Mica is a rock-forming mineral with a hexagonal flaky crystal. One of the main rock-forming minerals. The characteristics are insulation, high temperature resistance, and the most used in industry is sericite , which is widely used in coatings, paints, electrical insulation and other industries. The mica mine mainly includes biotite , phlogopite, muscovite , lithium mica, sericite , green mica , iron lithium mica, etc. The lapis lazuli is a mixed mineral of mica and quartz . The most widely used in industry is muscovite and phlogopite, which is an important mineral raw material for the extraction of lithium. Mica mines are widely found in Asia, Africa, and the Americas, but rarely in Europe. Until the 19th century, mica was of high value in Europe. As the colonists mined mica in Africa and South America, prices fell rapidly. Muscovite is the most used in industry, followed by phlogopite, which is widely used in the chemical industry such as building materials industry, fire protection industry, fire extinguishing agent, welding electrode, plastic, electrical insulation, paper making, asphalt paper, rubber and pearlescent pigment. Mica is an aluminosilicate mineral with a continuous layered siloxane tetrahedral structure. Divided into three sub-categories: muscovite, biotite and lithium mica. Muscovite includes muscovite and its subspecies (sica mica) and less common sodium mica; biotite includes phlogopite, biotite, iron biotite and manganese biotite; lithium mica is a variety of mica rich in lithium oxide Small scales. Muscovite and phlogopite are commonly used in industry, especially in the electrical industry. The chemical formula of mica is KAl2[AlSi3O10][OH]2, of which SiO245.2%, Al2O338.5%, K2O11.8%, H2O4.5%, in addition, a small amount of Na, Ca, Mg, Ti, Cr, Mn, Fe and F, etc. The chemical formula of phlogopite is KMg3[AlSi3O10][F,OH]2, of which K2O7~10.3%, MgO is 21.4~29.4%, Al2O3 is 10.8~17%, SiO2 is 38.7~45%, H2O is 0.3~4.5%, Contains a small amount of Fe, Ti, Mn, Na and F, and the like. Most of the mica are monoclinic crystals, which are in the form of stacked plates or book-like crystals. The well-developed crystals have hexagonal or hexagonal shapes with six crystal faces, sometimes forming pseudo hexagonal columnar crystals. Mica has a perfect cleavage and can be stripped. In theory, the muscovite can be peeled and divided into about 10, and the phlogopite can be peeled into pieces of about 5 or 10. The hidden cleavage of mica crystals is the imagery and compression. Muscovite flakes are generally colorless and transparent, but are often dyed in shades of green, brown, yellow and pink; the glass is glossy and the cleavage surface is pearly. Phlogopite is usually yellow, brown, dark brown or black; glass luster, cleavage surface is pearl or semi-metallic luster. The transparency of muscovite is 71.7~87.5%, and the phlogopite is 0~25.2%. The Mohs hardness of muscovite is 2~2.5, the phlogopite is 2.78~2.85; the elastic coefficient of muscovite is (1475.9~2092.7×106Pa(15050~21340kg/cm2), and the phlogopite is (1394.5~1874.05)×106Pa(14220) ~19110kg/cm2). First, industrial use The main use of the main use in the industry is muscovite, followed by phlogopite. It is widely used in the building materials industry, fire protection industry, fire extinguishing agents, welding electrodes, plastics, electrical insulation, paper, asphalt paper, rubber, pearlescent pigments and other chemical industries. Ultrafine mica powder is used as a functional filler for plastics, paints, paints, rubber, etc., which can improve its mechanical strength, enhance toughness, adhesion, anti-aging and corrosion resistance. In addition to its high electrical insulation, acid and alkali corrosion resistance, elasticity, toughness and slidability, heat-resistant sound insulation, small thermal expansion coefficient, etc., it is also the first to introduce a smooth surface, large diameter-to-thickness ratio, regular shape, and attached Strong and other characteristics. Second, mica medicinal Mica, sweet, flat, the main muscles do not feel like a dead person. Injury to the wind and evil and cold and hot, like the body sitting on the boat, dizziness, with the wind and evil spirits, enriching the five internal organs, increasing fertility, making the eyes bright, long-wearing body light and smart, extending life. Also known as Yunzhu, Yunhua, Yunying, Yunshui, Yunsha, Phosphate, produced in the depths of the mountains. China's mica minerals are unevenly distributed, although there are distributions in 20 provinces, municipalities and autonomous regions across the country, but most of them are concentrated in Xinjiang, Sichuan and Inner Mongolia. The country has found the origin 184, in Xinjiang 88, accounting for 67% of reserves, at Sichuan 27, accounting for 11.4% of reserves; at Inner Mongolia, 15, accounting for 8.6% of reserves; the remaining 54, the country's total reserves of 13 %, distributed in Hebei, Shanxi, Liaoning, Jilin, Heilongjiang, Shandong, Henan, Yunnan, Tibet, Qinghai and Shaanxi. 