China Nonferrous Metallurgy

This paper employs the fault tree analysis (FTA) method, taking the aluminum leakage incident from electrolytic cells as the top event, to construct a qualitative analysis model comprising 12 basic events. Analysis of minimal cut sets and minimal path sets identifies 11 distinct paths leading to aluminum leakage. Specifically, bottom leakage can be triggered by any single factor among X₁-X₉, whereas side leakage requires the combined effect of (X₁₀∨X₁₁) and X₁₂. The structural importance of events was calculated using the minimal cut set approximation method. The results indicate that the factors related to the cell bottom, such as poor lining material quality and poor furnace construction quality (I_φ=1), together with the burning through of the side steel shell (I_φ=1), have the greatest impact on the accident, followed by side corrosion and excessively high bath temperature (I_φ=0.5). Quantitative evaluation shows that the annual probability of the top event is approximately 4.40%, which closely matches actual statistical data, validating the model's effectiveness. Sensitivity analysis indicates that prioritizing control of high-probability, high-importance events (e. g. , X₁, X₂) can significantly reduce overall risk.