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。
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.
基金
国家自然科学基金
关键词
铝
电解生产
碳阳极
电化学反应
alumina electrolysis
carbon electrodes
catalyst
power consumption
pollutions
effect of additives
electrochemical reaction