1. Type of deposit Industrial mica deposits are divided into two major categories: muscovite deposits and phlogopite deposits. Each category can be divided into two sub-categories, in addition to fine mica ore. Muscovite and phlogopite deposits : ( 1) Granite pegmatite type muscovite deposit The ore deposits are prolific in the amphibolite facies metamorphic rocks, and the mica-containing pegmatite veins are generally developed with mixed lithology and granitization . The surrounding rocks are various aluminous and silicon-rich gneiss , granulite or schist. The veins often appear in groups, forming a pegmatite belt or a pegmatite field. According to the structure and ore-bearing properties of pegmatite, it can be divided into: 1 crystal type muscovite pegmatite: the muscovite in the vein is giant crystal, the piece is large, the area can reach 60-100cm2, and a large piece of white cloud can be obtained from it. Mother, and the mica flakes have good stripping performance; 2 meta-different type rare metal muscovite pegmatite: mica crystals are generally small, but the transparency is good, the impurity content is low, and the associated rare element minerals such as beryl , tantalite, niobium, tourmaline, lepidolite, etc. can utilization. The muscovite deposits of industrial value in the world are basically produced in the above two pegmatites. (2) Pegmatite contact metasomatic magnesia-silica muscovite deposit China's magnesium-silica muscovite K2{(Fe2+Mg)(Fe3+Al)3[Si7AlO20](OH)4} deposit is located in the East China Sea. The deposit is endowed with a deep fault zone and a metamorphic rock zone produced by eclogite. Magnesia-containing silicon muscovite pegmatite veins are produced in eclogites, hornblende schists and gneiss. But the main industrial ore bodies are produced in eclogites. The electrical properties of magnesium-silica muscovite fully meet the industrial requirements, adding a new industrial mica species to China. (3) Magnesium carbonate skarn type phlogopite deposit The deposits are mostly distributed in the crystalline schist , gneiss and marble of the Archean , Proterozoic or Paleozoic . The development of granite in the mining area is often accompanied by a series of complex rock masses, such as the stellite-diopside rock, diopside-golden mica rock. Many deposits of this type, such as Datong, Tonghua, many mining town square and Inner Mongolia belong to this type. (4) Ultrabasic-alkaline complex type phlogopite deposit The deposit is produced in an ultrabasic-alkaline complex. The area of ​​the complex rock is from tens to more than a thousand square kilometers and has an annulus structure. The scale of this type of deposit is large, the phlogopite can reach several million tons, the ore ratio is high, the mica content per cubic meter can reach several hundred kilograms to one ton, and the mica wafer area can reach 5-6 m2. Deposits formed due to hydration of the upper portion of vermiculite, may also be exploitation. This type is a newly discovered phlogopite deposit, which has high industrial utilization value from the perspective of phlogopite reserves, scale and prospects. In the former Soviet Union, it has become an important source of phlogopite, but so far, this type of phlogopite deposit has not been discovered in China. Broken fine mica deposit: (1) Muscovite potassium feldspar gneiss type muscovite deposit There are four layers of ore in the coarse-grained shallow-grain and black-cloud two-long gneiss in the Baiyun potassium gneiss. The average thickness is 1.6m, the ore-bearing rate is 56~68%, and the film diameter is generally less than 10mm. About 5mm. (2) Mica schist type mica deposit Occurred in the mica schist. (3) Mica pegmatite type mica deposit The pegmatite has been weathered, and the content of muscovite in the ore is 14-16%. Other minerals include quartz, feldspar and biotite. Mica mining for the electrical industry must be a mica block with an effective area of ​​more than 4 cm2 and no cracks or perforations. The non-mica minerals on the edges must not exceed 3 mm. After mica mining, the quality is divided into four categories according to the effective area, and the best special type area is larger than 65 square centimeters. The industry mainly uses mica natural crystals directly to process the desired products. The larger the mica crystal without defects, the higher its economic value. Therefore, in the process of beneficiation of mica ore, it is necessary to protect the natural crystals of mica from damage as much as possible. For the beneficiation of mica with a crystal contour area larger than 4 cm, it is mainly based on the difference in shape and friction coefficient between mica crystal and gangue. The commonly used methods are hand selection, friction selection and shape selection. For the crushed mica with a crystal contour area of ​​less than 4 cm, it is mainly sorted according to the difference between its physical and chemical properties on the surface of the gangue . The method used is flotation. (1) Slice mica beneficiation method and its process a, hand selection Workers select the mica that has been separated by monomer on the mining face or the pit ore heap; the mica and the gangue are broken by hand hammer, and then the mica is selected. b, friction dressing The mica crystal and the gangue are separated according to the difference between the sliding friction coefficient of the slab-shaped mica crystal and the rolling friction coefficient of the spheroidal