Let you know what mica is

1、 What is mica?
Mica (mica or glimmer) is one of the most widely distributed rock-forming minerals. It is the general name of layered aluminosilicates such as potassium, aluminum, magnesium, iron and lithium. Mica is generally polymorphic, of which monoclinic system is common, followed by cubic system, and the rest is rare. The most common minerals in the mica group are sericite, muscovite, phlogopite, lepidolite, biotite, etc. Mica is usually in the form of pseudohexagonal or rhombic plate-like, flaky and columnar crystals, and the flaky mica has the greatest development and utilization value. The color varies with the change of chemical composition, and darkens with the increase of iron content. Muscovite is colorless, transparent or light; The biotite is black to dark brown, dark green and other colors; The phlogopite is mainly yellow, brown, green or colorless; Lithium mica is light purple, rose red to gray. Glass luster, pearly luster on cleavage surface. Mohs hardness is generally 2~3.5, and specific gravity is 2.7~3.5. The cleavage of parallel bottom is very complete. Muscovite is one of the widely distributed rock-forming minerals, which occurs in all three major rocks. The argillaceous rocks can form sericite during low-grade regional metamorphism, and become muscovite when the degree of metamorphism is slightly higher. In the late stage of acid magma crystallization and pegmatization, a large amount of muscovite was generated. It can also be formed in the process of alteration from high temperature to medium and low temperature. The so-called greisenization is one of the high-temperature alteration processes, which can form a large amount of muscovite. The so-called sericitization is one of the medium-low temperature alteration, which can form a large number of sericite, mainly in sheet structure. The muscovite is weathered and broken into very fine scales, which can not only become debris in the clastic sediments, but also be one of the mineral components of argillaceous rocks.
Both muscovite and phlogopite have good insulation, high temperature resistance, luster, stable physical and chemical properties (acid resistance, alkali resistance and pressure resistance), good thermal insulation, elasticity and toughness, and the performance of being peeled into elastic transparent sheets. Therefore, it is widely used to make insulating materials in electronic and electrical industries. Mica fragments and powder are used as fillers, and lepidolite is also the main mineral raw material for lithium extraction.
Because of its large crystal size and bright color, mica minerals have long been used by human beings. In ancient Chinese books, there are records of its appellation: Huapi Lian, Tianbing, Tianpi, Dijin, Laozaojin, Melaleuca, Yuanmian, Yunmi Chi, Xionghei, etc. The pigments used in Cave 112 of the Tang Dynasty in the Mogao Grottoes in Dunhuang are shiny and shiny. According to X-ray diffraction analysis, they are made of natural muscovite finely ground. Excellent color rendering effect.
Although China has recognized and utilized muscovite and phlogopite for a long time, the formal exploration of mica deposits was carried out after the establishment of the People's Republic of China. Since 1952, the muscovite deposits in Danba, Sichuan and Tuguiwula, Inner Mongolia have been successively surveyed and explored, and good results have been achieved. In 1958, the National Mica Conference was held in Fanshi, Shanxi Province, and decided to vigorously carry out the general survey and exploration of mica. In that year, the discovery of the Aletai mica deposit in Xinjiang played a great role in the development of China's mica resources, and also accumulated experience for the general survey and exploration of mica deposits. Subsequently, the discovery and industrial use of the Donghai Muscovite deposit in Jiangsu added new industrial mica species in China. The discovery of mica deposits in Wula Mountain, Dabie Mountain, Qinling Mountains, Liaoning, Sichuan and Yunnan in Inner Mongolia has expanded the mica resources. Since the 1980s, departments of building materials, geology and mineral resources have carried out a general survey of broken mica and sericite. So far, Lubeishan Village in Lingshou, Hebei Province is the largest production and processing site of broken mica and biotite in China. After detailed investigation, the largest sericite ore deposit in China has been found in Chuzhou, Anhui Province and other places, with a reserve of more than 100 million tons and high quality. It is basically an open-pit mica mine, and is in a flaky structure that is easy to develop and use. The sericite industrial park in Daliu Town, Chuzhou City, which is under construction, is the largest sericite production base in China.
From the 1950s to the mid-1970s, China listed muscovite and phlogopite as strategic resources. The first one to be mined was the Danba mica mine in Sichuan. Later, the mica mines in Xinjiang, Inner Mongolia, Shanxi, Hebei, Shandong, Henan, Shaanxi, Yunnan and other provinces and autonomous regions were successively mined. The main state-owned mines include Xinjiang Altay, Sichuan Danba, Inner Mongolia Tugui Ula and other mines, as well as hundreds of county offices, towns and individual mines. Before 1978, the annual output of industrial raw material mica was 1700~2500t. After 1978, the output decreased year by year because of the fundamental changes in the consumption structure of mica.
2、 Mica sheet
The mica sheet is composed of polysilicon muscovite, quartz, garnet and rutile, and can appear albite, zoisite and hard chlorite. Garnet is rich in Fe and Mg, and the Si in polysilicon muscovite can reach 3.369, which is also a high-pressure combination. With insulation and low loss thermal resistance function, it is also a good black body.
Natural mica sheet is a mica part with a certain thickness and shape, which is made of thick mica after peeling, thickness setting, cutting, drilling or punching. This product is applicable to television, power capacitor, thermal relay, monitoring display, aerospace, aviation, communication, radar, heat-resistant framework sheet and other raw and auxiliary materials. There are: electric heater chip, electric heater guard, gasket, electronic segment, and light bulb. Because its material is natural mineral products, it has the characteristics of non-pollution, insulation, and good voltage resistance. It can cut various specifications of natural mica chips according to customer requirements.
