1. Product Overview & Grade Classification
Understanding calcium silicate board types is the first step in selecting the right insulation. Mingfa classifies its calcium silicate insulation board products into three temperature grades and three density ranges, giving engineers precise control over both thermal and mechanical performance.
LG-Standard
1000°C Grade
The workhorse calcium silicate board for general industrial insulation
Suitable for rotary kilns, furnace walls, ductwork, and process vessels. Compressive strength ≥2.0 MPa. Thermal conductivity ≤0.058 W/m·K at 100°C mean. Conforms to ASTM C533 Type I and comfortably exceeds its 649°C requirement. Available in HCS-17 (170), HCS-20 (200), HCS-23 (230), and HCS-25 (250) density variants.
LG-High Temp
1100°C Grade
For extreme heat zones where standard boards are insufficient
Exceeds ASTM C533 Type II (927°C) by 173°C. Formulated with enhanced xonotlite crystallinity for superior high-temperature phase stability. Compressive strength ≥2.5 MPa. Linear shrinkage ≤1.5% at 1100°C. Specified for cement burning zones, calcining furnaces, glass furnace regenerators, and aluminum melting furnace sidewalls.
High-Density & Special-Purpose
450-900 kg/m³
Structural insulation for load-bearing and demanding environments
MF-HD (800-850 kg/m³) for steel ladle backup; MFGB series (400-900 kg/m³) for ladle permanent linings and blast furnace stove support; MFBL (600 kg/m³) for glass furnace bottom and crown; MFDJ (300-400 kg/m³) for aluminum reduction cells. All high-density calcium silicate board types maintain the xonotlite crystal structure to 1000°C.
Density classification summary: Low-density (170-270 kg/m³) , maximum thermal efficiency, non-load-bearing, ideal for kiln backing and vessel insulation. Medium-density (270-450 kg/m³) , moderate strength for light structural loads, used in fireproof boards and aluminum cell bricks. High-density (450-900 kg/m³) , high compressive strength for load-bearing applications, steel ladles, glass furnace bottoms, and structural thermal breaks.
2. Technical Specifications , ASTM C533 Compliant
All Mingfa calcium silicate insulation board products are manufactured and tested to ASTM C533, the standard specification for calcium silicate block and pipe thermal insulation. The following table presents representative values for our principal grades.
| Property | LG-Standard HCS-25 | LG-High Temp SCS-25 | MF-HD High Strength | Test Method |
|---|---|---|---|---|
| Max Service Temp | 1000°C | 1100°C | 1000°C | ASTM C533 |
| Bulk Density | 250 ±10% kg/m³ | 270 ±10% kg/m³ | 800-850 kg/m³ | ASTM C302 |
| Compressive Strength | ≥2.0 MPa | ≥2.5 MPa | ≥13 MPa | ASTM C165 |
| Flexural Strength | ≥1.0 MPa | ≥1.2 MPa | ≥5.0 MPa | ASTM C203 |
| Thermal Cond. @ 100°C | ≤0.065 W/m·K | ≤0.065 W/m·K | ≤0.120 W/m·K | ASTM C518 |
| Thermal Cond. @ 200°C | ≤0.072 W/m·K | ≤0.075 W/m·K | ≤0.140 W/m·K | ASTM C518 |
| Thermal Cond. @ 400°C | ≤0.088 W/m·K | ≤0.095 W/m·K | ≤0.185 W/m·K | ASTM C518 |
| Linear Shrinkage (24 h) | ≤1.5% at 1000°C | ≤1.5% at 1100°C | ≤1.5% at 1000°C | ASTM C356 |
| Moisture Content | ≤4% | ≤4% | ≤4% | ASTM C533 |
| Flame Spread / Smoke | 0 / 0 | 0 / 0 | 0 / 0 | ASTM E84 |
| Fire Classification | A1 | A1 | A1 | EN 13501-1 |
3. Thermal Performance Curves & Worked Example
The thermal conductivity of calcium silicate insulation board follows a predictable linear relationship with temperature. For LG-Standard grade boards, the characteristic equation is:
λ = 0.056 + 0.00011t W/m·K
where t is the mean temperature across the insulation layer in °C
Worked Example , Furnace Wall at 400°C Mean Temperature: A process furnace operates with a hot face of 650°C and a cold face of 150°C. The mean temperature t = (650 + 150) / 2 = 400°C. Applying the formula: λ = 0.056 + (0.00011 × 400) = 0.056 + 0.044 = 0.100 W/m·K.
