AluChem AC-99 Tabular Aluminas are high-density, fully shrunk, coarse crystalline alpha aluminas that have been converted to the corundum form. Tabular Alumina is produced by sintering ball-formed calcined alumina at a temperature just under the 2040°C fusion point of aluminum oxide. These Tabular Alumina balls are then crushed, graded or screened, and ground to a wide range of granular or powdered particle size distributions.

The typical chemical and physical properties which characterize AluChem’s AC-99 Tabular Aluminas are presented in this product data. Some of these properties are highlighted by the following:

Chemical purity99.5% Al2O3
Chemical inertnessResistant to most alkalis and mineral acids
High densityTrue density of 3.96 with a bulk specific gravity of 3.55 and an apparent porosity of 4.0%
Low water absorption1.0%
Extreme hardness9 on the Mohs' scale and a Knoop hardness of 2,000
High thermal conductivity@ 100°C 0.069 cal/sec cm °C
Good resistance to thermal and mechanical shock
High heat capacitySpecific heat @ 20°C 0.21 cal/gm/°C
High electrical resistivity
Excellent abrasion resistance

General Characteristics

Chemical FormulaAl2O3
Bulk Specific Gravity3.55
Apparent Porosity4.0%
Water Absorption1.0%
Melting Temperature2040°C
Refractive Index1.76
Mohs' Hardness9
AppearanceWhite Crystalline Granules or Powder

Typical Chemical Composition

Al2O3, %99.5
SiO2, %0.04
Fe2O3, %0.06
Na20, %0.30
L.O.I. (300 - 1200°C), %0.00
Alpha Phase99+

Tyler Sieve Specifications for Standard Products

Screened Convertor Discharge BallsSize
-3/4 Inch + 1/2 Inch
Crushed SizesSieve Analysis
5% Max. On
Minus 1/4 Inch1/4 Inch
Minus 6 Mesh6 Mesh
Minus 8 Mesh8 Meshh
Minus 14 Mesh14 Mesh
Minus 28 Mesh28 Mesh
Ground SizesSieve Analysis
5% Max. On
Minus 48 Mesh48 Mesh
Minus 60 Mesh60 Mesh
Minus 100 Mesh100 Mesh
Minus 325 Mesh325 Mesh
Minus 325 MeshLow Iron 325 Mesh
Graded SizesSieve AnalysisSieve Analysis
2% Max. On5% Max. Through
1/4 Inch to 8 Mesh1/4 Inch10 Mesh
3 Mesh to 6 Mesh3 Mesh8 Mesh
6 Mesh to 14 Mesh6 Mesh20 Mesh
8 Mesh to 14 Mesh8 Mesh20 Mesh
14 Mesh to 28 Mesh14 Mesh35 Mesh
28 Mesh to 48 Mesh28 Mesh65 Mesh