Electrochemical behaviour of praseodymium (III) in molten chlorides

Castrillejo, Y.; Bermejo, Manuel R.; Arocas, Paloma Díaz; Martínez, Ana María; Barrado, E.

doi:10.1016/j.jelechem.2004.08.020

Cited by 129 publications

(114 citation statements)

References 30 publications

(36 reference statements)

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“…Due to the alloy formation, the electrodeposition of U 3+ on Al occurs at a more anodic potential compared to the inert W cathode. A similar behaviour has been reported on Al electrodes for other actinides (Am and Pu [9]) and for several lanthanides [16][17][18].…”

Section: Methodssupporting

confidence: 85%

On the formation of U–Al alloys in the molten LiCl–KCl eutectic

Cassayre

Caravaca

Jardin³

et al. 2008

Journal of Nuclear Materials

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U-Al alloy formation has been studied in the temperature range of 400 -550 °C by electrochemical techniques in the molten LiCl-KCl eutectic. Cyclic voltammetry showed that underpotential reduction of U(III) onto solid Al occurs at a potential about 0.35 V more anodic than pure U deposition. Open circuit potential measurements, recorded after small depositions of U metal onto the Al electrode, did not allow the distinction between potentials associated with UAl x alloys and the Al rest potential, as they were found to be practically identical. As a consequence, a spontaneous chemical reaction between dissolved UCl 3 and Al is thermodynamically possible and was experimentally observed.Galvanostatic electrolyses were carried out both on Al rods and Al plates. Stable and dense U-Al deposits were obtained with high faradic yields, and the possibility to load the whole bulk of a thin Al plate was demonstrated. The analyses (by SEM-EDX and XRD) of the deposits indicated the formation of different intermetallic phases (UAl 2 , UAl 3 and UAl 4 ) depending on the experimental conditions.

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Section: Methodssupporting

confidence: 85%

On the formation of U–Al alloys in the molten LiCl–KCl eutectic

Cassayre

Caravaca

Jardin³

et al. 2008

Journal of Nuclear Materials

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“…The so obtained curve (c) shows a pair of oxidation-reduction peaks, which can be attributed to the Nd(III)/Nd(0) reaction, assuming no reaction or very weak reaction between Li and Nd. This method has been widely used by many researchers [10,18,33]. Thus, the results show the reduction peak potential and the oxidation peak potential of curve (c) as -1.568 V and -1.328 V, respectively.…”

Section: Analysis Of Peak I Cmentioning

confidence: 98%

“…These experiments have been conducted by numerous researchers, who have reported that useful information on M-Cd intermetallic compound formation can be obtained [10,18,22,38]. Fig.…”

Section: Electrochemical Reaction Of Ndcl 3 In Licl-kcl At Cd-coated mentioning

confidence: 99%

“…Particularly, cyclic voltammetry (CV) and potentiometry are useful methods to provide various information such as electrode potential, diffusion coefficient, activity coefficient, intermetallic compound formation and corresponding Gibbs free energy of electroactive materials [17][18][19]. By using the methods, various studies have been conducted on the reaction characteristics of solid electrodes and liquid Cd electrodes against various chlorides such as UCl 3 , PuCl 3 , NpCl 3 , LaCl 3 , CeCl 3 , and PrCl 3 in the LiCl-KCl molten salt system [10,[20][21][22][23][24][25]. However, in the case of Nd, which has the highest ratio of RE in the spent fuel, several researchers provide meaning information such as the electrode potential and the diffusion coefficient for solid electrodes [11].…”

Section: Introductionmentioning

confidence: 99%

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Electrode Reactions of Nd3+/Nd Couple in LiCl-KCl-NdCl3 Solutions at Solid W and Liquid Cd Electrodes

