Recovery of europium by electrochemical reduction from sulfate solutions

Yörükoğlu, Abdulkerim; Girgin, İsmail

doi:10.1016/s0304-386x(01)00215-8

Cited by 15 publications

(5 citation statements)

References 17 publications

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“…The Eu 3+ ions, comparing with other Ln 3+ including Sm 3+ , are relatively easier to be reduced to Eu 2+ by reaching its half-filled 4 f shell (4f 7 ). [1][2][3] Several currently used methods for Eu separation take advantage of this difference between Eu 2+ and Sm 3+ . [4][5][6] One way to achieve this separation is to reduce Eu 3+ → Eu 2+ in a sulfate media to form precipitates of EuSO 4 (Sm 3+ ions don't precipitate), thus separating solid precipitates from the liquid (Sm 3+ ions remain in liquid).…”

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confidence: 99%

Selective Electrodeposition of Europium and Samarium in Molten LiCl-KCl with Copper and Aluminum Electrodes

Yang

Zhuo

et al. 2020

J. Electrochem. Soc.

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Separation of the adjacent lanthanide (Ln) pair such as Sm-Eu from each other using chemical methods is difficult due to their similar chemical features. In the present work, electrochemical separation of Eu and Sm from each other were studied in molten LiCl-KCl-1 wt% EuCl 3 -1 wt% SmCl 3 at 500 °C. By using a Cu reactive electrode, Sm was selectively separated from the salt because of the formation of several Cu-Sm intermetallic compounds while Eu remained in the salt. The formation of Al-Eu compounds occurs at a more negative potential than that of the Al-Sm compounds on Al electrode. However, the formation rate of Al-Eu compound is much higher than that of Al-Sm compound. With an electrolysis time of 0.5 h and a potential at −2.225 V (vs Ag(I)/Ag), the deposit on the electrode is mainly made up of Al-Eu compound. This study reveals the influence of working electrode on Eu-Sm separation and provides a potential method for adjacent lanthanide pair separation.

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confidence: 99%

Selective Electrodeposition of Europium and Samarium in Molten LiCl-KCl with Copper and Aluminum Electrodes

Yang

Zhuo

et al. 2020

J. Electrochem. Soc.

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“…[1][2][3][4][5][6][7] The reduction of Eu 3 + !Eu 2 + ions is used in the technology of separation of rare-earth raw materials. [7][8][9][10][11][12][13][14] Often, Eu 2 + compounds possess very interesting luminescent, [15][16][17] catalytic [18,19] and magnetic properties. [20][21][22] In terms of its properties, the Eu 2 + ion is similar to analogous ions of alkaline earth metals [13] and, in particular, strontium because of almost identical ionic radii (r(Eu 2 + ) = 0.112 nm, r(Sr 2 + ) = 0.127 nm).…”

Section: Introductionmentioning

confidence: 99%

“…This is due to the stability of 4f 7 (Eu), 4f 14 (Yb) shells, which are found in Ln 2+ ions after the pinching off of the outer 6 s 2 electrons [1–7] . The reduction of Eu 3+ →Eu 2+ ions is used in the technology of separation of rare‐earth raw materials [7–14] . Often, Eu 2+ compounds possess very interesting luminescent, [15–17] catalytic [18,19] and magnetic properties [20–22] …”

Section: Introductionmentioning

confidence: 99%

Europium (II) Sulfate EuSO₄: Synthesis Methods, Crystal and Electronic Structure, Luminescence Properties

et al. 2022

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In the present work, we report on the synthesis of EuSO4 powders by two different methods using EuS as starting material. The compound EuSO4 contains divalent europium and crystallizes in the orthorhombic crystal system, space group Pnma with parameters close to SrSO4. The compound exhibits near isotropic thermal expansion over the temperature range 300–700 K. EuSO4 was examined by Raman, Fourier‐transform infrared absorption and luminescence spectroscopy methods. EuSO4 is found to be an indirect bandgap material with a bandgap close to direct electronic transition. The emission lifetime of divalent europium d‐f emission in EuSO4 shows an unusual behavior for stoichiometric compounds, as it shortens upon cooling from 1.11(1) μs at room temperature to 0.44(1) μs at 77 K.

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“…Furthermore, the recovery of cerium from mixtures of rare earths can be done via oxidation of Ce(III) to Ce(IV), followed by separation from the other rare earths based on the significant change in the chemical properties [8,32,33]. Likewise, it has also been reported that europium can be separated from the neighboring lanthanides samarium and gadolinium via selective reduction of Eu(III) to Eu(II) [34][35][36]. Therefore the efficiency of separation and purification processes of lanthanides can be increased by taking advantage of their less-common oxidation states.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical oxidation of terbium(III) in aqueous media: influence of supporting electrolyte on oxidation potential and stability

et al. 2022

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Apart from the generally dominant trivalent oxidation state, several lanthanides can occur in divalent or tetravalent states as well. Changing the valence state alters the chemical properties and therefore gives the opportunity to ease intragroup lanthanide separations. The hydrated terbium(III) ion has a highly positive reduction potential (E 0 = + 3.1 V vs. SHE), but it can be oxidized to its tetravalent state and via ozonolysis or electrolysis and stabilized in highly concentrated carbonate solutions. In this study, terbium(III) is electrochemically oxidized to terbium(IV) in aqueous carbonate, nitrate and periodate media. Spectroscopic and elemental analysis were done to characterize terbium(IV) and to gain insight in the stability of these complexes in the aqueous electrolytes of carbonate, nitrate and periodate. In all these electrolytes, oxidation and stabilization were achieved at different pH, terbium concentration, salt concentration and applied potentials. The most promising electrolyte was found to be carbonate, since it allowed to attain more concentrated and more stable terbium(IV) solutions.

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Recovery of europium by electrochemical reduction from sulfate solutions

Cited by 15 publications

References 17 publications

Selective Electrodeposition of Europium and Samarium in Molten LiCl-KCl with Copper and Aluminum Electrodes

Selective Electrodeposition of Europium and Samarium in Molten LiCl-KCl with Copper and Aluminum Electrodes

Europium (II) Sulfate EuSO₄: Synthesis Methods, Crystal and Electronic Structure, Luminescence Properties

Electrochemical oxidation of terbium(III) in aqueous media: influence of supporting electrolyte on oxidation potential and stability

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Recovery of europium by electrochemical reduction from sulfate solutions

Cited by 15 publications

References 17 publications

Selective Electrodeposition of Europium and Samarium in Molten LiCl-KCl with Copper and Aluminum Electrodes

Selective Electrodeposition of Europium and Samarium in Molten LiCl-KCl with Copper and Aluminum Electrodes

Europium (II) Sulfate EuSO4: Synthesis Methods, Crystal and Electronic Structure, Luminescence Properties

Electrochemical oxidation of terbium(III) in aqueous media: influence of supporting electrolyte on oxidation potential and stability

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Europium (II) Sulfate EuSO₄: Synthesis Methods, Crystal and Electronic Structure, Luminescence Properties