Its main composition is SiO2-nH2O. It does not dissolve in water and non-organic acid, but dissolves in hydrofluoric acid and strong caustic alkali solution. It can adsorb humidity in the air. Due to the duration time difference of absorption to different substances composition, it can reach the purpose of separation and purification of mixed composition of different substances. It's used in refining of oil products for removing aromatic hydrocarbon substance or used in refining of oil products for removing aromatic hydrocarbon substance or used in separation, purification of effective composition of Chinese herbal medicine as well as in preparation of highly pure substance and medical flow aid.