The kinetics of thermal dissociation was studied for polydisperse systems (naturally occurring calcite and precipitated calcium
carbonate) with normal and Rosin-Rammler-Sperling distributions. Experimental rate constants at selected temperatures and
activation energies were calculated. The experimental results (kinetic curves) were compared with the theoretically derived
curves and the usability of the selected kinetic models for description of the kinetics in such systems was estimated.