CFD modeling of gas−liquid mixing and splashing in industrial-scale bottom-blowing furnace: Effects of melt viscosity
The co-processing of lead-containing waste materials in oxygen bottom-blowing lead smelting alters melt viscosity, which in turn governs gas−liquid mixing efficiency, splashing behavior, and furnace lining erosion. A multi-fluid volume of fluid (VOF) model, incorporating experimentally determined high-lead slag viscosity values, was applied to an industrial-scale bottom-blowing furnace to resolve these coupled phenomena. The simulations demonstrate that optimal gas−liquid mixing occurs at viscosity values of 0.01 and 0.5 Pa·s, whereas minimal splashing is confined to the viscosity range of 0.1−0.25 Pa·s, corresponding to temperatures of approximately 1076−1100 °C. The regions surrounding the oxygen lances are identified as the most susceptible to erosion. Shear stress increases with melt viscosity, rising particularly rapidly within the 0.1−0.25 Pa·s interval. To minimize erosion, the melt viscosity should be maintained within 0.01−0.1 Pa·s. These findings provide quantitative thresholds for viscosity control in industrial bottom-blowing furnaces processing lead-containing secondary materials, enabling trade-offs between mixing intensity, splashing suppression, and lining protection to be optimized on an operational basis.