Diatomaceous earth is a kind of biogenic siliceous sedimentary rock, mainly composed of ancient diatom remains. Its chemical composition is mainly SiO2, containing a small amount of Al₂O₃, Fe₂O₃, CaO, MgO, K₂O, Na₂O, P₂O₅ and organic matter. The main uses of diatomite are filter aids, fillers, adsorbents, catalytic carriers, environmentally friendly building materials and so on.