gangue. One of the devices used is a swash plate sorter. The machine is composed of a set of metal slanting plates, each of which has a length of 1350 mm and a width of 1000 mm, and the inclination angle of the next inclined plate is greater than the inclination of the upper inclined plate. A slit for collecting mica crystals is left at the lower end of each swash plate, and the width thereof is sequentially decreased in the order of slanting plates. The front edge of the slit is equipped with a triangular raft. During the sorting process, the large gangue rolls down to the stone pile; the mica and the smaller gangue block are blocked by the raft, and the sloping plate is dropped through the gap. The above process is repeated on the swash plate in turn to gradually separate the mica from the gangue. The friction beneficiation process and equipment are not perfect, so this method has not been widely used in mica ore dressing. C, shape dressing According to the shape of the mica crystal and the gangue, the ability to pass through the sieve slit and the sieve hole in the sieve is different, and the mica and the gangue are separated. When sorting, a sieve having two or more different sieve surface structures is used, generally the first sieve mesh is strip-shaped; the second sieve mesh is square. When the ore enters the sieve surface, due to vibration or rolling action, the flaky mica and small gangue can leak from the strip sieve to the second sieve; because the second layer is sieve, the gangue can be sieved. Lower flaky mica. The shape beneficiation method has the advantages of simple process, less equipment, high productivity, good sorting effect, etc., and thus has been widely used in mica mines . Mica broken process a, flotation Sorting according to the difference in surface physicochemical properties of mica and gangue. The ore is broken and ground to dissociate the mica monomer. Under the action of the agent, the mica becomes a foam product and is separated from the gangue. Mica flotation can be carried out in an acidic or alkaline slurry, and the long carbon chain amide cations and fatty acid anions are mica collectors . In the mica flotation process, three rough selections and three selections are required to obtain the mica concentrate. Therefore, mica ore float is used to recover mica and fine-grain mica below 14 mesh in pegmatite and mica schist. In China, mica ore flotation has not yet been produced and applied. B, wind selection Mica wind selection is mostly achieved through special equipment. The process is generally: crushing→sieving classification→wind selection. After the ore is crushed, the mica is basically formed into a flaky shape, and the gangue mineral feldspar, quartz and the like are in the form of massive particles. Accordingly, the multi-level grading is used to pre-divide the selected materials into narrower granules, and according to the difference in the levitation speed in the airflow, special air-conditioning equipment is used for sorting. The wind selection method is applicable to areas where water is scarce and has been used for actual production. After the raw ore is manually sorted out of large mica, it is fed into the concentrating plant to fix the rod sieve, and the size of the sieve is 100mm. After the +100mm material is broken into the jaw crusher , it will enter the XB-602 vibrating screen sorting together with the product under the bar screen. The sieve has two layers of sieves, the upper layer is a bar sieve made of angle steel, the sieve width is 20 mm; the lower layer is a 20×20 mm square hole sieve, and after sorting, three kinds of products are obtained: materials larger than 20 mm sieve size, Mica and Liansheng body were selected from the hand, and the mica of more than 4cm2 was manually picked up by artificial crushing; the materials of less than 20mm sieve joint and larger than 20mm square mesh were also selected from the middle of the hand, and the artificial body was broken. After that, mica larger than 4cm2 is sorted; materials smaller than 20mm square mesh are all discarded as tailings. The beneficiation process consists of two parts: re-election and flotation. The re-election uses the Humphrey spiral concentrator. The purpose is to remove coarse tailings. The selected coarse concentrate is re-elected into the flotation. Three mixing tanks are used before flotation. The first mixing tank is added with lignosulfonate (or sodium silicate ) to disperse the slime, and then the sodium carbonate is added to adjust the pH of the slurry to about 10; the second blending tank is added with the fatty amine acetate cation collector to make It interacts with the side of the muscovite and adsorbs it; the fat in the third blending tank is added with the amine acetate salt cation collector, so that it absorbs with the muscovite layer, and then the foaming agent is added. After a rough selection three times, the mica concentrate is obtained. The mica concentrate has a grade of 98% and a recovery rate of 85%. (4) Mica is mainly crystallized into monoclinic crystals. The crystals are pseudo-hexagonal flakes, scales, plates, and sometimes pseudo-hexagonal columns. Hardness 2~3, specific gravity 2.70~3.20. Mica powder has unique acid and alkali resistance chemical