High-Purity Sintered Tabular Alumina Aggregates with Low Porosity (≤ 5.0%) and High Volume Stability for Refractories

Engineered specifically to withstand intense thermal stress and molten slag erosion, HUAO Tabular Alumina is a fully dense, additive-free sintered α-alumina aggregate designed for long-campaign refractory and ceramic systems.

Manufactured in our ISO 9001, ISO 14001, and ISO 45001 certified production facility, fine-ground alumina powder is cold-formed via rolling and fired at ultra-high temperatures to ensure full volumetric shrinkage and crystal maturation. Operating two continuous sintering kilns with a total annual output of 50,000 metric tons, HUAO supplies premium tabular alumina that consistently exceeds national standard benchmarks.

The resulting material exhibits coarse, well-interlocked hexagonal α-Al₂O₃ crystals with an exceptionally clean chemical signature (Al₂O₃ ≥ 99.2%), low closed intra-granular porosity, and stable high-temperature volume retention.

• Controlled Crystal Morphology: Thick, well-developed hexagonal tablet crystals provide intrinsic fracture toughness, reducing structural spalling under thermal shock conditions.
• Low Additive High Purity: Zero inclusion of sintering aids like MgO or B₂O₃ maintains a pure α-Al₂O₃ matrix with minimal iron (Fe₂O₃ ≤ 0.02%) and silica (SiO₂ ≤ 0.09%) content.
• Reduced Matrix Moisture Absorption: Water absorption maintained at ≤ 1.5% minimizes liquid binder requirements in unshaped formulations, boosting green strength after curing.
• High Density & Scour Resistance: A dense structure with bulk density ≥ 3.50 g/cm³ and porosity ≤ 5.0% prevents aggressive fluid penetration and physical abrasion from turbulent molten metals.
• Improved Castable Placement: Carefully graded grain shapes contain minimal flat or flaky particles, promoting superior slurry rheology and lower friction during placement.

Serves as the principal aggregate in functional refractory shapes including sliding gate valves, purging plug cores, ladle shrouds, and continuous casting components subjected to continuous molten steel contact.

Incorporated into Alumina-Magnesia-Carbon (AMC), Magnesia-Spinel, and Alumina-Chromium bricks, as well as ultra-low cement castables (ULCC) for medium-frequency induction furnace linings.

Applied in hydrogen reformators, secondary synthesis reactors, and high-temperature kiln hearths requiring high thermal creep resistance and resistance to reducing gas atmospheres.

• Integrated Factory Scale & Supply Security: Operating two dedicated high-temperature sintering lines yielding 50,000 tons annually under strict ISO 9001, ISO 14001, and ISO 45001 management, HUAO guarantees continuous bulk supply and full batch consistency for large global projects.
• Superior Microstructural Toughness: Our additive-free sintering process yields pure alpha-alumina crystals with predominant closed intra-granular porosity, providing high mechanical strength and exceptional hot modulus of rupture (HMOR) under thermal loads.
• Enhanced Corrosion & Slag Resistance: Ultra-low silica (SiO₂ ≤ 0.09%) and iron (Fe₂O₃ ≤ 0.02%) content prevent the formation of low-melting glass phases, protecting furnace linings against aggressive molten metal infiltration.
• Cost-Effective Refractory Processing: Reduced water absorption (≤ 1.5%) and optimized grain shapes cut down liquid binder consumption while enhancing slurry workability, effectively reducing total customer installation costs.

HUAO delivers customized grain size distributions ranging from coarse aggregates (0-1mm, 1-3mm, 3-5mm, 5-8mm) to fine powders (200 mesh, 325 mesh). We support custom B2B packaging options including 25kg, 50kg multi-wall bags, 1000kg jumbo bulk sacks, 1250kg BB sacks, or specialized moisture-sealed barrier packaging designed for overseas maritime transit.

A1: Sintering without additives like MgO or B₂O₃ ensures an Al₂O₃ purity of ≥ 99.2%, preventing the creation of low-temperature liquid phases and keeping the matrix stable under extreme furnace conditions.

A2: HUAO Tabular Alumina maintains low water absorption (≤ 1.5%) and a reduced presence of flaky particles, allowing castable formulators to achieve liquid flowability with significantly less water.

A3: HUAO operates two high-temperature sintering production lines with an annual output capacity of 50,000 metric tons, governed under certified ISO 9001, ISO 14001, and ISO 45001 management systems.

We also provide other alumina products. If you would like to learn more about Calcined Alumina, please click here.