铝电解中新型碳阳极的反应过程及作用机理

来源期刊：中南大学学报(自然科学版)1989年第5期

论文作者：严大洲 刘业翔 肖海明

文章页码：505 - 511

关键词：氧化铝电解； 碳电极； 催化剂； 电能消耗； 杂质； 添加剂效应； 电化学反应

Key words：alumina electrolysis； carbon electrodes； catalyst； power consumption； pollutions； effect of additives； electrochemical reaction

摘    要：本文研究在碳阳极中添加La,Ce,Pr,Nd,Y等单一稀土化合物对阳极反应超电压的影响。试验结果表明,在工业电流密度范围内,可降低阳极反应超电压0.2～0.34V,节省电能600～1100kW·h/t·Al。文中对电极的电化学反应过程进行了研究,得到阳极反应的动力学方程,推导出稀土物料作为电催化剂的反应机理和作用模型。为了降低催化剂成本,可采用混合稀土代替单一稀土。

Abstract: The anodic overvoltage of fhe carbon anode in existing aluminium electrolysis process is 0. 4 to 0. 6 V, which is about 8 to 14 per cent of the cell voltage. The compounds of the rare earth elements (Ce, Y, Nd, Pr) or a mixture mixed with any two kinds of these elements were added into the graphite anodes or carbon anodes. The anodic overvoltage was measured by using steady state technique. The results indicate that anodic overvoltage was reduced by the rare earth additives which increased the electro-catalytic activities of the carbon anodes. In the range of industrial current densities (0. 5 to 1. 0 A/cm~2), the anodic overvoltage reduced by 0. 2 to 0. 34 V. The estimated energy saving will be 600 to 1100 kW·h/t·A1 By studying the electrochemical behaviour of the carbon anode, the Tafel equations were obtained. The mechanism and model of the anodic reaction in which the rare earth compounds were used as eletrocatalysts were also given.