工业水处理 ›› 2022, Vol. 42 ›› Issue (10): 125-131. doi: 10.19965/j.cnki.iwt.2021-1253

• 试验研究 • 上一篇    下一篇

高铁酸钠的电化学合成及铁阳极钝化机理研究

杨雪(), 曾亚南, 李俊国, 刘宝()   

  1. 华北理工大学冶金与能源学院,河北 唐山 063210
  • 收稿日期:2022-07-11 出版日期:2022-10-20 发布日期:2022-11-02
  • 作者简介:

    杨雪(1995— ),硕士研究生。电话:15732024790,E-mail:

    刘宝,博士。E-mail:

  • 基金资助:
    河北省自然科学基金高端钢铁冶金联合基金项目(E2021209043); 河北省高等学校科学技术研究项目(BJ2021034)

Electrochemical synthesis of sodium ferrate(Ⅵ) and passivation mechanism of the ferrous anode

Xue YANG(), Ya’nan ZENG, Junguo LI, Bao LIU()   

  1. College of Metallurgy and Energy,North China University of Science and Technology,Tangshan 063210,China
  • Received:2022-07-11 Online:2022-10-20 Published:2022-11-02

摘要:

以铁片为阳极、金属钛板为阴极,采用电化学氧化法合成高铁酸钠,研究了NaOH电解液浓度、制备温度和电流密度对高铁酸钠生成的影响及机理,并探析了高铁酸钠制备过程中铁阳极钝化的机理。结果表明,提高NaOH浓度和制备温度不仅有利于高铁酸钠的生成,同时也有利于提高电流效率;提高电流密度虽会增加高铁酸钠的生成量,但也会显著降低电流效率。综合考虑电流效率和制备成本,高铁酸钠的最佳制备条件为:NaOH浓度为14 mol/L、温度为45 ℃、电流密度为5 mA/cm2。在最佳制备参数下电解后,利用FESEM-EDS和XPS分析了铁电极的表面性质,长时间电解后的铁阳极表面生成了铁氧化物,且钝化后的铁阳极表面存在Fe2+和Fe3+。电化学氧化合成高铁酸钠过程中,铁阳极钝化生成Fe3O4是阳极失效的主要原因。

关键词: 电化学合成, 高铁酸钠, 阳极, 钝化

Abstract:

Sodium ferrate(Ⅵ) was synthetized using electrochemical oxidation with ferrous plate as anode and metal titanium plate as cathode. The influence of NaOH concentration,preparation temperature and current density on the generation of sodium ferrate(Ⅵ) was explored. The passivation mechanism of the ferrous anode was also investigated. The obtained results indicated that increasing NaOH concentration and preparation temperature not only beneficial to the generation of sodium ferrate(Ⅵ), but also beneficial to improve the current efficiency. Although enhancing current density improved the generated concentration of sodium ferrate(Ⅵ),the current efficiency significantly reduced. Considering the current efficiency and production costs,NaOH concentration of 14 mol/L,preparation temperature of 45 ℃,current density of 5 mA/cm2 was regard as the best parameter for the synthesis of sodium ferrate(Ⅵ). Under the optimum preparation parameters,the surface properties of ferrous electrode were analyzed by FESEM-EDS and XPS. The results showed that iron oxides were formed on the surface of the ferrous anode after passivation,and Fe2+ and Fe3+ existed on the surface of the ferrous anode after passivation. The generation of Fe3O4 during theelectrochemical oxidation process was the main reason for the passivation of ferrous anode.

Key words: electrochemical synthesis, sodium ferrate(Ⅵ), anode, passivation

中图分类号: