What is Exfoliated Vermiculite
This expanded mineral structure provides low bulk density, thermal resistance, aeration, absorption, and chemical stability, making it useful across industrial and agricultural applications.
Asbestos-free · B2B grade · Multi-use mineral
Exfoliated vermiculite for fireproofing, insulation, hydroponics, and lightweight construction
Dosar Ceramics supplies high-purity exfoliated vermiculite for industrial, construction, and agricultural applications that require low bulk density, thermal resistance, water retention, and dependable material consistency.
1150°CClassification temperature
0.063–0.0819Thermal conductivity W/mK
6.5–7.8Near-neutral pH range
Industrial supply overview
Why buyers choose this material
- Consistent industrial qualitySuitable for fireproofing, insulation, horticulture, and selected process industries.
- Application-based gradingAvailable in large, medium, fine, superfine, and raw grades for different end uses.
- Export-ready supplyWell suited to buyers looking for asbestos-free material with clear technical positioning.
Technical specifications
Exfoliated vermiculite is a lightweight, non-combustible hydrous phyllosilicate mineral expanded by heat treatment and used where insulation, water retention, stability, and reduced weight matter.
Why Exfoliated Vermiculite performs well
- Low thermal conductivity supports insulation and fireproofing systems.
- Near-neutral pH makes it suitable for horticulture and hydroponics.
- Mineral stability supports use in construction and industrial fillers.
- Expanded particle structure improves aeration, absorption, and weight reduction.
| Parameter | Value | Industrial relevance |
|---|---|---|
| Silicon Dioxide (SiO2) | 39.6 - 54.75% | Supports structural integrity and mineral stability. |
| Magnesium Oxide (MgO) | 23.48 - 23.5% | Contributes to thermal stability and high-temperature performance. |
| Thermal Conductivity | 0.063 - 0.0819 W/mK | Useful for insulation and heat management systems. |
| Classification Temperature | 1150°C | Supports fireproofing and refractory-related applications. |
| Cation Exchange Capacity | 60 - 100 meq/100g | Helps nutrient retention in horticulture and hydroponics. |
| pH (Aqueous) | 6.5 - 7.8 | Suitable for hydroponics, seed germination, and soil amendment use. |
Applications by industry
Our Exfoliated Vermiculite is supplied in multiple grades for construction, agriculture, insulation, and specialized industrial use.
Construction and fireproofing
It is fit for fireproof boards, insulating plasters, spray-applied fireproofing systems, and lightweight concrete where non-combustibility and thermal resistance are required.
Agriculture and hydroponics
It is suitable for seed starting, soilless media, hydroponic systems, and vertical farming because it helps retain water and nutrients while supporting root-zone aeration.
Industrial use
It is used in insulation products, refractory support roles, coatings, friction materials, fillers, and other specialty applications where low density and thermal stability are beneficial.
Grades and particle sizes
| Grade | Size range | Loose Bulk Density (LBD) | Best-fit applications |
|---|---|---|---|
| Large | 2.0 - 4.0 mm | 150 g/l | Hydroponic media, soil aeration, lightweight concrete aggregates. |
| Medium | 1.0 - 3.0 mm | 170 g/l | Potting mixes, general horticulture, fire-resistant board manufacturing. |
| Fine | 0.5 - 2.0 mm | 200 g/l | Seed starting, rooting, animal feed carriers, anti-condensation coatings. |
| Superfine | 0.25 - 1.7 mm | 300 g/l | Precision germination, friction materials, fire-resistant coatings. |
| Unexpanded Raw | 0.1 - 0.5 mm | 800 g/l | Feedstock for exfoliation plants and specialized industrial fillers. |
Compliance and market alignment
Safety assurance
Our exfoliated vermiculite is sourced from certified deposits and supplied as asbestos-free material, making it suitable for industrial, construction, and agricultural applications where safety and consistency are essential.
UAE construction relevance
Our material is fit for fireproofing systems, lightweight insulating plasters, and construction applications that require non-combustibility, thermal stability, and reliable performance in UAE and Gulf projects.
