Silicon Carbide for Refractories
Engineered for Extreme Heat
High-purity SiC grains and powders designed for kiln furniture, blast furnace bricks, tap hole clay, monolithic castables, and heat exchanger components. Five SiC grades (90–99%), customised PSD, low magnetic iron, and ready-to-press granules.
Why Silicon Carbide for Refractory Applications?
Silicon carbide outperforms traditional alumina-silicate refractories in thermal conductivity, thermal shock resistance, abrasion resistance, and chemical inertness — extending furnace campaign life by 2–3×.
3.21
Density (g/cm³)
29 GPa
Vickers Hardness
50–100
Thermal Cond. (W/m·K)
2400°C
Max Temp (Inert)
5×10⁻⁶
CTE (/K)
750
Specific Heat (J/kg·K)
1500°C
Max Temp (Air)
Mohs 9
Abrasion Rating
Typical Properties of Silicon Carbide
FerrumX SiC can be customised in purity, particle size, and material form. We adhere to a green production philosophy and work closely with customers to develop tailored solutions for demanding refractory applications.
| Property | Value | Significance for Refractories |
|---|---|---|
| Density | 3.21 g/cm³ | High bulk density enables dense packing in castables and bricks |
| Vickers Hardness | 29 GPa (Mohs 9) | Second only to diamond — superior abrasion & erosion resistance |
| Coefficient of Thermal Expansion | 5 × 10⁻⁶ /K | Low CTE provides exceptional thermal shock resistance (ΔT 350–500°C) |
| Thermal Conductivity | 50–100 W/m·K | 5–10× higher than alumina-silicate refractories — faster heat transfer, lower fuel consumption |
| Max Temperature (Air) | 1500°C | Passive SiO₂ layer forms at 800–1200°C, protecting against further oxidation |
| Max Temperature (Inert) | 2400°C | Structural integrity maintained in reducing / inert furnace atmospheres |
| Specific Heat | 750 J/kg·K | High heat capacity contributes to thermal mass stability |
| Chemical Resistance | Resistant to acids, alkalis, and molten salts | Non-wetting to molten aluminum, zinc, and cryolite |
Typical Properties of Silicon Carbide
FerrumX SiC can be customised in purity, particle size, and material form. We adhere to a green production philosophy and work closely with customers to develop tailored solutions for demanding refractory applications.
High-purity kiln furniture, gas cleaning, desulfurisation nozzles, heat exchangers, reactor linings
Blast furnace bricks & tiles, torpedo ladles, incinerator linings, crucibles
Aluminum reduction cells, ceramic filters, foam glass production
Blast furnace monolithics, tap hole clay, ramming pastes, mortars
Standard refractory bricks, castables, and copper industry components
| Grade | SiC Content | Si (Free Silicon) | SiO₂ + Si | Magnetic Iron (MI) | Typical Use |
|---|---|---|---|---|---|
| MET 99 | ≥99% | 69.3% | 29.7% | Max 100 ppm | Ultra-high-purity applications |
| MET 98 | ≥98% | 68.6% | 29.4% | 100–350 ppm | High-end refractory components |
| MET 97.5 | ≥97.5% | 68.25% | 29.25% | Per customer spec | Custom refractory formulations |
| MET 95 | ≥95% | 66.5% | 28.5% | Standard | Standard refractory bricks & castables |
| MET 90 | ≥90% | 63.0% | 27.0% | Standard | General-purpose refractory materials |
All grades can be supplied in different size ranges, shapes, and bulk densities. Grains are available in cubic or sharp-edged form according to customer requirements.
Particle Size Range
Three standard form categories — splits, blends, and fines — cover the full spectrum from coarse aggregates to sub-micron powders. RTP granules with SSA of 10–15 m²/g are also available.
