Mica, an aluminum silicate mineral with a continuous layered silica-oxygen tetrahedral structure. The characteristics of mica are insulation, high temperature resistance, glossy, stable physicochemical properties, good thermal insulation, elasticity and toughness, but also the performance of being stripped into a transparent sheet with elasticity. It is widely used in building materials industry, fire fighting industry, fire extinguishing agent, welding rod, plastics, electric insulation, paper making, asphalt paper, rubber, pearlescent pigment and other chemical industries.

China's mica resources are not abundant, according to the classification of deposits China's main output pegmatite-type high-quality white mica and metamorphic gneiss fragments of white mica. Pegmatite-type high-quality flake white mica is mainly distributed in Inner Mongolia Tugui Wula, Sichuan Damba, and Xinjiang Altay, this kind of mica itself is limited resources in China and has been basically depleted; metamorphic gneiss fragments of white mica is mainly distributed in the area of Hebei Lingshou, this kind of mica is extremely rich in resources in our country, but this kind of mica can not be used as a high-quality industrial raw materials due to the natural molding reasons, and is mainly used for building materials, fillers. It is mainly used as building materials and fillers.

According to the U.S. Geological Survey (USGS) issued by the U.S. Department of the Interior in January 2013 (U.S. Geological Survey, Mineral Commodity Summaries, January 2013), natural crushed mica, which is mainly used as filler, has a global production of about 1.1 million tons. The global production is about 1.1 million tons, of which mainland China, Russia and Finland have the highest production. China's mainland production of 760,000 tons, accounting for 90.91%; and more industrial value-added flake mica global production of 5,700 tons, of which India's production is the largest, a total of 4,000 tons, accounting for 70.18%, and mainly white mica-based. According to China's survey, the domestic production of 760,000 tons of products in 2011, mainly metamorphic gneiss fragments of mica, accounting for about 95% of the output, the main manufacturers for Hebei Lingshou, Xingtang area, and China's pegmatite-type high-quality white mica has been basically depleted or partially exhausted, so that China's demand for high-quality natural mica are dependent on imports, mainly imported from India, but also India also appeared to be a significant reduction in resources! The situation has impacted the survival and development of downstream industries such as pearlescent pigments, cosmetics, high-end insulation and refractory materials.

In order to solve the contradiction between resource depletion and demand increase, synthetic mica comes into being and will be able to solve this problem well. Synthetic mica is also known as fluorine gold mica. It is made from chemical raw materials by high temperature melting and cooling precipitation, and the molecular formula of its single crystal piece is KMg3 (AlSi3O10) F2, which belongs to monoclinic crystal system and is a typical layered silicate. Many of its properties are better than natural mica, such as temperature resistance of up to 1200 ℃ or more, under high temperature conditions, the volume resistivity of synthetic fluorine mica is 1000 times higher than that of natural mica, good electrical insulation, low vacuum outgassing at high temperatures, as well as acid and alkali resistance, transparency, can be divided into peeling and elasticity, etc., it is an important non-metallic insulating material for the motor, electrical appliances, electronics, aerospace and other important non-metallic insulating materials for the modern industry and high technology. More than 95% of the synthetic mica crystals obtained by endothermic method are small crystals, i.e. synthetic mica fragments, which can be made into a variety of insulating products, such as synthetic mica paper, laminates, mica powder, mica pearlescent pigments and mica ceramics, etc., and are widely used in household appliances and many other industrial sectors.

I. The origin of synthetic mica industry in China.

Domestic synthetic mica and its products technology development began in the late 1950s. 1963, after the establishment of Non-metallic Mineral Research Institute of the Ministry of Building Materials (the predecessor of Sinoma Artificial Crystal Research Institute), it firstly adopted the endothermic method to develop the successful synthetic mica. 40 years, Sinoma Artificial Crystal Research Institute has made 25 scientific research achievements in the field of synthetic mica technology development and popularization, and the technology of domestic growth of synthetic mica crystals of large size has ranked the leading level in the world. The technology of growing large-size synthetic mica crystals in China has ranked the leading level in the world.

Second, the current situation of the development of synthetic mica industry in China.

In the past 20 years, China's synthetic mica industry has formed new independent mica industry categories, including: mica single crystal sheet, mica powder, synthetic mica paper, synthetic mica ceramics, mica tape and other new categories or sub-division of industrial fields.

In terms of synthetic mica single crystal flakes, our country has the leading technology, through the endothermic method and crystal seeding method have grown synthetic mica large crystals, with the maximum area of 560cm2, which is the largest synthetic mica flakes in the world so far. Because the synthetic mica sheet does not contain structural water, the use of temperature far more than natural mica, up to 1100 ℃, is an excellent high-temperature electrical insulating materials, its use is far more extensive than natural mica. In addition to the electronic tube support plate, capacitors, heat-resistant insulating parts, in recent years, the research has also expanded a number of new applications, such as high-temperature and reliable electronic tubes, long-life water level meter, know the resistance of the surface of the thermocouple insulating skeleton, transmitting microwaves, rays, nuclear radiation, such as the window material, night-vision equipment, video screens, electronic probes, fluorescent ray spectrometers and spectroscopic crystal materials, long-wave neutron monochromator, and purification of radioactive wastewater, the new type of Adsorbent and so on.

