1.Silicon powder (also called micro silicon powder) (scientific name "Silica Fume, Microsilica, or Silica Fume), silicon powder and silicon ash. It’s an industrial electric furnace in the process of high temperature silicon and ferrosilicon smelting industry, along with the waste gas emitted by special capture device to collect smoke. In the escape of smoke, SiO2 accounted for about 90% of the total ash content, granularity is very small, the average particle size is almost nanoscale, known as the silicon powder.
2.Scientific name "silica fume," Micro-silica or fumed silica. And it has two colors, white or black. Fumed silica can be divided into two kinds, method of precipitation and gaseous phase.

3.Micro silica fume's average granule diameter is 0.15~0.20 µm,specific surface area is 15000 ~ 20000 m2/kg, and it has extremely strong surface active.
4.It possesses optical activity, pyroelectricity, and piezoelectricity. There are usually solid, liquid, and gaseous inclusion in the crystalloid, and it contains microelement ion, Ore are usually in grey, yellow, etc.

Application:

1.Micro silica in Concrete:
(1)Micro silica Makes high-grade concrete effectively enhances the strength  and pumpability of strong concrete. 
(2)Making high crack-resistance, self-waterproofing concrete, Micro silica be used in the subway, tunnel and basement of high-rise structures.
(3) Used in maritime works and chemical industry. Owing to the compactability, Micro silica can prevent effectively sulphate and chlorine ion from osmosizing and eroding Avoid the steel corroding in armoured concrete (RC), lengthen the life-span of concrete.
(4)Micro silica used in the construction item under water, such as pier, huge dam and drilling platform.
(5)Microsilica used in road surface concrete of expressway and large-scale bridge.
2.Micro silica in refractory:
(1)Micro silica Enhancing the fluid of pouring refractory, reducing the volume of used water, be easy to shape, and raising the production efficiency.
(2) Micro silica is a highly effective pozzolanic material, so it's easy to come into being Mullite Phase, under the premise that Al 2 O3 exists, enhance elevated temperature strength and thermal shock of refractory.