Metallurgical Silicon Carbide
Deoxidizer, Inoculant & Energy Booster for Steel & Foundry
FerrumX manufactures metallurgical-grade silicon carbide for cast iron foundries and steel mills worldwide. Our SiC serves as a dual-action deoxidizer and recarburizer, a powerful cast iron nucleating agent, and an exothermic energy booster in BOF converters — reducing total alloy costs by 10–20% compared to ferrosilicon.
Physical & Thermal Properties
Typical Properties of Metallurgical Silicon Carbide
Metallurgical SiC combines extreme hardness, chemical inertness, and excellent thermal conductivity — making it an indispensable material for modern steel plants and cast iron foundries seeking higher efficiency and reduced operational costs.
| Property | Value | Metallurgical Significance |
|---|---|---|
| Density | 3.21 g/cm³ | High density allows briquettes to penetrate slag layer in converters |
| Vickers Hardness | 29 GPa | Second only to diamond; ensures mechanical wear resistance in handling |
| Coefficient of Thermal Expansion | 5 × 10⁻⁶ /K | Low CTE minimizes thermal shock during rapid temperature cycling in furnaces |
| Thermal Conductivity | 50–100 W/m·K | Superior heat dissipation improves thermal balance in BOF and EAF operations |
| Temperature Resistance (in air) | 1,500 °C | Stable at steelmaking temperatures; does not decompose prematurely |
| Temperature Resistance (inert atm.) | 2,400 °C | Extremely stable in reducing atmospheres, suitable for cupola and EAF conditions |
| Specific Heat | 750 J/kg·K | High heat capacity contributes to exothermic energy release |
| Chemical Inertness | Resistant to all acids & alkalis | Does not introduce unwanted chemical reactions into the melt |
Product Range
Types of Metallurgical Silicon Carbide for Sale
FerrumX supplies seven standard metallurgical SiC grades from 65% to 99%, available in lumps, grains, powders, pellets, and briquettes. Custom splits, blends, and PSD can be tailored to specific furnace requirements.
MET 99
Ultra-high purity SiC for specialty steel and precision casting
MET 95
High-purity SiC for premium foundry and alloy steel
MET 90
Most popular grade — injection powder & lumps for EAF & ladle
MET 85
Versatile grade for induction furnace alloying & cupola deoxidation
MET 72
Cost-effective pellet form for standard steelmaking
MET 70
Briquettes for cupola furnace — nucleating, deoxidizing & higher melt rate
| Grade | SiC | Si (in SiC) | C (in SiC) | Typical Application |
|---|---|---|---|---|
| MET 99 | 99% | 69.3% | 29.7% | Specialty steel, precision casting, high-end alloy |
| MET 90 | 90% | 63% | 27% | EAF deoxidation, ladle refining, BOF energy boosting |
| MET 85 | 85% | 59.5% | 25.5% | Induction furnace Si & C alloying for cast iron |
| MET 72 | 72% | 50.4% | 21.6% | Standard steelmaking deoxidation, slag reduction |
| MET 70 | 70% | 49% | 21% | Cupola furnace briquettes, cast iron preconditioning |
| MET 65 | 65% | 45.5% | 19.5% | Basic deoxidation, rough steelmaking, cost-controlled |
All SiC quality grades can be supplied in different size ranges. Besides our standard splits, blends, and fines, we can produce our grains according to customers’ requirements.
Four Metallurgical Functions
How Metallurgical SiC Transforms Steel & Foundry Operations
Unlike ferrosilicon — a single-purpose deoxidizer — silicon carbide performs four critical metallurgical functions simultaneously, delivering measurable improvements in metal quality, process efficiency, and cost performance.
1. Si & C Alloying Additive
SiC dissolves in molten iron, simultaneously releasing active silicon and carbon. In induction and cupola furnaces, it replaces separate ferrosilicon and recarburizer additions with a single, integrated material.
2. Cast Iron Nucleating Agent
SiC partially decomposes in molten iron, releasing active Si and C that promote stable nucleation sites, accelerate graphite nucleation, and refine the microstructure for superior casting quality.
