Microsilica (silica fume) is a byproduct from silicon metal or ferrosilicon industries,is an amorphous silicon dioxide â?? SiO2 which is generated as a gas in submerged electrical arc furnaces during the reduction of very pure quartz. As the molten metal is produced, a silica-based gas is emitted. This gaseous fume, as it rises, cools rapidly and forms extremely minute,Amorphous, spherical particles. The microsilica is collected in a bag house, a system for filtering the hot air and gases vented from the furnace. This gas vapor is condensed in bag house collectors as very fine powder of spherical particles that average 0.1 to 0.3 microns in diameter with a surface area of 17 to 30 m2/g. Microsilica can be used in concrete and refractory materials. Microsilica ,when used in concrete, it can improve concreteâ??s properties such as compressive strength, bond strength and abrasion resistance, reduces permeability,and therefore helps in protecting reinforcing steel from corrosion. At the same time, Microslica can still be used in the procustion of refractory and porcelain, to raise intensity and durability, it also can be used in paint, coating resin rubber and other high molecular as a filler material to improve the material overall performance.