The name Vermiculite stems from the Latin word â€œvermiculusâ€ â€“ little worm â€“ which reflects its characteristic to expand form an ultra-lightweight aggregate to a worm like shape when heated.
Chemically, vermiculite is a hydrated magnesium aluminum silicate and exfoliates (expands) up to 20 times its original size when heated with over 1000 degrees Celsius. Exfoliated vermiculite is non-combustible, compressible, highly absorbent, and nonreactive and it also posesses high cation exchange capacity.
Vermiculite has a high melting point of 1330 degree Celsius, is non-conductive, reflects light and stores moisture and does not stratify when being frozen.
So what, will most readers ask? Well, Vermiculiteâ€™s crystal structure and chemical characteristics make it ideal for fire protection, insulation and many more applications, e.g. as a growing medium in horticulture / agriculture. Contrary to asbestos it is non-carcinogenic, absolutely safe and 100% recyclable!
|Typical Chemical Analysis||Physical Properties|
|Silicon (SiO2)||39.4%||Melting Point (Â°C)||1330|
|Magnesium (MgO)||25.2%||Specific Heat (1kJ/kg.K)||1.08|
|Aluminium (Al2O3)||8.8%||Specific Gravity (Crude)||2.5|
|Potassium (K2O)||4.5%||Mohs Hardness (Crude)||1 – 2|
|Iron (Fe2O3)||4.0%||pH (ISO 787-9)||7 – 8|
|Calcium (CaO)||1.8%||% Loss at 105Â°C (Expanded Product)||< 0.5|
|Carbonate (CO2)||1.4%||% Loss at 1000Â°C (Expanded Product)||< 6|