Process

CALPREC is produced by the lime recarbonation process. This is the most economical process existing today. By calcining limestone in lime kilns, quicklime is obtained, that is then converted into slaked lime and properly purified. Later on, it is recarbonated with the carbon dioxide produced during the calcination process, re-composing the calcium carbonate which was present in the limestone but now with predetermined features.

The lime kilns used for this process are natural gas fired to guarantee a high level of purity. In the case of food or pharmaceutical grade PCC, specific slaked limes are used.

The chemical reactions involved in the whole process are the following.

The peculiarity of this process comes from the possibility of controlling, to a great extent, not only the crystal size, but also the different crystallization forms of CaCO3 that can be obtained. The different carbonates are synthesized according to parameters such as the temperature, the reaction rate and the supersaturation of the system.