What is Silica Fume?

Silica Fume

Silica fume, a co-product from the production of silicon or ferrosilicon metal, is an amorphous silicon dioxide - SiO₂ which is generated as a gas in submerged electrical arc furnaces during the reduction of very pure quartz.  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.  Silica fume is used in a variety of cementitious (concrete, grouts and mortars), refractory, elastomer and polymer applications.

Silica fume is a mineral admixture, composed of submicron particles (100 to 150 times smaller than a grain of cement) of amorphous silicon dioxide.  Silica fume powder is gray to off-white in color, and is available in several product forms and packaging options.  Our products include:

• Undensified Silica Fume
• Densified Silica Fume

When used in cementitious applications (concrete, shotcrete, repair products and oil well grouts.), silica fume acts as both a filler - improving the physical structure by occupying the spaces between the cement particles - and as a “pozzolan” reacting chemically to impart far greater strength and durability to concrete.

In refractory and ceramic applications silica fume is used for its’ ability to modified flow characteristics and for the unique particle packing ability.

Ultra High Performance Concrete with f’c ≥ 150 MPa (22,000 psi)