Calcined Alumina Powder for Refractories
1. Stable crystal form and high refractoriness An α-phase conversion rate ≥94% provides a stable crystal form and improves refractory high-temperature performance. 2. High purity and low impurities Al₂O₃ ≥99.0% and very low Na₂O, SiO₂ and Fe₂O₃ content minimize adverse effects of...
Read the full description- D50 — Metric
- 1-5 μm
- Color
- White
- Mesh size
- 100 mesh, 200 mesh, 325 mesh, 500 mesh, 800 mesh
- True density
- ≥3.95 g/cm³
Bodan supplies this item to specification. Share the material, machine and required finish and we will confirm the grade, dimensions and packing for your order.
Advantages
Key features
-
Stable crystal form and high refractoriness
An α-phase conversion rate ≥94% provides a stable crystal form and improves refractory high-temperature performance.
-
High purity and low impurities
Al₂O₃ ≥99.0% and very low Na₂O, SiO₂ and Fe₂O₃ content minimize adverse effects of impurities on refractory performance.
-
Good thermal shock resistance
Excellent thermal shock resistance helps prevent cracking under rapid heating and cooling and extends refractory service life.
-
Good sintering activity
Micropowder grades provide good sintering performance, stable linear shrinkage and narrow particle-size distribution, improving refractory density and strength.
-
Good thixotropic flow in aqueous slurries
The material is easy to mill. Aqueous slurries have good thixotropic flow, while dry powder is easy to press and form.
Technical data
Specifications
- D50 — Metric
- 1-5 μm
- Color
- White
- Mesh size
- 100 mesh, 200 mesh, 325 mesh, 500 mesh, 800 mesh
- True density
- ≥3.95 g/cm³
- Melting point
- 2050℃
- Mohs hardness
- ≥9.0
- Crystal system
- Trigonal crystal system
- Max service temperature
- 1800℃
Product details
About this product
Product Overview
Calcined alumina powder is a stable α-alumina produced from industrial aluminum hydroxide or alumina by calcining above 1450℃. High purity, stable crystal form, high α-phase conversion and low impurities make it a suitable raw material for high-performance refractories.
Core Advantages
1. Stable crystal form and high refractoriness
An α-phase conversion rate ≥94% provides a stable crystal form and improves refractory high-temperature performance.
2. High purity and low impurities
Al₂O₃ ≥99.0% and very low Na₂O, SiO₂ and Fe₂O₃ content minimize adverse effects of impurities on refractory performance.
3. Good thermal shock resistance
Excellent thermal shock resistance helps prevent cracking under rapid heating and cooling and extends refractory service life.
4. Good sintering activity
Micropowder grades provide good sintering performance, stable linear shrinkage and narrow particle-size distribution, improving refractory density and strength.
5. Good thixotropic flow in aqueous slurries
The material is easy to mill. Aqueous slurries have good thixotropic flow, while dry powder is easy to press and form.
Technical Specifications
| Specification | Al2O3 | Fe2O3 | Na2O | SiO2 | α-phase conversion |
|---|---|---|---|---|---|
| Coarse powder | ≥99.0% | ≤0.05% | ≤0.10% | ≤0.10% | ≥96% |
| Micropowder | ≥99.0% | ≤0.05% | ≤0.10% | ≤0.10% | ≥95% |
Physical Properties
| Item | Property |
|---|---|
| Color | White |
| Crystal form | Trigonal crystal system |
| Mohs hardness | ≥9.0 |
| Melting point | 2050℃ |
| Maximum service temperature | 1800℃ |
| True density | ≥3.95 g/cm³ |
Applications
Monolithic refractories: high-alumina castables, ramming mixes, plastic refractories and spray mixes
Shaped refractories: corundum bricks, high-alumina bricks and corundum-mullite products
Furnace construction: blast-furnace linings, hot-blast stoves and ladle working linings
Refractory fibers: high-purity fiber products
Other applications: wear-resistant fillers, ceramic glazes, and grinding and polishing materials
Suitable for monolithic refractories such as high-alumina castables, shaped refractories such as corundum bricks, and furnace-building materials requiring high-temperature performance, thermal shock resistance and good processing properties.
Packaging
25 kg plastic woven bags / 25 kg per bag / Small orders and samples
Bulk bags / 1000 kg (1 ton) per bag / Large industrial orders
25 kg bags in a bulk bag / 40 × 25 kg bags per bulk bag / Flexible handling and efficient transport
25 kg paper bags on pallets / 25 kg per bag / Premium customers and moisture protection
Custom Packaging Service
Customized packaging can include:
Custom packaging capacities
Custom labels and branding
Special moisture- and contamination-resistant packaging
Use and Storage Recommendations
1. Combine coarse powder and micropowder
In refractory castables, coarse powder forms the skeleton and micropowder fills matrix voids. Select suitable grading according to the formulation to optimize density and performance.
2. Storage Conditions
Store in a dry, ventilated, low-humidity environment to prevent caking. Stack strictly according to requirements and protect against moisture.
3. Custom Services
Water washing, acid washing and other treatments can meet purity requirements. Fineness can be tailored to customer needs.
Frequently Asked Questions
How does calcined alumina powder differ from fused corundum?
Calcined alumina is α-alumina produced by high-temperature calcining, with a stable crystal form and good sintering activity. Fused corundum is made by arc melting. Calcined alumina is particularly suitable as a refractory matrix powder.
What is the difference between coarse powder and micropowder?
Coarse powder (100-800 mesh) is mainly used as refractory aggregate or filler. Micropowder (D50: 1-5 μm) has greater sintering activity and is mainly used in the matrix. Combining them can optimize refractory performance.
Can the product be used in high-temperature steelmaking environments?
Yes. High refractoriness and excellent thermal shock resistance support applications in blast-furnace linings, ladle castables and corundum bricks.
Are custom particle sizes available?
Yes. Fineness can be tailored, including 100, 200, 325, 500 and 800 mesh.
What is the minimum order quantity?
Standard orders start from one 25 kg bag. Bulk bags are normally shipped as complete units.
How can caking be prevented?
Store in a dry, low-humidity environment in sealed packaging. Follow stacking requirements and avoid moisture and excessive pressure.
Resources
Documents
Data sheets, test reports and packing details for this product are issued on request. Send an inquiry and our technical team will return the documents that match your application.
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