SiMn
Silico Manganese
An alloy of 65 to 68% manganese, 16 to 21% silicon and 1.5 to 2% carbon. It is smelted from the slag of high-carbon ferro manganese, or from manganese ore with coke and a quartz flux. Reducing quartz to silicon needs high temperatures and a lot of power.
Grades and chemistry
| Grade | Mn | Si | C | P | S |
|---|---|---|---|---|---|
| Low carbon | 60 | 14 | 11.5 max | 0.03 | 0.04 |
| Medium carbon | 60 | 14 | 2 | 0.03 | 0.04 |
| High carbon | 60 | 14 | 23 max | 0.03 | 0.04 |
| Special carbon | 65 | 17 | 2 | 0.03 | 0.04 |
Figures are percentages. Where a grade has a ceiling, it sits beneath the value.
Sizes, packing and use
Sizes
10–80 mm, 20–80 mm, 25–150 mm. Other lump sizes as per requirement.
Packing
1 ton jumbo bag or 50 kg jute bags.
Role in steelmaking
Deoxidiser and a combined manganese and silicon source for carbon and structural steel.