超导磁吸附卤水提锂研究

以某盐湖提钾后老卤为研究对象,其中锂含量仅有0.15g/L,镁锂比达到800∶1。磁性铝系吸附剂的饱和吸附容量为4.3mg/g,提锂后吸附剂利用超导磁选机实现与卤水的固液分离,同步实现洗盐和解吸,最终得到含锂解吸液产品。研究表明,超导磁选机采用钢网片聚磁介质,背景磁场强度2 400kA/m,吸附剂浓度10%,下料速度10cm/s的情况下,吸附剂的截留率达到99%以上。在500mL淡水洗盐,1.5L淡水解吸,解吸液中Li^+0.28g/L,Mg^2+0.57g/L,全流程卤水中锂的回收率在80%以上;吸附剂在磁选机进行100次吸附解吸循环,吸附剂累计丢失8.9%。该工艺有一定的工业利用价值。

Study on Lithium Extraction from Brine by Superconducting Magnetic Separation and Adsorption

Old brine with Li+ 0.15 g/L and Mg2+ 119.5 g/L after potassium extraction from a salt lake was researched. Saturated adsorption capacity of magnetic aluminum-based adsorbent is 4.3 mg/g. Separation of adsorbent from brine was carried out by superconducting magnetic separator to realize synchronization salt leaching and desorption. Final product is lithium-bearing stripping solution. The results show that retention rate of adsorbent is 99% above under the conditions including superconducting magnetic separator adopting steel mesh medium, background magnetic field strength of 2 400 kA/m, adsorbent concentration of 10%, and feeding speed of 10 cm/s. Recovery rate of lithium from brine in whole process is 80% above under the conditions including salt leaching with 500 mL fresh water, desorption with 1.5 L fresh water, and concentration of Li+ and Mg2+ in desorption solution of 0.28 g/L and 0.57 g/L respectively. Lost of adsorbent is 8.9% after 100 adsorption desorption cycles in magnetic separation system. This process has certain industrial value in practice.