添加剂对铝用碳素阳极消耗的影响

Effect of additives on consumption of carbon anodes in aluminium electrolysis

铝电解生产中 ,碳素阳极两组分 (石油焦和沥青结焦 )的活性差异带来阳极的选择性氧化 ,是造成碳素阳极过量消耗的主要原因之一 .基于阳极中杂质或添加剂对阳极活性产生的影响 ,作者采用分别测定石油焦和沥青结焦与CO2 反应活性的实验方法 ,研究了AlF3 及其它 5种添加剂 (分别用A ,B ,C ,AlF3 +C ,AlF3 +D代替 )对二者活性的影响 .结果表明 ,添加剂C提高了沥青结焦和石油焦的CO2 反应活性 ;添加剂AlF3 ,A ,B ,AlF3 +C及AlF3 +D均可不同程度地降低沥青结焦和石油焦的CO2 反应活性 ,并且使沥青结焦与石油焦的CO2 反应活性差距缩小 ,使得有可能在碳阳极中采用适宜添加剂 ,减缓其选择性氧化 ,降低阳极碳耗 .

Selective oxidation of carbon anode in aluminum electrolysis caused by reactivity difference between pitch coke and petroleum coke is one of the main causes for excess carbon consumption. Impurities and additives in carbon anodes may substantially affect chemical activity of the anodes. Petroleum coke and pitch binder have been doped with different additives (represented with A, B, C, AlF 3, AlF 3+C and AlF 3+D) and baked at 1 150 ℃, and reactivity of the obtained petroleum coke or pitch coke powders toward CO 2 has been investigated. Results show that additive C increases reactivity of petroleum coke and pitch coke, additives A, B, AlF 3, AlF 3+C and AlF 3+D decrease reactivity of petroleum coke and pitch coke to different degrees. But their effects on pitch binder is far more obvious than on petroleum, which means that it is possible to abbreviate selective oxidation of anodes and reduce the anode carbon consumption, particularly reduce the erosion of carbon dust in aluminum electrolysis by doping carbon anodes with appropriate additives. [