Sim

Kim²,

Paek

et al. 2018

International Journal of Electrochemical Science

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The behavior of Nd(III)/Nd(0) redox reaction at a solid tungsten (W) and liquid cadmium (Cd) electrodes in the LiCl-KCl-NdCl 3 system at 773 K was analyzed by using a cyclic voltammetry. The Nd(III)/Nd(0) reaction in the solid W electrode was found to occur in two steps through the process of Nd(II) ion generation. As the analytic results of the maximum current value according to scan rates in the region of 0.05 V/s to 0.3 V/s, the Nd(III)/Nd(II) reaction showed reversible reaction characteristics over the whole range, while the Nd (II)/Nd(0) reaction showed the reversible reaction in the region of 0.05 V/s to 0.2 V/s, as well as the quasi-reversible in the range of 0.2 V/s or higher. Furthermore, the diffusion coefficients of Nd(III) ion and Nd(II) ion were calculated by using the maximum current value, which were considerably consistent with the previous results of other researchers. The reduction potential of the Nd (III)/Nd(0) reaction in the liquid Cd electrode was measured as approximately 0.54 V higher than that of the solid W electrode because the reduced Nd formed an Nd-Cd intermetallic compound with a liquid Cd electrode, lowering the activity of Nd. To confirm this mechanism, experiments using Cd-coated W electrodes were conducted by using cyclic voltammetry and chronopotentiometry. The experimental results showed that 6 Nd-Cd intermetallic compounds were present. When the ratio of Cd is the highest, NdCd 11 is formed, and the potential in this case was very similar to the potential at the liquid Cd electrode. Furthermore, the Gibbs free energy and activity coefficient of Nd-Cd intermetallic compounds were calculated by analyzing the results of chronopotentiometry. The results could thermodynamically explain the potential difference of the Nd(III)/Nd(0) reactions occurring between the solid W electrode and the liquid Cd electrode.

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“…However, the drawbacks of hydrometallurgy processes are the low reaction rates and the serious environmental problems arising from the huge amounts of waste water generated in the process, which, in turn, need further processing. Alternatively, molten salt processing routes offer a more attractive ow sheet in view of the lower energy consumption, higher ef ciency and higher purity of the deposits [8][9][10] . The molten salt process is currently used in the production of reactive metals such as aluminium, magnesium, sodium, potassium and also in general for the production or separation of lanthanides from actinides 11) .…”

Section: Introductionmentioning

confidence: 99%

Electrochemical Recovery of Rare Earth Elements from Magnets: Conversion of Rare Earth Based Metals into Rare Earth Fluorides in Molten Salts

Abbasalizadeh

Malfliet²,

Seetharaman

et al. 2017

Mater. Trans.

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In the present work, selective extraction of rare earth (RE) metals from NdFeB magnets is investigated by studying the effects of various uxes, viz. AlF 3 , ZnF 2 , FeF 3 and Na 3 AlF 6 in the LiF-NdFeB system. The aim is to convert RE from RE magnet into the uoride salt melt. The results show the complete selective separation of neodymium (also dysprosium) from the magnet and formation of rare earth uoride, leaving iron and boron unreacted. The formed rare earth uoride can subsequently be processed in the same reactor through an electrolysis route so that RE can be deposited as a cathode product. The results of XRD and EPMA analysis of the reacted samples indicate that AlF 3 , ZnF 2 and FeF 3 can act as strong uorinating agents for extraction of rare earth from NdFeB magnet, converting the RE to REF 3 .The results con rm the feasibility of the rare earth metals recovery from scrap NdFeB magnet as raw material. The uoride conversion-electrolysis route suggested in the present work enables the extraction of rare earth metals in a single step using the above-mentioned uxes.

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Electrochemical behaviour of praseodymium (III) in molten chlorides

Cited by 129 publications

References 30 publications

On the formation of U–Al alloys in the molten LiCl–KCl eutectic

On the formation of U–Al alloys in the molten LiCl–KCl eutectic

Electrode Reactions of Nd3+/Nd Couple in LiCl-KCl-NdCl3 Solutions at Solid W and Liquid Cd Electrodes

Electrochemical Recovery of Rare Earth Elements from Magnets: Conversion of Rare Earth Based Metals into Rare Earth Fluorides in Molten Salts

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