Silicon metal is smelted from silica with a carbon reductant in a submerged-arc furnace. The industrial grade on this page is about 98% silicon, with iron, aluminum and calcium as the main residual impurities.
HSALLOY lists silicon metal as lumps or granules, silver-grey to dark grey with a metallic luster. The metal has a high melting point, high resistivity and is brittle. Buyers use it as an alloying addition in aluminum, as a deoxidizer in non-ferrous and special-steel melts, and as a feedstock for silicone oils in the chemical industry. Sister pages cover the named grades 553, 441 and 421.
Specification
| item | value |
|---|---|
| Si (approx.) | ~98% |
| CAS | 7440-21-3 |
| EINECS | 231-130-8 |
| Formula | Si |
| Molecular weight | 28.0855 |
| HS code | 2804.6900 |
| Appearance | Lump or powder granule, silver grey or dark grey, metallic luster |
Purity figure and identifiers taken from the source product page. Company grade article: industrial reduction SiO2 + 2C → Si + 2CO gives 97–98% Si; further melt / recrystallize / acid refine reaches 99.7–99.8%. Crystalline silicon melting point 1410 °C, boiling point 2355 °C, Mohs 7 — figures from the same article.
Where it is used
- Aluminum-alloy addition and non-ferrous deoxidation
- Special steel and silicon-steel alloying
- Chemical feedstock for dimethyl, amino, hydrogen and hydroxyl silicone oils, emulsifiers and defoamers
Process notes
- High melting point and heat resistance
- High resistivity; conductive in the high-temperature melt
- Brittle, strongly antioxidant in use
Questions buyers ask
What grades sit under this listing?
The company catalog also publishes Silicon Metal 553, 441 and 421. The grade article lists 553, 441, 411, 421, 3303, 3305, 2202, 2502, 1501 and 1101 as the usual Fe / Al / Ca codes.
Typical size and packing?
10–100 mm lumps in 1 MT big bags.
Main industries?
Aluminum alloys, special steel, and silicone chemicals.