Floating bead is a kind of fly ash hollow ball which can float on the water surface. It is gray white with thin and hollow wall. Its weight is very light. Its volume weight is 720kg / m3 (heavy weight), 418.8kg/m3 (light weight). Its particle size is about 0.1mm. Its surface is closed and smooth, its thermal conductivity is small, and its fire resistance is ≥ 1610 ℃. It is an excellent temperature maintaining refractory material. It is widely used in the production of light castable and oil drilling. The chemical composition of floating beads is mainly silicon dioxide and aluminum oxide. It has many characteristics, such as fine particles, hollow, light weight, high strength, wear resistance, high temperature resistance, insulation, insulation and flame retardant. It is one of the raw materials widely used in refractory industry.