铝基吸附剂固定床分离卤水锂资源过程研究

Study on lithium separation from brine by aluminum-based adsorbent in fixed bed

铝基锂吸附剂是一种非常适用于低锂品位、高镁锂比盐湖卤水提锂的吸附剂,具有无溶损、稳定性高等优点,也是目前唯一一种已投入工业化生产的吸附剂。使用自制的球形铝基锂吸附剂GLDH填充固定床,系统研究了吸附温度、进料流速、初始锂离子浓度和床层高度对GLDH固定床分离卤水锂资源过程中吸附穿透曲线的影响。结果表明:升高温度、增加床层高度、降低初始锂离子浓度和进料流速会导致穿透时间延长、穿透吸附容量升高。采用BDST、Clark、Thomas、Y-N和M-D-R 5种经验模型对锂吸附穿透曲线进行拟合,确定M-D-R模型能够较准确地描述固定床锂吸附过程。

Aluminum-based lithium adsorbent is very suitable for extracting lithium from salt lake brine with low lithium grade and high Mg2+/Li+ ratios.It has the advantages of no dissolution loss,high stability,which is the only adsorbent that has been put into industrial production.The homemade spherical aluminum-based lithium adsorbent GLDH was applied to lithium extraction in fixed bed.The effects of adsorption temperature,feed flow rate,initial Li+ concentration and bed height on the adsorption breakthrough curves of GLDH during lithium separation from brine in fixed bed were systematically studied.The results showed that increasing temperature and bed height as well as decreasing initial concentration and flow rate led to longer breakthrough time and higher breakthrough adsorption capacity. Five empirical models,including BDST,Clark,Thomas,Y-N and M-D-R models,were used to fit the lithium adsorption breakthrough curves.It was determined that the M-D-R model could accurately describe the lithium adsorption process in the fixed bed.