For a 50mm thick board, the thermal resistance R = thickness / λ = 0.050 / 0.100 = 0.50 m²·K/W. Heat flux q = (650 − 150) / 0.50 = 1,000 W/m². By comparison, an uninsulated 10mm steel shell at similar conditions would lose approximately 8,000-12,000 W/m². The calcium silicate board reduces heat loss by about 88-92%.
For LG-High Temp grade (1100°C), the coefficient b = 0.00012, giving λ = 0.056 + 0.00012t. For MF-HD (800 kg/m³), approximate λ = 0.095 + 0.00018t W/m·K at mean temperatures above 200°C. Full thermal conductivity curves for all grades are provided in the product technical data sheets , contact our engineering team for your specific operating conditions.
4. Standard & Custom Sizes
Mingfa stocks a comprehensive range of standard calcium silicate board dimensions for immediate shipment, and offers CNC-machined custom sizes to match your exact project requirements.
Standard Board Sizes
| Dimension | Typical Use |
|---|---|
| 600 × 300 mm | General furnace & kiln lining |
| 600 × 400 mm | Vessel & tank insulation |
| 1000 × 500 mm | Large-area rotary kiln backing |
| 1220 × 2440 mm | CNC cutting blank, max sheet size |
Thickness Range
Standard thicknesses: 20, 25, 30, 40, 50, 60, 75, 80, 100, 120 mm. Dimensional tolerance: ±1mm on length/width, ±0.5mm on thickness for boards ≤50mm, ±1mm for boards >50mm. Board flatness: ≤1mm per 300mm length. Thicker custom boards up to 150mm are available for specialized applications.
CNC Custom Machining
Complex profiles cut to your CAD drawings (DXF, DWG, or STEP format): beveled edges for curved kiln sections, pipe half-shells, tongue-and-groove interlocking edges, burner tube penetrations, thermocouple well cutouts. CNC accuracy: ±0.5mm. This eliminates on-site cutting, reduces installation time, and minimizes material waste.
5. Industry Application Matrix
Different industries demand different calcium silicate board types. Use this matrix to identify the recommended grade for your application.
| Industry | Application | Recommended Grade | Density (kg/m³) | Max Temp | Key Requirement |
|---|---|---|---|---|---|
| Cement & Lime | Rotary kiln backup insulation | LG-Standard / LG-High Temp | 230-270 | 1000-1100°C | Low thermal conductivity, dimensional stability |
| Steel | Ladle & tundish backup | MF-HD / MFGB-90 | 800-900 | 1000°C | High compressive strength under refractory load |
| Aluminum | Reduction cell bottom & sidewall | MFDJ-30Q / MFDJ-40 | 300-400 | 1000°C | Controlled thermal resistance, fluoride resistance |
| Glass | Furnace bottom, sidewall, crown | MFBL-60 / LG-High Temp | 600 / 270 | 1000-1100°C | Low iron content for glass quality |
| Petrochemical | Fired heater, reformer casing | LG-Standard | 200-250 | 1000°C | Consistent thermal performance, corrosion resistance |
| Power Generation | Boiler casing, HRSG insulation | LG-Standard | 200-250 | 1000°C | Long-term dimensional stability, non-settling |
| Fire Protection | Fire doors, structural steel, barriers | GF-1100 | 350-450 | 1100°C | A1 non-combustible, endothermic dehydration |
| Carbon | Baking furnace backup | Composite Brick | 400-600 | 1000°C | Chemical stability in reducing atmosphere |
| Non-Ferrous Casting | Molten metal contact | LG-High Purity | 230-270 | 1000°C | Fe₂O₃ <0.4%, non-stick to aluminum |
| Marine & Offshore | Exhaust, bulkhead, A60 fire divisions | GF-1100 / Waterproof Board | 350-450 | 1100°C | Water resistance, fire rating, light weight |
6. How to Specify & Order
To receive an accurate quotation from our calcium silicate insulation board supplier team, please provide the following information in your inquiry. Well-specified inquiries receive quotes within 24 hours.
