PR 1680 DO
An 80% silicon carbide deoxidizer and taphole-clay aggregate for steelmaking and blast-furnace service.
PR-1680-DO is an 80% silicon carbide (SiC 80) composite deoxidizer and refractory aggregate. It deoxidizes carbon, alloy, and special steel while serving as the core aggregate in blast-furnace taphole clay.
What it is
What PR 1680 DO Is & Where It Is Used
PR 1680 DO is an 80% silicon carbide composite deoxidizer made by high-temperature smelting of quartz sand and petroleum coke. It suits deoxidation in carbon, alloy, and special steel, and can replace more expensive ferrosilicon powder and alloy powder.
Beyond deoxidation it is the core aggregate for blast-furnace taphole clay, filling the refractory matrix to raise slag resistance and thermal-shock stability at the iron taphole.
Deoxidation Mechanism
Deoxidation Mechanism
As a deoxidizer, PR 1680 DO reacts with dissolved oxygen to form SiO₂ and CO:
SiC + 3[O] → SiO₂ + CO↑. The reaction promotes oxygen diffusion into the slag and is exothermic, raising bath temperature. Unoxidized carbon and silicon dissolve into the melt, adding carburization and silicon enrichment.
In EAF reduction the high-temperature exothermic reaction shortens deoxidation time, reduces fluorite consumption and fluorine pollution, and improves element recovery. The carbon and silicon not oxidized further raise the bath’s carbon and silicon content.
Key Advantages
Key Advantages
PR 1680 DO combines deoxidation performance with refractory utility:
Rapid deoxidation
Early slag formation, strong reducing atmosphere, abundant foaming.
Better element recovery
Silicon absorption comparable to ferrosilicon; carbon recovery well above traditional carbon agents.
Also a carburizer
Partly replaces separate carbon-increasing agents.
Cleaner steel
Refines grain, removes harmful impurities, stabilizes quality.
Dust-free charging
Fast reaction, no dust pollution during charging.
Higher casting temperature
Better billet quality and lower unit cost.
Technical Specifications
Technical & Physical Specifications
Typical specifications for PR 1680 DO (80% SiC).
Typical specifications
| Item | Typical value |
|---|---|
| SiC Content | ≥ 80% |
| SiO₂ Content | ≤ 10% |
| Free Carbon (F.C.) | ≤ 10% |
| Fe₂O₃ Content | ≤ 1.0% |
| S Content | ≤ 0.05% |
| Moisture | ≤ 1% |
| Particle Size | 0–3 mm / 0–5 mm / 0–10 mm / 200 mesh (customizable) |
| Appearance | Black, light gray, or light green spherical/powdery |
Usage
Key Usage Points & Methods
Typical dosage is 3–6 kg per ton of steel. For ladle pre-deoxidation add 20–30% of the total to the ladle bottom before tapping, then add the remainder into the steel stream via a chute as tapping reaches one-third of ladle capacity, completing within 30 seconds.
In EAF reduction, skim 40–80% of the oxidized slag, add a little carbon powder, then charge the SiC deoxidizer in one or several batches; the slag whitens in about 5 minutes. Maintain the reducing atmosphere with further small additions.
For blast-furnace taphole clay the common grade is C80% 200#–0, with particles finer than 0.074 mm controlled above 80%. Silicon carbide content in large-furnace gunning mix is typically > 90%.
Applications
Applications
Deoxidation during converter tapping
Ladle-bottom pre-deoxidation plus stream addition for carbon, alloy, and special steel.
EAF reduction phase
With carbon powder to hold a reducing atmosphere and shorten deoxidation.
LF refining
Rapid white-slag formation for precise composition control.
Blast-furnace taphole clay
Core aggregate raising slag resistance and high-temperature strength.
Special steel smelting
High purity and deoxidation efficiency cut inclusions in special grades.
FAQ
PR 1680 DO — Frequently Asked Questions
Yes. Extensive practice shows 80% SiC fully replaces ferrosilicon and high-carbon manganese, with more stable chemistry, shorter deoxidation time, and lower cost.
Same mechanism, but 80% has lower S/N/H impurities — better suited to alloy and special steels needing higher purity.
Typically 3–6 kg per ton of steel, split between ladle-bottom pre-deoxidation and stream addition during tapping; adjust to grade and furnace.
The exothermic reaction raises temperature; 8 kg per ton gives an average +48.4 °C (range 40.3–70.3 °C) and cuts EAF power by 10–40 kWh/t.
C80% 200#–0 grade with sub-0.074 mm particles above 80%; SiC content in large-furnace mix typically > 90%.
Add when the bath is one-quarter to one-half melted; best results above 1620 °C. As a ferroalloy additive it improves molten-iron fluidity and acts as an inoculant.
