Amorphous silicon powder with active
chemical properties, can burn in oxygen.7~99. Then melt it and crystallization, use acid
to remove impurities, get the purity of 99. Amorphous silicon powder is dark gray powder,
is in fact a microcrystal. Is sell as
polycrystalline, single crystal morphology, the formal is cheap, the latter is expensive. It can react with halogen, nitrogen,
carbon and other non-metallic at high temperature, also can react with
magnesium and calcium, iron and other metals, form of silicide.99% Si of silicon metal ),
the remaining impurities is iron, aluminium, calcium. Concentrated sodium hydroxide solution can dissolve the amorphous silicon
powder, release hydrogen. Custom CNC parts Semiconductor silicon
used in producing semiconductor device of high purity silicon metal.32 to 2.
Silicon metal smelting is a high
energy-consuming production, Chinese silicon metal production has
long-standing, along with the national energy policy tightening and energy
saving, and emission reduction and new energy development advocating, metal
silicon smelting has become the primary products and technology, many of Chinese
new energy industry construct metal silicon, polycrystalline silicon,
monocrystalline silicon, solar cell and other a series of cycle of industrial
chain, in the next few years will inevitably affect the development of the
field of energy and new energy applications. The produced silicon
purity is 97~98%, called silicon metal. Through the above process and device to
remove impurities in silicon, make the silicon metal purified into ultra pure
silicon products.
According to statistics, in 1985 the world total consumption of silicon metal
is about 500000 tons, the silicon which is used for aluminum alloy metal is accounted
for about 60%, for the silicone is less than 30%, for semiconductor is accounted
for about 3%, others used for steel smelting and precision ceramic.
Metallic silicon can be used for preparing
super pure silica, through crushing the raw material, impurity compounds,
crystallization purification of three sequential steps of principle, adopts the
combination of various procedures operations: the metal silicon broken into
fine particles to increase the surface area; pass into the oxygen, chlorine,
hydrochloric acid in the silicon particles, conduct combination reaction in the
silicon impurity, in order to make the impurities in silicon generated into oxide
or chloride by high temperature; use high temperature to make low sublimation
temperature chloride evaporation removal, again using the individual element
segregation coefficient and oxide eutectic solidification characteristics, with
the intermediate technology or directional solidification technique further
removal the impurities in silicon. Crystalline silicon is less active, even at high
temperatures will not react with oxygen, it will not dissolve in any kind of
inorganic acid and organic acid, but soluble in nitric acid and hydrofluoric
acid mixed acid and concentrated sodium hydroxide solution. Amorphous silicon
powder is virtually insoluble in all including hydrofluoric acid, inorganic
acid and organic acid, but soluble in nitric acid and hydrofluoric acid mixed
acid.34 g
/ cm 3, Mohs hardness is 7, brittle.At present,
the international general put the silicon goods into metal silicon and
semiconductor silicon. Silicon metal is made of quartz and coke in the electric
heating furnace smelted into products, principal component silicon content is
about 98% ( in recent years, also have content 99. Silicon has amorphous
silicon powder and
amorphous silicon two allotropes.
In industry, metal silicon is usually prepared
by reduction of silica in an electric furnace carbon.
Source:. Crystalline silicon has the crystal structure of
diamond and semiconductor properties, the melting point is 1410 ,
boiling point is 2355,
the density is 2.
Due to its different use, it is divided into a variety of specifications. Silicon metal
component is silicon, thus having similar properties with silicon.8% silicon metal
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