Synthetic mica powder is divided into dry milling powder and wet milling powder according to the milling equipment and process. The coarse powder of dry grinding powder is mainly used for making low hydrogen or ultra-low hydrogen welding rods, and the fine powder is used for artificial marble, architectural coatings and mold release agents for rubber products. Wet ground mica powder is the base material for making mica beads and light pigmented mica titanium. Mica titanium is mainly used in plastics, paints, high-grade cosmetics and high-grade automobile paints.

Synthetic mica cardboard can be made from synthetic mica fragments as raw material after high-pressure hydraulic pulping and special paper-making machine. Inorganic glued synthetic mica board is temperature resistant to 900°C, smoke-free and odorless under high temperature and environmentally friendly. It is mainly used in electric iron, electric rice cooker, air conditioner, oven and other home appliances and industrial electric furnace, oven and plastic heating ring and other equipment.

Microcrystalline synthetic mica ceramics have the advantages of dense texture, high strength, electrical insulation, high temperature resistance, corrosion resistance, etc., and have been widely used in motors, electrical appliances, instruments, vacuum devices, and high-precision, non-magnetic gyroscope coil skeleton for missiles and rockets.

Fire-resistant mica tape is a fire-resistant material made by bonding synthetic mica paper and other insulating films with silicone resin on a glue dipping machine. It is an indispensable material for fireproof wires and cables.

China's synthetic mica industry after just a few decades of development, as well as the formation of a complete industrial chain and industrial system, synthetic mica products have been widely used in various industrial sectors. According to statistics, in 2011, the output of synthetic mica in China accounted for nearly 90% of the total output of synthetic mica in the world, and China has become the most important market of the global synthetic mica industry.

Problems in China's synthetic mica industry

1. The main problem in the development of synthetic mica market is the toxicity of the products. As the molecular structure of mica will be cracked under high temperature, white mica and gold mica will release the water of crystallization, and fluorine gold mica will gradually release the fluorine examples with nearly 10% of its content. The toxicity and corrosiveness of fluoride ions are extremely strong, and the materials used in fire-resistant cables containing fluoride ions will be hazardous to personal safety. On the surface of the foreign market survey, the international several big mica tape manufacturers are only production of white mica tape and gold mica tape, one of the reasons is that Europe and the United States environmental protection regulations are very strict, to expand the synthetic mica industry is very cautious. Nearly 80% of the synthetic mica produced in China is fluorine gold mica, therefore, the toxicity of synthetic mica has become an important factor affecting its market development.

2, the overall scale of enterprises is small, and the investment in research and development is insufficient. China's synthetic mica industry out of a few leading manufacturers, most of the manufacturers in the industry belong to small and medium-sized enterprises, small production scale, weak financial strength, product production technology is mainly through the technology transfer of scientific research institutions to obtain, most of the enterprises lack of their own scientific research team and scientific research strength.

3、Research on the application of synthetic mica is relatively backward. At present, China's research on the application of synthetic mica is still very backward, basically staying in the imitation stage. For example, the synthetic mica powder produced by dry method in China is mainly used for special welding rods, while in foreign countries, it is widely used, such as plastic parts in automobiles, tires, televisions, computer housings and so on.

Fourth, the future development trend of China's synthetic mica industry

1、Increase investment in scientific research to expand the reference field of synthetic mica. At present, color mica, water-expanded mica and large motors are in urgent need of high-temperature heat-conducting mica and other new varieties of development as well as to become the leading direction of the future technology research and development of the synthetic mica industry.

2, synthetic mica and its products to choose cheaper chemical raw materials, reduce production costs, improve price competitiveness, to be market-oriented, around the market demand for new technology process product innovation.

China's synthetic mica industry after more than 40 years of development, especially in the last 20 years on the synthesis of fluorine gold mica to increase R & D efforts, has now taken shape. Domestic fluorine gold mica crystal growth and system R & D has independent R & D strength, has developed products have been widely used in national defense, industrial appliances and civil appliances and other fields. With the accelerated pace of globalization of the world economy, the consumption of high-quality natural mica mineral resources is also accelerating. The replacement of natural mica by synthetic mica has become the trend of the future development of the industry. Domestic synthetic mica enterprises should be based on the existing scale, and urgently need to increase investment in research and development, in the development of more synthetic mica new products at the same time efforts to broaden the application of synthetic mica, the industry bigger and stronger, and walk in the forefront of the world.