Operating Temperature
Hot face temperature and expected cold face / shell temperature. This determines whether LG-Standard (1000°C) or LG-High Temp (1100°C) is appropriate. Always include your peak operating temperature, not just the average.
Dimensions & Quantity
Board length x width x thickness (mm). Quantity in pieces, square meters, or cubic meters. If you have a continuous area to insulate, provide total area and we will calculate board count. Standard sizes ship faster; custom sizes add 3-5 days to lead time.
Density & Delivery Port
Required density (or we can recommend based on your load conditions). Preferred Incoterm: FOB Qingdao, CIF to your port, or EXW. Include your destination port for accurate freight quotation. Container loading optimization included at no extra charge.
Minimum Order Quantity: 1 pallet (approx. 1-2 m³) for standard boards. Custom sizes: 1 m³ minimum. Free A4 samples available for evaluation. Lead time: 15-20 working days standard, 20-30 days for custom/OEM. Packaging: Fumigated ISPM 15 wooden pallets, UV-stabilized PE wrap, edge protectors, steel/PET strapping.
7. Frequently Asked Questions
What is the difference between calcium silicate board and fiber cement board?
These are fundamentally different materials for different applications. Fiber cement board is a building material , a mixture of cement, cellulose fibers, and sand , used for cladding, soffits, and wet-area wall linings. It contains no xonotlite crystal phase and degrades above 150-200°C as the cement binder dehydrates. Calcium silicate insulation board is an industrial insulation product made from lime and silica reacted in autoclaves to form xonotlite (6CaO·6SiO&sub2;·H&sub2;O) crystals. It is rated to 1000-1100°C, has thermal conductivity around 0.06 W/m·K at ambient (versus ~0.25 for fiber cement), and is designed specifically for high-temperature thermal insulation. Fiber cement board cannot be used in any application requiring fire resistance above 200°C. Calcium silicate board is not suitable as a building cladding material due to its lower flexural strength and moisture sensitivity (it must be kept dry or protected from weather).
How do I cut calcium silicate insulation board?
Calcium silicate board cuts easily with standard woodworking tools. For straight cuts in boards up to 50mm thick, use a carbide-tipped circular saw with a 40-tooth blade , this produces clean, accurate cuts with minimal dust. A jigsaw with a carbide blade handles curved cuts and cutouts. Thin boards (≤25mm) can be scored with a utility knife or carbide scriber and snapped cleanly along the score line. For thicker boards (>50mm), a table saw with dust extraction is recommended. Always use dust extraction and wear a P2/N95 respirator: the dust is a nuisance particulate, not toxic, but can be irritating to the respiratory tract. Cutting generates a fine white powder; wet-cutting (spraying a light mist of water at the cut line) suppresses dust effectively. All cut edges should be sealed if the board will be exposed to moisture , use a light brush coat of sodium silicate solution or specified edge sealant.
Is calcium silicate insulation board moisture resistant?
Standard calcium silicate board is hygroscopic , it absorbs moisture from the air and from direct water contact. The microporous structure (88-92% porosity) readily wicks water by capillary action. This is both a feature and a limitation. In service, the board should be kept dry. If a board becomes wet before installation, it can be dried by gradual heating (ramp up at ≤50°C/hour to 150°C, hold until dry). Wetting does not degrade the xonotlite crystal structure, so mechanical and thermal properties are fully recovered after drying , unlike mineral wool, which can compact and lose insulation value when wet. For applications requiring moisture resistance (outdoor installations, marine, LNG, offshore), Mingfa offers water-repellent treated boards that resist water absorption while maintaining fire classification. These boards are treated with a siloxane-based water repellent integrated during manufacture. For standard boards, protect from rain and standing water during transport, storage, and before the weatherproof cladding or jacketing is applied.