Calcite - Mineral and Chemical Structure
Calcite is the name of a mineral and chemical structure of this mineral forming carbonated rocks is CaCO3. It has a crystallized, colorless and transparent structure with glassy brightness in various forms (crystallized as rombaeder, scalenoeder). It is easily ground and a white powder is obtained. Its hardness is 3 according to the Moh’s scale and its density is in the range of 2.6-2.7. The mineral, produced with the name of calcite in our country, is the main mineral of carbonated rocks (limestone, marble, chalk).
These formations are as follows;
Limestones (unmetamorphosed): White rocks from primary rocks are used by grinding in countries such as France and Egypt.
Marbles are formed by the recrystallization of limestones by metamorphism. In our country, it is used as marble in the construction sector and those with white and large crystals are used in the micronized filling industry, the subject of our report.
Crystal calcites are formed as pure transparent crystals in crack fillings between limestone formations. Generally, commercial production is not possible.
Chalk is an organic fossils found in England, France and some parts of Europe. Its degree of whiteness is around 87-88 and it is easy to grind. But it is not produced in our country.
Commercially produced calcite (calcium carbonate) formations in the world are White colored limestones, White colored pure limestones, Coarse crystal marbles (produced in Turkey), and White chalk formations.
Among these, those with the highest whiteness are the large crystal marbles. However, the energy used in grinding is higher than the others. Çanakkale Karabiga Region is one of the largest crystal calcite formations in our country. The calcite deposits formed with the granite contact have high whiteness and are easy to grind, but have a lower whiteness than the formations found in the Aegean Region and Niğde. Bayramiç, Biga and Ezine have marble beds. Balıkesir Erdek and Manyas gave very rich coarse crystal marble beds and quarries. In Thrace, there are marble and dolomitic marble beds in Yıldız mountains in Thrace and Bursa Orhaneli. Bursa Orhangazi, Keles, İnegöl have rich marble beds, but production is very small. Izmir Tire, Gölmarmara, Akhisar, Torbalı have marble beds. Their degree of whiteness is lower than those previously stated. Muğla Yatağan and Kavaklıdere regions have rich marble beds, which are easy to grind, with a smaller crystal structure, purer chemical structure and a very high whiteness. Niğde region has very rich reserves and the calcite deposits are the whitest formations in Turkey. There are calcite quarries in this region which increase production rapidly. Today, many manufacturers supply raw materials from these quarries in Niğde region. In recent years, investments in Niğde have increased significantly. The regions mentioned above are the regions with a rich reserves, whic can be expressed in tens of millions of tons. Apart from these, in almost all regions of Anatolia, it is possible to find calcite formations which do not have production and reserve detection. The sum of known reserves can be expressed in hundreds of millions of tons. The most important points attracting attention in the reserves of Turkey are as follows;
The percentage of CaCO3 is high.
- The impurities such as silica, iron and magnesium are very low.
- The degree of whiteness after grinding is very high.
- The high level of whiteness in the ore is always preferred because it provides savings of the titanium dioxide in the paint and plastic, and the optical brightener on the paper.