Bubble Alumina is used for the production of high temperature insulating refractories. Whilst possessing limited mechanical properties, bubble alumina is an excellent refractory and insulating material for applications up to 1850 ͦC. It is an electric arc furnace product made from high purity alumina and the product chemistry is similar to that of white aluminum oxide. Alumina bubbles are formed from molten alumina. The melt is atomized with compressed air which leads to the hollow spheres. Due to its hollow spheres it has a low bulk density and extremely low thermal conductivity. Bubble Alumina is chemically inert. The melting point is approximately 2100ºC.
Bubble Alumina is used in the production of lightweight insulating refractories where low thermal conductivity and high temperature properties are the prime requirements. Alumina Bubble is also used effectively for loose-fill refractories, i.e. low density, high insulation refractory castable, concrete, or to produce ceramic bodies useful in a range of applications with temperatures up to 1850°C (3272°F). It is also used to form pores in high porosity abrasives and as a media to filtrate aggressive liquids or melts.