SCI和EI收录∣中国化工学会会刊

Chinese Journal of Chemical Engineering ›› 2023, Vol. 59 ›› Issue (7): 42-50.DOI: 10.1016/j.cjche.2022.11.013

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Performance comparison of lithium fractionation from magnesium via continuous selective nanofiltration/electrodialysis

Yong Xu1, Qingbai Chen3, Yang Gao1, Jianyou Wang1,2, Huiqing Fan1, Fei Zhao1   

  1. 1. Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China;
    2. College of Chemical Engineering and Material, Quanzhou Normal University, Quanzhou 362000, China;
    3. Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
  • Received:2022-08-14 Revised:2022-11-09 Online:2023-10-14 Published:2023-07-28
  • Contact: Jianyou Wang,E-mail:wangjy72@nankai.edu.cn
  • Supported by:
    The authors are grateful for research financial support by the National Key Research and Development Program of China (2017YFC0404003), the Tianjin Natural Science Foundation (21JCZDJC00270), the China Postdoctoral Science Foundation (2021M701875), the Tianjin Special Project of Ecological Environment Management Science and Technology (18ZXSZSF00050), the Tianjin Science and Technology Support Project (19YFZCSF00760) and the Fundamental Research Funds for the Central Universities (63221312).

Performance comparison of lithium fractionation from magnesium via continuous selective nanofiltration/electrodialysis

Yong Xu1, Qingbai Chen3, Yang Gao1, Jianyou Wang1,2, Huiqing Fan1, Fei Zhao1   

  1. 1. Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China;
    2. College of Chemical Engineering and Material, Quanzhou Normal University, Quanzhou 362000, China;
    3. Center for Water and Ecology, State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China
  • 通讯作者: Jianyou Wang,E-mail:wangjy72@nankai.edu.cn
  • 基金资助:
    The authors are grateful for research financial support by the National Key Research and Development Program of China (2017YFC0404003), the Tianjin Natural Science Foundation (21JCZDJC00270), the China Postdoctoral Science Foundation (2021M701875), the Tianjin Special Project of Ecological Environment Management Science and Technology (18ZXSZSF00050), the Tianjin Science and Technology Support Project (19YFZCSF00760) and the Fundamental Research Funds for the Central Universities (63221312).

Abstract: Although selective nanofiltration (SNF) and selective electrodialysis (SED) have been widely adopted in the field of Mg2+/Li+ separation, their differences have not been illustrated systematically. In this study, for the first time, SNF and SED processes in continuous mode were studied for Li+ fractionation from the same brine with high Mg/Li ratios and their differences were discussed in detail. For a fair analysis of the two processes, typical factors were optimized. Specifically, the optimal operating pressure and feed flow rate for SNF were 2.4 MPa and 140 L·h-1, respectively, while the optimal cell-pair voltage and replenishment flow rate for SED were 1.0 V and 14 L·h-1, respectively. Although the Li+ fractionation capacity of the two processes were similar, the selectivity coefficient of SNF was 24.7% higher than that of SED and, thus, the Mg/Li ratio in purified stream of the former was 19.0% lower than that of the latter. Due to higher ion driving force, SED had clear advantages in recovery ratio and concentration effects. Meanwhile, the specific energy consumption of SED was 20.1% lower than that of SNF. This study provided a better understanding and guidance for the application and improvement of the two technologies.

Key words: High Mg/Li brine, Purification, Membrane, Nanofiltration, Electrodialysis, Lithium recovery

摘要: Although selective nanofiltration (SNF) and selective electrodialysis (SED) have been widely adopted in the field of Mg2+/Li+ separation, their differences have not been illustrated systematically. In this study, for the first time, SNF and SED processes in continuous mode were studied for Li+ fractionation from the same brine with high Mg/Li ratios and their differences were discussed in detail. For a fair analysis of the two processes, typical factors were optimized. Specifically, the optimal operating pressure and feed flow rate for SNF were 2.4 MPa and 140 L·h-1, respectively, while the optimal cell-pair voltage and replenishment flow rate for SED were 1.0 V and 14 L·h-1, respectively. Although the Li+ fractionation capacity of the two processes were similar, the selectivity coefficient of SNF was 24.7% higher than that of SED and, thus, the Mg/Li ratio in purified stream of the former was 19.0% lower than that of the latter. Due to higher ion driving force, SED had clear advantages in recovery ratio and concentration effects. Meanwhile, the specific energy consumption of SED was 20.1% lower than that of SNF. This study provided a better understanding and guidance for the application and improvement of the two technologies.

关键词: High Mg/Li brine, Purification, Membrane, Nanofiltration, Electrodialysis, Lithium recovery