Its name stems from the Latin word “vermiculus” – little worm – 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 30 times its original size when heated with over 1000 degrees Celsius. Exfoliated vermiculite is non-combustible, compressible, highly absorbent, and nonreactive and it also has 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, Vermiculite’s crystal structure and chemical characteristics make it ideal for fire protection, insulation and many more applications, e.g. as a growing medium in nurseries. Contrary to asbestos it is non-carcinogenic, absolutely safe and 100% recyclable!
|Chemical Analysis||Physical Properties|
|Silicon (SiO2)||39.4%||Melting Point (°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 105°C (Expanded Product)||< 0.5|
|Carbonate (CO2)||1.4%||% Loss at 1000°C (Expanded Product)||< 6|