Vermiculite Boards are lightweight inorganic thermal insulation materials manufactured mainly from expanded vermiculite and selected inorganic binders. Through controlled forming and drying processes, the products develop a stable porous structure that provides effective thermal insulation, practical mechanical strength and reliable dimensional stability under elevated temperatures.
Compared with many conventional lightweight insulation materials, vermiculite-based products offer a useful combination of insulation performance, machinability and structural reliability. They can be cut, drilled and machined into different forms to meet the requirements of industrial equipment, thermal protection structures and fire-resistant assemblies. This makes them suitable not only for standard bricks and boards, but also for customized machined parts used in more complex designs.
To meet modern safety expectations, Firebird Vermiculite Boards are manufactured with a clear commitment to 100% asbestos-free raw materials. The products are intended for applications where non-combustibility, heat resistance, good workability and reliable insulation performance are required.
In steel ladle applications, vermiculite boards are mainly used as back-up insulation behind the permanent lining, rather than as the hot-face working lining. Their function is to reduce heat loss, lower steel shell temperature and improve the thermal efficiency of the ladle lining system.
For steel ladles, the insulation material must withstand not only high temperature, but also mechanical pressure from the lining structure and repeated thermal cycling during operation. If the insulation layer has poor strength or high shrinkage, it may crack, powder, collapse or create heat bridges after long-term use.
Firebird high-density vermiculite boards provide better compressive strength and dimensional stability, making them suitable for ladles, tundishes and other metallurgical vessels where both insulation and structural reliability are required.
Recommended grades:
VI-900, VI-1000, VI-1100 and VI-1200 are more suitable for ladle back-up insulation and high-load areas. VI-1300 and VI-1400 can be considered for special machined blocks or structural insulation parts.
In aluminum reduction cells, vermiculite boards are used for sidewall insulation, bottom insulation and structural thermal protection. The purpose is not only to reduce heat loss, but also to help maintain a controlled and stable thermal balance inside the cell.
Aluminum reduction cells operate for long periods, so the insulation material must have stable thermal performance, low shrinkage and enough strength to resist installation pressure and long-term structural load.
Firebird vermiculite boards are especially suitable for aluminum applications because they are machinable, dimensionally stable and available in different density levels. Lower-density boards can be used where insulation is the main requirement, while higher-density boards are preferred for bottom areas, load-bearing positions and machined insulation components.
Recommended grades:
VI-475, VI-600 and VI-700 can be used for side insulation where lower thermal conductivity is required. VI-900, VI-1000 and VI-1200 are more suitable for bottom insulation, load-bearing areas and machined parts.
Vermiculite boards are widely used as internal liners for fireplaces and wood-burning stoves. They can be installed as back liners, side liners, bottom plates, baffle plates and combustion chamber liners.
In fireplace applications, vermiculite boards help keep the combustion chamber temperature higher, improve heat reflection inside the firebox and protect the metal stove body from direct flame exposure. This helps improve combustion efficiency and extend the service life of the appliance.
The boards are lightweight and easy to process, making them suitable for both standard stove liners and customized replacement parts. They can be cut, grooved, drilled or machined according to the stove design.
For fireplace and stove use, the key factors are not only temperature resistance, but also thermal shock resistance, installation fit and resistance to cracking caused by wood impact or tight fixing. Proper installation clearance and suitable board thickness are important for long service life.
Recommended grades:
VI-600 and VI-700 are suitable for common back and side liners. VI-700, VI-800 and VI-900 are recommended for baffle plates, top liners and parts exposed to higher thermal stress or mechanical impact.
| Technical Properties of Vermiculite Boards | |||||||
|---|---|---|---|---|---|---|---|
| Property | VI-400 | VI-475 | VI-600 | VI-700 | VI-750 | VI-800 | |
| Maximum Service Temperature | °C | 1100 | 1100 | 1100 | 1100 | 1100 | 1100 |
| Bulk Density | kg/m³ | 400 | 475 | 600 | 700 | 750 | 800 |
| Compressive Strength | MPa | 1.3 | 2.5 | 4.2 | 4.5 | 5.0 | 6.0 |
| Bending Strength | MPa | 0.6 | 0.8 | 1.6 | 2.0 | 2.1 | 2.2 |
| Reversible Linear Thermal Expansion (20–750°C) |
% | 11×10-6 | 11×10-6 | 11×10-6 | 11×10-6 | 11×10-6 | 11×10-6 |
| Linear Reheat Shrinkage (1000°C × 12 h) |
% | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| Thermal Conductivity | |||||||
| 200°C | W/m·K | 0.09 | 0.10 | 0.11 | 0.13 | 0.14 | 0.16 |
| 400°C | 0.11 | 0.12 | 0.13 | 0.15 | 0.16 | 0.18 | |
| 600°C | 0.14 | 0.14 | 0.16 | 0.17 | 0.18 | 0.20 | |
| 800°C | 0.15 | 0.16 | 0.18 | 0.19 | 0.20 | 0.22 | |
| Note: The values shown are typical test results obtained under standard conditions and may vary depending on production batches, product dimensions and testing methods. | |||||||
| Technical Properties of Vermiculite Boards | |||||||
|---|---|---|---|---|---|---|---|
| Property | VI-900 | VI-1000 | VI-1100 | VI-1200 | VI-1300 | VI-1400 | |
| Maximum Service Temperature | °C | 1100 | 1200 | 1200 | 1200 | 1200 | 1200 |
| Bulk Density | kg/m³ | 900 | 1000 | 1100 | 1200 | 1300 | 1400 |
| Compressive Strength | MPa | 6.5 | 7.0 | 8.0 | 9.5 | 12 | 14 |
| Bending Strength | MPa | 2.3 | 2.6 | 2.7 | 2.9 | 3.0 | 3.2 |
| Reversible Linear Thermal Expansion (20–750°C) |
% | 11×10-6 | 11×10-6 | 11×10-6 | 11×10-6 | 11×10-6 | 11×10-6 |
| Linear Reheat Shrinkage (1000°C × 12 h) |
% | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 | 1.0 |
| Thermal Conductivity | |||||||
| 200°C | W/m·K | 0.18 | 0.16 | 0.19 | 0.21 | 0.23 | 0.24 |
| 400°C | 0.20 | 0.19 | 0.22 | 0.23 | 0.25 | 0.26 | |
| 600°C | 0.22 | 0.22 | 0.24 | 0.25 | 0.27 | 0.28 | |
| 800°C | 0.24 | 0.25 | 0.26 | 0.28 | 0.30 | 0.30 | |
