硝酸-喷雾热解法回收磷酸铁锂正极废料的研究  

Recovery of lithium iron phosphate cathode waste by nitric acid-spray pyrolysis method

作　　者：汪思琪 桑子容 韩培林 姚家涛 张勇[1] WANG Siqi;SANG Zirong;HAN Peilin;YAO Jiatao;ZHANG Yong(School of Materials Science and Engineering,Wuhan Institute of Technology,Wuhan 430205,China)

机构地区：[1]武汉工程大学材料科学与工程学院,湖北武汉430205

出　　处：《武汉工程大学学报》2024年第1期50-54,共5页Journal of Wuhan Institute of Technology

基　　金：青海省科技计划项目(2020-GX-103);海西州科技计划项目(2019-101)。

摘　　要：采用硝酸浸出锂离子,调节pH沉铁后获得纯净的硝酸锂溶液,经喷雾热解可获得碳酸锂粉体。并利用X射线衍射、扫描电子显微镜、电感耦合等离子体发射光谱对其晶体结构、微观形貌、杂质离子含量进行表征。结果表明:在最佳酸浸条件:硝酸浓度4 mol/L、反应温度65℃、反应时间3 h,锂离子浸出率达到97.47%;在最佳喷雾热解条件:n(硝酸锂)∶n(甲醇)=1.0∶1.5配制混合溶液,热解温度为700℃,碳酸锂的转化率可达到99%以上,纯度可达到98.4%;所得产品为类球形,分散性较好。本方法有效避免了回收过程中其他杂质离子的引入,减少了除杂、洗涤的成本,且锂综合回收率较高。Pure lithium nitrate solution was obtained by leaching lithium ions with nitric acid and adjusting the pH during iron precipitation.Lithium carbonate powder was prepared by spray pyrolysis.The crystal structure,microstructure and impurity ion content were characterized by X-ray diffraction,scanning electron microscopy and inductively coupled plasma emission spectroscopy.The results show that the leaching rate of lithium ion is 97.47%under the optimum acid leaching conditions with 4 mol/L of nitric acid concentration,at 65℃for 3 h.The conversion of lithium carbonate is more than 99%and its purity is 98.4%under the optimum spray pyrolysis conditions with n(LiNO3)∶n(CH3OH)=1.0∶1.5 of mixed solution and 700℃of pyrolysis temperature.And the obtained product has a spherical shape with good dispersion.This method effectively avoids the introduction of other impurity ions in the recovery process,reduces the cost of impurity removal and washing,and has a high comprehensive recovery of lithium.

关 键 词：磷酸铁锂 硝酸 喷雾热解 碳酸锂 

分 类 号：X705[环境科学与工程—环境工程]