Specifications
The main property of vermiculite in determining its commercial value, is the ability to dramatically increase in the volume (slough) by firing in the temperature range 400-1000 oС.
Exfoliated vermiculite is a loose porous material because of scaly particles of silver, gold or yellow color, is spurred by firing vermiculite concentrate - hydromica containing between elementary layers of bound water.
The main characteristics of expanded vermiculite are volumetric bulk weight (density) and grain composition (fraction). Volumetric bulk density depends on the grain composition, the degree of enrichment (vermiculzation) of crude, the temperature and duration of firing, the form of grains, the presence of gangue.
The density of exfoliated vermiculite with grain size 2-8 mm of 65-110 kg/m3, with smaller grains, it increases to 130-150 kg/m3.
Thermal conductivity at 100 ºC is 0, 048 - 0, 06 W / m• K, and with increasing temperature to 400 ºC rises to 0,11-0,14 W / m• K.
| Options | Units | Description |
| Density | Кg/m3 | 65-150 |
| Thermal conductivity | Wt / м • К | 0,048-0,06 |
| Melting | oС | +1350 |
| Coefficient of thermal expansion | 0,000014 | |
| Toxicity | nontoxic | |
| Color | Silver, gold or yellow |
|
| Temperature of | oС | -260 до +1200 |
| Sound absorption coefficient (1000Hz) | 0,7 - 0,8 |
Depending on the size of grains swollen vermiculite is divided into the following fractions:
| Fraction | Grain size (mm) | Density (кg/m3) | Coefficient conductivity (W / m•K) |
Factor absorption at 1000 Hz |
| 0 (Super Micron) |
до 0,5 | 145-350 | 0,06 | 0,1 |
| 0,5 (Micron) |
- 0,5 + 0,18 | 120-130 | 0,059 | 0,2 |
| 1 (Super Fine) |
- 1 + 0,63 | 110-120 | 0,052 | 0,38 |
| 2 (Fine) |
- 2 + 0,71 | 90-110 | 0,051 | 0,45 |
| 4 (Medium) |
- 4 + 1,4 | 75-100 | 0,048 | 0,71 |
| 8 (Large) |
-8 + 2,8 | 65-85 | 0,046 | 0,8 |
Exfoliated vermiculite is not toxic, chemically inert, biologically stable material does not emit harmful elements at elevated temperatures.
In the chemical composition of vermiculite include:
| SiO2 | Fe2O3 | FeO | Al2O3 | MgO | CaO | K2O | Mn | Na2O | TiO2 | pH(H2O) |
| 33 - 36 | 5 - 17 | 0,2 - 0,27 | 6 - 18 | 14-25 | 1,2 - 2 | 3 - 5 | 0,05 - 0,07 | 0,5 | 0,4 - 0,47 | 6,8 - 7,0 |
The low density and thermal conductivity is characterized by swollen vermiculite as a promising material for use as a heat-insulating filler in the construction of buildings.
High temperature resistance allows for the use of vermiculite in the manufacture of heat-resistant and fire retardant insulation.
Chemical and biological inertness and nesmachivaemost molten metal can be used swollen vermiculite in metallurgy and chemical industry.