Mullite Refractory Castables are high-performance monolithic refractory materials primarily composed of mullite phase (3Al₂O₃·2SiO₂). With a high melting point of approximately 1910℃, mullite provides excellent thermal stability, low thermal expansion, and strong resistance to thermal shock and mechanical wear.
Compared with conventional castables, mullite-based castables offer better dimensional stability at high temperatures, improved service life, and superior resistance to thermal cycling. They are widely used in industrial furnaces where stable performance under continuous high-temperature operation is required.
Xintai provides high-quality mullite refractory castables with stable performance, strict quality control, and reliable supply capacity for global industrial applications.
Technical Specifications
| Item | ML-70 | ML-80 | ML-90 |
|---|---|---|---|
| Al₂O₃ + SiO₂ (%) | ≥70 | ≥80 | ≥90 |
| Aggregate Type | Mullite | Mullite | High-purity Mullite |
| Bulk Density (g/cm³, 110℃ × 24h) | 2.6 – 2.7 | 2.7 – 2.8 | 2.8 – 2.9 |
| Max. Service Temperature (℃) | 1600 | 1650 | 1750 |
| Cold Crushing Strength (MPa, 110℃ × 24h) | ≥80 | ≥100 | ≥120 |
| Cold Crushing Strength (MPa, 1100℃ × 3h) | ≥100 | ≥120 | ≥150 |
| Permanent Linear Change (%) (1100℃ × 3h) | ±0.3 | ±0.3 | ±0.3 |
| Permanent Linear Change (%) (1500℃ × 3h) | ±0.5 | ±0.5 | ±0.5 |
| Mixing Water Requirement (%) | 4.5 – 5.5 | 4.5 – 5.5 | 4.5 – 5.5 |
Key Features
- High Refractoriness: Mullite phase provides excellent heat resistance, suitable for long-term service up to 1600–1750℃.
- Low Thermal Expansion: Stable volume change ensures structural integrity under repeated heating and cooling cycles.
- Excellent Thermal Shock Resistance: Strong resistance to rapid temperature fluctuations reduces cracking and extends furnace life.
- Good Wear Resistance: High mechanical strength enables resistance to abrasion and material erosion in harsh working environments.
- Chemical Stability: Stable performance under acidic and neutral slag environments, reducing material degradation.
- Long Service Life: Optimized formulation improves durability and reduces maintenance frequency.
Typical Applications
Mullite Refractory Castables are widely used in high-temperature industrial equipment, including:
- Steam boilers and boiler linings
- Petrochemical tubular heating furnaces
- Furnace doors and observation ports
- Kiln linings in cement and building material industries
- Heat treatment furnaces
- Industrial heating furnaces and incinerators
- Non-ferrous metal furnace linings
- High-temperature duct and transition zones
- Rotary kiln hot zone linings
Production Details
Raw Materials: High-quality mullite aggregate, alumina powder, silica materials, calcium aluminate cement, and additives
Manufacturing Process: Accurate batching, intensive mixing, particle grading optimization, and strict quality inspection
Quality Control: Each batch is tested for chemical composition, bulk density, strength, and thermal properties to ensure stable performance
Packing and Shipping Details
Packaging: 25 kg per bag, moisture-proof sealed bags
Shelf Life: 3 months when stored in a dry, cool environment
Storage Conditions: Keep sealed, avoid moisture and direct exposure to rain
Shipping: Available by sea, land, or containerized transport; palletized packing optional for long-distance delivery
Frequently Asked Questions (FAQ)
Q1: What is mullite refractory castable made of?
It is mainly composed of mullite aggregate (Al₂O₃ + SiO₂ system), combined with calcium aluminate cement and fine refractory powders.
Q2: What is the maximum service temperature of mullite castables?
Depending on the grade, the working temperature ranges from 1600℃ to 1750℃.
Q3. Where is mullite refractory castable commonly used?
It is widely used in boilers, heating furnaces, petrochemical furnaces, kiln linings, furnace doors, and high-temperature duct systems.
Q4: What are the main advantages of mullite castable?
It offers low thermal expansion, excellent thermal shock resistance, good wear resistance, and stable performance at high temperatures.
Q5: Can mullite castable be used in direct flame contact?
Yes, it has good thermal resistance and can withstand direct flame exposure in industrial furnace environments.
