With the development of technology, new hollow spherical materials (glass, ceramic, carbon) are developed and have been used in many areas of science. 

Refractory bricks or products made of these hollow spherical materials have many advantages such as high temperature resistance, insulation, good thermal stability and high strength. Since hollow spherical materials have low bulk density and low thermal capacity, it can improve the thermal efficiency, shorten the production cycle and greatly reduce the weight of furnaces. They can be directly used as the lining of high temperature furnaces. 
 

Alumina bubble brick and products can be used under 1800℃ for a long term. They also have good chemical stability and corrosion resistance. They can keep stable under a hydrogen atmosphere. 
 

Alumina bubble bricks are made of alumina as the raw material in an electric arc furnace. Firstly, melt the raw materials at 2200℃, pour and blow the liquid by high pressure and then cool it into a solid. 
 

The obtained hollow spheres are screened to remove large debris and fine particles. Then remove iron with a magnetic iron. Remove broken balls with a ball selecting machine. The finished products are packed.