What is Vermiculite?
Vermiculite is a hydrated magnesium aluminum sheet silicate mineral closely related to mica, and has all of the thermal and chemical resistance mica is known for.
When subjected to heat, vermiculite expands and forms particles that are revered for being:
- Lightweight
- Incombustible
- Compressible
- Highly absorbent, soaking up to three times its volume in water
- Non-reactive
- Highly effective in cation exchange capacity
It’s colour can vary slightly according to it’s origin, from greyish to brown
Vermiculite is mined using open cast mining techniques in many countries across the globe including South Africa, China and Brazil.
It is then classified into grades and shipped to the processing plants where rock and other impurities are removed.
The ore granules are then exfoliated using a high temperature furnace before being processed further towards the intended application. Learn more
Vermiculite Solutions
Horticulture
Vermiculite is always used in the horticultural sector in its exfoliated form and it has the benefits of improving soil aeration while retaining moisture and nutrients to feed roots, cuttings and seeds for faster, maximum growth.
Hydroponic
Hydroponics is the method of growing plants in soilless formulations using mineral nutrient solutions. Vermiculite is a popular hydroponic media favoured for its affordability.
Packaging
Vermiculite is used in packaging because it is lightweight, reducing shipping costs. It is also an excellent impact absorber making it ideal for fragile goods.
Automotive
Finer grades of exfoliated vermiculite are used in friction linings primarily for the automotive market.
Construction
Lightweight, fire-resistant, and insulating construction materials are produced when Vermiculite is used as an aggregate.
Other applications
Vermiculite’s water-wicking, lightweight, and thermal-resistant properties make it ideal for many other industrial applications
Exfoliated Vermiculite (Vermitek)
Vermiculite is mined using open cast mining techniques where the ore is separated from other minerals and then screened or classified into several basic particle sizes. Every care is taken in mining operations to minimize the impact on the environment and to restore land to its natural condition when mining ends.
Vermiculite is imported as a concentrate of vermiculite flakes within a
size range of <1 mm to 8 mm. It is an inert material. On rapid heating to 900 - 1000oC, vermiculite's interlayer water expands to form steam. The pressure of this steam evolution forces the silicate layers apart from one another and
the vermiculite flake forms an elongated concertina-like
particle 20 - 30 times its original thickness (The name "vermiculite" is
derived from the Latin word vermicularis, meaning "worm like" on
account of the elongated, twisted and curved columns produced after
exfoliation)