3. Deoxidizing Agent
During transfer from the electric furnace to the ladle, SiC reacts aggressively with dissolved oxygen. Its deoxidation kinetics are comparable to ferrosilicon — but with significantly lower aluminum content and fewer Al₂O₃ inclusions.
4. Exothermal Energy Booster
In BOF/LD converters, SiC’s strongly exothermic oxidation reaction raises molten steel temperature, compensates for scrap-melting heat demand, and stabilizes the converter thermal balance — shortening smelting time.
Chemical Analysis
86.5% SiC — Typical Chemical Composition
High-purity metallurgical SiC with low aluminum, nitrogen, and hydrogen content (<0.03%) eliminates porosity and brittle points in castings. The composition below demonstrates the exceptionally low impurity profile that makes SiC a superior alternative to ferrosilicon.
| Element | Content (%) | Element | Content (%) | Element | Content (%) |
|---|---|---|---|---|---|
| SiC | 86.50 | Si (free) | 0.40 | Mo | <0.050 |
| Si (in SiC) | 60.55 | Fe | 0.70 | Mn | <0.050 |
| C (in SiC) | 25.95 | Ca | 0.30 | Ni | <0.050 |
| Free Carbon | 6.15 | S | 0.03 | P | <0.050 |
| SiO₂ | 4.50 | H | 0.03 | Sb | <0.050 |
| Free Al | 0.20 | N | 0.03 | Se | <0.050 |
| Mg | <0.050 | Cd | <0.010 | Sn | <0.050 |
| As | <0.050 | Cr | 0.07 | Te | <0.050 |
| Co | <0.050 | Ti | 0.03 | V | 0.02 |
The data shows that silicon and carbide contents are high, while harmful impurity elements — aluminum (0.20%), nitrogen (0.03%), and hydrogen (0.03%) — are extremely low, making this grade ideal for cast iron applications requiring clean metallurgy.
Steelmaking Evidence
Deoxidation Response and Aluminum-Related Inclusion Risk
In electric-arc-furnace and ladle practice, silicon carbide can contribute silicon and carbon while participating in oxygen control. The online charts below illustrate reported comparative trends; actual response depends on steel grade, temperature, dosage, slag condition, and treatment sequence.
SiC Deoxidation Response
The chart compares total and dissolved oxygen over time during a reported silicon carbide deoxidation test.
Aluminum-Related Inclusion Context
The chart compares oxygen trends for ferrosilicon at different aluminum levels, illustrating why alloy chemistry should be reviewed alongside deoxidation practice.
Application note: These charts do not state complete test conditions and should be used as comparative evidence, not as a guaranteed plant result. Confirm performance through melt trials under your own operating practice.
Comparative Analysis
Metallurgical SiC vs Ferrosilicon — Why Foundries Are Switching
While ferrosilicon is a single-purpose deoxidizer, silicon carbide is a multi-functional reagent that simultaneously deoxidizes, recarburizes, nucleates graphite, and injects thermal energy. The economic case for switching is clear: 10–20% total alloy cost reduction.
