Tabular Alumina is high-density, fully shrunk, coarse crystalline alpha alumina that has been converted to the corundum form. It is a completely crystallized ?-alumina sintered at slightly below the melting point of imported alumina after batching, grinding and molding.
Tabular Alumina is produced by sintering ball-formed alumina at a temperature under the 2040°C fusion point of aluminum oxide. The crystals are arranged in a tabular staggered way, which increases the mechanical strength of the particles.
Tabular alumina has characteristic large, well developed hexagonal tablet shaped ?-alumina crystals of up to 200?m length.
Properties:
1. Complete crystallization, High purity up to 99.5% Al2O3
2. Good resistance to alkalis and mineral acids
3. Low water absorption less than 1%
4. High hardness and toughness
5. High thermal conductivity
6. Excellent thermal shock resistance
7. Good abrasion resistance.
8. High volume stability
9. High anti-bending strength
Applications:
Tabular Alumina is widely used in refractories including sliding gate, purging plug brick, nozzle, well block as well as kiln furniture, electronic industries, petrochemical industries and ceramic industries. The usage of tabular alumina almost covers every step in steeling manufacturing.
Technical data:
Typical physical properties
Specific gravity 3.96 g/cm3
Bulk density 3.45-3.5g/cm3
Apparent porosity 2-5%
water absorption rate 0.7-1.5%
Mohs' Hardness 9.0
Knoop hardness 2000kg/cm3
Thermal conductivity (100?)0.069 cal/sec cm?
Heat capacity (20?)0.21cal/gm/(100?)
Melting temperature 2050?
Max. service temperature min 1800?
Refractive Index 1.76
Appearance White granules or powder
Chemical composition?%?
Index AL2O3 SiO2 Fe2O3 Na2O
Guarantee Value min 99.2 max 0.18 max 0.1 max 0.4
Typical Value 99.45 0.05 0.02 0.32
Key Physical Index
Index Bulk density(g/cm3) Porosity(%) Water absorption rate(%)
Guarantee Value min 3.5 max 5.0 max 1.5
Typical Value 3.56 2.35 0.72
