工业铝电解过程中PFC排放机理探讨  

Study on the mechanism of PFC emission during the industrial aluminum electrolysis process

作　　者：秦庆东[1] 邱仕麟 

机构地区：[1]贵州理工学院材料与冶金工程学院,贵阳550003 [2]中国铝业郑州有色金属研究院有限公司,郑州450041

出　　处：《轻金属》2015年第6期23-27,共5页Light Metals

基　　金：贵州省教育厅招标项目(黔教合KY字[2014]270)

摘　　要：本文研究工业铝电解生产过程PFC的排放过程,探讨了排放机理,结果显示PFC的生产直接受到生成电位的影响,而生成电位与氧化铝浓度密切相关,氧化铝浓度越低,电流密度越大,过电压越高,容易生产PFC;氧化铝浓度的降低,使得电解质与阳极表面的润湿性随之降低,电阻增大,导致电流密度增加,过电压上升;电解质中氧化铝浓度很低时,阳极表面电解质熔体的络合铝氧离子不能补充到阳极表面去放电,致使阳极表面的铝氧氟离子的浓度极化扩散过电压升高,最终导致了PFC的生产,阳极效应发生;铝电解过程非效应PFC持续排放的产生是因氧化铝浓度的变动等使得电解槽局部产生持续效应,由于小的局部效应通过的电流很低,PFC持续排放的强度也很低。In this study, the process of PFC emission during industrial aluminum electrolysis was studied, at the same time the mechanism of emission was discussed. The results showed that the emission of PFC were affected by production potential, however, the production potential was affected by the alumi- na concentration, i. e. , the lower alumina concentration, the higher over voltage. As a result, the PFC became more. The reduction of alumina concentra- tion leaded to the weak on wettability between anode and electrolyte. And then both the resistance and the over voltage were enhanced. As the alumina concentration reached a very low value, the aluminum - oxygen ion complexation of electrolyte could not reach to the surface of anode, so this leaded to the enhancing of over voltage and the PFC and anode effect began to emission. The reason of PFC emission of non - anode effect was the change of alumina concentration and local anode effect. When the small local anode effect was occurring, the passing carrent was low and the continous emission intensity was also low.

关 键 词：铝电解 PFC 阳极效应 非阳极效应 排放机理 

分 类 号：TF821[冶金工程—有色金属冶金]