Home > Blog > Bubble Alumina for Castable Refractory

Bubble Alumina for Castable Refractory

Bubble Alumina for Castable Refractory

Bubble alumina is a lightweight, insulating refractory material made from alumina (aluminum oxide) bubbles and refractory cement. It’s commonly used in castable applications for its unique properties. This unique material brings a host of benefits to the table, revolutionizing the way we approach high-temperature applications.

Key Features

  • Low Density: Compared to solid refractory materials, bubble alumina has a significantly lower density (around 1500 kg/m³), making it lighter and easier to handle. This translates to reduced weight load on structures and potentially improves energy efficiency.
  • High Insulation: The hollow ceramic bubbles within the material provide excellent thermal insulation, reducing heat loss and energy consumption in high-temperature applications.
    Good Refractoriness: Bubble alumina typically has a maximum use temperature of around 1800°C (3272°F), making it suitable for various high-temperature processes.
  • Easy Installation: As a castable material, bubble alumina can be mixed with water and readily poured into desired shapes, offering versatility and simplifying installation compared to pre-formed refractory bricks.


  • Furnace linings and insulation.
  • Kiln and oven insulation.
  • Boiler refractory linings.
  • Molten metal handling equipment.
  • High-temperature piping and ductwork insulation.


  • Strength: While its low density is advantageous, bubble alumina has lower mechanical strength compared to denser refractory materials. Therefore, it’s not suitable for applications requiring high structural load-bearing capacity.
  • Abrasion Resistance: Its lightweight nature might make it less resistant to abrasion and physical wear compared to denser refractories.
  • Chemical Resistance: Depending on the specific formulation, bubble alumina may not be resistant to certain chemicals or acidic environments. It’s crucial to check the compatibility with intended use cases.

Additional Information

  • Bubble alumina is often supplied as pre-mixed bags or dry components requiring mixing with water and binder.
  • Different grades and formulations of bubble alumina exist, offering varying properties and temperature limits.

In the world of refractory materials, Bubble Alumina for castables represents a remarkable advancement, opening up new possibilities for industries requiring high-temperature resistance, insulation, and reduced structural weight. Its unique combination of properties makes it a versatile choice, contributing to improved efficiency, longevity, and cost-effectiveness in a variety of applications. As technology continues to advance, Bubble Alumina is poised to play a pivotal role in shaping the future of refractory solutions.

Related Posts

Request a Quote

All information provided will be kept confidential.
Interested in our products? Please send your inquiry in the form below: