Activated alumina is a type of porous, high-surface-area aluminum oxide with excellent adsorption, catalytic, and drying properties. The 3-5mm particle size variant widely used in industrial applications due to its balanced mechanical strength and adsorption efficiency. This spherical granular material typically appears white or light red, featuring numerous capillary pores that enable its superior performance.

Key Characteristics

• Physical Properties
  The 3-5mm activated alumina exhibits a bulk density of ≥0.7g/m³ and a high specific surface area exceeding 250m²/g. Its mechanical strength reaches 150N per particle, significantly higher than molecular sieves (typically ≤60N), making it resistant to softening, swelling, or cracking even when immersed in water.
• Chemical Stability
  Composed primarily of Al₂O₃ (molecular weight 102), it demonstrates excellent chemical inertness, being insoluble in water, ethanol, and most organic solvents. The material maintains stability over time without pulverization and exhibits no toxic or odorous properties.
• Regenerability
  A critical advantage is its ability to regenerate through thermal treatment, allowing repeated reuse in adsorption-drying cycles.

Applications

1. Drying and Dehydration
   Widely used in air dryers, petrochemical plants, and oxygen production facilities for trace moisture removal from gases and liquids. Its water adsorption capacity exceeds 2.1ml/kg, making it suitable for high-humidity environments.
2. Water Treatment
   Effective for fluoride removal in drinking water purification, with high adsorption selectivity and minimal interference from other contaminants. It commonly employed in waterworks and hydrogen peroxide solution manufacturing plants.
3. Catalyst Support
   Serves as a carrier in chemical reactions due to its large surface area and stable X-P type crystal structure. The 3-5mm size provides optimal flow dynamics in fixed-bed reactors. 

4. Industrial Separation
   Used in gas purification processes (e.g., CO₂, SO₂ removal) and transformer oil decontamination. In adsorption towers, it often layered below molecular sieves to prevent moisture-induced sieve degradation.

Technical Advantages

The material’s unique combination of strength, adsorption capacity, and cost-effectiveness makes it indispensable in industries including oil refining, chemical manufacturing, and environmental engineering. When properly installed in drying systems, the 3-5mm granules provide long-term reliability with minimal maintenance requirements.