Introduction
Q1: Why does size change which process step FeSi75 fits best?
Because each step has a different "reaction environment." In the furnace or during tapping you have more time and higher turbulence. In the ladle or late trimming you usually need faster response and tighter control. Smaller sizes dissolve faster but can generate more dust loss; larger sizes dissolve more slowly but handle better and react more calmly.
So the right question is not "which size is best," but "where am I adding it, and how fast do I need it to act?"
Here's a simple reference table used in many real trade discussions.
| FeSi75 Size/Form | Typical Process Stage Where It Fits Best | Why It Works There |
|---|---|---|
| 10–100 mm lumps | Furnace addition, early alloying | Slow, steady dissolution; robust handling |
| 10–50 mm lumps | Tapping stream, general alloying | Good balance of handling and melting speed |
| 3–10 mm granules | Ladle alloying, controlled additions | Faster dissolution; better dosing accuracy |
| 1–5 mm granules | Late trimming, small corrections | Quick response when timing is tight |
| 0–3 mm fines | Special controlled systems only | Very fast, but higher dust/loss risk if unmanaged |
This isn't a strict rule, but it's a reliable starting point.
Q2: Which FeSi75 sizes are most suitable for furnace addition?
For furnace addition, lumps are usually preferred (10–50 mm or 10–100 mm). Furnace conditions give the material time to dissolve, and the bigger size reduces dust loss during charging. If you don't need an instant chemistry change, lumps usually give stable results with less mess.
Q3: What sizes work best for tapping or in-stream addition?
Many operations like 10–50 mm lumps for tapping because they melt fast enough in a turbulent stream but still handle well. If the size is too large, dissolution can lag. If it's too fine, you may lose material as dust before it enters the melt effectively.
If you're trying to keep recovery steady, tapping-stage additions often benefit from a consistent lump size and controlled fines.
Q4: What sizes are most suitable for ladle additions and alloy trimming?
These steps usually reward granules, because reaction speed and control become more important:
3–10 mm is a common "safe" choice: fast enough, still manageable.
1–5 mm is often used when you need quick corrections and tight timing, especially if you have good dosing control.
If ladle additions feel inconsistent, it's often a sign the size range is mixed or the fines ratio is high.
Q5: When does very fine FeSi75 (0–3 mm) make sense?
Fine material can be useful in specific controlled systems, but it's not a universal solution. Fines can:
blow away during handling
oxidize faster in humid conditions
be trapped by slag more easily
react so quickly that overshoot becomes easier
So if you use fines, it's best when you have a controlled feeding method and your handling losses are managed by packing and unloading practices.
Conslusion
If your pain point is slow melting : consider moving from large lumps to 10–50 mm or 3–10 mm.
If your pain point is dust loss and messy handling : move away from fines and overly small sizes; use lumps or controlled granules.
About Our Products
We supply FeSi75 (also FeSi72 / FeSi65 / FeSi45) in common export sizes including 10–100 mm, 10–50 mm, 3–10 mm, 1–5 mm, and 0–3 mm, with stable screening and COA support.
If you want the fastest quotation, send:
grade (FeSi75/72/65/45)
size range + (optional) max fines %
quantity & packing (jumbo bags or 25 kg)
destination port & shipping window
We'll reply with the closest matching specification and a workable FOB/CIF offer.
