A novel mechanism model of the fluidized bed roaster in the zinc roasting process

The fluidized bed roaster in the zinc roasting process, namely zinc roaster, is one of the most important reactors in the zinc smelter, because its products are the raw material for downstream processes. However, the product quality cannot be measured online in practical zinc smelters. To provide the foundation for optimizing the operation of the zinc roaster, a novel mechanism model of the zinc roaster is developed as a soft sensor to predict product quality in this study. First, the reaction kinetics of the zinc roaster is analyzed, and the kinetics model is constructed based on the shrinking unreacted core model. In this model, the diffusion reaction at the moving interface is identified as the controlling step, which significantly simplifies the model's complexity. Subsequently, utilizing two-phase fluidization theory, a simplified well-mixed model characterizes the hydrodynamic properties of the zinc roaster. The model parameters are estimated through particle swarm optimization, and a simulation study based on industrial data demonstrates the effectiveness of the proposed mechanism model.