The main producers of mica in the world are India, the United States, South Africa, Brazil, Madagascar, Canada, Argentina and Russia. Indian mica deposits are distributed in the northeast, northwest and east of India, and there are mainly four pegmatite zones. The age of pegmatite formation is 850 ~ 265438±000Ma. India's muscovite is famous for its quality and quantity, and three-quarters of the world's high-quality muscovite comes from India. American mica is mainly distributed in the southeastern States, producing many series of fine mica, but less high-quality mica. Madagascar and Canada are rich in phlogopite. Russian muscovite deposit is mainly distributed in the Mantua and Biliusa ore belts in Irkutsk. It is reported that thousands of pegmatite dikes containing industrial mica have been found in Mam-Chua area, and there is a phlogopite deposit in Kovdor area of kola Peninsula, where vermiculite is mined in the upper part of the deposit.
In mica application, flaky mica is generally mainly used in electrical and electronic industries. With the development of science and technology, mica consumption structure has changed. It is estimated that the world demand for crushed mica will continue to grow at an average annual rate of 65,438+0.5%. For example, in the United States, the consumption of broken mica accounts for 70% ~ 80% of the total consumption of mica, and stripped mica only maintains its traditional market. It can be seen that in the future, crushed mica will be mainly produced, with broad development prospects and expanding application fields. For example, building materials, ceramics, paint, rubber, plastics and other departments will use a large number of broken mica.
The United States and South Africa are the largest producers of vermiculite in the world. According to the statistics of 1985, the output of vermiculite in these two countries accounts for about 93% of the world's output. American products are mainly produced and sold, while South African products are mostly sold to Europe.
China is one of the few countries with rich mica resources in the world. There are 24 mica mining areas/kloc-0, distributed in 18 provinces and regions. Industrial raw material mica is mainly concentrated in Xinjiang, Sichuan and Inner Mongolia, accounting for 87.4% of the country's total reserves. It is a large mica mining base in China. Since the 1970s, the output of flaky mica in China has generally declined, and the broken mica has increased from dozens of tons to thousands of tons. In recent years, mica processing products have developed rapidly and gradually formed a series, which can produce nearly 30 varieties in 6 categories, including mica flakes, mica powder, mica paper, mica capacitors, mica insulation products and mica electric heating elements. At present, mica paper products have all varieties corresponding to flaky mica products. In the motor industry, mica paper mostly replaces flaky mica. Mica manufacturing technology keeps pace with large-scale integrated circuits, high-temperature plastics and optical fibers, and is considered to be one of the four major technologies that have contributed to the contemporary electrical and electronic industry abroad. With the development of China's motor, electronics and household appliances industries, the demand for mica insulation materials will increase rapidly, and China's mica industry will surely have greater development. Therefore, in order to adapt to the product structure adjustment of mica industry and promote its better development, we should pay attention to: ① strengthening mica geological work and actively searching for new mica deposits; (2) Pay attention to strengthening the research on efficient recovery mining method of mica, carry out research on mineral processing technology and new mineral processing equipment, and try to choose mica as much as possible; ③ Actively develop new products, such as mica paper products, mica powder, mica ceramics, reinforced plastics and pearlescent pigments. Another example is the ultra-fine muscovite powder product developed by Furong Mining Company in Jurong County, Jiangsu Province, which can be used as additives and fillers in coatings, plastics, rubber, paper making and other industries.
Vermiculite is mainly distributed in the United States, South Africa and Russia. There are few vermiculite resources in China, and their distribution is unreasonable. The known reserves are about 2000× 105t, accounting for 5% of the world's total reserves. Because the application research of vermiculite started late, the domestic demand is very small (about 1× 104t/a), and the raw vermiculite ore is mainly used for export. In the long run, vermiculite should be mainly used in China. It can be predicted that vermiculite resources are far from meeting the needs of future construction. Research on developing new products should be strengthened to make full use of them.