Silica according to the production method is broadly divided into precipitation method of silica and fumed silica.
There is no difference between silica produced by fumed method and silica produced by precipitation method, and the chemical name is silicon dioxide. However, fumed silica is produced by combustion of silicon tetrachloride and air, and the fineness reaches more than 1000 mesh, while precipitated silica is produced by adding sulfuric acid into sodium silicate. The fineness is only 300-400 mesh. Fumed silica production of silica is expensive, not easy to absorb moisture. It is used in paints as matting agent. Precipitation method of silica is cheap, easy to absorb moisture.
Precipitated silica external properties, bonding, anti-aging, anti-caking, coagulation, controlled release, carrier, flow aid, improve printing effects, mechanical effects, special additives, reinforcing thermoplastics, rheology control, whitening. Hydrophobic silica is easily soluble in oil and is used as a reinforcing filler in rubber and plastics to improve the mechanical strength and tear index of the products. Due to the different manufacturing methods, there are some differences in their physicochemical properties and microstructures, thus their application fields and application effects are also different.
Precipitated silica, also known as hydrated silica, light silica, soluble in caustic soda and hydrofluoric acid. It is stable to other chemicals, resistant to high temperature decomposition, and does not burn. It has high electric insulation, large porosity, large internal surface area, good water absorption and non-toxic.
The difference between precipitation silica and vapor phase silica:
First, it is the difference of production process.
Secondly, it is the difference of the wide range of adaptability.
Third, is the particle size and the use of the effect of the difference.
Fourth, of course, the most important is the price, the difference in enterprise costing.