盐湖提锂尾液中锂回收的吸附试验研究

Experimental Study on Adsorption of Lithium in Lithium Extraction Tail Solution from Salt Lake 

中文关键词:  盐湖提锂尾液  锂吸附剂  选择性  锂回收

英文关键词:Lithium extraction tail solution  Lithium adsorbent  Adsorption selectivity  Lithium recovery

中文摘要:

      从高镁锂比盐湖提锂生产尾液中回收锂,可实现锂资源高效回收利用,对企业经济效益的提高具有重要意义。以东台吉乃尔盐湖提锂尾液为原料,系统性研究了铝系层状锂吸附剂JW-LAHS对提锂尾液中锂的静态、动态吸附和解吸过程。结果表明,吸附剂的静态吸附容量为7.3 mg/g,镁锂分离因子为27.98；最佳动态吸附条件为床层高度24.8 cm,进料流速3.5 mL/min,此时穿透时间为22.0 min,Li⁺ 吸附率大于95%,饱和时间为210 min,饱和吸附容量达到5.5 mg/g,表明锂吸附剂适合从高镁锂比提锂尾液中回收锂。BDST模型能够准确预测床层穿透时间,误差小于8.61%。使用去离子水进行解吸,增大解吸流速能够加速Li⁺脱出,但对Mg²⁺ 的解吸无明显影响。解吸流速为4.6 mL/min,解吸360 min时,Li⁺ 解吸率为83.25%,总解吸液的镁锂比值为0.7,仅为提锂尾液(80)的0.88%。循环20次后吸附容量仍能保持原来的82%以上,表明锂吸附剂循环稳定性良好。

英文摘要:

      Recycling the lithium in the tail solution of lithium extraction from salt lake to realize efficient recovery and utilization of lithium resources is significant to increase the economic benefits of the enterprises.In this paper,the batch and dynamic experiments were carried out to investigate the adsorption and desorption performance of aluminum salt layered lithium-adsorbent JW-LAHS in the lithium extraction tail solution from East Taijinar Salt Lake.The static adsorption capacity of adsorbent JW-LAHS is 7.3 mg/g,and the separation factor of magnesium and lithium is 27.98.When fixed bed height at 24.8 cm and feed flow rate at 3.5 mL/min,breakthrough time is 22.0 min,adsorption saturation time is 210.0 min,adsorption saturation capacity is 5.5 mg/g,and adsorption rate of Li⁺ before bed breakthrough is more than 95%.This indicates that the adsorbent JW-LAHS is suitable for lithium recovery from the lithium extraction tail solution with a high Mg/Li ratio.The BDST model can accurately predict the breakthrough time with an error less than 8.61%.Deionized water was used for desorption.It is found that increasing flow rate can accelerate the Li+ desorption process,while it has no remarkable influence on the Mg²⁺ desorption process.When the feed flow rate is at 4.6 mL/min for 360 min,the desorption rate of Li⁺ is up to 83.25%.The Mg/Li mass ratio of the desorption solution is only 0.88% of the lithium extraction tail solution(Mg/Li mass ratio 80).The adsorption capacity of JW-LAHS remains more than 82% after 20 cycles,indicating good cycling stability of the adsorbent.