Refractory mica

Mika

Mica is a group of minerals containing potassium, water, aluminum silicate, manganese, and iron. Mica, a type of phyllosilicate, has a two-dimensional crystal plate or structure that provides a clear, elastic surface. Among the major minerals that make up rock, mica are found in all three major rock types, namely igneous, sedimentary, and metamorphic. The presence of abundant silicon oxide in mica adds many capabilities to it; Including elasticity and hardness, even at high temperatures. Mica is also considered as an insulator.

Out of 28 different species of mica, only 6 of them are mined as rock minerals. Light muscovite, black or dark biotite, brown phlogopite, paragonite, which can only be detected from muscovite by microscopy, pink lipidolite and green gluconite are the most extractable species of mica, respectively. Of these, only phlogopite and muscovite are used in industry. Mica miners are mostly located in Canada, the United States, India, Russia and Madagascar. Of course, the extraction process is not so simple and requires blasting and drilling in mica mines.

Mica sheets and blocks are commonly used in electronic equipment, as electrical and thermal insulation, as well as in the insulation of generators and electric motors, etc. Also, mica shields and glass gauges are used from corrosive and acidic solutions to ensure that the liquid level is measured.

One of the unique features of mica is the following:

Physical: Mica is transparent and easily divided into thin sheets. These sheets are thin, colorless, elastic and non-compressible.
Chemical: Since mica contains iron, magnesium, potassium, sodium fluoride, lithium and other elements, they are quite stable against reaction with water, acids (except hydroflora and concentrated sulfur), alkalis, ordinary solvents and oils. .
Electrical: Dielectric strength greater than 25 volts / mm, low power loss, high electrical resistance, and low temperature coefficient are some of the extraordinary properties of mica, which leads to its resistance to electric arc and corona (conductor) phenomenon. The corona phenomenon, around high voltage lines with alternating current, causes electrical losses, which sometimes occur more severely in the form of an electric arc and complete discharge.
Thermal: Mica is fireproof, non-combustible, non-flammable and injectable and can also withstand a maximum temperature of 1832 degrees Fahrenheit (equivalent to 1000 degrees Celsius). Of course, this depends on the type and amount of mica used in the product. In general, mica has excellent thermal stability and low thermal conductivity. Therefore, it is exposed to high temperatures without any visible effect.
Mechanical: Mica is very hard and has a high tensile strength. In addition, it has good elasticity and flexibility. Due to the high compressive strength of mica, it can be machined, drilled or cut by hand.

As mentioned earlier, only two types of mica are used in industry:

Muscovite, which takes its name from Moscow in Russia, is also known as white mica or Indian mica. Muscovite, with its high potassium content, has better voltage resistance than phlogopite. This type of mica, because it is not a good electrical conductor, can withstand high temperatures up to more than 2192 degrees Fahrenheit (equivalent to 1200 degrees Celsius). In addition, Muscovite, like other types of mica, can be torn into thin films. These unique properties make muscovite a vital material in the manufacture of electrical equipment, including electric motors and generators.
Due to its higher magnesium content, fluogip has a higher thermal resistance than muscovite, and for this reason, it is used in the field of rubber, ceramics, talc, paper and refractory materials, as well as electrical insulation.
Muscovite and phlogopite enter the market in various forms, among which the following can be mentioned:

Mica refractory sheet; These fireproof sheets owe their reputation to their amazing insulating power and stunning chemical and electrical resistance at high temperatures. These properties become more apparent when these sheets are used as durable amplifiers. Mica refractory sheets are produced in a rectangular shape and are used in various fields from the production of industrial furnaces to everyday household appliances such as hair dryers. Because effective and efficient insulation is necessary to ensure the operation of the device in the best, safest and most economical way possible.
Mica refractory tape; These strips are made of muscovite mica sheets or phlogip impregnated with a special resin based on fiberglass or polyethylene. The very thin thickness of mica refractory tapes, along with other features such as their resistance to acidic and alkaline conditions, as well as their waterproofness and shock and vibration resistance, make them suitable for use in various fields such as computer centers, underground trains, weapons. Military, telecommunication centers, insulation of electric cables and coils, ships and optical fibers.
Mica refractory plates; These panels, due to high temperature and electrical resistance, penetration against chemicals and oils and most importantly, environmental friendliness, due to the lack of asbestos in it, have various applications in the manufacture and insulation of various parts and equipment. Which can be used in working conditions with High voltage, the process of molding the glass industry and induction furnaces.
Refractory mica talc; This type of mica, also known as clear mica, is very soft and looks greasy when touched. These small sheets, although flexible, are not elastic and do not dissolve except in acidic minerals and in small amounts. This makes talcum powder a good choice for making underwater glasses or measuring liquid levels in high pressure boilers; Because by protecting these glasses against water, oil and acidic liquids, it prevents cracking and damage to the glasses and increases their lifespan. In addition, mica talc is also used in the cosmetics, food and plastics industries.
Mica powder; Due to its unique properties, this material is used in various industries, including the industry of cosmetics, pads and rubber, paint, paper and floor and wall coverings.