磷酸铁锂正极粉选择性提锂  

Selective Extraction of Lithium from Lithium Iron Phosphate Positive Powder

作　　者：鲁俊雀 黄宁湘 刘勇奇 付中梦 许添斌 LU Junque;HUANG Ningxiang;LIU Yongqi;FU Zhongmeng;XU Tianbin(Hunan Brunp Recycling Technology Co.,Ltd.,Changsha 410604,China;Guangdong Provincial Key Laboratory of Battery Recycling,Foshan 528000,Guangdong,China;Hunan Province University Science and Technology Industrial Park,Changsha 410604,China)

机构地区：[1]湖南邦普循环科技有限公司,长沙410604 [2]广东省电池循环利用企业重点实验室,广东佛山528000 [3]湖南省大学科技产业园,长沙410604

出　　处：《有色金属（冶炼部分）》2023年第12期32-37,共6页Nonferrous Metals（Extractive Metallurgy)

基　　金：湖南省宁乡市科技重大专项项目(NXKJ-ZDZX-202102)。

摘　　要：废旧磷酸铁锂电池中,Li具有非常高的经济回收价值。采用无机盐Fe_(2)(SO_(4))_(3)浸出体系、Fe_(2)(SO_(4))_(3)-H 2O 2协同浸出体系从废旧磷酸铁锂极片粉中选择性回收锂,考察了浸出剂种类、反应时间、温度、液固比、浸出剂添加量及氧化剂种类等对选择性浸出Li的影响。结果表明:硫酸铁浸出体系液固比5 mL g,添加1.5倍原料的硫酸铁,在20℃下浸出反应20 min,Li浸出率为91.19%,P浸出率仅为0.02%;硫酸铁-过氧化氢协同浸出体系液固比5 mL g,反应温度20℃,Fe_(2)(SO_(4))_(3)添加量为原料的0.6倍,反应20 min后,加过氧化氢调pH至4.1~4.6,Li浸出率可达99.09%,P浸出率为0,Li的选择性浸出效果极好。Fe_(2)(SO_(4))_(3)-H 2O 2协同浸出体系节约Fe_(2)(SO_(4))_(3)用量60%,浸出剂易循环再生利用,所得磷铁渣较纯,Fe P摩尔比为0.976,可用于制备新的LFP正极材料。In spent lithium iron phosphate batteries,lithium has a considerable recovery value.Inorganic salt Fe_(2)(SO_(4))_(3)and Fe_(2)(SO_(4))_(3)-H 2O 2 were used as the leaching agent to extract lithium from lithium iron phosphate positive powder.The effects of the type of leaching agent,reaction time,temperature,ratio of liquid-solid(L S),Fe_(2)(SO_(4))_(3)dosage and type of oxidant on the selective lithium extraction process were investigated.The results show that 91.19%of lithium and only 0.02%of P were leached out under the optimal conditions including L S=5 mL g,Fe_(2)(SO_(4))_(3)dosage of 1.5 times of raw material,reaction temperature of 20℃,and reaction time of 20 min.The leaching rate of Li is 99.09%and leaching rate of P is 0 under the conditions including L S=5 mL g,temperature of 20℃,Fe_(2)(SO_(4))_(3)dosage of 0.6 time of raw material,reaction time of 20 min,and pH value of 4.1—4.6 adjusted with H 2O 2,which the selective leaching effect of Li is excellent.The leaching system of Fe_(2)(SO_(4))_(3)-H 2O 2 saves 60%of the amount of Fe_(2)(SO_(4))_(3),and the leaching agent is easily utilized by recycling ring.The obtained ferric phosphate slag is pure and the molar ratio of Fe P is 0.976,which can be used to prepare new LFP cathode materials.

关 键 词：废旧磷酸铁锂电池 硫酸铁 过氧化氢 锂 浸出 

分 类 号：TF803.2[冶金工程—有色金属冶金]