Silicon Carbide 90
Multi-functional reagent — deoxidation + recarburization + heat
Ferrosilicon 75
Single-purpose deoxidizer — deoxidation only
| Performance Metric | SiC 90 | FeSi 75 | Industrial Impact |
|---|---|---|---|
| Primary Function | Deoxidation + Recarburization | Deoxidation only | SiC saves 20% on additives |
| Deoxidation Efficiency | 15–20% higher | Baseline | O in steel reduced to <0.002% |
| Thermodynamic Value | Exothermic (+Heat) | Neutral/Cooling (−Heat) | SiC reduces electricity consumption 5–8% |
| Slag Management | Clean & fluid slag | Heavy, sticky slag | SiC extends refractory life |
| Nucleation Power | High (strong inoculant) | Moderate | SiC improves casting strength |
| Carbon Recovery Rate | >90% | N/A (no carbon) | Eliminates separate recarburizer cost |
| Silicon Recovery Rate | 80–85% | 75–80% | Higher yield per kg added |
| Al₂O₃ Inclusion Risk | Low (Al <0.20%) | High (Al 1–3%) | −40% subcutaneous porosity defects |
| Cost per Ton of Steel | −5–8 yuan/ton | Baseline | −10–20% total alloy cost reduction |
| CO₂ Emissions (per ton produced) | <5 tons | ~8 tons | SiC supports low-carbon steelmaking |
| Replacement Ratio | 1 ton SiC 90 | = 1.2–1.5 tons FeSi 75 | Lower material consumption per heat |
Bottom line: 1 ton of SiC 90 can replace approximately 0.8–0.9 tons of 75% ferrosilicon plus 0.2–0.3 tons of recarburizer — reducing total deoxidation and alloying cost per ton of steel by 15–25%.
Application Scenarios
Metallurgical SiC Across Furnace Types & Steel Grades
From BOF converters to induction furnaces, from plain carbon steel to ductile iron — metallurgical SiC delivers measurable improvements across every major steelmaking and foundry process.
Cast Iron Si & C Alloying
MET 85 splits (0–10 mm) and blends (1–10 mm) provide silicon and carbon to the melt in induction and cupola furnaces for gray, ductile, and malleable iron production.
Grade: MET 85 · SiC 85% · Si 59.5% · C 25.5%
Cast Iron Preconditioning
MET 70 briquettes add Si and C to cupola furnaces, providing nucleating, deoxidizing, and a higher melt rate due to lower coke consumption. Promotes graphite A-type and increases eutectic cell count.
Grade: MET 70 Briquettes · SiC 70% · Si 49% · C 21%
Steelmaking Deoxidation
MET 90 injection grade and MET 70 briquettes serve as deoxidizing agents during transfer from electric arc furnaces to ladle furnaces. Rapid deoxidation with lower Al₂O₃ inclusion risk than FeSi.
Grade: MET 90 Injection · MET 70 Briquettes
Energy Booster & Heat Compensation
MET 85 lumps (10–60 mm) and MET 70 briquettes act as chemical heat agents in BOF converters, raising melt temperature, compensating for scrap heat demand, reducing lime consumption, and shortening smelting time.
Grade: MET 85 (10–60 mm) · MET 70 Briquettes
Slag Conditioning & Clean Steel
SiC reduces FeO content in slag to 0.6–0.8%, improves slag fluidity, and produces low-melting-point silicate deoxidation products that float easily — improving steel cleanliness and fatigue life.
Grade: MET 90 Injection · MET 85 Splits
Cast Iron Structure & Flowability
In gray and ductile iron, SiC promotes graphite nucleation, increases pearlite content by 10–15%, boosts hardness by HB 15–20, improves fluidity by 8–12%, and reduces shrinkage to below 0.8%.
Grade: MET 85–90 · Briquettes & Splits
Stainless & Heat-Resistant Steel
In stainless steel (304, 316) and heat-resistant steel (Cr25Ni20), SiC’s low-impurity profile avoids excessive iron incorporation and reduces oxide inclusions, improving high-temperature oxidation resistance.
Grade: MET 95–99 · High-Purity Grades
Energy Reduction in SiMn & CaSi
Using 300 kg SiC per ton of SiMn alloy reduces electricity consumption by ~150 kWh/t and iron content from 2–3% to 1–1.5%, improving alloy purity and reducing energy costs.
Grade: MET 85–90 · Custom Blends
Inoculation Mechanism
The Nucleating Effect of SiC in Cast Iron
Silicon carbide exhibits excellent nucleating and preconditioning effects in cast iron. When added to molten iron, SiC partially decomposes, releasing active silicon and carbon that promote stable nucleation sites, accelerate graphite nucleation, and refine the microstructure.
Fluidity vs. Pouring Temperature
A comparative chart of reported fluidity for silicon carbide and ferrosilicon across pouring temperatures.