stability , heat resistance and non-combustibility, and good insulation. It is increasingly used in international and domestic markets. Can be used in the building materials industry instead of asbestos products. The industry mainly uses its insulation and heat resistance, as well as acid, alkali, pressure and strip resistance, as insulation materials for electrical equipment and electrical equipment; secondly, it is used to manufacture steam boilers and smelting furnaces. Windows and mechanical parts. Mica crushed and mica powder can be processed into mica paper, or it can replace various mica sheets to produce various low-cost, uniform thickness insulation materials. The physical properties of mica mainly depend on the size of mica crystals, the stripping properties determined by cleavage and hardness, and the color transparency and elasticity of mica. Industrial mica is mostly in the form of a plate or a book-like crystal, and the crystals vary in size from a few millimeters to several tens of centimeters. Generally, as long as the effective area of ​​the crystal is greater than or equal to 4 cm2, it has direct use value. Of course, the larger the crystal area, the higher the value. The stripping performance of mica is determined by the cleavage and hardness of mica. Mica's unique crystal structure gives it a very complete set of bottom cleavage, which is an important property of industrial mica technology processing and stripping. In theory, muscovite can be stripped to about 10, and phlogopite can be stripped to about 5-10. Therefore, muscovite and phlogopite can be stripped of flat sheets of any thickness according to industrial requirements to meet the mica of electrical and electronic industries. Requirements. The hardness of mica is low, the muscovite is 2-2.5, the magnesia-silica muscovite is 2.37, and the phlogopite is 2.78-2.85. The harder the mica is, the more difficult it is to peel. Muscovite and magnesium-silica muscovite have better stripping performance, and phlogopite is slightly worse. Mica color characteristics used to characterize the mica insulation properties, light industrial muscovite mica generally is better, phlogopite, followed worst insulation biotite. Muscovite has a modulus of elasticity of 15346-21760bar and phlogopite of 14500-19480bar. When industrial mica is used as an insulating material, its elasticity is strictly required. The advantages and disadvantages of mica insulation performance are the most important factors determining the value of industrial use. The mica insulation performance is determined by the electrical properties of mica. The electrical properties of mica are determined by testing the breakdown voltage and breakdown strength. According to the test results of mica in various mining areas in China, when the mica sheet thickness is 0.015 mm, the average breakdown voltage is 2.0-5.7 kV, and the breakdown strength is 133-407 kV/mm. When some muscovite in China is heated at 100~600 °C, the elasticity and surface properties are unchanged; after 700~800 °C, the dehydration, mechanical and electrical properties are changed, the elasticity is lost and becomes brittle; at 1050 °C, the structure damage. When the phlogopite is around 700 °C, the electrical performance is better than that of the muscovite. (4) Mechanical strength and density Project Muscovite phlogopite mechanical tensile 166700 ~ 353039 (1700 ~ 3600) 156906 ~ 205939 (1600 ~ 2100) Strength and compression 813951 ~ 1225831 (8300 ~ 12500) 294199 ~ 588399 (3000 ~ 6000) kPa Shear 210843 ~ 296063 (2150 ~ 3019) 82768 ~ 135332 (844 ~ 1380) Density, g/cm 3 2.7 ~ 2.88 2.7 ~ 2.9 Note: The unit of the number in brackets is kg/cm 2 . Although China has known and utilized muscovite and phlogopite very early, the formal exploration of mica deposits was carried out in 1952 after the establishment of the People’s Republic of China, and successively carried out on the muscovite deposits in Danba, Sichuan and Tuguiwula, Inner Mongolia. The census exploration has achieved good results. In 1958, the National Mica Conference was held in Shanxi Province, and it was decided to vigorously carry out the census exploration work of Mica. In the same year, the discovery of the Altaytai Mica deposit in Xinjiang played a major role in the development of mica resources in China, and also as a survey of mica deposits. Exploration work has accumulated experience. Subsequently, the discovery of the Magnesium-silica muscovite deposit in the East China Sea was used by the industry to add new industrial mica species to China. Mica deposits in Wulashan, Dabieshan, Qinling, Liaoning, Sichuan and Yunnan in Inner Mongolia have been discovered successively, expanding mica resources. Since the 1980s, building materials, geology and mining departments have carried out a survey of crushed mica and sericite mines. After detailed investigation, the mined mica mine in Shanmenkou, Tanzhuang Township, Lingshou, Hebei Province was discovered, and sericite deposits were discovered in Inner Mongolia, Liaoning, Hubei and other places. Progress has also been made in industrial application research of crushed mica and sericite. In the 1950s to the mid-1970s, China listed muscovite and phlogopite as strategic resources. The earliest mining