White carbon black, namely hydrated silica, is a very important reinforcing agent in rubber industry. At present, the market is mainly produced by precipitation method. The particle size of the primary particles of white carbon black is 30~50nm, which is approximately spherical, and there is contact between the particles. The primary particles form aggregates through van der Waals force, and the aggregates are connected to each other to form the polymer. The abundant hydrogen bonds on the surface of the primary particles are the main reason for the easy agglomeration of the primary particles. White carbon black is a general term for white powdered X-Ray amorphous silicate and silicate products, mainly refers to precipitated silica, gaseous silica and ultrafine silica gel, including powdered synthetic aluminum silicate and calcium silicate, etc. White carbon black is a porous material, and its composition can be expressed by SiO2·nH2O, in which nH2O exists in the form of surface hydroxyl. Soluble in caustic soda and hydrofluoric acid, insoluble in water, solvents and acids (except hydrofluoric acid). High temperature resistant, non-flammable, tasteless, odorless, with good electrical insulation.