Silicon Si powder CAS 7440-21-3

Item No.: Tr-Si
Silicon powder is a non-toxic, odorless, non-polluting inorganic non-metallic material. It has good temperature resistance, acid and alkali corrosion resistance, high insulation.
Purity(%): >99.95
Silicon Si powder Properties
About Silicon Si powder:
Silicon fume (micro silicon powder or silicon fume), also known as micro silicon powder, scientifically named "silicon fume", is a process of smelting industrial silicon and ferrosilicon in an industrial electric furnace at high temperatures. The smoke and dust escaping with the exhaust gas is collected and processed by a special collection device. Become. The scientific name of silicon powder is "micro silicon powder" or "silicon powder", which is a process of high-temperature smelting of industrial silicon and ferrosilicon in an industrial electric furnace. The smoke and dust escaping from the exhaust gas are collected and processed by a special trap. In escaping smoke and dust, the content of SiO2 accounts for about 90% of the total smoke and dust. Its particle size is very small, and the average particle size is almost nanometer level, so it is called silicon powder.
Silicon powder is a non-toxic, odorless, non-polluting inorganic non-metallic material. Because it has good temperature resistance, acid and alkali corrosion resistance, high resonance coefficient, high insulation, low expansion, stable chemical properties, and high hardness, it is widely used in chemicals, electronics, integrated circuits, electrical appliances, plastics, and coatings, Advanced paint, rubber and other fields.
Secondly, only carbon, silicon is the most abundant element on earth, with an abundance of 277,000 ppm. It usually exists in the form of silicate, which is found in many rocks, clays and soils. Silicon is obtained by reducing silicon dioxide (sand, SiO 2) with carbon. Through zone refining, components used in applications that require high-purity materials (such as semiconductor devices) can be further purified, and the resulting purity is better than 1:109. There are two allotropes of silicon. Brown silicon is a powder, white crystalline (metal) silicon is gray, and the latter is more widely used. Lump silicon has no reactivity with oxygen, water and acids (except HF), but it is soluble in hot alkali.
Silicon has many applications in various industries. For example, ultra-high purity silicon is used in the semiconductor industry due to its semiconductor properties. Silicon is also used as an alloying element in certain alloys (such as ferrosilicon, an alloy of iron and silicon used to introduce silicon into steel and cast iron). It is also used in glass manufacturing. Feel free to send an inquiry to get the latest price if you would like to buy Silicon Si powder in bulk.

Silicon Si powder CAS 7440-21-3
Specifications of nano silicon powder
nano silicon powder APS(nm): 2-1000nm
nano silicon powder Purity(%): >99.95
nano silicon powder Specific surface area(m2/g): 60
nano silicon powder Volume density(g/cm3): 0.09
nano silicon powder Density(g/cm3): 2.3
nano silicon powder Crystal form: Sphere
nano silicon powder Color: yellow
nano silicon powder CAS No.: 7440-21-3
nano silicon powder EINECS No.: 231-130-8
Product performance of silicon powder
High purity, the scattered performance is good, particle size small, distributed even, is bigger than, the high surface activity the surface area, the pine installs the density to be low, activeness good and so on characteristics. Nanometer silicon may with the graphite either a carbon nanometer tube, or nanometer titanium nitrides and so on compound, makes lithium battery’s cathode material, may enhance lithium battery’s capacity and the service life. Is the new generation electro-optic semiconducting material, has the wide gap energy.

