磷酸-酒石酸体系协同浸出废旧磷酸铁锂工艺  

Synergistic leaching process of waste LiFePO_(4) with phosphoric acid-tartaric acid system

作　　者：肖忠良[1] 夏宇博 宋刘斌[1] 向优涛 赵亭亭 罗静 刘远佳 邓鹏辉 颜群轩 XIAO Zhongliang;XIA Yubo;SONG Liubin;XIANG Youtao;ZHAO Tingting;LUO Jing;LIU Yuanjia;DENG Penghui;YAN Qunxuan(School of Chemistry and Chemical Engineering,Changsha University of Science and Technology,Changsha 410114,Hunan,China;Hunan Jinkai Cycle Technology Co.,Ltd.,Hengyang 412800,Hunan,China)

机构地区：[1]长沙理工大学化学化工学院,湖南长沙410114 [2]湖南金凯循环科技股份有限公司,湖南衡阳412800

出　　处：《化工学报》2024年第12期4780-4792,共13页CIESC Journal

基　　金：国家自然科学基金项目(21501015,21545010,31527803);湖南省自然科学基金项目(2022JJ30604)。

摘　　要：从废旧磷酸铁锂(LiFePO_(4))动力电池中回收有价金属,实现其资源化利用是当前亟待解决的问题。提出磷酸-酒石酸混合浸出体系,对废旧LiFePO_(4)的全组分浸出回收工艺进行研究。通过单因素实验结果得到浸出条件的大致范围,再采用响应曲面法对不同浸出条件进行优化得到最佳浸出工艺。结果表明:在磷酸浓度为3.1 mol/L、酒石酸(TA)浓度为1.3 mol/L、液固比6.8∶1、搅拌速度500 r/min、反应温度65℃下反应5 h,Li和Fe的浸出率分别为97.55%和98.67%。实验结果表明,酒石酸可以与磷酸浸出释放的Fe^(3+)进行络合,混合酸的协同作用几乎将废料中所有的Li、Fe都浸出到溶液中。通过调整浸出液中Li∶Fe∶P的摩尔比,采用喷雾干燥-烧结法合成再生磷酸铁锂(RE-LiFePO_(4))。该工艺在整个回收过程中几乎没有废酸、废气排放,实现了废旧LiFePO_(4)的全组分绿色回收。Recycling valuable metals from waste LiFePO_(4) power batteries and realizing their resource utilization is an urgent problem at present.In this study,a mixed leaching system of phosphoric acid and tartaric acid was proposed,and the total component leaching recovery process of waste LiFePO_(4) was studied.The approximate range of leaching conditions was obtained through the results of single factor experiments,and then the response surface method was used to optimize different leaching conditions to obtain the best leaching process.The results showed that the leaching rates of Li and Fe were 97.55%and 98.67%respectively when the concentration of phosphoric acid was 3.1 mol/L,the concentration of tartaric acid was 1.3 mol/L,the liquid-solid ratio was 6.8∶1,the stirring speed was 500 r/min and the reaction temperature was 65℃for 5 h.The experimental results show that tartaric acid can be replaced with the Fe^(3+)released by phosphate,and the synergy of mixed acids will immerse all Li and Fe in the waste into the solution.By adjusting the molar ratio of Li∶Fe∶P in the leaching solution,the regenerated LiFePO_(4)(RE-LiFePO_(4))was synthesized by spray drying-sintering method.In the whole recovery process,there is almost no waste acid and waste gas emission,and the green recovery of all components of waste LiFePO_(4) is realized.

关 键 词：废旧磷酸铁锂电池 回收 混合浸出 响应曲面法 喷雾干燥法 

分 类 号：O646[理学—物理化学]