Vermiculite is a natural product from the class of phyllosilicates and there belonging to the family of clay minerals. The word has its origin in the Latin "vermiculus and means something like ‘worm’. The name describes at the same time the fascinating property of this mineral to inflate through the effect of heat, the distended untreated vermiculite looks then like little worms. This property of inflating is called exfoliation.
In chemical terms, this light brown to gray mineral consists of an aluminum-iron-magnesium silicate compound. The crystal lattice is applied in several layers, between which water of crystallization are stored, which upon heating escapes and leads to the effect of puffing.
An important application is the insulation industry. Due to its low thermal conductivity and low density (when expanded), it is ideal as an insulating material, for example, in sonic and high-temperature areas, as well as in the field of fire protection and as lining of furnaces or other ovens (refractory material). Other possible applications are in the materials industry, as an additive for cement and plaster. Vermiculite is an excellent bonding substance for spilled liquids, for example in case of accidents.
A special characteristic of this material is the ability to ion exchange in the crystal lattice. In this case, potassium ions are replaced with hydrated calcium or magnesium ions. This property makes vermiculite particularly suitable for use in agriculture and forestry, as well as in horticulture, where it can be used as "soil improvers", for composting / rotting or as carrier material for fertilizers, herbicides or insecticides.
Name | Chemical Formula | Amount | Einecs No | Cas No | EU Classification |
Vermiculite | (Mg,Fe,Al)3(Al,Si)4O10(OH)2-4H20 | 85-95% | 310-127-6 | 1318-00-09 | No Classification |
Color and shape: | golden brown to silvery-white, flake-shaped |
Reactivity: | non reactive (except in very strong acids) |
Solubility: | insoluble (most liquids) |
Cation exchange capacity: | 80 – 100 me /100g |
pH (in water): | 7 - 9 |
Moister content: | 3.0 % |
Combustibility: | non-combustible |
Melting point: |
1300°C - 1430 °C |
ICP Chemical Analysis
Component | Typical wt % |
SiO2 |
41.59 |
TiO2 |
0.71 |
AI2O3 |
10.88 |
Fe2O3 |
7.69 |
MnO |
0.09 |
MgO |
25.66 |
CaO |
1.64 |
Na2O |
0.07 |
K2O |
0.11 |
P2O5 |
0.32 |
SO3 |
< 0.3 |
H2O |
9.18 |
Grainsizing
Crude vermiculite grade Micron: | 0.25 – 0.71 mm |
Bulk density: | ca. 850 – 1000 kg/m³ |
Grit content: | < 10% |
Minimum % by weight retained in range indicated: | 80% |
Packaging
1200 kg plastic bags (Big Bags) |
Color and shape: | golden brown to silvery-white, flake-shaped |
Reactivity: | non reactive (except in very strong acids) |
Solubility: | insoluble (most liquids) |
Cation exchange capacity: | 80 – 100 me /100g |
pH (in water): | 7 - 9 |
Moister content: | 3.0 % |
Combustibility: | non-combustible |
Melting point: |
1300°C - 1430 °C |
ICP Chemical Analysis
Component | Typical wt % |
SiO2 |
41.59 |
TiO2 |
0.71 |
AI2O3 |
10.88 |
Fe2O3 |
7.69 |
MnO |
0.09 |
MgO |
25.66 |
CaO |
1.64 |
Na2O |
0.07 |
K2O |
0.11 |
P2O5 |
0.32 |
SO3 |
< 0.3 |
H2O |
9.18 |
Grainsizing
Crude vermiculite grade Superfine: | 0.300 – 1.5 mm |
Bulk density: | ca. 700 – 950 kg/m³ |
Grit content: | < 10% |
Minimum % by weight retained in range indicated: | 80% |
Packaging
1200 kg plastic bags (Big Bags) |