silica fume is also called fumed silica, it is used in the refractory , construction and concret industry .

Silica fume is a byproduct of producing silicon metal or ferrosilicon alloys. Silicon metal and alloys are produced in electric furnaces. The raw materials are quartz, coal, and woodchips. The smoke that results from furnace operation is collected and sold as silica fume, rather than being landfilled. Silica fume consists primarily of amorphous (non-crystalline) silicon dioxide (SiO2), its average granule diameter is 0.15~0.20 µm, specific surface area is 15000~20000m2/kg, and it has extremely strong surface active. Because of its fine particles, large surface area, and the high SiO2 content, silica fume is a very reactive pozzolan when used in concrete. At the same time, silica fume can still be used in the production of refractory and porcelain; to raise intensity and durability .it also can improve the material overall performance as a filler, used in paint, coating, resin, rubber and other high molecular material

Silica fume