The new model for description of calcium carbonate precipitation in the rotating disk precipitation reactor has been elaborated. The model has taken into account not only kinetics of the multiphase reaction but also crystal growth rate. The obtained, during the precipitation process, crystal morphology data have been compared with the model simulation results. The obtained simulation results fully agree with the experimental data and explain why independent of the Ca(OH)(2) concentrations and speeds of disk rotation the obtained, in the reactor, ultrafine calcite powder has the same nanometric size (about 30 nm). The proposed model very well describes the CaCO3 crystals formation in the rotating disk reactor and can be used and recommended for accurate calculation of the particle size and distribution obtained by gas-liquid precipitation in the reactor. (C) 2010 Elsevier B.V. All rights reserved.