摘要
采用恒压酸浸技术,对废炭渣(WCR)进行高效解毒并再生成锂离子电池可用的高纯石墨产品(PGC)。运用正交试验和单因素试验相结合的方法,对浸出条件进行优化。结果表明,在浸出温度为60℃、初始酸浓度为12%、浸出时间为180 min和液固比为25:1的最优条件下,可获得符合商业石墨要求的99.5%纯度石墨产品。同时,以氢氧化钠溶液为沉淀剂,在pH=11的条件下,镍、钴、锰和铝的回收率分别达到96.92%、87.5%、97.83%和92.17%。此外,通过蒸发结晶工艺还可以回收纯度超过99%的NaF副产物。整个流程中氟的损失率小于0.5%,从而消除氟对环境的污染风险。此流程展现了可观的环境效益和经济效益。
Waste carbon residue(WCR)was efficiently detoxicated and regenerated to high-purity graphite(PGC)used in lithium-ion batteries through the constant-pressure acid leaching technique.The leaching conditions were optimized by the combination of orthogonal and single-factor experiments.Results show that PGC with 99.5%purity is regenerated at temperature of 60℃,initial acid concentration of 12%,leaching time of 180 min,and liquid-to-solid ratio of 25:1,satisfying the requirements of commercial graphite.Meanwhile,the sodium hydroxide precipitation process was designed to recover valuable components from leachate efficiently.Ni,Co,Mn,and Al recoveries reach 96.92%,87.5%,97.83%,and 92.17%,respectively,at pH=11.Moreover,the co-product NaF can be recovered with purity over 99%via evaporative crystallization.The loss rate of fluorine is less than 0.5%,thereby eliminating the pollution risk of fluorine to the environment.The proposed process shows considerable environmental and economic benefits.
作者
诸向东
肖劲
毛秋云
张振华
唐雷
仲奇凡
Xiang-dong ZHU;Jin XIAO;Qiu-yun MAO;Zhen-hua ZHANG;Lei TANG;Qi-fan ZHONG(School of Metallurgy and Environment,Central South University,Changsha 410083,China;National Engineering Laboratory for Efficient Utilization of Refractory Nonferrous Metal Resources,Central South University,Changsha 410083,China;Department of Educational Science,Hunan First Normal University,Changsha 410205,China)
基金
the financial supports from the National Natural Science Foundation of China(Nos.52174338,51904349)
the Natural Science Foundation of Hunan Province,China(No.2021JJ30796)。
关键词
恒压酸浸
废炭渣
阳极材料再生
氢氧化钠沉淀
氟化钠
constant-pressure acid leaching
waste carbon residue
anode material regeneration
sodium hydroxide precipitation
NaF