提锂尾渣制备电池用磷酸铁工艺研究  

Research on the Process of Preparing Battery Grade Iron Phosphate from IithiumExtraction Tailings

作　　者：饶媛媛 徐懋 胡在京 姚停 方继明 蒋阳[2] Rao Yuanyuan;Xu Mao;Hu Zaijing;Yao Ting;Fang Jiming;Jiang Yang(Hefei Guoxuan Battery Material Co.,Ltd.,Hefei 230012,China;School of Materials Science and Engineering,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥国轩电池材料有限公司,安徽合肥230012 [2]合肥工业大学材料科学与工程学院,安徽合肥230009

出　　处：《广东化工》2025年第5期37-40,共4页Guangdong Chemical Industry

摘　　要：随着锂电池回收产业的高速发展,为了符合市场发展方向,回收相关的技术路线也越来越趋向于优先提取价值较高的金属元素,但与此同时提取尾渣再利用技术难度大的问题严重制约了锂电池中有价元素的闭路循环。为了高值回收利用磷酸铁锂电池废料提锂后的尾渣,本文对其开展了硫酸溶解以及除杂过程条件优化的研究,重点研究了前处理条件对提锂尾渣中Al元素选择性浸出的影响以及除铜剂用量对铁磷浸出液中Cu的影响,进一步地研究了硫酸浓度、溶解固液比、溶解温度对提锂尾渣溶解效果的影响,并制备出符合行业销售标准的电池用磷酸铁。结果表明,使用稀硫酸进行预处理,当pH=1时添加提锂尾渣质量1.5%的助剂,所得除铝铁磷渣含铝量由3185.9 ppm下降至473 ppm,铁磷渣再用2.5倍摩尔量的硫酸进行溶解3小时,溶解液固比为5∶1,溶解温度为60℃。溶液加入一定量的氨水调整pH后加入除铜剂除Cu至26 ppm,随后加入适量磷源以调整P:Fe=1.2~1.05之间并加入氨水为沉淀剂调节pH至1.5~2时可得到组成满足行业规范标准并且形貌呈现为片层状的电池用磷酸铁,可直接用于磷酸铁锂正极材料的生产。With the rapid development of the lithium battery recycling industry,in order to conform to the direction of market development,the technical routerelated to recycling is also increasingly inclined to give priority to the extraction of metal elements with higher value,but at the same time,the difficulty of extractingtailings reuse technology seriously restricts the closed circuit cycle of valuable elements in lithium batteries.In order to recover and utilize the tailings of lithium ironphosphate battery waste after lithium extraction with high value,this paper carried out a study on the optimization of conditions of sulfuric acid dissolution andimpurity removal process,focusing on the influence of pre-treatment conditions on the selective leaching of Al from lithium extraction tailings and the influence ofthe amount of copper removal agent on the Cu in the leaching solution of iron phosphorus.The effects of sulfuric acid concentration,solution solid liquid ratio anddissolution temperature on the dissolution of lithium tailings were further studied,and the battery-grade iron phosphate was prepared in line with industry salesstandards.The results show that when pH=1 is used for pretreatment with dilute sulfuric acid and 1.5%additive is added to extract the mass of lithium tailing slag,the aluminum content of the slag decreases from 3185.9 ppm to 473 ppm,and the iron-phosphorus slag is dissolved with 2.5 times the molar amount of sulfuric acidfor 3 hours,the solution liquid-solid ratio is 5∶1,and the dissolution temperature is 60℃.After a certain amount of ammonia is added to the solution to adjust thepH,copper removal agent is added to remove Cu to 26ppm,and then an appropriate amount of phosphorus source is added to adjust the P∶Fe=1.2~1.05 andammonia water is added as a precipitator to adjust the pH to 1.5~2,the battery iron phosphate can be composed to meet the industry standard and the morphology islamellar.It can be directly used in the production of lithium iron phosphate cathode materials.

关 键 词：提锂尾渣 除铝 硫酸浸出 磷酸铁 回收 

分 类 号：TQ115[化学工程—无机化工]