... 1240 Microsilica , also called silica fume, it is a byproduct of silicon metal or ferrosilicon alloys. Silicon metal and alloys are ... fume, rather than being land filled. Silica fume consists primarily of amorphous (non-crystalline) silicon dioxide (SiO2), its average granule ... strong surface active.Microsilica can be used in a variety of cementation products, such as concrete, grouts, and mortars as ...