AbstractThe intrinsic reaction rate constant for calcium carbonate decomposition was determined based on a structural model (grain model). Experiments were conducted with thin slab type pellets (thickness 0.044 ‐ 0.086 cm) in the temperature range of 670‐740°C under isothermal conditions for determining the rate constant. The effective diffusivity, effective thermal conductivity, and heat and mass transfer coefficients were determined from experimental data obtained from cylindrical pellets (L/D ≈︁ 1) at 840 and 875°C, taking into consideration the temperature variations in the solid. The results obtained are in good agreement with the values reported in l