Vermiculite is versatile for applications from Fireproofing to Horticulture:
Vermiculite in Fireproofing Coating
Vermiculite has been a major ingredient in most fire-proof door cores, and safes. Essentially they are used for the same reasons they have been used in fire-proof plasters – they are light, they are inert and inorganic, and they are fire-proof.
The fireproofing characteristics of vermiculite concrete are recognized nationwide by insurance companies, state rating bureaus and local building officials. Underwriters’ Laboratories have assigned up to 4-Hour ratings to systems that employed vermiculite as one of the components. A range of products, from boards and panels to spray applied plasters, use the excellent fire resistance properties of exfoliated vermiculite.
Basic Benefits of Vermiculite in Fire-protection and Fire-proofing
Weighs approximately 60% less than many sand products, so with lightweight plasters
- 4 times more resistant to heat transmission than sand plasters
- Permits savings in heating and air conditioning costs
- Conserves energy
- Non-combustible and non-toxic
- Provides up to 5-hour fire protection with minimum weight and thickness
- More than 50 fire tested designs by recognized laboratories
Reduces sound transmission between partitions
- Cannot rot or decay
- Strong but not brittle
- Endures freeze-thaw exposure
- Successfully used on major construction projects
Vermiculite as Growing Medium
Vermiculite is well established as a growing medium.
It is most commonly used in compost formulations, usually in combination with peat/soil. Vermiculite /peat compost formulations provide an ideal condition for plant growth. The presence of vermiculite particles in the compost aids aeration, improves moisture retention and promotes the steady release of added fertilizers while vermiculite itself contributes potassium, magnesium and a number minor elements.
The air / water ratios for vermiculite and peat compost are ideal for the stimulation of root growth and production of healthy young plants. Vermiculite is sterile when processed. Vermiculite is also used as a carrier and extender for fertilizer, pesticides and herbicides. It is also used in a ground form for encapsulating seeds.
Advantages using vermiculite:
- Encourage better aeration
- Promotes good drainage
- Prevents excessive temperature fluctuation damaging the seedling/cuttings
- Buffers the nutrient supply in the mixture
- Stimulate root growth giving quick anchorage of the plant
Vermiculite as Packing Material
Highly Absorbent Cushioning with Environmentally Safe Vermiculite
Vermiculite is widely used as a loose fill packaging material. It pours easily around irregular shaped objects and acts as a cushion against impact, shock and rough handling. Lightweight, absorbent, nonabrasive, vermiculite packing material is ideal for shipping hazardous waste, flammable liquids and industrial products, especially when leakage could occur. Being inorganic, vermiculite is fireproof. It is also a highly absorbent loose fill material and can safely retain leaks from packed materials. Vermiculite is UN approved for use in transporting hazardous liquids and materials.
Vermiculite as Brake and Friction Material
Improvements in Performance of Vermiculite-Containing Non Asbestos Organic Brake Friction Materials
The effects of vermiculite on the structural properties and performance of a model non asbestos organic (NAO) dry brake friction material have been evaluated. The incorporation of 8%, 12%, and 20% (volume percent, V%) vermiculite has been tested. Structural tests show an 18% improvement in flexural strength. Dynamometer performance shows a significant improvement in fade pressure stability and low temperature effectiveness. Preform strength, Gogan hardness, thermal compression, and thermal expansion have also been evaluated.
Expanded vermiculite is widely used in friction material at present, and provide with a soft texture, a hollow structure, and excellent sound absorption performance, so it can effectively reduce braking noise and the specific weight of the product. It is preferred as a brake additive because of its unique ability to expand and withstand high temperatures. Fine thermally exfoliated Vermiculite is used for heat dissipation, resulting in better fade and recovery. As an asbestos replacement, it won’t thermally shock brake drums. Recovery testing using Vermiculite shows a drastic reduction in airline pressure required for continuous braking.
Vermiculite as Lightweight Insulation
Exfoliated vermiculite can be used as a replacement for dense aggregates to produce a lightweight insulating concrete. This finds use as in-situ roof and floor screeds and in the fabrication of precast products. It is also used as a back fill where improved insulation is required.
Lightweight roof screeds, as a slope to drain, not only shed water but can reduce the steel structure design while providing a smooth insulating roof substrate for the roof membrane.
Vermiculite concrete roof deck systems allow architects, engineers and contractors versatility in design, high performance and reasonable cost. These systems will use a lightweight concrete consisting of portland cement, water and vermiculite concrete aggregate. It is recommended that all vermiculite roof deck systems be applied by an applicator familiar with using and applying lightwieght vermiculite concrete
When compared with structural grade concrete, vermiculite concrete is 15% of the weight. This results in considerable savings from the footings thru the structural steel.
Vermiculite concrete can be applied over a variety of bases, allowing architects and engineers ample flexibility in their design criteria. The thickness of the concrete can be varied to permit necessary slope to drain.
Vermiculite concrete has excellent insulating properties. Three inches of vermiculite concrete is equivalent to 1 1/2″ of rigid board insulation layed over steel decks. One inch of vermiculite concrete is equal in insulating value to 20 inches of regular concrete.
Vermiculite insulating concrete is easily placed by modern specially designed pumping equipment. Up to 25,000 square feet can readily be placed in one day.
Vermiculite concrete is suitable for installation over most structurally sound roofing systems with structural decks of concrete, metal, or wood. Care must be taken to properly vent decks poured over impervious materials.
Other Applications with Vermiculite
Refractory and high temperature insulation
Bonded with alumina cements, fire clays and silicates vermiculite can be used to produce a wide range of products which can be used at high temperatures up to 1100°C. Pressed silicate bonded shapes and blocks are manufactured in intricate shapes and various sizes for high temperature insulation in kilns, furnaces, boilers and night storage heaters.
Special coatings, gaskets and seals
Vermiculite ground by milling before or after exfoliation is used to produce special coatings and paints. High performance gaskets and seals, increased fire resistance of organic foams and polymer systems, are also possible with these more sophisticated grades of vermiculite.
Lightweight plasters based on gypsum or cement mixes have high coverage, good workability, excellent fire resistance and very good adhesion to low suction backgrounds. They can be hand or spray applied.
Exfoliated vermiculite is used as a support and carrying medium for a wide range of nutrients, fat concentrates, vitamins and molasses. A high liquid uptake is possible while still retaining good handling characteristics.
Moist Vermiculite for Incubating Turtle Eggs
At the Charles Darwin Research Station, one of the most prestigious and well-publicized research facilities in the world, vermiculite has been used in the incubation chambers and for the bedding material for newly hatched turtles and has proven to be so successful.