CIESC Journal ›› 2024, Vol. 75 ›› Issue (12): 4780-4792.DOI: 10.11949/0438-1157.20240617

• Energy and environmental engineering • Previous Articles     Next Articles

Synergistic leaching process of waste LiFePO4 with phosphoric acid-tartaric acid system

Zhongliang XIAO1(), Yubo XIA1, Liubin SONG1(), Youtao XIANG1, Tingting ZHAO1, Jing LUO1, Yuanjia LIU1, Penghui DENG1, Qunxuan YAN2()   

  1. 1.School of Chemistry and Chemical Engineering, Changsha University of Science and Technology, Changsha 410114, Hunan, China
    2.Hunan Jinkai Cycle Technology Co. , Ltd. , Hengyang 412800, Hunan, China
  • Received:2024-06-04 Revised:2024-08-16 Online:2025-01-03 Published:2024-12-25
  • Contact: Liubin SONG, Qunxuan YAN

磷酸-酒石酸体系协同浸出废旧磷酸铁锂工艺

肖忠良1(), 夏宇博1, 宋刘斌1(), 向优涛1, 赵亭亭1, 罗静1, 刘远佳1, 邓鹏辉1, 颜群轩2()   

  1. 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
  • 通讯作者: 宋刘斌,颜群轩
  • 作者简介:肖忠良(1964—),男,博士,教授,xiaozhongliang@163.com
  • 基金资助:
    国家自然科学基金项目(21501015);湖南省自然科学基金项目(2022JJ30604)

Abstract:

Recycling valuable metals from waste LiFePO4 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 LiFePO4 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 Fe3+ 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 LiFePO4 (RE-LiFePO4) 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 LiFePO4 is realized.

Key words: waste LiFePO4 battery, recycle, mixed leaching, response surface method, spray drying process

摘要:

从废旧磷酸铁锂(LiFePO4)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LiFePO4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Fe3+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-LiFePO4)。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LiFePO4的全组分绿色回收。

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

CLC Number: