides in molten salts, Mater. Trans., 58(2017), No. 3, p. 400. doi: 10.2320/matertrans.MK201617
|
[128] |
Y.S. Yang, C.Q. Lan, L.Y. Guo, Z.Q. An, Z.W. Zhao, and B.W. Li, Recovery of rare-earth element from rare-earth permanent magnet waste by electro-refining in molten fluorides, Sep. Purif. Technol., 233(2020), p. 116030. doi: 10.1016/j.seppur.2019.116030
|
[129] |
L. Massot, P. Chamelot, and P. Taxil, Cathodic behaviour of samarium(III) in LiF–CaF2 media on molybdenum and nickel electrodes, Electrochim. Acta, 50(2005), No. 28, p. 5510. doi: 10.1016/j.electacta.2005.03.046
|
[130] |
M. Gibilaro, L. Massot, P. Chamelot, L. Cassayre, and P. Taxil, Electrochemical extraction of europium from molten fluoride media, Electrochim. Acta, 55(2009), No. 1, p. 281. doi: 10.1016/j.electacta.2009.08.052
|
[131] |
B.A. Frandsen, S.D. Nickerson, A.D. Clark, A. Solano, R. Baral, J. Williams, J. Neuefeind, and M. Memmott, The structure of molten FLiNaK, J. Nucl. Mater., 537(2020), p. 152219. doi: 10.1016/j.jnucmat.2020.152219
|
[132] |
J.S. Zhang, Impurities in primary coolant salt of FHRs: Chemistry, impact, and removal methods, Energy Technol., 7(2019), No. 10, p. 1900016. doi: 10.1002/ente.201900016
|
[133] |
C. Hamel, P. Chamelot, and P. Taxil, Neodymium(III) cathodic processes in molten fluorides, Electrochim. Acta, 49(2004), No. 25, p. 4467. doi: 10.1016/j.electacta.2004.05.003
|
[134] |
H.M. Zhu, Rare earth metal production by molten salt electrolysis, [in] G. Kreysa, K. Ota, and R.F. Savinell, eds., Encyclopedia of Applied Electrochemistry, Springer, New York, 2014, p. 1765.
|
[135] |
Y.F. Wang, J.B. Ge, W.Q. Zhuo, S.Q. Guo, and J.S. Zhang, Electrochemical separation study of LaF3 in molten FLiNaK salt, J. Nucl. Mater., 518(2019), p. 162. doi: 10.1016/j.jnucmat.2019.03.007
|
[136] |
H. Qiao, T. Nohira, and Y. Ito, Electrochemical formation of Pd–La alloy films in a LiF–NaF–KF–LaF3 melt, J. Alloys Compd., 359(2003), No. 1-2, p. 230. doi: 10.1016/S0925-8388(03)00203-2
|
[137] |
M.H. Brooker, R.W. Berg, J.H. Von Barner, and N.J. Bjerrum, Raman Study of the hexafluoroaluminate ion in solid and molten FLINAK, Inorg. Chem., 39(2000), No. 16, p. 3682. doi: 10.1021/ic000260h
|
[138] |
M.Y. Zhang, J.B. Ge, J.S. Zhang, and L.E. Liu, Redox potential measurement of AgCl in molten LiCl−KCl salt using chronopotentiometry and potentiodynamic scan techniques, Electrochem. Commun., 105(2019), p. 106498. doi: 10.1016/j.elecom.2019.106498
|
[139] |
A. Roine, Chemical reaction and equilibrium software with extensive thermo-chemical database, Outokumpu HSC 6.0, 2010. https://www.hsc-chemistry.com/.
|
[140] |
Y.F. Wang, J.B. Ge, W.Q. Zhuo, S.Q. Guo, and J.S. Zhang, Electrochemical extraction of lanthanum in molten fluoride salts assisted by KF or NaF, Electrochem. Commun., 104(2019), p. 106468. doi: 10.1016/j.elecom.2019.05.017
|
[141] |
V. Constantin, A.M. Popescu, and S. Zuca, Preliminary studies of the obtaining of solid metallic cerium from fluoride melts, J. Nat. Res. A, 58(2003), No. 1, p. 57.
|
[142] |
V. Constantin, A.M. Popescu, and M. Olteanu, Electrochemical studies on cerium(III) in molten fluoride mixtures, J. Rare Earths, 28(2010), No. 3, p. 428. doi: 10.1016/S1002-0721(09)60127-7
|
[143] |
P. Fedorov, Systems of alkali and rare-earth metal fluorides, Russ. J. Inorg. Chem, 44(1999), No. 11, p. 1703.
|
[144] |
A. Grzechnik, N. Khaidukov, and K. Friese, Crystal structures and stability of trigonal KLnF4 fluorides (Ln= Y, Ho, Er, Tm, Yb), Dalton Trans., 42(2013), No. 2, p. 441. doi: 10.1039/C2DT31483E
|
[145] |
V. Dracopoulos, B. Gilbert, and G.N. Papatheodorou, Vibrational modes and structure of lanthanide fluoride–potassium fluoride binary melts LnF3–KF (Ln=La, Ce, Nd, Sm, Dy, Yb), J. Chem. Soc., Faraday Trans., 94(1998), No. 17, p. 2601. doi: 10.1039/a802812e
|