Calcium carbonate is an essential and versatile mineral which finds its way into our daily life.
Origins
Calcium carbonate is one of the most abundant minerals on Earth and accounts for about 4% of the Earth’s crust. It can be found in nature in three principal rock types: chalk, limestone, and marble.
Ground Calcium Carbonate (GCC)
Most calcium carbonate deposits are made up of the remains of marine organisms that have sedimented to the bottom of a shallow sea. These organisms, such as crustaceans, algae, and coral, absorb calcium carbonate from the water and use it to form their skeletons and shells. When they die, their remains form sedimentary deposits on sea-beds which build up over time to form rock. Chalk, a soft rock, is the result of poorly compacted sedimentary calcium carbonate rock, whose diagenesis is incomplete. Once the sedimentation process is complete, this results in the formation of limestone. Marble, the hardest form of calcium carbonate, is a metamorphic rock, which is the result of the recrystallization process of limestone, under conditions of high pressure and temperature.
Precipitated Calcium Carbonate (PCC)
Calcium carbonate can also be produced synthetically in the form of Precipitated Calcium Carbonate (PCC). PCC is created through the conversion of limestone into Cao and CO2 and the subsequent reaction of both purified components in a chemical reactor. The final product has the same chemical composition as GCC, but is higher purity and has different properties in terms of particle size distribution and particle shape. The high whiteness and opacity of carbonates lend themselves to a great many applications, from building materials to paper and paint, to construction and foodstuffs.
Physical Properties
- High brightness
- Blocky particle shape
- Odorless
- Thermal conductivity
- Insoluble in water
- Relatively soft (3 on Mohs scale)