废旧三元正极材料中选择性提锂

Selective recovery of lithium from spent ternary cathode material

对废旧三元正极材料(LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2))进行硫酸化焙烧-水浸选择性提锂研究。在98%硫酸用量为6 ml、焙烧温度为650℃、焙烧时间为2 h、研磨样品d 50为6μm、固液比为1 g/7 ml和加水20℃浸出2 h的条件下,20 g三元材料所得浸出液中的Li浓度为5.65 g/L,回收率为93.68%,而Mn、Co和Ni的浓度分别为0.25 g/L、0.06 g/L和0.15 g/L,回收率分别仅为1.02%、0.22%和0.62%,选择性提锂效果显著。XRD和SEM分析表明,硫酸化焙烧可使三元材料转化为易溶的硫酸锂(Li_(2)SO_(4))和难溶的Mn、Co及Ni氧化物,但焙烧后样品的结晶度较差,造成Mn、Co和Ni部分溶出。

Selective recovery of lithium from spent ternary cathode materials(LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2))by sulfation roasting-water leaching was studied.Under the following processing conditions such as leached under 6 ml 98% sulfuric acid,650℃ roasting temperature,2 h roasting time,6μm grinding sample of d 50,1 g/7 ml solid-liquid ratio,20℃ leaching temperature and 2 h leaching time,the concentration of Li of 20 g ternary material was 5.65 g/L,the recovery rate was 93.68%,the concentration of Mn,Co and Ni was 0.25 g/L,0.06 g/L and 0.15 g/L,while the recovery rates were only 1.02%,0.22% and 0.62% respectively in the leachate.The selective lithium recovery effect was significant.XRD and SEM analysis showed that sulphated roasting could convert the ternary material into easily soluble lithium sulfate and insoluble Mn,Co,Ni oxides,but the crystallinity of the sample after firing was poor,resulting in partial dissolution of Mn,Co and Ni.