300kA铝电解槽阴极破损机理研究

研究了300 kA大型铝电解预焙槽的阴极破损机理,电解槽停止运行后通过干法剖炉,现场取样分析与观测,研究阴极炭块破损现象,阴极炭块发生断裂、漏眼,表面存在腐蚀坑.由钠渗透、阴极生成碳化铝、电毛细现象、铝和电解质等向阴极炭块缝隙渗透是造成阴极膨胀开裂的原因.分析了影响槽寿命的因素,认为提高阴极质量,加强电解槽启动初期管理,并通过采用石墨化阴极等新材料新技术,不但可降低炉底压降,形成完好的炉帮,而且有效地提高槽寿命.

Deterioration Mechanism of Cathode in 300 kA Prebaked Anode Aluminum Reduction Cells

The deterioration mechanism of a 300 kA large-scale prebaked aluminum reduction cell was studied.After a shutdown,the cell was dissected dryly for sampling analysis and observation,then the deterioration of carbonized cathode was investigated,such as breakage,leaks and surface corrosion pits.It was revealed that the causes of cathode's expansion cracking are mainly the sodium penetration,Al4C3 formed on cathode surface,electrocapillarity and electrolyte penetration into cathode gaps.Discusses the influencing factors on the service life of the cells were carried out.To lengthen the service life of the reduction cell,the following measures are regarded as efficient and suggested to take: improving the quality of carbonized cathode,strengthening the management of electrolysis cell from the very beginning and introducing such newly-developed materials and technologies as the graphitized cathode.In this way the voltage drop on cell bottom can be decreased so as to maintain well the cell wall.