Precipitated Calcium Carbonate

Calcium carbonate, which is also recognized as the chemical formula CaCO₃, makes up almost five percent of the earth’s crust and is found all throughout the planet. CaCO₃ is a combination of CaO (calcium oxide) and CO₂ (carbon dioxide). Calcium carbonate’s most common natural forms are chalk, limestone, and marble. These forms of the material are produced by the sedimentation of prehistoric sea animal shells. Although chalk, limestone, and marble are indistinguishable in chemical terms, they are different from each other in many other ways. These differentiations include the material’s purity, whiteness, thickness and homogeneity (meaning how uniform its composition is). Calcium carbonate is a material that is as abundant as it is useful. With many different applications for the material throughout a variety of industries, it could be argued that calcium carbonate is one of the most useful and versatile materials in existence.

Precipitated Calcium Carbonate (PCC), also called PCC, is a synthetic calcium carbonate. PCC production requires consistent quicklime quality to produce a quality calcium carbonate. The precipitated calcium carbonate production process consists of decarbonating limestone, which separates the CaO (calcium oxide) and CO₂ (carbon dioxide). Precipitated calcium carbonate is produced by slaking high-calcium quicklime to create a calcium hydroxide lime slurry, (Ca(OH)₂), that is then combined with captured carbon dioxide (CO₂). This process generates a very white and pure calcium carbonate with a controlled crystalline structure.

An even precipitation process allows good control of the crystallization and particle size of the PCC. Lime reactivity is key to achieving a finer particle size distribution and particle shape of PCC, as well as the stability of the process. Variations in quicklime quality can result in difficulties slaking and inconsistent particle size. This can lead to downtime, not meeting your customers’ needs, additional waste, and impact on your overall bottom line.

Over time, equipment used to produce precipitated calcium carbonate may need updated or replaced due to normal wear and tear or for the integration of new technologies. Carmeuse supplies advanced equipment solutions for lime storage, handling, and slaking through our wholly owned subsidiary, Storage & Transfer Technologies (STT).

Our expert engineers can design the right solution to keep your PCC production running smoothly, from new lime handling systems and slakers, to retrofits and upgrades for your existing equipment. For additional information related to our lime handling expertise, visit the STT website.