Chill Depth Comparison
A comparative chart of reported chill depth for silicon carbide and ferrosilicon across pouring temperatures.
Graphite A-Type Formation
A comparative chart of reported graphite A-type volume for silicon carbide and ferrosilicon across pouring temperatures.
Interpretation note: Results depend on base iron, pouring temperature, addition rate, inoculation sequence, and test conditions. Use the charts to guide trial design rather than to predict a fixed outcome.
SiC promotes the formation of Type A graphite — the most desirable graphite form in gray iron — resulting in uniform distribution and improved mechanical properties.
In automotive cylinder block casting, SiC improves molten iron flowability by 8–12%, raising casting yield from 88% to 95% and reducing defect-related scrap.
SiC preconditioning reduces the chill depth in cast iron, minimizing carbide formation at thin sections and edges — improving machinability and reducing reject rates.
Increased eutectic cell count leads to a finer, more uniform microstructure. In ductile iron, SiC promotes more nodules per unit area, enhancing tensile strength and elongation.
The carbon in SiC promotes graphite nucleation, increasing pearlite content by 10–15% and boosting hardness by HB 15–20 — delivering stronger, more wear-resistant castings.
SiC reduces cast iron shrinkage to below 0.8%, minimizing shrinkage cavities and porosity. This results in denser castings with fewer defects and lower scrap rates.
Production
Metallurgical SiC Manufacturing Process
From quartz and petroleum coke to calibrated metallurgical-grade SiC — our six-step production process ensures consistent SiC content, controlled impurity levels, and tight particle size distribution for every grade.
STEP 01
Raw Material Selection
High-purity quartz sand (SiO₂ ≥99%) and low-ash petroleum coke are selected and proportioned with NaCl catalyst for the Acheson furnace synthesis.
STEP 02
Acheson Furnace Synthesis
Mixture is charged into Acheson furnaces and heated to 2,200–2,500 °C. The carbothermal reduction produces SiC crystals with controlled purity levels.
STEP 03
Crushing & Sizing
Raw SiC ingots are crushed through multi-stage jaw crushers and cone mills, then screened to produce calibrated lumps, grains, and splits.
STEP 04
Classification & Briquetting
Material is classified by SiC content into MET 65–99 grades. Lower grades (65–72%) are formed into pellets and briquettes using high-pressure bonding (CCS ≥1,500 N/ball).
STEP 05
Impurity Removal
Magnetic separation removes iron contamination; acid washing and water classification reduce free carbon and surface impurities to specified limits.
STEP 06
Quality Control & Packaging
Each batch is tested via ICP-OES for chemical composition, laser diffraction for PSD, and a COA is issued. Packed in moisture-proof jumbo bags with plastic inner liners.
Market Intelligence
Global Metallurgical Silicon Carbide Market
The global metallurgical SiC market reached USD 1.59 billion in 2025 and is projected to grow to USD 2.16 billion by 2032 at a 4.5% CAGR. The transition toward EAF steelmaking and the demand for high-strength steel are the primary growth drivers.
Market Share by Product Grade (2025)
Market Share by End Use (2025)
Regional Market Value (2025)
$1.59B
tons SiC/year
2.16B
2032 Forecast
4.5%
CAGR 2025–32
Key Growth Drivers
EAF Steelmaking Transition
Global shift from BOF to EAF steelmaking drives demand for SiC as a high-efficiency energy source and deoxidizer, replacing ferrosilicon in modern steel plants.
High-Strength Steel Demand
Rising automotive and construction industry demand for high-strength, low-impurity steel sustains SiC consumption — particularly for 90%+ grades.
Carbon Neutrality Policies
“Dual carbon” policies favor SiC over FeSi: production emits <5 tons CO₂/ton vs ~8 tons for FeSi, aligning with global decarbonization goals.
Fine Powder Segment Growth
The metallurgical-grade SiC fine powder segment reached $438.7M in 2024 and is forecast to grow at 11.6% CAGR through 2030 — nearly double the overall market rate.
