摘要
本文开展了硫酸-氧气体系常压浸出废旧磷酸铁锂正极粉工作,重点研究了酸料比、液固比、浸出温度、浸出时间和气体流量等对组分浸出规律的影响。结果表明,随着酸料比的提高,Li^(+)浸出率先增大后小幅度下降,而Fe和PO_(4)^(3-)浸出率则同步提高;随着液固比的提高,Li^(+)浸出率呈现先增大后下降的趋势,而Fe和PO_(4)^(3-)浸出率则先减小后增大。此外,浸出温度、浸出时间和气体流量的提高均有利于提高Li^(+)浸出率,并抑制Fe和PO_(4)^(3-)的浸出。较佳条件下,Li^(+)浸出率高达99.0%,而Fe和PO_(4)^(3-)浸出率均低至0.31%。热力学和动力学分析结果表明,Fe^(2+)的氧化是整个浸出反应的决速步骤,且浸出渣为FePO_(4)·2H_(2)O。
Spent lithium iron phosphate cathode powder was treated with sulfuric acid and oxygen under atmospheric pressure,and the effects of acid-to-material ratio,liquid-to-solid ratio,temperature,reaction time,and gas flow rate on the leaching behavior of components were comprehensively investigated.Results indicate that the leaching rate of Li^(+)rose initially and then slightly decreased as the acid-to-material ratio increased,while the leaching rates of Fe and PO_(4)^(3-)showed synchronous improvement.However,the leaching efficiency of Li^(+)exhibited a trend of first increasing and then decreasing with the increase of liquid-to-solid ratio,whereas the Fe and PO_(4)^(3-)leaching rates initially decreased and then rose.Additionally,higher leaching temperatures,extended leaching times,and increased gas flow rates all contributed to improvement of Li^(+)leaching efficiency as well as the suppression of the leaching rate of Fe and PO_(4)^(3-).Under optimal conditions,the Li^(+)leaching efficiency reached 99.0%,while the Fe and PO_(4)^(3-).leaching rates remained as low as 0.31%.Thermodynamic and kinetic analyses reveal that the oxidation of Fe^(2+)served as the ratedetermining step in the overall leaching process,with the leaching residue identified as FePO_(4)·2H_(2)O.
作者
李立平
王辉
张军礼
黄司平
LI Liping;WANG Hui;ZHANG Junli;HUANG Siping(Guangdong Guanghua Sci-tech Co.,Ltd.,Shantou 515000,China)
出处
《化工技术与开发》
2026年第1期19-24,共6页
Technology & Development of Chemical Industry
基金
广东特支计划粤东粤西粤北地区人才支持专项(2024TQ08L468)。
关键词
硫酸
氧气
废旧磷酸铁锂正极粉
常压浸出
浸出规律
sulfuric acid
oxygen
spent lithium iron phosphate cathode power
atmospheric leaching
leaching law
