Hydrated silica (English name: Hydrated silica; Silica oxide hydrate), also known as white carbon black, or light silica, is mainly composed of silica, a white amorphous powder (Figure 1), which is light and loose, soluble in caustic soda and hydrofluoric acid, and insoluble in water, solvents and acids (except hydrofluoric acid). High temperature resistance, non flammable, odorless, odorless, and excellent electrical insulation. Its properties are similar to carbon black, but it appears white. The molecular formula and structural formula can be represented by SiO2 · nH2O, where nH2O exists in the form of surface hydroxyl groups. Its macroscopic structure is similar to that of carbon black, with particles in a spherical shape and single particle contact in a chain like structure (secondary structure). The chain branch structure interacts with hydrogen bonding forces to form clumps of aggregates. The original particles are extremely fine, forming aggregated fine particles after absorbing water in the air. There are hydroxyl groups on the surface of white carbon black particles, mainly including isolated hydroxyl groups, adjacent hydroxyl groups, and silica groups (see Figure 2 and 3). The adsorption of polar substances by adjacent hydroxyl groups is very important. The presence of these groups endows the surface of white carbon black with strong hydrophilicity, large surface area and dispersion ability, and high mechanical strength and tear resistance indicators. High temperature non decomposition, high insulation, small particle size, large specific surface area, and high structural properties. Mainly used as an excellent light colored reinforcing agent, lubricant, insulation material, etc. in the rubber industry. It can be prepared by reacting dilute sodium silicate solution with dilute hydrochloric acid.