Expanded perlite is a kind of inorganic silicate material, which is non-toxic, tasteless, acid and alkali resistant. It is formed by high-temperature expansion above 1000 ℃, and widely used in dozens of fields such as building energy conservation and heat preservation, sound insulation, soil improvement, soilless cultivation, low-temperature storage and transportation, food, medicine, filtration, high refractory materials, military industry, electric locomotive, etc.