Vermiculite Grades & Particle Sizes

Exfoliated vermiculite is available in a range of particle-size grades. Grade selection affects particle profile, bulk density, surface area, handling characteristics and suitability for different applications.

VX Resources Canada processes exfoliated vermiculite at our facility in Gananoque, Ontario. Our principal commercial grades are Superfine, Fine and Medium, with Large/Coarse and Micron grades available for application-specific requirements.

Vermiculite Grade Classification

Vermiculite grade terminology describes different particle-size fractions of the mineral. Because vermiculite is a naturally occurring mineral, particle-size distribution, colour, bulk density and other physical characteristics can vary according to mineral source and production conditions.

Superfine Vermiculite
A fine particle-size grade suited to applications where increased surface area, close distribution through a mixture or high absorbency is beneficial.

Fine Vermiculite — 0–2 mm
A smaller particle-size grade suited to fine growing-media blends, hydroseeding, absorbent applications and a range of commercial and industrial formulations.

Medium Vermiculite — 2–5 mm
A versatile general-purpose grade widely used in horticultural growing media and other commercial applications where a larger particle profile and open structure are desirable.

Large / Coarse Vermiculite
A larger particle-size grade available for applications requiring a coarser, lightweight expanded mineral structure. Available from VX Resources on request.

Micron Vermiculite
A very fine vermiculite grade available for specialized industrial and formulated-product applications. Available from VX Resources on request.

Particle-Size Distribution

Commercial vermiculite grades represent particle-size distributions rather than an absolute size of every individual particle. Natural variation, exfoliation and handling can result in material occurring above or below the principal particle-size range.

VX Resources maintains grade specifications appropriate to the mineral source and intended application. Customers requiring a defined sieve distribution or other particle-size specification should contact VX Resources to confirm the appropriate product for their application.

Loose Bulk Density

Loose bulk density (LBD) is the mass of loose exfoliated vermiculite per unit of volume and is normally expressed in kilograms per cubic metre (kg/m³).

LBD can vary considerably according to mineral source, particle-size grade, degree of exfoliation and production conditions. Finer grades also generally exhibit different bulk-density characteristics from coarser grades.

For specification-sensitive applications, product-specific bulk-density information can be provided for the material being supplied.

Natural Mineral Variation

Vermiculite is a naturally occurring mineral. Normal variation may occur in colour, particle shape, particle-size distribution, loose bulk density and mineral composition between sources and production batches.

VX Resources works with established mineral suppliers and processes material in Canada to produce commercial grades for a range of applications.

Where an application requires defined physical, chemical or performance characteristics, customers should confirm their requirements with VX Resources before ordering.

Chemical Composition

The chemical composition of vermiculite varies naturally according to its geological source. Vermiculite typically consists predominantly of magnesium, aluminum, iron and silicon-bearing mineral components, with smaller quantities of other naturally occurring elements.

For applications where chemical composition is material to product performance or regulatory requirements, source-specific technical documentation can be provided for the material being supplied.

Choosing the Correct Grade

The appropriate vermiculite grade depends on the intended application and required physical characteristics.

VX Resources can assist commercial customers in selecting a suitable grade based on particle size, bulk density, application and volume requirements.

Standard commercial supply is available in Superfine, Fine and Medium grades. Large/Coarse and Micron grades may be supplied for application-specific requirements.