Metal Slicon

Silicon metal can be classified according to the content of three main impurities of iron, aluminum and calcium contained in it, Which can be divided into 553, 441, 411, 421, 3303, etc. different grades.

Industrially, metallic silicon is usually produced by reducing silica with carbon in an electric furnace.

Chemical reaction equation: SiO2 + 2C → Si + 2CO
The purity of silicon obtained in this way is 97~98%, which is called metal silicon. It is then melted and recrystallized, and impurities are removed with acid to obtain metallic silicon with a purity of 99.7~99.8%.
The composition of metal silicon is mainly silicon, so it has similar properties to silicon.
Crystalline silicon is relatively inactive, it does not combine with oxygen even at high temperature, it is insoluble in any inorganic acid and organic acid, but it is soluble in mixed acids of nitric acid and hydrofluoric acid and concentrated sodium hydroxide solution.
A large amount of silicon is used for smelting into ferrosilicon alloy as an alloying element in the iron and steel industry, and as a reducing agent in the smelting of many kinds of metals. Silicon is also a good component in aluminum alloys, and most cast aluminum alloys contain silicon.