Description:          

Microsilica (Silica Fume) is a mineral composed of ultrafine amorphous spheres of silicon dioxide (SiO2), produced during the manufacture of silicon or ferrosilicon. 

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.

At present the classification standards of silica fume industry is based on the activated SiO2 content

Application:
When it is used in concrete, it acts as a filler and as a cementitious material. The small microsilica particles fill spacesbetween cement particles and between the cement past matrix and aggregate particles. Microsilica also combines with calcium hydroxide to form additional calcium hydrate through the pozzolanic reaction. Both of these actions result in a denser, stronger and less permeable material.