Simulation of Thermal Decomposition of Partially Calcined Spherical Limestone Injected into a Molten Iron Bath

To reduce the consumption of energy and materials, it is necessary to develop a more efficient method for refining iron. The use of partially calcined limestone as a refining flux is expected to increase the mass transfer and reaction area via thermal decomposition of CaCO₃ and violent CO₂ generation. A model was developed to simulate the decomposition of the limestone particles in molten iron using multi-physics analysis, in which the equations for multiphase flow, heat transfer, and chemical reactions were solved simultaneously. The particle penetration behavior and the temperature and mass distributions of CaCO₃ were calculated as a function of time. A large amount of CO₂ is generated in a short period, which is expected to generate a strong stirring effect and destroy the flux particles.