Tiny Bubbles

Hollow insulating spheres made from high-purity alumina are often referred to as bubble alumina. These spheres have been available commercially for over 40 years, but it is only within the past 10 to 15 years that they have gained acceptance as a versatile and lightweight refractory mineral. Continual energy loss makes bubble alumina an excellent insulating material that can withstand exceptionally high temperatures, as described in this article.