Yan-ke Wu, Guo-qing Yan, Song Chen,  and Li-jun Wang, Electrochemistry of Hf(IV) in NaCl–KCl–NaF–K2HfF6 molten salts, Int. J. Miner. Metall. Mater., 27(2020), No. 12, pp. 1644-1649. https://doi.org/10.1007/s12613-020-2083-3
Cite this article as:
Yan-ke Wu, Guo-qing Yan, Song Chen,  and Li-jun Wang, Electrochemistry of Hf(IV) in NaCl–KCl–NaF–K2HfF6 molten salts, Int. J. Miner. Metall. Mater., 27(2020), No. 12, pp. 1644-1649. https://doi.org/10.1007/s12613-020-2083-3
Research Article

Electrochemistry of Hf(IV) in NaCl–KCl–NaF–K2HfF6 molten salts

+ Author Affiliations
  • Corresponding author:

    Yan-ke Wu    E-mail: luckwyk@163.com

  • Received: 19 March 2020Revised: 21 April 2020Accepted: 26 April 2020Available online: 30 April 2020
  • The cathodic reduction mechanism of Hf(IV) ions in a fused NaCl–KCl–NaF–K2HfF6 salt system was studied in various NaF concentrations at 1073 K to obtain a purified dendritic Hf metal. The results of cyclic voltammetry and square wave voltammetry indicated that the reduction process comprised two steps of Hf(IV) → Hf(II) and Hf(II) → Hf at low NaF concentrations (0 < molar ratio of [F/Hf 4+] ≤ 17.39) and one step of Hf(IV) → Hf at high NaF concentrations (17.39 < molar ratio of [F/Hf 4+] < 23.27). The structure and morphology of the deposits obtained in potentiostatic electrolysis in the one-step reduction process were analyzed and verified by X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectrometry. In the one-step reduction process, the disproportionation reaction between the Hf metal and Hf complex ions was inhibited, and a large dendrite Hf metal was achieved in molten salt electrorefining.

  • loading
  • [1]
    T. Iwasakl and K. Konashi, Development of hydride absorber for fast reactor-application of hafnium hydride to control rod of large fast reactor, J. Nucl. Sci. Technol., 46(2009), No. 8, p. 874. doi: 10.1080/18811248.2007.9711595
    [2]
    T. R. Tricot, The metallurgy and functional properties of hafnium, J. Nucl. Mater., 189(1992), No. 3, p. 277. doi: 10.1016/0022-3115(92)90382-U
    [3]
    M. Zukic, D.G. Torr, J.F. Spann, and M.R. Torr, Vacuum ultraviolet thin films. Ⅰ—Optical constants of BaF2, CaF2, LaF3, MgF2, Al2O3, HfO2, and SiO2 thin films, Appl. Opt., 29(1990), No. 28, p. 4284. doi: 10.1364/AO.29.004284
    [4]
    A. Srivastava, R.K. Nahar, and C.K. Sarkar, Study of the effect of thermal annealing on high k hafnium oxide thin film structure and electrical properties of MOS and MIM devices, J. Mater. Sci.-Mater. Electron., 22(2011), No. 7, p. 882. doi: 10.1007/s10854-010-0230-8
    [5]
    J.H. Choi, Y. Mao, and J.P. Chang, Development of hafnium based high-k materials—A review, Mater. Sci. Eng. R, 72(2011), No. 6, p. 97. doi: 10.1016/j.mser.2010.12.001
    [6]
    G.S. Chen, O. Masazumi, and O. Takeo, Electrochemical studies of zirconium of zirconium and hafnium in alkali chloride and alkali fluoride-chloride molten salts, J. Appl. Electrochem., 20(1990), No. 1, p. 77. doi: 10.1007/BF01012474
    [7]
    J.Y. Poinso, S. Bouvet, P. Ozil, J.C. Poignet, and J. Bouteillon, Electrochemical reduction of hafnium tetrachloride in molten NaCl–KCl, J. Electrochem. Soc., 140(1993), No. 5, p. 1315. doi: 10.1149/1.2220977
    [8]
    X. Liu, Y.K. Wu, S. Chen, B. Song, and L.J. Wang, Electrochemical reduction behavior of Hf(IV) in molten NaCl–KCl–K2HfCl6 system, Rare Met., 35(2016), No. 8, p. 655. doi: 10.1007/s12598-014-0345-9
    [9]
    Y.K. Wu, Z.G. Xu, S. Chen, L.J. Wang, and G.X. Li, Electrochemical behavior of zirconium in molten NaCl–KCl–K2ZrF6 system, Rare Met., 30(2011), No. 1, p. 8. doi: 10.1007/s12598-011-0187-7
    [10]
    A. Novoselova and V. Smolenski, Electrochemical behavior of neodymium compounds in molten chlorides, Electrochim. Acta., 87(2013), p. 657. doi: 10.1016/j.electacta.2012.09.064
    [11]
    R.B. Prabhakara, S. Vandarkuzhali, T. Subramanian, and P. Venkatesh, Electrochemical studies on the redox mechanism of uranium chloride in molten LiCl–KCl eutectic, Electrochim Acta., 49(2004), No. 15, p. 2471. doi: 10.1016/j.electacta.2004.02.002
    [12]
    L. Cassayre, J. Serp, P. Soucek, R. Malmbeck, J. Rebizant, and J.P. Glatz, Electrochemistry of thorium in LiCl–KCl eutectic melts, Electrochim,Acta, 52(2007), No. 26, p. 7432. doi: 10.1016/j.electacta.2007.06.022
    [13]
    L.P. Polyakova, P. Taxil, and E.G. Polyakov, Electrochemical behavior and codeposition of titanium and niobium in chloride-fluoride melts, J. Alloys Compd., 359(2003), No. 1-2, p. 244. doi: 10.1016/S0925-8388(03)00180-4
    [14]
    R.S. Nicholson and I. Shain, Theory of stationary electrode polarography: single scan and cyclic methods applied to reversible, irreversible, and kinetic systems, Anal. Chem., 36(1964), No. 4, p. 706. doi: 10.1021/ac60210a007
    [15]
    A.J. Bard and L.R. Faulkner, Electrochemical Methods: Fundamentals and Applications, 2nd ed., John Wiley & Sons, Inc., New York, 2001.
    [16]
    C. Hamel, P. Chamelot, and P. Taxil, Neodymium(Ⅲ) cathodic process in molten fluoride, Electrochim. Acta, 49(2004), No. 25, p. 4467. doi: 10.1016/j.electacta.2004.05.003
    [17]
    J.K. Stalick and R.M. Waterstrat, The hafnium-platinum phase diagram, J. Phase Equilib. Diffus., 35(2014), No. 1, p. 15. doi: 10.1007/s11669-013-0268-4
  • 加载中

Catalog

    通讯作者: 陈斌, bchen63@163.com
    • 1. 

      沈阳化工大学材料科学与工程学院 沈阳 110142

    1. 本站搜索
    2. 百度学术搜索
    3. 万方数据库搜索
    4. CNKI搜索

    Figures(11)  / Tables(3)

    Share Article

    Article Metrics

    Article Views(2874) PDF Downloads(66) Cited by()
    Proportional views

    /

    DownLoad:  Full-Size Img  PowerPoint
    Return
    Return