Cenospheres (Expanded Mineral Materials Containing Alumina and Silica) are a by-product of coal-burning power plants and is a lightweight, inert, hollow sphere filled with air or inert gas. It's belong to inorganic chemical, and it's a kind of recycled materials, containg Al2O3, SiO2, Fe2O3, CaO, etc. The density is range from 0.7-1.0 g/cc. They are composed of aluminosilicate glass, which has a high melting point, low heat conductivity, resistance to chemical attack and high physical strength. Cenospheres have the appearance of a dry, free-flowing powder that varies in colour from grey to off-white depending upon the nature of the source. Features Low density Free-flowing Spherical shape High crushing strength Higher thermal properties Chemically inert Advantages: Oil well, Cement slurries, Refectories paint and Coatings, Foundries. Cenospheres range from 5-600 microns. A variety of standard grades are available with very accurate particle size top cuts and distribution ranges. Please advise which size you prefer, then relevant details can be shared with you.