Metallurgical Grade Silicon Carbide (SiC) Deoxidizer: Cost-Effective Solutions for Steel Deoxidation & Slag Conditioning

In Electric Arc Furnace (EAF) and Basic Oxygen Furnace (BOF) steelmaking, tapping deoxidation efficiency and alloy recovery directly determine the overall cost per ton of liquid steel. Traditional deoxidation relying on Ferrosilicon (FeSi75) combined with petroleum coke recarburizers not only incurs high material costs, but also frequently causes poor slag fluidity, Submerged Entry Nozzle (SEN) clogging during continuous casting, and re-sulfurization risks.

Metallurgical Grade Silicon Carbide Deoxidizer (SiC) is a strong exothermic composite deoxidizing agent. By leveraging the synergistic reduction of Si and C during tapping and Ladle Furnace (LF) refining, SiC enables deep deoxidation and recarburization, serving as an ideal metallurgical additive to replace expensive ferrosilicon and optimize slag performance in modern steel mills.


       


Metallurgical Mechanisms & Solutions for Steel Mill Pain Points

1. Significantly Lower Deoxidation & Recarburization Costs


  • Pain Point: Volatile market prices of Ferrosilicon (FeSi 75%) increase tapping costs per ton of steel.

  • Solution: SiC contains 88%–95% active silicon carbide. In the deoxidation reaction, 1 kg of SiC theoretically replaces approximately 1.15 kg of Ferrosilicon (FeSi75) and 0.35 kg of recarburizer. By partially or completely replacing Ferrosilicon, steel mills can reduce deoxidation material procurement costs by 15%–25%.


2. Strong Exothermic Effect & Thermal Compensation


  • Pain Point: Severe heat loss during tapping leads to higher power consumption or longer oxygen blowing during refining.

  • Solution: The reaction between silicon carbide and dissolved oxygen in liquid steel (SiC + 2[O] → SiO₂ + CO↑) is strongly exothermic. Adding 1 kg of SiC provides noticeable thermal compensation to the melt, helping stabilize tapping temperatures and shortening LF heating cycles.


3. Improved Slag Fluidity & Reduced SEN Clogging


  • Pain Point: Corundum inclusions (Al₂O₃) generated by aluminum deoxidation readily adhere to the inner wall of the tundish nozzle, leading to interrupted continuous casting.

  • Solution: Microscopic SiO₂ generated by SiC deoxidation rapidly reacts with CaO in the slag to form a low-melting calcium silicate slag system. This enhances slag fluidity while promoting the flotation and absorption of deoxidation products, significantly minimizing the risk of nozzle clogging


Chemical & Physical Specifications

We supply tailored chemical grades and particle sizes based on your specific melting practice (EAF, BOF, or secondary refining):


Chemical / Physical Parameter
SiC 95% Grade (Premium)
SiC 90% Grade (Standard)
SiC 88% Grade (Economic)
SiC (Silicon Carbide)
≥ 95.0%
≥ 90.0%
≥ 88.0%
Free C
≤ 1.5%
≤ 2.5%
≤ 3.5%
Fe₂O₃
≤ 0.8%
≤ 1.2%
≤ 1.5%
S (Sulfur)
≤ 0.05%
≤ 0.08%
≤ 0.10%
P (Phosphorus)
≤ 0.03%
≤ 0.04%
≤ 0.05%
Standard Sizing
0–10 mm, 1–5 mm, 1–10 mm
0–10 mm, 10–50 mm
10–50 mm, 压块 (Briquettes)

Particle Size Control Note: Sizing can be custom-screened for ladle bottom placement or wire-injection systems. Fines content is strictly kept below 3% to prevent dust loss caused by de-dusting exhaust systems.


Economic Comparison: SiC Deoxidizer vs. Traditional "FeSi + Recarburizer"

Estimated tapping deoxidation cost comparison for an EAF steel mill with an annual output of 1,000,000 tons of carbon/low-alloy steel:


Evaluation Metrics
Traditional Solution (FeSi 75% + Petroleum Coke)
Optimized Solution (SiC Composite Deoxidizer)
Metallurgical Benefits
Primary Additive Combo
Ferrosilicon 75% + Petroleum Coke
SiC Deoxidizing Grains / Briquettes
Material unit cost reduced by 20%+
Oxygen Activity Control (a[O])
Long refining needed to reach 20–30 ppm
Rapidly drops to 15–20 ppm
Shortens LF refining time by 3–5 min
Alloy Yield / Recovery
Silicon recovery ~75%
Si recovery ≥ 82%, C recovery ≥ 85%
Substantially higher alloy recovery rates
Continuous Casting Sequence Rate
Requires frequent nozzle flushing or Ca-wire treatment
Inclusions float efficiently with minimal nozzle buildup
Sequence casting heats increased by 15%–20%

Standard Operating Procedure for Ladle Deoxidation

To ensure SiC deoxidizer reacts completely at the bottom of the ladle, the following ladle bottom placement method is recommended:


1.1. Ladle Bottom Pre-Addition:When 1/10 of tapping is complete。

When about 10% of total liquid steel is tapped into the ladle from the BOF or EAF, drop the pre-weighed SiC deoxidizer (along with appropriate lime) into the tapping impact zone at the ladle bottom.

2.2. Tapping Impact & Agitation:Driven by liquid steel stream impact。

Utilize the thermal energy and kinetic impact of the falling steel stream to rapidly dissolve SiC. Microscopic CO gas bubbles generated during reaction bubble upward, stirring the liquid steel and accelerating inclusion flotation.

3.3. Slag Conditioning:At the LF refining station。

Upon arrival at the LF station, adjust slag with fine-grain SiC based on measured oxygen activity to quickly form a white, weakly reducing slag system.

4.4. Final Composition & Temperature Inspection:Prior to continuous casting。

After completing deoxidation and micro-alloying adjustments, perform spectral analysis and temperature measurements before sending the ladle to the continuous casting machine.


Quality Assurance & Global Export Packaging

To address concerns regarding batch consistency and transportation degradation for overseas buyers, we maintain strict quality control and export packaging protocols:


  1. Rigorous Size Screening: Multi-layer vibrating screens perform secondary screening to remove fines, ensuring materials are not drawn away by dust collection systems during furnace addition.

  2. Moisture-Proof Sealed Packaging: Packed in 1000 kg jumbo bags with an inner PE moisture-proof liner and bottom discharge spout. Rainproof and moisture-proof for long-distance sea freight and open-air storage.

  3. Certified Test Reports: Every batch comes with a factory Certificate of Analysis (COA). Third-party inspection certificates from SGS, AHK, or Intertek are available upon request.



Welcome to your inquiry!

Service Hotline:+86 15837207537    Whatsapp:8615837207537    Email:info@lsalloy.com