was the Sichuan Danba mica mine. Later, Xinjiang, Inner Mongolia, Shanxi, Hebei, Shandong, Henan, Shaanxi, Yunnan, etc. The mica mines in the provinces and autonomous regions are successively mined. The main state-owned mines include Xinjiang Altay, Sichuan Danba, Inner Mongolia Tuguiwula and other mines, as well as hundreds of county offices, townships and individual mines. Before 1978, the annual output of industrial raw material mica was 1700~2500t. After 1978, the output decreased year by year due to the fundamental changes in the consumption structure of mica. a. Low comprehensive utilization rate: comprehensive utilization of mica, foreign countries have achieved no waste in the factory, and 100% of raw materials are used. The comprehensive utilization rate of mica in China is about 40%, and it is still necessary to expand its application fields. b. The application field is narrow: In recent years, the field of comprehensive utilization of foreign mica has been expanding, and it has achieved good applications in the fields of building materials, earthquake resistance, lubrication, organic and inorganic composite materials, and sealing materials. There are 10 categories and more than 100 varieties of products processed comprehensively. China's application field is relatively narrow, and now it can produce 6 categories, nearly 30 varieties. Strengthen technical research, improve comprehensive utilization rate and continuously expand application areas, and broaden the market. development trend From the general trend, due to the success of synthetic crystal mica crystals, the demand for large mica in the world will gradually decrease, so the exploitation of natural large mica will decrease year by year. However, the demand for debris mica will continue to increase. The existing high-quality mica in the world is still far from meeting the needs, and the development of synthetic mica is accelerating. The current consumption structure of mica has changed. It is estimated that the demand for mica in the world will continue to decline at a rate of 4.6% per year, while the demand for broken mica will continue to grow at an average rate of 1.5% per year. Mica comprehensive utilization products----mica paper and wet-milled mica powder and mica deep-processing products are all relatively popular products on the international market. Nowadays, the demand for domestic sheet mica will decrease year by year, the demand for tube feeding mica will be balanced, and capacitor chips and other thick mica will be basically saturated. Natural flaky mica is generally replaced by alternative materials. However, as a comprehensive utilization product of mica, mica paper and mica powder as well as deep-processed products such as mica insulation products and mica paper appliances have begun to sell well. (1) The mica paper market machinery department has long determined that mica insulation materials for motors mainly use mica paper instead of mica flakes. In 1987, China's new power generation equipment capacity was 9.2 million kilowatts. It is usually calculated by adding 5 tons of mica paper to the newly added capacity of 100,000 kilowatts. It requires about 460 tons of mica paper. China's energy industry is the focus of development in the future. During the "Seventh Five-Year Plan" period, it is planned to reach a capacity of 10 million kilowatts of generating units per year. The annual requirement for mica paper is not less than 500 tons, and a total of more than 2,500 tons is required. In addition, in 1987, China's power generation installed capacity has reached 100 million kilowatts. If 20-30% replacement maintenance is considered, the mica paper required for maintenance is also considerable. In addition, there are a large number of industrial and household appliances that also require a large number of products such as insulating cardboard . The domestic mica paper market is promising. (2) The production of mica powder in the national electric welding rod requires about 15,000 tons of mica powder per year, 140,000 tons of mica powder for linoleum paper, 2,000 tons of mica powder for fire-fighting equipment, plus the newly developed mica powder application field, from development In the trend, the demand for mica powder may increase further. Pin Brazing,Pin Brazing Machine,Pin Brazing Equipment,Pin Brazing Kit CHANGZHOU JINDA WEDLING CO.,LTD , https://www.jd-welding.com Species introduction
Mineral characteristics
The main purpose
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The beneficiation of mica ore is the enrichment process of raw mica . Raw mica refers to mica crystal of any thickness in the original ore with a contour area greater than or equal to 4 cm2. The amount of raw mica in raw ore is called the raw mica mineralization rate, which is usually expressed by the weight of raw mica contained in the unit ore volume (kg/m3). The ratio of the total weight of raw mica in the concentrate obtained from the ore dressing to the total weight of the raw mica contained in the ore is called the recovery rate. Production example
Process characteristics
Physical properties
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Heat resistance
develop and use
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