钛系吸附剂在西藏碳酸盐型盐湖中的应用研究

Application research of titanium adsorbent of carbonate⁃type salt lake in Tibet

钛系吸附剂具有吸附容量高、选择性好、寿命长、稳定性高等特点,在西藏碳酸盐型盐湖提锂方面具有广阔的应用前景。基于转盘式连续离子交换装置,研究了钛系吸附剂在西藏碳酸盐型盐湖中的工艺影响因素,考察了该吸附剂的多周期吸附性能和稳定性。研究结果表明:高进料Li+质量浓度可有效提高吸附驱动力,从而提高吸附容量;当使用优化分配后的吸附柱,进料流速为10 BV/h、水洗卤流速为8 BV/h、水洗酸流速为8 BV/h时,吸附容量为7.53 mg/g,解吸液锂平均质量浓度为1 500 mg/L,平均选择性为S((Li/Na))=4.67、S((Li/K))=36.48、S((Li/Ca))=13.49、S((Li/Mg))=32.51,具有较高的吸附和分离效率。此外,串联或并联解吸形式对于解吸液Li+质量浓度影响较小,主要影响解吸液pH,因此可以根据实际项目需求进行工艺调整。

Due to its high adsorption capacity,excellent selectivity,long life and high stability,titanium adsorbent has a use-ful application prospect in lithium extraction from carbonate salt lake in Tibet.The process effects of titanium adsorbent in carbonate-type salt lakes in Tibet were investigated by using the rotary table continuous ion exchange device,and its multi-cycle adsorption performance and stability were examined.The results showed that a high feed Li+mass concentration could effectively increase the adsorption driving force and thus improve the adsorption capacity.When an optimized allocation of adsorption columns was used,combined with a feed flow rate of 10 BV/h,a water-rinse brine flow rate of 8 BV/h,and a water-rinse acid flow rate of 8 BV/h,the adsorption capacity reached 7.53 mg/g,while the average lithium concentration in the de-sorption liquid was 1500 mg/L,and the average selectivity was S(Li/Na)=4.67,S(Li/K)=36.48,S(Li/Ca)=13.49,and S(Li/Mg)=32.51,demonstrating high adsorption and resolution efficiency.In addition,the desorption series-and parallel-connection modes had little impact on the lithium mass concentration in desorption liquid but mainly affected the pH of the desorption liquid,which could be adjusted according to actual project requirements.