SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2020, Vol. 28 ›› Issue (3): 749-757.DOI: 10.1016/j.cjche.2019.11.004

• Separation Science and Engineering • Previous Articles     Next Articles

Negatively charged organic-inorganic hybrid silica nanofiltration membranes for lithium extraction

Xiaoxian Wu, Haoyue Liu, Yibin Wei, Ying Fei, Hong Qi   

  1. State Key Laboratory of Material-Oriented Chemical Engineering, Membrane Science and Technology Research Center, Nanjing Tech University, Nanjing 210009, China
  • Received:2019-08-02 Revised:2019-10-11 Online:2020-06-11 Published:2020-03-28
  • Contact: Hong Qi
  • Supported by:
    This work is supported by the National Natural Science Foundation of China (21490581), the China Petroleum and Chemical Corporation Limited Project (317008-6) and the Innovation Driven Development Special Fund Project of Guangxi Province (AA17204092) and the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).

Negatively charged organic-inorganic hybrid silica nanofiltration membranes for lithium extraction

Xiaoxian Wu, Haoyue Liu, Yibin Wei, Ying Fei, Hong Qi   

  1. State Key Laboratory of Material-Oriented Chemical Engineering, Membrane Science and Technology Research Center, Nanjing Tech University, Nanjing 210009, China
  • 通讯作者: Hong Qi
  • 基金资助:
    This work is supported by the National Natural Science Foundation of China (21490581), the China Petroleum and Chemical Corporation Limited Project (317008-6) and the Innovation Driven Development Special Fund Project of Guangxi Province (AA17204092) and the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD).

Abstract: Effective extraction of lithium from high Mg2+/Li+ ratio brine lakes is of great challenge. In this work, organic- inorganic hybrid silica nanofiltration (NF) membranes were prepared by dip-coating a 1,2-bis(triethoxysilyl)ethane (BTESE)-derived separation layer on tubular TiO2 support, for efficient separation of LiCl and MgCl2 salt solutions. We found that the membrane calcinated at 400 ℃ (M1-400) could exhibit a narrow pore size distribution (0.63-1.66 nm) owing to the dehydroxylation and the thermal degradation of the organic bridge groups. All as-prepared membranes exhibited higher rejections to LiCl than to MgCl2, which was attributed to the negative charge of the membrane surfaces. The rejection for LiCl and MgCl2 followed the order: LiCl N MgCl2, revealing that Donnan exclusion effect dominated the salt rejection mechanism. In addition, the triplecoated membrane calcined at 400 ℃ (M3-400) exhibited a permeability of about 9.5 L·m-2·h-1·bar-1 for LiCl or MgCl2 solutions, with rejections of 74.7% and 20.3% to LiCl and MgCl2, respectively, under the transmembrane pressure at 6 bar. Compared with the previously reported performance of NF membranes for Mg2+/Li+ separation, the overall performance of M3-400 is highly competitive. Therefore, this work may provide new insight into designing robust silica-based ceramic NF membranes with negative charge for efficient lithium extraction from salt lakes.

Key words: Nanofiltration, Membrane, BTESE, Water lithium resource, Lithium recovery

摘要: Effective extraction of lithium from high Mg2+/Li+ ratio brine lakes is of great challenge. In this work, organic- inorganic hybrid silica nanofiltration (NF) membranes were prepared by dip-coating a 1,2-bis(triethoxysilyl)ethane (BTESE)-derived separation layer on tubular TiO2 support, for efficient separation of LiCl and MgCl2 salt solutions. We found that the membrane calcinated at 400 ℃ (M1-400) could exhibit a narrow pore size distribution (0.63-1.66 nm) owing to the dehydroxylation and the thermal degradation of the organic bridge groups. All as-prepared membranes exhibited higher rejections to LiCl than to MgCl2, which was attributed to the negative charge of the membrane surfaces. The rejection for LiCl and MgCl2 followed the order: LiCl N MgCl2, revealing that Donnan exclusion effect dominated the salt rejection mechanism. In addition, the triplecoated membrane calcined at 400 ℃ (M3-400) exhibited a permeability of about 9.5 L·m-2·h-1·bar-1 for LiCl or MgCl2 solutions, with rejections of 74.7% and 20.3% to LiCl and MgCl2, respectively, under the transmembrane pressure at 6 bar. Compared with the previously reported performance of NF membranes for Mg2+/Li+ separation, the overall performance of M3-400 is highly competitive. Therefore, this work may provide new insight into designing robust silica-based ceramic NF membranes with negative charge for efficient lithium extraction from salt lakes.

关键词: Nanofiltration, Membrane, BTESE, Water lithium resource, Lithium recovery