China Nonferrous Metallurgy

High-temperature corrosion in the waste heat boiler (WHB) of a copper flash smelting furnace frequently occurs in the ceiling area between the front wall of the radiation section and the baffle, which has consistently constrained the safe and efficient operation of the WHB. This study aims to mitigate high-temperature corrosion and avoid localized overheating of the water-cooled walls by constructing a three-dimensional model of the radiation section, investigating the flow and heat transfer characteristics of the flue gas, and conducting structural optimization of the boiler to reduce corrosion issues. The results reveal that flue gas impingement on the ceiling is the primary cause of high-temperature corrosion in the radiation section. Increasing the inlet size of the boiler and adjusting the structure and position of the baffle can effectively reduce ceiling corrosion by controlling the flue gas velocity and temperature. In contrast, variations in the parameters of the air for sulfation injection exert negligible influence on the flue gas temperature field. Numerical simulation results were further used to optimize the boiler inlet size and baffle configuration. After expanding the front wall inlet cross-section to 4.1m×4.5m (width×height), the average flue gas velocity decreased by 14%, and the maximum velocity decreased by 21%. Moreover, the distance between the corrosive temperature zone (1467~1531K) and the ceiling increased by 2.6m. These findings demonstrate that the optimized boiler structure effectively suppresses the upward impact of flue gas and reduces ceiling temperature, thereby mitigating corrosion.