With the calcium-magnesium slag generated in recycling process of spent Li-ion batteries as raw material,battery-grade lithium carbonate was prepared by adopting a process consisting of leaching for decomposition,purification,lithium precipitation and carbonization for decomposition.The results show that with the addition of MgSO4·7H2O at 1.1 times of the theory amount,initial pH of 1.5,reaction time of 2.0 h,solid-liquid ratio of 1∶6,reaction temperature of 90 ℃,and final pH of 3.5,the leaching rate of Li can reach 98.39％and the mass concentration of Li in the lixivium is 18.03 g/L.Then,the obtained lixivium is subjected to processes of defluorination with resin,impurity removal with NaOH,and Na2CO3 precipitation,and crude lithium carbonate can be obtained with purity of 95.11％.By adopting a process consisting of carbonization,removal of calcium and magnesium with resin,and pyrolysis,a battery-grade lithium carbonate with purity of 99.64％can be prepared.It is shown that by using this processing technique,the lithium recovery rate can reach 95.08％,presenting good prospect in industrial application.
关键词
废旧锂离子电池/浸出/净化/碳化分解/电池级碳酸锂/电池回收/钙镁渣
Key words
spent Li-ion battery/leaching/purification/carbonization for decomposition/battery-grade lithium carbonate/battery recycling/calcium-magnesium slag
维普
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