摘要
电池级碳酸锂是锂电池的关键材料,目前锂辉石硫酸法工艺是主要制备途径,该方法存在酸雾污染环境、设备腐蚀和产品质量不稳定等问题。与硫酸法工艺对比,碱压煮法生产碳酸锂工艺具有生产流程短、环保效果好、锂回收率高和加工成本低等优点,成为当前行业关注的热点技术。本文结合中国恩菲工程技术有限公司的生产实践和锂盐行业的研究成果,系统阐述了碱压煮法生产电池级碳酸锂的反应机制和最佳工艺流程,并重点探讨了转型焙烧、碱压煮和碳酸氢化-热析等关键工序的影响因素。进一步明确了其最佳控制条件是:转型焙烧工序温度1000~1150℃;碱压煮工序碱比1.9~2.1,反应温度235℃,反应时间1 h;碳酸氢化-热析工序碳酸氢化温度小于40℃,热解温度大于90℃,一次碳酸氢化用液固比30∶1~40∶1,二次碳酸氢化液固比20∶1~25∶1。以此推动碱压煮法生产电池级碳酸锂集成技术的系统研究和成功开发,为锂盐产业绿色高效发展提供新的思路和解决方案。
Battery grade lithium carbonate is the key material of lithium battery,which is mainly obtained from sulfuric acid process of spodumene.The whole process is in acid and high sodium environment,there are problems such as acid mist pollution,equipment corrosion and unstable product quality in the production process.Compared with sulfuric acid process,alkali pressure leach process for producing battery grade lithium carbonate has the advantages of short process,good environmental protection,strong adaptability of raw materials and strong compatibility of sulfuric acid process.Through experiments and system optimization,a new alkali pressure leach process was established,it included transformation roasting,soda pressure leaching and twice carbonation-crystallization.In the 1960s and 1970s,China conducted phased research on alkali pressure leach process,carried out small-scale experiments,semi industrial experiments and continuous autoclave industrialization experiments,and obtained the main technical parameters.Since then,due to the popularization and application of sulfuric acid process,the research on alkali pressure leach process related technologies was interrupted.After 2012,China ENFI conducted systematic research and experimental verification on alkali pressure leach process,and developed a new alkali pressure leach process route with friendly environment and low cost.This paper introduced the reaction mechanism and process of producing battery grade lithium carbonate by alkali pressure leach process.The new alkali pressure leach process solved the problems existing in the previous alkali pressure leach process.First,the system did not discharge waste water,realizing the recycling and echelon utilization of water resources.It was estimated that the water consumption of per unit lithium carbonate product was less than 25 m^(3).Second,the energy consumption was reduced by adopting multi-stage flash evaporation,cold and hot flow echelon heat exchange and other technologies,and the steam consumption of per unit pr
作者
杜国山
杨永亮
徐月和
唐建文
Du Guoshan;Yang Yongliang;Xu Yuehe;Tang Jianwen(China ENFI Engineering Corporation,Beijing 100038,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2021年第11期1394-1402,共9页
Chinese Journal of Rare Metals
基金
中国博士后科学基金项目(2020M680826)
国家重点研发计划项目(2018YFC1902501)资助
关键词
碳酸锂
碱压煮(SPLE)工艺
碳酸氢化
热分解
lithium carbonate
soda pressure leach(SPLE) process
carbonation
thermal decomposition
