Mica: High-Performance Temperature-Resistant Filler
A short overview of the mineral Mica
Mica is a group of silicate minerals characterized by their distinctive layered structure. These layers are composed of thin, flat sheets that can be easily split and can vary in color, degree of transparency, and chemical composition. The most common types of mica include muscovite, biotite, and phlogopite, though it should be noted that muscovite is known for its transparent properties, while biotite and phlogopite are often darker and opaque.
light muscovite mica
dark phlogopite mica
Technical Properties
• Density: 2.85 g/cm³
• Hardness: 2.5 (Mohs scale)
• High resistance to high temperatures
• Low oil absorption
• High aspect ratio (1:30)
• Lamellar-shaped particles
• pH value: 9.5
• Thermal expansion coefficient of muscovite: 7*10-6/K
• Thermal expansion coefficient of phlogopite: 27*10-6/K
Chemical Formula of Mica
Muscovite: Kal2[AlSi3O10](OH)2
Phlogopite: K(Mg,Fe2+)3[AlSi3O10](OH)2
This chemical difference is important to determine the color and the physical properties of mica.
Mineralogy: Phyllosilicates
The crystal structure of mica belongs to the group of phyllosilicates and is characterized by regular layering. This structure allows mica to easily split and form thin, transparent layers. Mica exhibits a variety of colors and degrees of transparency, ranging from light, translucent tones to dark, opaque variations.
The industrial use of mica requires elaborate processing, which includes crushing, separation with hydrocyclones, flotation, as well as drying and grinding.
Mica of HPF: High-Quality Products
Our Mica – An Important Raw Material for Polymeric Applications
Today, mica plays an important role in many industrial sectors. Its fields of application are wide-ranging; from insulating and building materials to cosmetic products. The usage of mica is extremely varied and extends across different fields and application areas:
Plastics:
Polyamide 6 and Polyamide 66 are the most widely used technical plastics worldwide. They are utilized for their high heat resistance, high hardness, and rigidity. Thanks to the use of mica, it is possible to produce large, low-deformation, and high-temperature-resistant parts for automotive applications (e.g., engine covers). In this case, light parts are often reinforced with muscovite and darker ones with phlogopite.
The use of TREMICA® muscovite and TREFIL® phlogopite, surface-modified and lamellar-shaped, influences the mechanical and thermal properties of the polyamide compound in various cases:
• Improved shrinkage isotropy• Significant reduction in shrinkage
• Reduction in warpage sensitivity
• Increased tensile strength and tensile modulus
• Increased rigidity while maintaining toughness
Paints and Coatings:
Mica fillers are also used in various paints and coatings:
- In silicate paints to improve durability and gloss
- In dispersion-based paints and plasters for external applications to prevent cracking
- In anti-corrosion coatings as an adhesive and barrier filler
- As a matting agent in powder coatings
- In high-temperature coatings due to their high heat resistance
- In decorative paints to achieve an attractive appearance
Cosmetics:
In addition, mica is used in decorative cosmetics to give products such as eyeshadows and lipsticks a sparkling effect.
Production of Mica
The production of mica is a complex process divided into various stages. Initially, the mineral is extracted from deposits. Subsequently, it is crushed and ground to reduce particle size. After crushing, the mica is separated from other minerals, often using hydro cyclones. In a flotation process, it is suspended in water, allowing mica particles to rise to the surface and be collected. After flotation, it is dried and ground to achieve the desired particle size. Depending on the intended use, the mica may undergo surface treatment. After that, it is ready for use in various applications.
Occurrence and Extraction of Mica
Mica is a common mineral found in various geological formations. It is a component of igneous, metamorphic, and sedimentary rocks. Muscovite is particularly common in quartz-rich granites or pegmatites. Additionally, muscovite is also found in metamorphic rocks such as phyllite. Due to its extraordinary weather resistance, muscovite can even be found in sedimentary rocks such as sandstone. In contrast, biotite alters much more easily and is mainly found in granites or diorites.
The extraction of mica takes place in several countries, with the main producers being the United States, India, and China. In particular, the Indian states of Jharkhand, Bihar, and Rajasthan have significant mica deposits, but it is also extracted in Europe. The extraction occurs in open-pit or underground mines, depending on the geological formation of the deposit and local conditions. Various methods are used, such as blasting and mechanical or manual extraction.
History of Mica
The term "mica" is first mentioned in 1546 and dates back to the German mineralogist Georgius Agricola (1494-1555), who listed the term in his work "De Natura Fossilium Libri X." The term "mica" comes from Latin and translates to "sparkle" or "shine."
Information on Other Industrial Fillers
Use our information guide to receive more details on other fillers for industrial purposes. We are also happy to provide you with further information personally.
FAQ
What properties does mica have?
Mica is a group of phyllosilicate minerals that are distinguished by their perfect cleavage into thin, flexible sheets. They have a low hardness of 2-4 on the Mohs scale and vary in color from white to brown to black. Micas are thermal and electrical insulators, heat-resistant, and chemically inert.
How you can use mica?
Thanks to its properties, mica finds multiple applications. In the electrical and electronics industry, it is used as an insulating material in capacitors, resistors, and as support for heating wires. In the construction industry, mica serves as an additive in paints and coatings to improve durability and gloss. Additionally, it is used in cosmetics to give products such as eyeshadows and lipsticks a shimmering effect.
What benefits does mica offer?
The effectiveness of mica in these applications is based on its high heat resistance, excellent insulating capabilities, and optical properties. In electronics, it ensures safety and efficiency by acting as an insulator for electrical components. In paints and coatings, mica improves durability and gives a characteristic shimmer. In cosmetics, it provides shine and transparency to products.
How is mica produced?
The production of mica-based products begins with the extraction of the mineral from deposits, followed by crushing and grinding to reduce particle size. Subsequently, the mica is separated using hydrocyclones and suspended in water in a flotation process to obtain pure mica particles. After drying and further grinding, surface treatment may be carried out depending on the intended use, before the mica is used in various applications.
MORE INFORMATION?
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