Catalytic Role of Process Dust in SO2-to-SO3 Conversion in Flash Smelting Heat Recovery Boilers

The aim of this work is to examine the catalytic role of copper smelter, copper converter, and nickel smelter process dusts in SO2-to-SO3 conversion at 750°C. To clarify the role of specific oxides in greater detail, synthetic dusts containing varying concentrations of either CuO or Fe3O4 were also studied. All studied dusts catalyzed SO3 conversion. Among the industrial flue dusts, the highest concentration of SO3 formed in the presence of copper smelter dust. Comparing individual oxides, CuO had a greater impact on the SO3 formation. Such catalytic effects of smelter dusts may lead to SO3 concentrations in the process gas so high that sulfuric acid dew point corrosion may occur.