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Calcium carbonate rocks are spread throughout the world, which is why they have been among the most widely used raw materials for more than 5000 years. Long ago, the
Egyptians built their pyramids with limestone, and today we still use hundred of millions of tonnes of calcium carbonate in the building industry alone. However, although the
deposits are plentiful, only a few are of sufficiently high quality to be worked and even a fewer number of deposits will provide raw materials for industrial and agricultural uses
other than the construction and roads building industry. Only if the purity, degree of whiteness, thickness and homogeneity are acceptable is commercial extraction worthwhile. After quarrying, further treatment is required to
process natural calcium carbonates of the highest quality, known generically as Ground Calcium Carbonate (GCC).
Precipitated Calcium Carbonate (PCC) is a synthetic calcium carbonate produced industrially by means of a recarbonisation process. Both GCC or PCC can be used in a wide range of applications. For each end use there exists a tailor-made product, where fineness and particle size distribution are optimally balanced to meet the technical demands of that particular requirement. - Paper: Over the last 30 years, the use of calcium carbonate has grown significantly as technology in the paper industry has moved from acid to neutral sizing. Today, calcium carbonate is the most widely used mineral in paper-making. GCC and PCC are used both as a filler and a coating pigment, and help produce papers with high whiteness and gloss and good printing properties.
- Plastics: Calcium carbonate is by far the most important mineral for compounding with polymers. By weight it accounts for more than 60% of the filler and reinforcements market. Main applications include plasticised and rigid PVC, unsaturated polyesters, polypropylene and polyethylene. Other important areas of use include rubber, foamed latex carpet-backings, sealants and adhesives.
Calcium carbonate is not only a filler added to reduce costs and extend petroleum based resources, many properties of the plastic can be influenced by the use of calcium carbonate. Breathable PE-films for hygiene products and the building industry, for example, can only be produced with the incorporation of a filler such as calcium carbonate.
- Coatings: In paints and coatings, calcium carbonate has established itself as the main extender. Fineness and particle-size distribution can contribute to the opacity of
coatings. Moreover, calcium carbonate can offer improvements in weather resistance, anti-corrosion and rheological properties, coupled with low abrasiveness,
low electrolyte content, and a pH stabilising effect. In water-based systems calcium carbonate reduces the drying time.
- Environment: As a natural product, calcium carbonate is perfect for environmental protection applications. For example, flue gas desulphurisation, drinking water
treatment, waste water treatment and forest and lake liming for the neutralisation of acid rain, are all growth areas for the use of calcium carbonate. It has a natural
buffer-effect and works as a pollution-filter. These properties, likewise, apply to the derivative products.
- Agriculture: Calcium fertilisers were one of the first to be widely used. The Greeks and Romans were aware of their attributes. Their use guarantees an adequate supply of calcium to plants and stabilises the pH-value of the soil. These characteristics make calcium carbonate an important fer tiliser for the agriculture and forestry sectors. Every year, in Europe alone, more than 4.5 million tonnes are supplied to this market. Other agricultural-related uses of calcium carbonate include its use as a calcium supplement in animal feed
compounds.
- Others: Glass, ceramics and blackboard chalk, together with cleaning, dental care and cosmetic products are produced by the wide range of industrial manufacturers who rely on calcium carbonate. As a natural mineral, calcium carbonate has a multitude of characteristics that make it an ideal raw material for widely differing uses. No one calcium carbonate is exactly like another, whichever property is needed a high grade product is there to meet the demand. Diverse requirements such as low iron oxide content for the production of high-quality glasses, the authorisation for uses in foodstuffs, good buffering-effect or low abrasion, can be met by an existing grade of calcium carbonate.
Sources: www.ima-eu.org/cca.html |
