Talc is one of the world's most soft rock.
Chemical name is hydrated magnesium silicate talc. The chemical formula which best characterizes the talc is 3, mgo style 4 sio2 · H2O, [there are represented as Mg3Si4O10 (OH) 2], chemical name: hydrated magnesium silicate, monoclinic system. 63.47% of pure talc theory: SiO2, MgO style by 31.68%, 4.75% H2O. The crystal shape is flake (layered), leaf, acicular or blocky.
The structure of pure talc by a layer of brucite (magnesium hydroxide. MgO style · H2O) sandwiched between two layers of silica, overlay each other between the layers, adjacent layers of talc by weak van der Waals force. The basic structural unit of the surface does not contain the hydroxyl and other active ions, thus talc hydrophobic and chemical inertness.
Talc insoluble in water and weak acid and weak base, not burning, not conduct electricity. Although the chemical properties of talc are not lively, it has a strong affinity for some organic matter, which means it is oil-wet hydrophobic. Temperature in 700-900oc talc gradually lose the hydroxy (water) or structure; The melting point of 1557 oc. Mineral collection usually show flake or density lump, color white, gray, pink, black, etc. Pure talc have oily luster, soapy. Mohs hardness is 1, the density of 2.75.
Although the nature of talc and colorful and varied, but there are four common, namely: stability, low hardness, the layered structure, oil-wet hydrophobic. The nature of the minerals are rarely like this combination of so many advantages. Talc itself determines the characteristics of its functional filler is a kind of rare. In numerous should, talc can not only play the role of general packing cost reduction, and can significantly enhance the performance of these products. This makes talc as filler, widely used in papermaking, plastics, paint, ceramics, cosmetics, medicine, rubber, agricultural products, fertilizer and other industries.
People have long believed that talc is white, in fact, talc can be gray, green, blue, pink, or black.
Talc ore geology
Talc in metamorphic minerals is one of the most common. Although the talc deposits in different geological condition distribution around the world, but not many of exploitation and utilization value.
The formation of talc ore deposit
Talc ore deposit is carried by the thermal fluid flow required for one or several kinds of mineral composition (magnesium oxide, silicon dioxide, carbon dioxide) under the action of the existing rock evolution. The formation of geological structure in talc ore deposit plays an important role. Favorable geological structure would lead to hot fluid through the rock, the rock has micro permeability, promote the reaction of the rock to a great extent. Talc ore deposit depends on the size and shape of the hydrothermal activity intensity. Extrusion and deformation in parallel, then make the evolution of rock, finally in the crystallization of talc ore deposit formation.
The type of talc ore deposit
Talc ore deposit is classified according to the evolved into is the parent rock of the category to partition, there are four categories: magnesium carbonate derived orebody, serpentinite derived orebody, siliceous or silicon aluminum rock derivative ore, magnesium sedimentary deposit ore.
Nature of pure talc is rare, usually accompanied by other minerals. The most common is chlorite, magnesite and dolomite. Some ore body contains a small amount of quartz, tremolite. The number of species and associated minerals determines the nature of the industrial products, thus determines the function and the application field of talc. Talc associated ore impurities will not only reduce the purity, will also have very obvious effects on the performance of the final product. For example, the carbonate talc aging resistance of plastic, metal, iron and heavy metal, thermal stability have adverse effect. Haicheng talc belong to carbonate - talc, essence on the material, do is very careful, maximum reduce the existence of carbonate, ensure the quality of the product.
On the left side of the chart is chlorite, it is one of the most common carbonate, very similar on the structure and chemical properties of talc (talc is a kind of hydrated magnesium silicate, chlorite is hydrated magnesium aluminum silicate). Aluminumand iron content determines the classification of chlorite. Like talc, chlorite also has softness, layer structure and organic (has the characteristics of the affinity of organic matter), but relatively talc, chlorite reactivity and hydrophilic bigger.
Chlorite is a kind of hydrated magnesium aluminum silicate salt,
chemical formula: (car - x - y Fey Alx) O10 (OH) 8