废磷酸铁锂正极粉浸出液中氟的脱除  

Removal of fluorine from the leaching solution of spent LiFePO4 positive powder

作　　者：赵毅 孙亮 李玉虎 任如山[1] 贺欣豪 杨裕东 ZHAO Yi;SUN Liang;LI Yuhu;REN Rushan;HE Xinhao;YANG Yudong(Faculty of Materials Melallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,Jiangxi,China)

机构地区：[1]江西理工大学材料冶金化学学部,江西赣州341000

出　　处：《江西冶金》2023年第3期179-185,共7页Jiangxi Metallurgy

基　　金：江西省教育厅科学技术资助项目(GJJ180437)。

摘　　要：氟是锂电池正极材料回收过程中主要的有害杂质之一,过量的氟不仅腐蚀设备,还导致产品品质劣化。因此,文中开展了改性TiO_(2)吸附脱除废磷酸铁锂正极粉浸出液中氟的研究,考察了改性TiO_(2)用量、温度等工艺参数对废磷酸铁锂正极粉浸出液中氟脱除效果的影响规律,探究了改性TiO_(2)对浸出液中氟的吸附热力学和动力学。结果表明,吸附剂用量和初始pH值对改性TiO_(2)吸附除氟性能的影响显著。改性TiO_(2)最佳的吸附除氟条件为:吸附剂用量为24 g/L、反应温度为25℃、反应时间为1 h、初始pH值为7.5。在此条件下,氟脱除率可达98.97%,吸附后液中氟浓度仅为4.7 mg/L。改性TiO_(2)对废磷酸铁锂正极粉浸出液中氟的吸附热力学符合Langmuir吸附等温模型,饱和吸附量为128.21 mg/g,吸附动力学模型为拟二级动力学模型。Fluorine is one of the main harmful impurities in the recycling process of lithium anode materials.Excessive fluorine will cause not only equipment corrosion but also product quality deterioration.This paper carried out a study on the adsorption removal of fluorine in the leaching solution of waste lithium iron phosphate positive powder by modified titanium dioxide,illustrated the law of influence on the removal effect of fluorine in the leaching solution of spent lithium iron phosphate cathode powder covering the modified titanium dioxide dosage,temperature and other process parameters,and investigated the modified titanium dioxide in leaching liquid fluoride adsorption thermodynamics and kinetics.The results show that the amount of both adsorbent and initial pH value shed significant light on the adsorption and fluorine removal performance of modified titanium dioxide.The optimal adsorption and removal conditions of modified titanium dioxide are as follows:the dosage of adsorbent is 24 g/L,the reaction temperature is 25℃,the reaction time is 1 h and the initial pH value is 7.5.Under these circumstances,the fluorine removal rate reached 98.97%,and the concentration of fluorine in the adsorbed solution was only 4.7 mg/L.The adsorption thermodynamics of fluoride in the leaching solution of waste lithium iron phosphate positive electrode powder by modified titanium dioxide conform to the model of Langmuir adsorption isotherm,the saturated adsorption capacity is 128.21 mg/g,and the adsorption kinetic model is a pseudosecond-order kinetic model.

关 键 词：改性TiO_(2) 除氟 浸出液 吸附 废旧锂电池 

分 类 号：TQ424.3[化学工程] X703.1[环境科学与工程—环境工程]