1. Test items of precipitated silica (precipitated hydrated silica)
The chemical formula of precipitated silica is SiO2•nH2O. Precipitation method silica testing items mainly include silica content, color, 45μm sieve residue, heating loss, ignition loss, pH value, total copper content, total manganese content, total iron content, phthalic acid two Butyl ester absorption value, water soluble matter, 300% constant elongation stress, 500% constant elongation stress, tensile strength, elongation at break, physical form, dispersibility, specific surface area and other indicators.

2. Test items for highly dispersed precipitated silica (highly dispersed precipitated hydrated silica)
The test items of high-dispersion precipitated silica are basically the same as those of ordinary precipitated silica, but the test items of technical indicators and typical values are added. Therefore, the technical indicators of high dispersion precipitated silica also need to detect the two indicators of median particle size and particle proportion. The typical value stipulates that three indicators of total surface area, CTAB adsorption specific surface area and dispersion degree need to be detected.

3. Fumed silica (fumed silica) testing items
The appearance requirement of fumed silica is fluffy white powder. The specific test items mainly include nitrogen adsorption specific surface area, loss on ignition, silica content, aluminum oxide content, titanium dioxide content, iron oxide content, carbon content, chloride content, suspension PH value, 105 ℃ volatilization material, tap density, 45μm sieve residue and other indicators.