摘要
电控离子交换(Electrochemically switched ion exchange,ESIX)系统内对电极具有保持溶液电中性、增强提锂效果且使系统形成闭合回路的关键作用。在ESIX技术盐湖提锂过程中人们主要关注锂离子捕获电极,关于对电极的研究较少。而本文研究了不同类型对电极对ESIX系统提锂性能的影响。分别采用聚吡咯/导电炭黑/聚偏二氟乙烯(PPy/C/PVDF)、活性炭/导电炭黑/聚偏二氟乙烯(AC/C/PVDF)和石墨板电极作为ESIX系统中锰酸锂/导电炭黑/聚偏二氟乙烯(LiMn_(2)O_(4)/C/PVDF)提锂膜电极的对电极,考察了这3种ESIX系统在氯化物型高镁锂比模拟卤水(Mg/Li~50)中的提锂性能。结果表明,当PPy/C/PVDF作为对电极时可有效吸附卤水中Cl^(-),且ESIX系统提锂性能最优,Li^(+)吸附量为13.9 mg/g;当PPy/C/PVDF电极湿膜厚度增加至1 mm时,ESIX系统对Li^(+)的提取率可达44.2%,Li^(+)/Mg^(2+)分离因子可达56.82。因此,针对不同的阴离子型盐湖卤水设计匹配的对电极对ESIX技术在盐湖提锂领域的发展具有重要的理论指导意义。
The counter electrode in the electrochemically switched ion exchange(ESIX)system plays a key role in maintaining the electric neutrality of the solution,influencing the adsorption capacity of the system and making the system form a closed loop.However,in the process of lithium extraction from salt lakes by ESIX technology,attention is mainly paid to the lithium-ion capture electrode,but less to the counter elec⁃trode.Therefore,in this paper,the effects of different types of counter electrodes on the lithium extraction performance of ESIX system are studied.The polypyrrole/conductive black carbon/polyvinylidene difluoride(PPy/C/PVDF),active carbon/conductive black carbon/polyvinylidene difluoride(AC/C/PVDF)and graphite plate film electrode are used as the counter electrode of extraction lithium in the ESIX system,for the lithium manganate/conductive black carbon/polyvinylidene difluoride(LiMn_(2)O_(4)/C/PVDF)film electrode.We investi⁃gate the lithium extraction performance of the ESIX system in the simulated chloride-type brine with high Mg/Li ratio(Mg/Li~50).The results show that it can effectively adsorb Cl^(-)in the brine and the extraction perfor⁃mance of the ESIX system is the best when PPy/C/PVDF is used as the counter electrode and the Li^(+)adsorp⁃tion capacity in the system is 13.9 mg/g.When the wet film thickness of PPy/C/PVDF electrode increased to 1 mm,the extraction rate of Li^(+)in the source solution of the ESIX system could reach 44.2%,and the system Li^(+)/Mg^(2+)separation factor is 56.82.Therefore,it has the important theoretical guiding significance for the de⁃velopment of ESIX technology in the field of salt lake lithium extraction to design the corresponding counter electrodes for different kinds of chloride-type salt lake brine.
作者
林冯翔
宋高晋
张忠林
高凤凤
郝晓刚
LIN Feng-xiang;SONG Gao-jin;ZHANG Zhong-lin;GAO Feng-feng;HAO Xiao-gang(College of Chemical Engineering and Technology,Taiyuan University of Technology,Taiyuan,030024,China)
出处
《盐湖研究》
CAS
CSCD
2023年第3期1-9,共9页
Journal of Salt Lake Research
基金
国家自然科学基金(No.22108188,No.U21A20303,No.U20A20141)。
