超声强化铝电解废阴极炭水浸-碱浸工艺研究  

Ultrasonic enhanced water-alkali leachingprocess for aluminum electrolysis spent cathode carbon

作　　者：张选 许磊[1,2,3] 任义尧 李幸福 魏群 谢诚 ZHANG Xuan;XU Lei;REN Yiyao;LI Xingfu;WEI Qun;XIE Cheng(Faculty of Metallurgical and Energy Engineering,Kunming University of Science and Technology,Kunming 650093,China;State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization,Kunming University of Science and Technology,Kunming 650093,China;National Local Joint Laboratory of Engineering Application of Microwave Energy and Equipment Technology,Kunming University of Science and Technology,Kunming 650093,China)

机构地区：[1]昆明理工大学冶金与能源工程学院,云南昆明650093 [2]昆明理工大学复杂有色金属资源清洁利用国家重点实验室,云南昆明650093 [3]昆明理工大学微波能工程应用及装备技术国家地方联合工程实验室,云南昆明650093

出　　处：《中国有色冶金》2025年第1期138-148,共11页China Nonferrous Metallurgy

基　　金：国家自然科学基金面上项目(52374305);云南省科技厅重点项目(202101AS070023);科技厅杰出青年项目(202301AV070009);国家重点研发子课题(2018YFC1901904)。

摘　　要：铝电解过程会产生大量的废阴极炭,其中不仅含有大量碳,而且含有大量可溶性氟化物,堆积处理不仅污染环境,而且浪费资源。本文针对目前文献已有研究中处理工艺存在的问题,采用超声波辅助水浸-碱浸工艺处理废阴极炭,进行工艺条件优化试验,且对阶段性产物进行了表征分析,且对有无超声波辅助的水浸-碱浸效果进行了对比,得到以下主要结论。水浸较优工艺条件为水浸时间50 min、水浸温度25℃、液固比7∶1、超声波功率300 W,此条件下除氟率为32.31%,对浸出液进行蒸发结晶处理,回收得到纯度为99.4%的氟化钠;碱浸较优工艺条件为碱浸时间60 min、碱浸温度70℃时、液固比10∶1、初始NaOH溶液浓度1.25 mol/L、超声波功率400 W,该条件下除氟率可达92.24%,所得碱浸液经盐酸中和处理后得到纯度为95.7 wt.%的冰晶石粉末;超声碱浸后的废阴极炭的EDS分析表明经过超声水浸和超声碱浸,废阴极炭中的氟化钠、冰晶石、氧化铝等组分被有效去除;超声碱浸主要由扩散过程控制,表观活化能为18.61 kJ/mol;超声强化浸出工艺较常规搅拌浸出工艺的处理时间缩短了92.4%,除氟率提升了13.98%。本研究证实了超声水浸-超声碱浸工艺可以有效实现废阴极炭的无害化处理及有价值组分回收。Aluminum electrolysis generates a significant amount of spent cathode carbon,which not only contains a substantial amount of carbon but also a considerable amount of soluble fluoride.The improper disposal of this waste not only leads to environmental pollution but also results in the loss of valuable resources.In this paper,in order to solve the problems existing in the treatment processes studied in the current literature,an ultrasonic-assisted water-alkaline leaching method to treat spent cathode carbon.The process was investigated and the process conditions were optimized.The intermediate products were characterized and analyzed,and the effects of water-leaching-alkaline leaching,both with and without ultrasonic assistance,were compared.The following key findings were obtained.The optimal conditions for water leaching are a leaching time of 50 min,a temperature of 25 ℃,a liquid-to-solid ratio of 7∶1,and an ultrasonic power of 300 W.Under these conditions,the fluorine removal rate is 32.31%,and the recovered product is sodium fluoride,with a purity of 99.4 wt.%.The optimal process conditions for alkali leaching are 60 min of alkali leaching time,70 ℃ of alkali leaching temperature,10∶1 liquid-to-solid ratio,1.25 mol/L initial NaOH solution concentration,and 400 W of ultrasonic power.Under these conditions,the fluorine removal rate can reach 92.24%,and the obtained alkali leaching solution is treated with hydrochloric acid to obtain cryolite powder with a purity of 95.7 wt.%.EDS analysis of spent cathode carbon following ultrasonic alkali leaching revealed that it primarily contained only carbon,indicating that ultrasonic water and alkali leaching effectively removed sodium fluoride,cryolite,alumina,and other components.The ultrasonic alkali leaching process was primarily controlled by diffusion,with an apparent activation energy of 18.61 kJ/mol.The ultrasonic-enhanced leaching process reduced the processing time by 92.4% compared to the conventional stirring leaching process,while the fluorine removal r

关 键 词：废阴极炭 超声水浸-超声碱浸 无害化处理 氟化钠回收 冰晶石回收 炭回收 扩散过程控制 

分 类 号：TF821[冶金工程—有色金属冶金] X758[环境科学与工程—环境工程]