Microsilica / Silica Fume
Microsilica / Silica Fume is a mineral composed of ultrafine amorphous spheres of silicon dioxide (SiO2), produced during the manufacture of silicon or ferrosilicon. The average particle is 0.15-0.20 micron in diameter. Specific Surface Area is ranging from 15,000 to 20,000 m^2/kg, has dynamic surface activity.
The main ingredient of silica fume is amorphous silicon dioxide, as the rising of furnace gas, there are some impurities, such as floating C, Fe2O3, CaO, K2O, Na2O and so on. The colors of silica fume range from white, hoary, grey to dark grey as the rise of C, Fe2O3 content.
Not densified: 450 kg/m^3.
Densified: 650 kg/m^3.
Not densified: 350 - 400 kg/m^3.