Part 1: Product Overview

Raw vermiculite, also known as vermiculite ore or vermiculite flakes, is a phyllosilicate secondary metamorphic mineral containing magnesium and aluminum hydroxide. It is formed from biotite or phlogopite through hydrothermal alteration or weathering. It gets its name from its ability to expand and bend like a leech upon heating and dehydration.

Our raw vermiculite is selected from high-quality ore sources and processed through crushing, sieving, and purification, retaining the typical layered structure of mica minerals. Its most prominent feature is high-temperature expandability: when heated to 800–1000°C, it rapidly expands by 8–25 times in volume to form loose and porous expanded vermiculite.

Raw vermiculite appears in flake or granular form, characterized by clear stratification, good exfoliation, low impurity content, and high expansion ratio. It serves as the core raw material for producing expanded vermiculite and related products.

Part 2: Core Advantages & Properties

High‑Temperature Expandability (Core Property)

The greatest value of raw vermiculite lies in its thermal expansion. At 800–1000°C, interlayer crystal water vaporizes rapidly, causing volume expansion of 8–25 times and forming lightweight porous expanded vermiculite. Expansion ratio directly determines the grade of raw vermiculite.

Easy Transportation & Storage

With a relatively high bulk density (approximately 600–1100 kg/m³), raw vermiculite is more suitable for long‑distance transportation and long‑term storage than expanded vermiculite, reducing logistics costs.

Layered Structure & Excellent Exfoliation

It features a mica‑like layered structure and can be split into thin flakes along cleavage planes, facilitating processing and classification.

Good Chemical Stability

Chemically stable, acid and alkali resistant, and hardly decomposes or reacts under normal temperature conditions.

Rich in Mineral Elements

Contains K, Mg, Ca, Fe and trace elements such as Mn, Cu, Zn, which can provide nutrients for plants after expansion.

Non‑Toxic & Eco‑Friendly

Natural mineral material, non‑toxic, odorless, non‑radioactive, safe and environmentally friendly.

Core Indicators of Raw Vermiculite

Item	Unit	Index
Expansion Ratio	times	8–25
Bulk Density	kg/m³	600–1100
Moisture Content	%	≤5–8
Sand Content	%	≤5
Bulk Density After Expansion	kg/m³	50–200
Mohs Hardness	-	1–1.5

Part 3: Main Application Fields

As a raw material, raw vermiculite is mainly used in two categories: as feedstock for expanded vermiculite, and for direct applications.

I. As Raw Material for Expanded Vermiculite (Core Use)

The largest application of raw vermiculite is as feedstock for expanded vermiculite. After calcination and expansion at high temperatures, expanded vermiculite is widely used in:

Building Fireproof Materials

Fireproof coatings, fireproof boards, fire door cores, steel structure cladding materials.

Industrial Fields

Friction materials, sealing materials, high‑temperature insulation, adsorbents.

Thermal Insulation Materials

Wall insulation, roof insulation, pipeline insulation, lightweight concrete.

Agriculture & Horticulture

Soil conditioner, soilless cultivation medium, seedling covering material.

Note: For detailed applications of expanded vermiculite, please refer to our "Expanded Vermiculite" product introduction.

II. Direct Application Fields

Raw vermiculite can be used directly without expansion, with unique value in the following fields:

Drilling Fluid Materials (Oilfield Drilling)

Lost circulation material: 4–20 mesh raw vermiculite flakes are directly used for plugging in petroleum drilling fluids. Their flaky structure forms bridging seals in fractures, effectively stopping abnormal circulation of drilling fluid.

Advantage: Lower cost than expanded vermiculite, reliable plugging effect, commonly used in oilfield drilling.

Building Material Fillers

Lightweight concrete aggregate: Raw vermiculite can be mixed with cement to produce lightweight concrete. Although denser than expanded vermiculite concrete, it has lower cost.

Thermal insulation mortar filler: Used to formulate thermal insulation mortar and reduce thermal conductivity.

Gypsum products: Adding raw vermiculite improves fire resistance and thermal insulation of gypsum boards.

Friction Materials

Brake pads & clutch discs: Raw vermiculite flakes can be directly used in friction material formulations to improve wear resistance and thermal stability. Partial surface expansion during friction enhances friction performance.

Fireproof Material Base

Fireproof coating filler: Raw vermiculite powder acts as a filler in fireproof coatings; it expands in case of fire to form an insulating layer.

Fire door core filling: Raw vermiculite granules serve as filling material for fire door cores, expanding to seal gaps in fire.

Packaging Materials

Shockproof packaging: Raw vermiculite flakes have certain cushioning properties and can be used as filling material for fragile goods.

Adsorption Materials

Oil adsorption: Raw vermiculite has certain adsorption capacity and can be used to absorb surface oil stains.

Pet litter: Used as moisture‑absorbing and deodorizing component in pet litter.

Horticultural Basic Materials

Soil bottom drainage layer: Large‑particle raw vermiculite can be placed at the bottom of flower pots to improve drainage.

Potting soil ingredient: Mixed with soil and humus, though less effective than expanded vermiculite.

Part 4: Product Specifications & Technical Parameters

Product Specification Table

Product Form	Specification (Mesh/Particle Size)	Expansion Ratio	Bulk Density (kg/m³)	Main Applications
Raw Vermiculite Flakes (Large Granule)	4–6 mesh, 6–10 mesh, 10–20 mesh	8–25 times	700–1100	Oilfield plugging, fire door cores, packaging materials
Raw Vermiculite Granules	20–40 mesh, 40–60 mesh, 60–80 mesh	8–25 times	600–1000	Feedstock for expanded vermiculite, building material fillers
Raw Vermiculite Coarse Powder	80–100 mesh, 100–150 mesh	8–20 times	600–900	Friction materials, fireproof coating fillers
Raw Vermiculite Fine Powder	200 mesh, 325 mesh	5–15 times	500–800