Silica fume, also known as micro silica is an amorphous silicon dioxide, silica. It is an ultrafine powder collected as a by-product of the silicon and ferrosilicon alloy productionThe main field of application is as pozzolanic material for high performance concrete.
Technical Specifications:
SiO2 â?? Silica : >90%
Color : Grey
Application
Because of its extreme fineness and high silica content, silica fume is a very effective pozzolanic material. Standard specifications for silica fume used in cementitious mixtures are ASTM C1240,[8] EN 13263.[9]
Silica fume is added to cement concrete to improve its properties, in particular its compressive strength, bond strength, and abrasion resistance. These improvements stem from both the mechanical improvements resulting from addition of a very fine powder to the cement paste mix as well as from the pozzolanic reactions between the silica fume and free calcium hydroxide in the paste.
Addition of silica fume also reduces the permeability of concrete to chloride ions, which protects the reinforcing steel of concrete from corrosion, especially in chloride-rich environments such as coastal regions and those of humid continental roadways and runways (because of the use of deicing salts) and saltwater bridges.
Effects of silica fume on different properties of fresh and hardened concrete include
a) Workability: With the addition of silica fume, the slump loss with time is directly proportional to increase in the silica fume content due to the introduction of large surface area in the concrete mix by its addition. Although the slump decreases, the mix remains highly cohesive.
b) Segregation and bleeding: Silica fume reduces bleeding significantly because the free water is consumed in wetting of the large surface area of the silica fume and hence the free water left in the mix for bleeding also decreases. Silica fume also blocks the pores in the fresh concrete so water within the concrete is not allowed to come to the surface.
Application Areas:
High performance concrete
High strength, low permeability concrete
Industrial flooring
Water tanks and sumps
Chemical storage tanks
Basements and sewerage pipelines
Refractory mixes etc.
Petroleum Referineries
Tunnels
Silicon dioxide, also known as silica (from the Latin silex), is a chemical compound that is an oxide of silicon with thechemical formula SiO2. It has been known since ancient times. Silica is most commonly found in nature as quartz, as well as in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and most abundant families of materials, existing both as several minerals and being produced synthetically. Notable examples include fused quartz, crystal, fumed silica, silica gel, and aerogels. Applications range from structural materials to microelectronics to components used in the food industry.
:: Physical character ::
A stable chemical,flame-resisting,insoluble in any solvent except strong alkali or hydrofluoric acid.
Superficial polarity,thermal stability,performance of adsorption and separation are all better than that of fine-pored silica gel.
:: Color ::
light yellow.
:: Chemical molecular formula ::
SiO2.nAl2O3.xH2O.
:: Use ::
With higher surface area and drying ability,the absorbent is being widely used in many fields.For its higher compression strength and lower rattle loss, it has longer life and higher performance-value ratio than fine-pored silica gel.
:: Main application ::
1.drying of gas
2.drying of natural gas
3.drying of liquid gas
4.drying of compressed air
:: Technical Data ::
Item Specifications
Adsorption capacity,%
(25?,wt) RH=10%, = 5.5
RH=20%, = 9.0
RH=40%, = 19.0
RH=650%, = 30.0
RH=80%, = 35.0
Pore volume, ml/g Approx. 0.4
Specific surface area, m2/g 600-800
Bulk density ,g/L Approx. 750
SiO2 content % Approx. 97
Al2O3 content, % Approx. 3
Moisture content % = 3.0
Compression strength,N %= 200
:: Size ::
2-4mm, 1-3mm
:: Packaging ::
25 kg per compound bag or 500kg per container bag.
:: Remarks ::
Packing and size may be customized per your specific requirements
