铝电解过程中干式防渗料中的铝热还原反应  

Study on aluminothermic reduction reaction in the dry barrier of aluminum electrolytic process

作　　者：张立达 王耀武 刘佳智 狄跃忠 彭建平 Zhang Lida;Wang Yaowu;Liu Jiazhi;Di Yuezhong;Peng Jianping(School of Metallurgy,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学冶金学院,辽宁沈阳110819

出　　处：《轻金属》2021年第5期30-35,共6页Light Metals

基　　金：国家重点研发计划项目(2018YFC1901905)。

摘　　要：电解过程中,干式防渗料中除了存在电解质的渗透反应外,还存在着金属铝的渗透,金属铝会与防渗料发生铝热还原反应。本论文通过X射线衍射物相分析与扫描电镜分析对大修电解槽废防渗料的组成及铝热还原后防渗料的组成进行研究,探讨了防渗料中铝热还原反应的影响因素。研究结果表明,在工业电解槽运行过程中,渗透进入防渗料中的铝很容易与防渗料中的SiO 2发生还原反应生成单质硅或含硅合金,这种铝热还原反应速率随着温度的升高和防渗料中硅铝比的升高而升高;当干式防渗料中存在NaF或Na 3AlF 6时,会促进铝热反应的进行,但当防渗料中存在熔融的氟化物电解质时,反应速率会降低。In addition to electrolyte permeation in the dry barrier,there is also some aluminum permeation in the process of aluminum electrolysis and the aluminum will react with dry barrier.The composition of the spent dry barrier and the dry barrier after aluminothermic reduction were analyzed by X-ray diffraction phase analysis and SEM analysis,so as to study influence factors of aluminothermic reduction in the dry barrier.The results show that the aluminum infiltrated into the dry barrier is easy to react with SiO 2 in the dry barrier to form silicon atom or silicon-containing alloys.The aluminothermic reduction rate increases with the rise of temperature and the ratio of SiO 2 to Al 2O 3 in the dry barrier.The aluminothermic reaction will be accelerated when NaF or Na 3AlF 6 exists in the dry barrier,and it will be decreased when the molten fluoride electrolyte exists in the dry barrier.

关 键 词：铝电解槽 干式防渗料 铝热还原 含硅合金 电解质 

分 类 号：TF821[冶金工程—有色金属冶金]