3、 Mica powder
Mica powder is a kind of non-metallic mineral, which contains a variety of components, mainly SiO2, with a content of about 49%, and Al 2O 3 content of about 30%. Mica 1 has good elasticity and toughness. Insulation, high temperature resistance, acid and alkali resistance, corrosion resistance, strong adhesion and other characteristics are excellent additives. It is widely used in electrical appliances, welding electrodes, rubber, plastics, paper making, paint, paint, pigment, ceramics, cosmetics, new building materials and other industries. With the continuous development of science and technology, people have opened up new application fields.
4、 Phlogopite
Phogopite, one of muscovite minerals, is an aluminosilicate containing iron, magnesium and potassium. If the iron in the phlogopite composition is not too much, it can be used as electrical insulating material, and thus plays an important role.
The phlogopite can be divided into dark phlogopite (brown or green in various colors) and light phlogopite (light yellow in various colors).
Light phlogopite is transparent and has glass luster; Dark phlogopite is translucent. Glass luster to semi-metallic luster, cleavage surface is pearly luster.
The sheet is elastic and non-conductive. Colorless or brownish yellow under microscope transmission light. Pure phlogopite is a superior insulating material in the electrical industry, and is also widely used in stone paint.
5、 Synthetic micaSynthetic mica, also known as fluorophlogopite, is prepared by crystallization of chemical raw materials through melting and cooling at high temperature. The formula of its single crystal is KMg3 (AlSi3O10) F2, which belongs to monoclinic system and is a typical layered silicate.
Many of its properties are superior to natural mica, such as temperature resistance up to 1200 ℃. Under high temperature conditions, the volume resistivity of synthetic fluorophlogopite is 1000 times higher than that of natural mica. It is characterized by good electrical insulation, extremely low vacuum outgassing at high temperature, and acid and alkali resistance, transparency, strippability and elasticity. It is an important non-metallic insulating material for modern industry and high technology, such as motors, electrical appliances, electronics, aviation, etc.
6、 Mica use
Muscovite is the most widely used in industry, followed by phlogopite. It is widely used in building materials industry, fire protection industry, fire extinguishing agent, welding electrode, plastic, electrical insulation, paper, asphalt paper, rubber, pearlescent pigment and other chemical industries. Ultra fine mica powder can be used as functional filler for plastics, coatings, paints, rubber, etc., to improve its mechanical strength, enhance its toughness, adhesion, anti-aging and corrosion resistance. In addition to its extremely high electrical insulation, acid and alkali corrosion resistance, elasticity, toughness and sliding, heat and sound insulation, low coefficient of thermal expansion and other properties, it is also the first to introduce the characteristics of the second surface of the sheet, such as smooth surface, large diameter to thickness ratio, regular shape, strong adhesion and so on.
In industry, it is mainly used as insulating material for electrical equipment and electrical equipment by its insulation and heat resistance, as well as its acid resistance, alkali resistance, pressure resistance and stripping resistance; Secondly, it is used for manufacturing steam boiler, furnace window of smelting furnace and mechanical parts.
Mica chips and mica powder can be processed into mica paper, and can also be used to replace mica sheets to produce various insulating materials with low cost and uniform thickness.
Medicinal: Mica, sweet taste, mild nature, "This Classic": "It is used to control the skin and muscles of the body, stroke, cold and heat, such as in cars and boats, remove evil spirits, soothe the five internal organs, benefit the essence of children, and brighten the eyes.". "Bielu": "The lower qi strengthens the muscles, continues to eliminate and replenish the middle, cures the five pains and seven injuries, loses less qi and stops dysentery.
Mica has high insulation strength, high resistance, low dielectric loss, excellent dielectric properties such as arc resistance and corona resistance, and good physical and chemical properties such as hard texture, high mechanical strength, resistance to high temperature and rapid temperature change, and resistance to acid and alkali. Therefore, it is widely used in radio industry, aviation industry, motor manufacturing, and also widely used in coatings, paint, plastics, linoleum, paper, oil field drilling In the fields of decoration and cosmetics, it can reduce the damage of ultraviolet rays or other light and heat to the paint film, increase the acid, alkali and electrical insulation properties of the coating, improve the frost resistance, corrosion resistance, toughness and compactness of the coating, reduce the permeability of the coating, and prevent spots and cracks. Mica powder can also be used in roofing materials to prevent rain, keep warm, and insulate heat, etc. Mica powder can be mixed with mineral wool resin coating, and can be used for decoration of concrete, stone, and brick exterior walls. Mica powder is used for asphalt felt, pipe mortar, and cement; In rubber products, mica powder can be used as lubricant, film remover, and filler for high-strength electrical insulation, heat-resistant, acid-resistant and alkali-resistant products. Mica can also be used as mica paper, mica plate, mica ceramic, pearlescent mica pigment, mica melting and casting products, etc.
In industry, it is mainly used as insulating material for electrical equipment and electrical equipment by its insulation and heat resistance, as well as its acid resistance, alkali resistance, pressure resistance and stripping resistance; Secondly, it is used for manufacturing steam boiler, furnace window of smelting furnace and mechanical parts. Mica chips and mica powder can be processed into mica paper, and can also be used to replace mica sheets to produce various insulating materials with low cost and uniform thickness.