How is Silicon Si powder produced?
Silicon with a purity of 96-99% is made by reducing quartzite or sand with high-purity coke. The reduction is carried out in an electric arc furnace, and the excess SiO2 is used to prevent the accumulation of silicon carbide (SiC):
SiO 2 + 2 C→Si + 2 CO
2 SiC + SiO 2 →3 Si + 2 CO
This reaction is called the carbothermal reduction of silicon dioxide and is usually carried out in the presence of scrap iron, which contains a small amount of phosphorus and sulfur, thereby forming ferrosilicon. Ferrosilicon is an iron-silicon alloy containing different proportions of elemental silicon and iron, accounting for about 80% of the world's elemental silicon production. Ferrosilicon is mainly used in the steel industry), mainly used as an alloy additive in iron or steel, and Used for steel deoxidation in integrated steel plants. Another reaction sometimes used is the thermite reduction of silica, as shown below:
3 SiO 2 + 4 Al→3 Si + 2 Al 2 O 3
Leaching 96-97% of powdered pure silicon with water can produce ~98.5% pure silicon for use in the chemical industry. However, for semiconductor applications, even higher purity is required, which is produced by reducing tetrachlorosilane (silicon tetrachloride) or trichlorosilane. The former is made by chlorinating waste silicon, while the latter is a by-product of organic silicon production. These compounds are volatile, so they can be purified by repeated fractional distillation and then reduced to elemental silicon using very pure zinc metal as a reducing agent. The resulting sponge-like silicon wafers are melted and then grown to form cylindrical single crystals, which are then refined through zones. Other routes use silane or tetraiodosilane (SiI4).
Another method used is to reduce sodium hexafluorosilicate, a common waste product in the phosphoric acid fertilizer industry, with metallic sodium: this is highly exothermic and therefore does not require an external fuel source. Ultra-fine silicon has a higher purity than almost all other materials: the production of transistors requires that the impurity level of silicon crystals is less than 10 per 10 1 part, and the impurity content of less than 12 per 101 part is needed and obtained under special circumstances.

Applications of Silicon Si powder:
Silicon powder is finely processed by crushing, purifying, grinding, grading and other processes using silicon dioxide (SiO2), also known as quartz. It has high purity, white color and reasonable particle gradation, and has unique properties and a wide range of uses.
Silica fume is an efficient active admixture, which can significantly improve the strength, impermeability, frost resistance and durability of concrete. The characteristics of silica fume concrete have attracted people's attention, and silica fume concrete is widely used in water conservancy and hydropower engineering, construction engineering, highway engineering and bridge engineering.
(1) Good insulation: Due to the high purity of silicon powder, low impurity content, stable performance, and excellent electrical insulation, the cured product has good insulation and arc resistance.
(2) It can reduce the exothermic peak temperature of the curing reaction of the epoxy resin, reduce the linear expansion coefficient and shrinkage rate of the cured product, thereby eliminating the internal stress of the cured product and preventing cracking.
(3) Corrosion resistance: Silica powder is not easy to react with other substances, and does not chemically react with most acids and alkalis. Its particles are uniformly covered on the surface of the object, and it has strong corrosion resistance.
(4) The particle gradation is reasonable, which can reduce and eliminate precipitation and delamination during use; it can increase the tensile and compressive strength of the cured product, improve the wear resistance, and increase the thermal conductivity of the cured product and increase the resistance. Combustion performance.
(5) Silica powder treated with silane coupling agent has good wettability to various resins, good adsorption performance, easy to mix, and no agglomeration.
(6) Silica powder is used as a filler and added to the organic resin, which not only improves the performance of the cured product but also reduces the product cost.

Storage conditions of silicon powder
This product should be stored in dry, cool and sealing of the environment, can not be exposure to air, in addition should avoid the heavy pressure, according to ordinary goods transportation.
Packaging of silicon powder
Vacuum packing of nano silicon powder , 1kg/bag, or as your request.

Silicon Si powder Properties

Other Names Silicon Si powder, Si, Si powder, nano silicon powder
CAS No. 7440-21-3
Compound Formula Si
Molecular Weight 28.08 g/mol
Appearance brown, or silvery
Melting Point 1414°C 
Boiling Point 2900°C 
Density 2330kg/cm3
Purity >99.95%
Electrical Resistivity 3-4 microhm-cm @ 0 °C
Poisson's Ratio 0.064 - 0.28
Specific Heat 0.168 Cal/g/K @ 25 °C
Thermal Conductivity 1.49 W/cm/K @ 298.2 K
Thermal Expansion  (25 °C) 2.6 µm·m-1·K-1
Young's Modulus 51-80 GPa
Exact Mass N/A
Monoisotopic Mass N/A

Silicon Si powder Health & Safety Information

Safety Warning Warning
Hazard Statements H315-H319-H335
Hazard Codes H228
Risk Codes 11
Safety Statements 16-33-36
RTECS Number VW0400000
Transport Information UN 1346 4.1/PG 3
WGK Germany 2
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