PRODUCT - Minerals
Micronized Calcite
We can offer Micronized Calcite and Calcite quarry stone.
| Component | Percentage |
| CaO | more than 55% |
| MgO | less than 0.6% |
| Fe2O3 | less than 0.3% |
| SiO2 | less than 0.3% |
| CaCO2 | more than 98% |
| Brightness | more than 95% |
Particle size: 400mesh,500mesh,600mesh,700mesh,800mesh,1000mesh,1250mesh
Use for paint industries,paper production,plastic prodcution,chemical production and so on.
Calcite
The carbonate mineral Calcite is a chemical or biochemical calcium carbonate corresponding to the formula CaCO3 and is one of the most widely distributed minerals on the Earth's surface. It is a common constituent of sedimentary rocks, limestone in particular. It is also the primary mineral in metamorphic marble. It also occurs as a vein mineral in deposits from hot springs, and also occurs in caverns as stalactites and stalagmites. Calcite is often the primary constituent of the shells of marine organisms, e.g., plankton (such as coccoliths and planktic foraminifera), the hard parts of red algae, some sponges, brachiopoda, echinoderms, most bryozoa, and parts of the shells of some bivalves, such as oysters and rudists). Calcite represents the stable form of calcium carbonate; aragonite will change to calcite at 470°C, and vaterite, or µ-CaCO3, is less stable still.
Calcite crystals are trigonal-rhombohedral, though actual calcite rhombohedrons are rare as natural crystals. However, they show a remarkable variety of habits including acute to obtuse rhombohedrons, tabular forms, prisms, or various scalenohedrons. Calcite exhibits several twinning types adding to the variety of observed forms. It may occur as fibrous, granular, lamellar, or compact. Cleavage is usually in three directions parallel to the rhombohedron form. Its fracture is conchoidal, but difficult to obtain.
It has a Mohs hardness of 3, a specific gravity of 2.71, and its luster is vitreous in crystallized varieties. Colour is white or colourless, though shades of gray, red, yellow, green, blue, violet, brown, or even black can occur when the mineral is charged with impurities. Calcite is transparent to opaque and may occasionally show phosphorescence or fluorescence. It is perhaps best known because of its power to produce strong double refraction of light, such that objects viewed through a clear piece of calcite appear doubled in all of their parts - a phenomenon first described by Rasmus Bartholin. A beautifully transparent variety used for optical purposes comes from Iceland, called Iceland spar. Acute scalenohedral crystals are sometimes referred to as "dogtooth spar".
Single calcite crystals display an optical property called birefringence. The birefringent effect (using calcite) was first described by the Danish scientist Rasmus Bartholin in 1669. At a wavelength of ~590 nm calcite has ordinary and extraordinary refractive indices of 1.658 and 1.486, respectively [1].
Calcite can be either dissolved by groundwater or precipitated by groundwater, depending on several factors including the water temperature, pH, and dissolved ion concentrations. Calcite exhibits an unusual characteristic called retrograde solubility in which it becomes less soluble in water as the temperature increases. When conditions are right for precipitation, calcite forms mineral coatings that cement the existing rock grains together or it can fill fractures. When conditions are right for dissolution, the removal of calcite can dramatically increase the porosity and permeability of the rock, and if it continues for a long period of time may result in the formation of caverns.
Mining
The mineral is worked by shallow pits. During mining the calcite is sorted out into different grades depending upon the colours as they fetch different prices and also, because their suitability depends upon the colours. The mineral is used invariably in the form of fine powder. Few important mine-owners have their own pulverizing plants; others sell to pulverizers. Generally calcite is supplied in three qualities:
- Best white (super-fix)
- White (Calico)
- Grey white (Gemco)
Industrial Applications
Calcite in pulverized form finds use mostly as filler in rubber and textile goods. A considerable quantity is also used in the ceramics industry for the preparation of glazes. Super white quality of calcite in powder form (-300 mesh) is used in the manufacture of paint and distemper. Calcite is now insecticides. It is also used in the manufacture of cement, calcium carbide, metal polish and sometimes also as a fluxing agent. The transparent and clear crystals are used in the optical industry, for the manufacture of nicol prism. Principal characteristics which make iceland-spar of special value for use in optical instruments are its very high birefringence, high degree of purity, perfect crystalline structure and transparency. The mineral must be in pieces at least 25mm. long, 12mm. thick, colourless, transparent and free from cloudy inclusions, cavities, and foreign substances.