Silicon metal 553 is the metallurgical / chemical grade whose name encodes the three residual impurities the company uses to classify silicon: iron, aluminum and calcium. Silicon content on this page is approximately 98%.
The metal is smelted from silica in a submerged-arc furnace. Appearance is lump or granule, silver-grey or dark grey with metallic luster. Compared with tighter grades on this site (441, 421), 553 is the workhorse listing for buyers who specify the 553 code in aluminum foundries, special-steel shops and silicone intermediate plants.
Specification
| item | value |
|---|---|
| Grade | 553 |
| Si (approx.) | ~98% |
| Main residuals | Fe, Al, Ca (grade code 553) |
| CAS | 7440-21-3 |
| EINECS | 231-130-8 |
| Formula | Si |
| Molecular weight | 28.0855 |
| HS code | 2804.6900 |
No Fe / Al / Ca percentage table was published on the 553 product page. Do not invent those limits. Grade naming rule is explained on the company article “Silicon Metal grade”: codes such as 553 / 441 / 421 follow Fe, Al and Ca content.
Where it is used
- Aluminum alloy additions and non-ferrous deoxidation
- Special steel and silicon-steel alloying
- Silicone-oil intermediates: dimethyl, amino, hydrogen-containing and hydroxyl oils, emulsifiers, defoamers
Process notes
- High melting point, heat resistance and resistivity
- Brittle solid with metallic luster
- Used where a standard 553 impurity code is specified
Questions buyers ask
What does 553 mean?
On this site, silicon grades are named from the iron, aluminum and calcium residuals. 553 is one of the published codes; sister pages cover 441 and 421.
Silicon content?
Approximately 98% on the product page. The grade article describes 97–98% for industrial silicon after furnace reduction.
Packing?
1 MT big bag, size 10–100 mm.