Hydroponics and agriculture
It is suitable for hydroponics, seed germination, and soilless growing media because of its high water retention, aeration support, and near-neutral pH.
Frequently asked questions
What is exfoliated vermiculite?
Exfoliated vermiculite is natural vermiculite ore that has been heated to high temperatures (typically 800–1000 °C), causing the layered flakes to expand into lightweight, worm‑like granules with many air pockets inside.
How does exfoliation work?
When heated, water trapped between the silicate layers of raw vermiculite flashes into steam, pushing the layers apart and increasing volume by roughly 8–14 times the original volume.
What is the typical expansion ratio?
Exfoliated vermiculite generally expands to about 8–14× its original volume, depending on ore quality, moisture content, particle size, and exfoliation temperature profile.
What is the chemical composition of exfoliated vermiculite?
Typical expanded product contains mainly silica (SiO₂ ~30%), iron oxide (Fe₂O₃ ~16%), aluminium oxide (Al₂O₃ ~14–15%), calcium oxide (CaO ~9–10%), and minor alkalis, with average moisture around 7–8% and loss on ignition near 11%.
Is exfoliated vermiculite chemically inert?
Yes; properly exfoliated vermiculite is generally chemically inert, stable in neutral to slightly alkaline environments, and resistant to most industrial chemicals and fertilizers, which makes it suitable for refractories, construction, and agriculture.
What is the bulk density range?
Exfoliated vermiculite has a very low bulk density, typically in the range of 150-170 kg/m³ for coarser grades and up to around 250–300 kg/m³ for fines or partially compacted products.
What are the main thermal‑insulation properties?
Because of its layered, air‑filled structure, exfoliated vermiculite is a poor conductor of heat, giving low thermal conductivity (good K‑factor for insulation) and making it useful in loose‑fill insulation, fire‑protection, and refractory mixes.
Is vermiculite a good fire‑resistant or fire‑proof material?
Exfoliated vermiculite is non‑combustible, stable at high temperatures, and widely used in fire‑protection boards, insulation coatings, and refractory castables to improve fire resistance and thermal shock resistance.
What particle sizes are available?
Common industrial grades span from fine powder or 0.5–1 mm (for coatings, agriculture, and fillers) up to 3–6 mm flakes (for loose‑fill insulation, floating concrete, and refractory aggregates).
Is exfoliated vermiculite safe for plants?
Yes. It is non-toxic, sterile, and improves soil aeration and moisture retention, making it ideal for seed germination and hydroponic systems.
How is exfoliated vermiculite used in agriculture?
In horticulture, it is used as a soilless growth medium or additive to improve aeration, moisture retention, and nutrient‑holding capacity, promoting seed germination, root development, and reduced leaching.
What are the construction and building applications?
Exfoliated vermiculite is used in lightweight concrete blocks, rendering plasters, fire‑proof boards, loose‑fill cavity insulation, and ceiling sprays because of its low density, fire resistance, and thermal‑insulation properties.
Is exfoliated vermiculite safe to handle?
Modern exfoliated vermiculite from certified sources is generally regarded as safe to handle; however, it is advisable to avoid inhalation of dust and use standard industrial hygiene practices (respirators, PPE) in large‑scale processing.
Can exfoliated vermiculite be mixed with binders?
Yes; it can be combined with inorganic binders such as sodium silicate, cement, or gypsum to form moulded insulation panels, fire‑proof boards, or refractory pre‑cast shapes.
What should buyers check in exfoliated vermiculite specifications?
Key specs to specify include: bulk density, moisture content, LOI, particle size distribution, pH, and fire‑resistance / application‑specific performance data (e.g., thermal conductivity, compressive strength in mixes).
What are the main uses of exfoliated vermiculite?
Exfoliated vermiculite is used in:
- Fireproofing and insulation
- Lightweight concrete and plaster
- Horticulture and hydroponics
- Packaging and spill absorption
What is the difference between vermiculite and perlite?
Vermiculite retains more water and nutrients, while perlite provides better drainage and aeration. Vermiculite is ideal for moisture retention, whereas perlite is better for preventing overwatering.