从低浓度含钴浸出液中制取电池级氧化钴

Preparation of battery-grade cobalt oxide from low concentration cathode leachate of LIB

研究了从低浓度含钴浸出液中制取电池级氧化钴的工艺。采用碳酸氢铵调节盐酸浸出液的pH值至5,加入Na2S溶液除杂。用P507+磺化煤油体系萃取净化液中的Co2+,硫酸反萃回收硫酸钴。当溶液pH=2,60℃时,(NH4)2C2O4按1∶1的比例加入反萃液中,同时加入20%的聚乙二醇作为分散剂沉钴。滤渣在55℃条件下真空干燥、在400℃下焙烧,制备得到粒度分布均匀的Co3O4粉末。根据SEM及ICP-AES对产物进行定性定量分析可知,Co3O4的纯度为95.30%,Co的回收率为71.2%。

The battery-grade cobalt oxide was prepared from the leach solution with low concentration of cobalt. The pH of the hydrochloric acid leaching solution was adjusted to 5 by ammonium bicarbonate solution to remove Al3＋, and Na2S was added to remove Cu2＋. Co2＋ was extracted using organic phase composition of P507 ＋ sulfonated kerosene after clearing, and the recovery of cobalt sulfate was stripping with sulfuric acid. Co was precipitated by saturated （NH4）2C2O4 solution in the condition of 60 ℃, pH=2, cobalt solution ： （NH4）2C2O4, solution=1 ： 1, with 20% polyethylene glycol as dispersing agent. The filter residue was dried under the vacuum condition at the temperature of 55 ℃, then the filter residue was roasted at the temperature of 400 ℃ for 2.5 h, and finally the particles of Co3O4 could be obtained. According to the analysis of SEM and ICP-AES, the purity of Co3O4 was 95.30%, and the recovery rate of Co was 71.2%.