Physical and chemical properties of Silica fume:
Name: Microsilica or Silica fume
Silica fume: the appearance is grey or gray – white powder, and the refractoriness is >1600℃.Bulk density: 200-250kg/m3.
The fineness of silica fume: the fineness of the silica fume less than 1um is over 80%, the average particle size is from 0.1 to 0.3um, and the specific surface area is 20 – 28 m2/g. The fineness and specific surface area are about 80-100 times of the cement and 50-70 times of the fly ash.
Particle morphology and mineral structure: during the formation process of silica fume, the amorphous phase is formed by the action of surface tension due to the effect of surface tension during the formation of phase change, and the surface is smooth. Some are aggregates with multiple spherical particles adhered together. It is a very high surface area and highly active volcanic ash. With silica fume, tiny spheroids can be lubricated.
The appearance is grey powder, SiO2 content is 92%, and has high densified and semi densified microsilica products. It can be applied to high-grade refractories, baffle, silicon carbide cover and so on. It is used as a necessary admixture.
Silica Fume Application:
1, used for mortar and concrete in high-rise buildings, wharf, dams, water conservancy, railway, highway, bridge, culvert, tunnel, subway, airport runway, concrete pavement and coal roadway anchor reinforcement.
2. In the material industry:
(1) high-grade, high-performance, low cement refractory castables and prefabricated parts, the service life is three times of ordinary castables, the refractoriness is increased by about 100℃, and the high temperature strength and thermal shock resistance are obviously improved. It has been widely used in the industries of coke oven, iron making, steelmaking, rolling, non-ferrous metal, glass, ceramics and power generation.
(2) large iron runner and ladle materials, air permeable bricks, and mending materials.
(3) the construction and application of self flow refractory castable material and dry wet injection.
(4) the oxide – bonded silicon carbide products (ceramic kiln furniture, flame-sheet, etc).
(5) high temperature calcium silicate lightweight heat insulation material.
(6) the corundum mullite is used to push the plate in the electric porcelain kiln.
(7) high temperature wear resistant materials and products.
(8) corundum and ceramic products.
(9) Sialon bonded products. In addition to the widespread use of castable refractory materials, a large number of applications have been obtained in the electrofusion and sintered refractory materials.
3, new wall materials, decorative materials:
(1) wall insulation polymer mortar, thermal insulation mortar, interface agent.
(2) cement based polymer waterproof material.
(3) light aggregate heat preservation and energy saving concrete and products.
(4) the inner and outer wall buildings are processed with putty powder.
|Index items||Standard Value|
|SiO2(Silicon Dioxide)||Min. 92.0%|
|Fe2O3 (Iron Oxide)||Max. 0.50%|
|Al2O3(Aluminium Oxide)||Max. 0.70%|
|CaO(Calcium Oxide)||Max. 0.50%|
|MgO(Magnesium Oxide)||Max. 0.50%|
|K2O(Potassium Oxide)||Max. 0.70%|
|Na2O(Sodium Oxide)||Max. 0.40%|
|Moisture Content(H2O)||Max. 1.5%|
|Loss on Ignition(L.O.I) @ 975℃||Max. 3.0%|
|Percent Retained On 45μm (325 sieve)||Max. 1.5%|
|Bulk Density||300-650 kg/m3|