氯化铁对磷酸铁锂中锂浸出性能研究  

Leaching Performance of Ferric Chloride to Lithium from Lithium Iron Phosphate

作　　者：牛勇 时东[1,2] 罗超 彭小五 张禹泽 李丽娟 宋富根[1,2] NIU Yong;SHI Dong;LUO Chao;PENG Xiao-wu;ZHANG Yu-ze;LI Li-juan;SONG Fu-gen(Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Engineering Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining,810008,China;Qinghai Technology Research and Development Center of Comprehensive Utilization of Salt Lakes Resources,Xining,810008,China;University of Chinese Academy of Sciences,Beijing,100049,China)

机构地区：[1]中国科学院青海盐湖研究所,中国科学院盐湖资源综合高效利用重点实验室,青海西宁810008 [2]青海省盐湖资源综合利用技术研究开发中心,青海西宁810008 [3]中国科学院大学,北京100049

出　　处：《盐湖研究》2023年第1期87-95,共9页Journal of Salt Lake Research

基　　金：国家自然科学基金项目(1707601);中国科学院青年创新促进会项目(2021430);中国科学院绿色制造创新研究院项目(IAGM2020C26)。

摘　　要：随着新能源电动汽车的发展,磷酸铁锂(LiFePO_(4),LFP)电池的报废量逐年剧增,由于其有价金属锂含量低,回收经济性差,近年来废旧LFP的低成本回收成为研究热点。基于同构诱导置换浸出,以FeCl_(3)为浸出剂,在固-液反应体系中探究了FeCl_(3)对LFP中的锂浸出的影响因素,利用未反应核收缩模型探究了两个浸出阶段的宏观动力学。结果表明,增大FeCl_(3)/LFP摩尔比、减小固液比和升高反应温度可以显著促进锂的浸出;在浸出前4 min内,锂浸出速率主要受固态产物层内扩散过程控制,表观活化能为6.68 kJ/mol;4 min后锂浸出速率受流体膜外扩散、产物层内扩散和化学反应混合机制的控制。With the development of electric vehicles,the discard amount of lithium iron phosphate(LiFePO_(4),LFP)batteries were increasing by years.However,due to the low content of valuable metal lithium,the recycling economic value is poor,and the recycling of spent LiFePO_(4)at low cost has become a research hotspot.In this paper,based on the isomorphic induced displacement leaching method,FeCl_(3)as the leaching agent and a solid-liquid reaction system was used to explore the influence factors of leaching of lithium.The unreacted shrinking core model was used to study macrokinetics of leaching process.The results show that increasing FeCl_(3)/LFP molar ratio,decreasing solid-liquid ratio and increasing reaction temperature can significantly promote leaching of lithium.In the 4 minutes before leaching,the leaching rate was mainly controlled by product layer diffusion,and the apparent activation energy is 6.68 kJ/mol.After 4 minutes,the leaching rate was controlled by the mixing mechanism of film diffusion,product layer diffusion,and chemical reaction.

关 键 词：磷酸铁锂 锂 浸出 动力学 未反应核收缩模型 

分 类 号：TQ131.11[化学工程—无机化工]