Silica sol belongs to colloid. It is odorless, tasteless and nontoxic. Its chemical molecular formular is mSiO2．nH2O. 　　Since the colloid grains are minute (10-20nm) and have relatively large specific surface area, the grains themselves are colorless and transparent, so they do not affect the natural color of the materials to be covered. 　　With low viscosity, it can soak the places where water soaks, therefore, it presents excellent dispersion and permeability when being mixed with other substances. 　　When the moisture contained in silica sol are evaporated, the colloid grains firmly adhere to the material surface and the combination of silicon and oxygen is then formed between grains. It is a good adhesive.

Use：
Used as the cohesive agent for various fireproof materials. It has high bonding strength and high heat-resisting performance (1500-1600℃), etc.