Description:
The mica mineral group includes 34 phyllosilicate minerals, all with a layered, platy texture. The mineral has been known for millennia: Mica was first mined in India about 4,000 years ago, where it was used primarily in medicines. The Mayans used it for decorative effect in stucco to make their temples sparkle in the sun. Today it is used in everything from electrical products to makeup.
Mica is highly reflective, and its excellent cleavage allows it to split into thin sheets; these tough, flexible sheets are the distinguishing characteristic of the mineral group. Thin sheets are transparent or, if deeply colored, translucent. Micas are stable when exposed to electricity, light, moisture and extreme temperatures.
PreRish Tri Exim Pvt. Ltd. (PEPL) is the reckoned name worldwide for its quality Mica products. PEPL is the biggest supplier and exporter of Mica of any form accordance to the required grade.
| Chemical Names: | MICA; Muscovite |
| Molecular Formula: | KAl2[AlSi3O10](OH)2 or Al2K2O6Si |
| Molecular Weight: | 256.239 g/mol |
Types and Uses of Mica:
- Commercial Mica
- Principal Mica
Commercial forms of mica can be grouped as either unmanufactured or manufactured. Unmanufactured mica can be divided into two classes: 1. sheet mica and 2. Scrap mica, which includes flake mica. The majority of manufactured mica, which has been shaped or punched, is used in electrical products.
Principal forms of mica minerals used in commercial applications are biotite, muscovite and phlogopite. Biotite is generally used in its ground (particulate) form as a soil additive; muscovite and phlogopite have applications in sheet and ground forms. Muscovite sheet mica is recovered only from pegmatite deposits; phlogopite sheet mica is recovered from pyroxenites.
Muscovite is the principal mica used by the electrical industry to manufacture mica-based capacitors capable of operating at temperatures or frequencies that are destructive to polypropylene capacitors. Phlogopite mica is used in plastic composites for automotive applications because of its dimensional stability, increased stiffness and improved heat distortion temperature.
Mica also used as Welding Electrodes Cables and Wires Foundry Works Texture Paints Acoustical Plaster Ceiling tiles Plastics Oil Drilling Wells and in Beauty Products.
| PHYSICAL PROPERTIES OF MICA GRADE | ||
| Characteristic | Unit | Muscovite |
| Colour | Silver / Ruby / Green | |
| Density | gm/cm3 | 2.6 – 3.2 |
| lb/ln3 | 0.095-0.116 | |
| Specific Heat | 0.21 | |
| Hardness | Moh Scale | 2.8 – 3.2 |
| Shore Test | 80 – 105 | |
| Optic Axial Angle | 55 – 75 | |
| Tensile Strength | kgf/cm2 | about 1750 |
| lbf/in2 | about 25000 | |
| Shear Strength | kgf/cm2 | 2200 – 2700 |
| lbf/in2 | 31000 – 38000 | |
| Compression Strength | kgf/cm2 | 1900 – 2850 |
| lbf/in2 | 27000 – 32000 | |
| Modulus of Elasticity | kgf/cm2 x 10-3 | 1400 – 2100 |
| lbf/in2 X 10-6 | 20 – 30 | |
| Coefficient of expansion per °C perpendicular to cleavage plane | 9 X 10-6 – 36 X 10-6 | |
| Calcining Temperature | C | 700 – 800 |
| F | 1290 – 1470 | |
| Maximum operating temperature | C | 500 – 600 |
| F | 930 – 1110 | |
| Thermal conductivity | ||
| Perpendicular to cleavage planes | Gm.cal/sec/cm2/C/cm | about 0.0013 |
| BTU/hr/ft2/0f/ft | about 0.31 | |
| Parallel to cleavage planes | Gm.cal/sec/cm2/C/cm | |
| BTU/hr/ft2/0f/ft | ||
| Water of constitution % | 4.5 | |
| Moisture absorption | Very low | |
| Apparent electric strength | 0.001″ to 0.003″ KV/mm | 120 – 200 |
| thick Volts per 0.001″ | 3000 – 5000 | |
| R.M.S. at 15° C (60°F) | 0.01″ to 0.05″ KV/mm | 40 – 80 |
| thick Volts per 0.001″ | 1000 – 2000 | |
| Permittivity at 15°C(60oF) | 7-Jun | |
| Power Factor (loss tangent) | @ 15° C (60° F) | 0.0001 – 0.0004 |
| Volume Resistivity | 25° C (77° F) ohm cm | 40 x 1013-2 x 1017 |
| Acid reaction | Affected by Hydrofluoric Acid | |
| CHEMICAL COMPOSITION OF MICA | |
| Silica (SiO2) | 45.57% |
| Alumina (Al2O3) | 33.10% |
| Potassium Oxide (K2O) | 9.87% |
| Ferric Oxide (Fe2O3) | 2.48% |
| Sodium Oxide (Na2O) | 0.62% |
| Titanium Oxide (TiO2) | Traces |
| Calcium Oxide (CaO) | 0.21% |
| Magnesia (MgO) | 0.38% |
| Moisture at 100oC | 0.25% |
| Phosphorus (P) | 0.03% |
| Sulphur (S) | 0.01% |
| Graphite Carbon (C) | 0.44% |
| Loss on Ignition (H2O) | 2.74% |