基于常压酸浸的铝电解浮选炭渣深度提纯工艺  

Deep Purification Technology of Aluminum Electrolysis Flotation Carbon Slag Based on Atmospheric Acid Leaching

作　　者：李晓庆 何柳 王璇 周军[1,2] 彭茜 姚桢 刘卫[1,2] LI Xiao-qing;HE Liu;WANG Xuan;ZHOU Jun;PENG Qian;YAO Zhen;LIU Wei(School of Materials and Architectural Engineering,Guizhou Normal University,Guiyang 550025,China;Guizhou Engineering Research Center for Carbon Materials Aluminum Electrolysis,Guiyang 550025,China)

机构地区：[1]贵州师范大学材料与建筑工程学院,贵阳550025 [2]贵州省铝电解炭素材料工程技术研究中心,贵阳550025

出　　处：《有色金属（冶炼部分）》2023年第2期57-63,共7页Nonferrous Metals（Extractive Metallurgy)

基　　金：贵州省科学技术基金资助项目(黔科合基础[2020]1Y224,黔科合基础-ZK[2022]一般321);贵州省科技计划项目(黔科合支撑[2020]4Y036号)。

摘　　要：炭渣作为铝电解生产过程中排放的危险固体废弃物,目前主要通过浮选工艺处理,但由于浮选炭渣碳含量较低且存在二次污染风险,限制了其资源化利用前景。采用常压酸浸对浮选炭渣进行深度提纯,依次研究了盐酸浓度、酸浸温度、液固比、搅拌速率、酸浸时间对提纯效果的影响,并通过XRD、XRF、浸出毒性分析探索浮选炭渣处理前后的物相组成、元素含量及氟离子浸出浓度的变化规律。结果表明,随着盐酸浓度、酸浸温度、液固比、搅拌速率、酸浸时间的增加,浸出渣碳含量呈现先增加后减缓的变化趋势。在盐酸浓度4 mol L、酸浸温度60℃、搅拌速率1200 r min、液固比25、浸出时间4 h的最佳条件下,浮选炭渣的碳含量由82.67%提高至98.05%,氟离子浸出浓度从137.80 mg L降低至62.49 mg L。常压酸浸工艺具备实现浮选炭渣深度提纯的技术可行性。Aluminum electrolysis carbon slag is a dangerous solid waste continuously produced and inevitable in aluminum electrolysis industry.At present,carbon slag is mainly treated by flotation process.However,due to the low carbon content of flotation carbon slag and the risk of secondary pollution,the prospect of its resource utilization is limited.Effects of HCl concentration,acid leaching temperature,L S,stirring rate and leaching time on treatment effect were studied by atmospheric pressure acid leaching depth purification.XRD,XRF,leaching toxicity analysis were used to explore the changes of phase composition,element content,leaching toxicity before and after treatment of carbon slag.The results show that carbon content of leached slag rises first and then slows down with the increase of hydrochloric acid concentration,acid leaching temperature,L S,stirring rate,and acid leaching time.Carbon content of carbon slag rises from 82.67%to 98.05%and fluorine leaching concentration drops from 137.8 mg L to 62.49 mg L under the optimum conditions including HCl concentration of 4 mol L,acid leaching temperature of 60℃,stirring rate of 1200 r min,L S=25,and leaching time of 4 h.The atmospheric acid leaching process has technical feasibility to realize deep purification of flotation carbon slag.

关 键 词：铝电解 浮选炭渣 常压酸浸 深度提纯 回收炭材料 

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