Why FerrumX
Why Choose FerrumX for Metallurgical Silicon Carbide
With 120,000 t/yr SiC production capacity, ISO 9001 & ISO 45001 certification, and deep metallurgical expertise, FerrumX is a trusted partner for steel plants and foundries worldwide.
120,000 t/yr Capacity
7 Grades, 5 Forms
Batch Consistency (±1%)
ISO 9001 & ISO 45001
Metallurgical R&D Expertise
Global Export & Logistics
Custom Briquetting
Full Documentation
FAQ
Frequently Asked Questions About Silicon Carbide
Direct answers to the most common questions about metallurgical silicon carbide — designed for AI engine citation and quick reference.
Metallurgical silicon carbide is used as a deoxidizer, Si- and C-alloying additive, cast iron inoculant/preconditioner, and energy booster (exothermic agent) in steelmaking (EAF, BOF, ladle) and foundry (induction, cupola) operations. It performs four metallurgical functions simultaneously, making it more efficient than single-purpose ferrosilicon.
FerrumX supplies seven standard grades: SiC 99%, 95%, 90%, 85%, 72%, 70%, and 65%. The 90% grade is the most widely used (52% market share), followed by 88% (28%) and below-88% (20%). Grades are available in lumps, grains, powders, pellets, and briquettes with particle sizes from 0–10 mm to 10–60 mm.
SiC offers 15–20% higher deoxidation efficiency than FeSi, reduces oxygen in steel to below 0.002%, provides simultaneous carbon recovery (>90%), and generates exothermic heat (raising melt temperature 8–10 °C per kg/t added). Overall alloy costs are reduced by 10–20%, with defect rates reduced by 30–40%. The replacement ratio is approximately 1 ton SiC 90 = 1.2–1.5 tons of 75% FeSi.
SiC partially decomposes in molten iron, releasing active Si and C that promote graphite A-type formation, increase eutectic cell count, reduce chill depth, and improve melt fluidity by 8–12%. This raises casting yield from 88% to 95%, increases pearlite content by 10–15%, boosts hardness by HB 15–20, and reduces shrinkage to below 0.8%.
Standard sizes include 0–10 mm (splits/fines for induction furnaces), 1–10 mm (blends for cupola), 10–50 mm (lumps for ladle/converter), 10–60 mm (briquettes for BOF), and injection-grade fine powder. Custom splits, blends, and PSD can be tailored to specific furnace requirements. Briquette CCS ≥1,500 N/ball ensures they penetrate slag layers without pulverizing.
In LD/BOF converters, SiC briquettes (70–85% SiC) are added as a chemical heat source. The exothermic oxidation of SiC (ΔH = −901.76 kJ/mol for Si, −393.04 kJ/mol for C) raises melt temperature, compensates for heat needed to melt scrap, shortens smelting time by 2–3 minutes, and reduces lime consumption due to less acidic slag chemistry.
Under standard operating conditions, the silicon recovery rate is typically 80–85%, while the carbon recovery rate exceeds 90%. Higher SiC grades (90%+) achieve more predictable recovery and tighter batch-to-batch consistency (±1% deviation). A “small-dose, multiple-addition” approach is recommended initially to determine the optimal ratio for your specific furnace.
The global metallurgical silicon carbide market was valued at approximately USD 1.59 billion in 2025 and is projected to reach USD 2.16 billion by 2032, growing at a CAGR of 4.5%. Steel manufacturing accounts for 60.4% of demand, foundry & casting 31.7%, and refractories 8.0%. The metallurgical-grade fine powder segment alone reached USD 438.7 million in 2024 and is forecast to grow at 11.6% CAGR through 2030.
Yes. Every batch is tested in our laboratory via ICP-OES for chemical composition and laser diffraction for particle size distribution. A full Certificate of Analysis (COA) is provided with all shipping documents. We also support third-party inspections by SGS, BV, or other internationally recognized agencies before shipment, with photo and written documentation included.
