摘要
In the production of lithium-ion batteries(LIBs)and recycling of spent LIBs,a large amount of low-concentration lithium-containing wastewater(LCW)is generated.The recovery of Li from this medium has attracted significant global attention from both the environmental and economic perspectives.To achieve effective Li recycling,the features of impurity removal and the interactions among different ions must be understood.However,it is generally dificult to ensure highly efficient removal of impurity ions while retaining Li in the solution for further recovery.In this study,the removal of typical impurity ions from LCW and the interactions between these species were systematically investigated from the thermodynamic and kinetics aspects.It was found that the main impurities(e.g.,Fe^+,AIP^+,Ca^2+,and Mg^2+)could be efficiently removed with high Li recovery by control-ling the ionic strength of the solution.The mechanisms of Fe^3+,Al^+,Ca^2+,and Mg^2+removal were investigated to identify the controlling steps and reaction kinetics.It was found that the precipitates are formed by a zero-order reaction,and the activation energies tend to be low with a sequence of fast chemical reactions that reach equilibrium very quickly.Moreover,this study focused on Li loss during removal of the impurities,and the corresponding removal rates of Fe^+,Al^+,Ca^2+,and Mg^2+were found to be 99.8%,99.5%,99%,and 99.7%,respectively.Conse-quently,high-purity LisPO4 was obtained via one-step precipitation.Thus,this research demonstrates a potential route for the effective recovery of Li from low-concentra-tion LCW and for the appropriate treatment of acidic LCW.
基金
support for this research from the National Key Research and Development Program ofChina(No.2017YFB0403300 and 2017YFB0403305)
the National Natural Science Foundation of China(Grant Nos.51425405,51674022,and L1624051)
Key Program of Chinese Acadermy of Sciences KFZD-SW-315
1000 Talents Program of China(Z.S),as well as the Shanxi Provincial Science and Technology Major Projects(MC2016-05).