Analysis of Softening–Melting Behavior of Sinters and Their Packed Bed Considering Internal Structure Particles - Part 1: Convergence Simulation Reflecting Sinter Structure Obtained by X-ray Computed Tomography

This study introduces a new convergence simulation procedure for representing the softening–melting behavior of reduced sinter at a higher resolution in the cohesive zone by incorporating the inner structure obtained by X-ray computed tomography. Boundary conditions for the actual sinter shape, including internal voids, were integrated into a dynamic calculation scheme. The composition distribution inside, corresponding to the total reduction degree, was computed by applying a three-dimensional reaction–diffusion model, and the core–shell structure within the ore was modeled as two distinct phases based on the local reduction degree. The Bingham fluid model was applied to track the fluidic behavior of the softened sinter, and an elastic force term was added to the reduced iron shell to represent its hardness. The stiffness parameter in this model was optimized by comparing the softening–melting behavior of single sinter particles across different overall reduction degrees when held at temperatures of 1573–1673 K under load. Additionally, we present an example calculation using a packed bed deformation model that extends the single sinter softening deformation model. This study confirmed the ability to evaluate the softening deformation behavior and accompanying structural changes of individual sinter particles. This series of procedures is useful for understanding the deformation behavior of mixed iron ore types in a packed bed from both micro and macro perspectives and could serve as a powerful method for designing rigorous operations for ultra-low carbon emission operations.