Calcium carbonate

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) - created by nature over millions of years

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) - created by man in a matter of hours

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)
   

A broad portfolio and worldwide presence

Imerys owns calcium carbonate assets in over 21 countries, including 3 dedicated Technology Centers, 48 production sites, and 15 deposits located in Europe, North and South America and South-East Asia. 

Imerys combines high-quality feed materials, state of the art processing techniques and in-depth market knowledge to generate a broad portfolio of ground calcium carbonate (GCC) and precipitated calcium carbonate (PCC) products to serve construction, paper, paint, plastics, rubber, adhesives, food and pharmaceuticals, agriculture and industry.

Essential for tomorrow's world 

The high whiteness and opacity of carbonates lend themselves to a great many applications.

In paints and coatings, Imerys calcium carbonates are cost-effective multifunctional fillers that improve whiteness, opacity and matting. They make ideal replacements for titanium dioxide. 

In plastics, Imerys engineered calcium carbonates improve the quality of breathable films for diapers, hygiene, medical and roofing applications. They are excellent reinforcement agents maximizing mechanical properties in PVC building profiles and flooring.

In paper production, Imerys calcium carbonates are cost-effective filler substitutes for wood fiber where they improve brightness and paper optics. As paper and paperboard coatings, they enhance whiteness and opacity as well as the printability of the finished paper. 

In animal feed, food and beverage, and pharmaceuticals, Imerys calcium carbonates provide a valuable source of the bone-building mineral, calcium. 

In adhesives and sealants, finely ground calcium carbonates can be used at high loadings where they improve rheological properties, improve whiteness and opacity and generate cost savings. 

In industry, Imerys limes are valued raw materials and process enablers for the steel industry, sugar industry, water treatment and the building industry. In oil and gas production, ground calcium carbonates reduce filtration loss in drilling fluid formulations.

Calcium carbonate is an abundant and very versatile mineral, making it a key mineral for the future. Placing innovation at our core, we strive to meet and anticipate the future needs of our customers in present and new economy environments.

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