Analysis and simulation of monodispersed, nanostructured calcite obtained in a controlled multiphase process

Abstract

In the presented experiments the carbonation process in multiphase system was carried out using the reactor with rotating discs. Calcite was produced by controlled fast precipitation through gaseous carbon dioxide adsorption in calcium hydroxide slurry with the constant discus revolution speed rate equal to 120 r min−1. Initial concentration and volume of the slurry was equal to 23 mM l−1 or 54 mM l−1 and 1 l or 2 l, respectively. The size of monodispersed single crystals precipitated in the aqueous solution was strongly dependent on the process parameters and varied (scanning electron microscope pictures, ImageJ Programme calculation) from 90 nm to 320 nm. To explain the way of single calcite crystal nucleation and growth the simulation of the crystals formation has been performed. This simulation bases on the new model, which takes into account kinetics of the multiphase reaction, crystals nucleation and their growth. Crystal morphology data obtained during the precipitation process have been compared with the model simulation results. The internally consistent model very well describes formation of the calcite nanoparticles and can be used and recommended for accurate calculation of the particle and aggregates size as well as their distribution in the reactor.