新型磁性纳米锂离子筛的合成

Synthesis of a new-style nano magnetic lithium ion sieves

采用狭道式撞击流反应器,将Fe3O4爆发式成核过程与快速包覆MnCO3+Li2CO3薄膜的过程同步进行,制备出具有核壳结构的纳米Fe3O4/MnCO3+Li2CO3前驱体;然后,通过在450℃下高温焙烧和稀酸酸浸脱锂工艺得到一种组成为Fe3O4/HxMnyO4的磁性纳米锂离子筛。实验优化了爆发式成核过程与液相快速包膜过程的主要操作参数。采用BET、TEM、EDX、XRD等手段对产物进行了分析表征。结果表明,磁性纳米锂离子筛的平均粒径约为40 nm,比饱和磁化强度为27.581 emu.g-1,磁矫顽力为138.64 G。与普通锂离子筛相比,纳米锂离子筛薄膜在固相扩散方面优势明显,有望在海水提锂过程中发挥独特的作用。

Nano Fe3O4/MnCO3＋Li2CO3 precursor was prepared by synchronizing explosive nucleation of Fe3O4 and fast coating of MnCO3＋Li2CO3 in a mini-channel impinging stream reactor.Subsequently,the precursor was heat-treated at 450℃ and immersed in dilute hydrochloric acid to obtain nano magnetic lithium ion sieves（LIS） composed of Fe3O4 / HxMnyO4.The main factors affecting explosive nucleation and fast coating processes were investigated and optimized.The as-prepared products were characterized by BET,TEM,EDX,and XRD.The mean particle size of nano magnetic LIS was about 40 nm,specific magnetism was 27.581 emu·g-1,and coercive intensity was 138.64 G.Compared with ordinary LIS,nano LIS film had obvious advantages in solid phase diffusion,and promised unique capacity in lithium uptake from seawater.