Also known as micro-silica or silica fume silica fume cohesion. Is ferro-alloys in smelting ferrosilicon and silicon metal (silicon metal), the mine produced a large number of thermal furnace highly volatile SiO2 and Si gas, gas emissions and air after the condensation precipitation by rapid oxidation. It is a large-scale industrial by-product of smelting, the whole process needs to recall the Dust environmental protection equipment, as compared the quality of light needed to use encryption encryption equipment.
[Edit this paragraph] ﹑ a micro-physical and chemical properties of microsilica:
1, silica fume: the appearance of gray or off-white powder for refractoriness ﹑> 1600 ℃. Bulk density: 200 to 250 kilograms / cubic meter. The chemical composition of silica fume in the following table:
Project SiO2 Al2O3 Fe2O3 MgO CaO NaO PH
Average of 75 ~ 96% 1.0 ± 0.2% 0.9 ± 0.3% 0.7 ± 0.1% 0.3 ± 0.1% 1.3 ± 0.2% neutral
2, the fineness of silica fume: silica fume is less than 1μm in size accounted for more than 80%, with an average particle size in the 0.1 ~ 0.3μm, specific surface area: 20 ~ 28m2 / g. Its fineness and specific surface area of cement is about 80 ~ 100 times, fly ash of 50 to 70 times.
3, particle morphology and phase structure of mine: in the formation process of silica fume as a result of the process of phase transition by the role of surface tension, forming a non-crystalline amorphous phase round spherical particles, and relatively smooth surface, some is more than a round ball particles of aggregate stick together. It is a large surface area, high activity of the ash material. Silica fume mixed materials, a small spherical body can play the role of lubrication.

Link:

http://blog.nationmultimedia.com/ggbfs/2009/05/26/entry-4