Mica use and technical and indicators

Sheet mica is generally used for electronic tube sheets and capacitor sheets for the radio industry, mica sheets for motor manufacturing, various specifications for use in household appliances, telephones, and lighting. Broken mica can produce a variety of mica paper, used as insulation material, widely used in the electrical industry; production of various mica powder, mostly used in linoleum roofing materials, also used in cable wrap and electrode production; also used in the production of mica ceramics Mica fused cast products, mica reinforced plastics, pearlescent pigments and new mica building materials.
The primary raw material used in industry is called industrial raw material mica, which refers to the raw ore mined by the mine. The mica block with both sides flattened and the effective area is greater than or equal to 4cm 2 obtained through preliminary mineral processing . Industrial raw material mica appearance quality conditions: cracks, perforations, bonds, wrinkles, inlays, continuous biological and feathery stalk layers are not allowed in the effective area, and weathered mica with complete loss of elasticity and flexibility is not allowed; mica crystals Mica fragments that are easy to fall off are not allowed, and non-mica minerals and full-chip biotite coatings are not allowed on the surface of the crystal; non-mica minerals on the edges of mica crystals, not more than 3 mm in the radial direction, non-mica minerals with concave angles The depth shall not exceed 7mm; the maximum thickness of the thickest side of the wedge-shaped mica shall not exceed 10mm; the thickness of the plate-like mica crystal is not limited.
The industrial raw material mica is divided into the following inscribed rectangles of the largest effective area of either side according to the mica crystal: special, I, II, III, IV5, and divided into two grades according to the proportion of the effective area of the spots. Mica sheet processed with industrial raw material mica into a thickness of 0.1 to 2 mm and an effective area of 4 cm 2 or more is called thick mica. According to the appearance quality and use, it is divided into special grades A, B, C and 4, according to the maximum within the film. The area of the inscribed rectangle is divided into 9 models. The thick mica is further stripped and processed into thin mica. A representative sample shall be selected for electrical performance testing and the breakdown voltage shall not be lower than the relevant requirements.
The broken mica is the general term for the fine mica produced and the waste residue after processing and stripping. According to the professional standard ZBQ-6303-87 of the People's Republic of China, according to the requirements of use, the broken mica is divided into three categories: I, II and III. Class I is used to make non-calcined powder mica paper; Class II is used for making calcined powder mica paper, and Class III is used for grinding mica powder. The quality indicators should meet the requirements of the following table.



Other requirements for various fine products of fine mica raw materials are summarized as follows:
The technical requirements of mica paper for pulping mica scales: the thickness of the scale should be micron or thinner, the thickness of each piece should be uniform, the diameter of the scale should be larger than the thickness, generally should be greater than 50, better than 100, but should meet different The requirements for soaking, mica scales are uniform in size, with few surface defects, clean and pure.
Requirements of mica powder for natural mica ceramics (mica glass): mica powder is white, moisture is less than 1.5%, magnetic content is less than 0.02%, pH is 7.0-8.0, sand content is less than 0.1%, and HCl soluble content is less than 4. %.
Synthetic mica ceramics (mica plastic) requirements for mica powder: mica powder greater than 98%, glass phase less than 0.8%, carbide less than 0.02%, olivine, mullite less than 0.5%, Fe, Ca impurities less than 0.2%, other Less than 0.2%.
Mica ceramics have certain requirements on the particle size of mica powder due to the different molding processes. Generally, the mica powder used in hot press forming is mainly -60+120 mesh. The mica powder used for die casting is mainly -80+120 mesh.
Sericite is a subspecies of densely packed microcrystalline aggregates of muscovite. It can be stripped into pole pieces with a thickness of 1 μm or less and used as a filler and oil drilling mud. There is currently no uniform requirement for its quality. Generally, the fineness is 0.2 to 1 μm for papermaking filler, 20 to 200 mesh for plastic filler, and 160 to 250 mesh for rubber filler. For ceramic batching, high whiteness and good plasticity are required; in coating, it is required to have Fine fineness, heat resistance is not less than 500 °C.