Standard Splits
Narrow, controlled particle size fractions for precise PSD engineering.
mesh: 6×10 / 7×12 / 10×18 / 14×30 / 18×34 / 34×70 / 36×70 / 80×180
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Standard Blends
Pre-mixed particle size distributions for ready-to-use refractory formulations.
mm: 0–0.2 / 0–0.35 / 0–0.5 / 0–1
F-series: 80F / 50F / 35F / 10F / 6F
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Standard Fines
Fine powders and sub-micron grades for matrix development and reactive bonding.
mm: 0–0.1 / 0–0.06 / 4 μm
F-series: 100F / 200F / 325F / 500F / 800F / 1200F
DIN: DIN70 / DCF
Ready-to-Press (RTP) Granules: Based on fine powders with specific surface areas of 10–15 m²/g, including sintering additives and temporary binders.
SiC Refractory Bonding Types
SiC’s covalent bonding nature means mechanical cohesion is achieved through secondary bonding phases. Each bonding type delivers distinct performance characteristics for specific furnace conditions.
Nitride-Bonded (Si₃N₄)
Service: ≤1700°C · SiC ≥75% · Si₃N₄ ≥20%Elemental silicon powder reacted with nitrogen at 1400°C forms a dense Si₃N₄ bonding matrix. Exceptional non-wetting properties against molten aluminium, zinc, and cryolite.
Oxide-Bonded (SiO₂)
Service: ≤1650°C · SiC ≥90% · SiO₂ ~10%SiO₂ micropowder forms a protective glass film wrapping SiC particles during firing. Superior oxidation resistance — service life 2× longer than clay-bonded.
Oxynitride-Bonded (Si₂ON₂)
Service: ≤1600°C · Balanced SiC + Si₂ON₂Combines the oxidation resistance of oxide bonding with the non-wetting properties of nitride bonding. Used in high-performance kiln furniture and waste-to-energy boilers.
Clay-Bonded
Service: ≤1300°C · SiC ≥85% · Fireclay 10–40%The most cost-effective SiC refractory. Fireclay binder provides good formability and thermal cycling stability for standard-temperature applications.
SIALON-Bonded (Si₆₋zAlzOzN₈₋z)
Service: ≤1700°C · SiC ≥70% · Sialon ≥20%Al₂O₃ + Si₃N₄ react to form the SIALON bonding phase. Exceptional high-temperature strength and slag resistance for severe-duty applications.
Recrystallised (R-SiC)
Service: ≤1600°C · SiC ≥99% · Bond-freeSintered at >2200°C in Ar atmosphere. SiC evaporates and recondenses at particle junctions — no bonding phase needed. Highest purity and thermal shock stability.
Application Tiers by Purity
Three tiers of SiC refractory performance — from ultra-high-purity critical components to standard furnace exteriors.
Tier 1: High Purity, Low MI
For critical high-performance components requiring SiC ≥99% and MI ≤100 ppm.
Tier 2: High-End Standard
For high-end applications requiring high SiC purity with controlled MI (≤100–350 ppm).
Tier 3: Standard Refractory
For applications where high purity is not critical — closer to furnace exterior conditions.
SiC vs Alumina-Silicate Refractories
Silicon carbide delivers 5–10× higher thermal conductivity, 2–3× longer campaign life, and superior chemical resistance compared to conventional fireclay and high-alumina refractories.
| Property | SiC Refractory | Alumina-Silicate | Advantage |
|---|---|---|---|
| Thermal Conductivity | 50–100 W/m·K | 5–10 W/m·K | SiC 5–10× |
| Max Temperature (Air) | 1500°C | 1300–1450°C | SiC +200°C |
| Max Temperature (Inert) | 2400°C | ~1800°C | SiC +600°C |
| Thermal Shock Resistance (ΔT) | 350–500°C | 150–250°C | SiC 2× |
| Abrasion Resistance | Mohs 9, 29 GPa | Mohs 9 (Al₂O₃), but lower toughness | SiC |
| Chemical Inertness | Resistant to acids, alkalis, slags | Susceptible to acidic slag attack | SiC |
| Molten Metal Wetting | Non-wetting (Al, Zn, cryolite) | Wetting — requires coatings | SiC |
| Material Cost | Higher | Lower | Alumina-Silicate |
| Campaign Life | 2–3× longer | Baseline | SiC (lower lifecycle cost) |
| Fuel Efficiency Gain | 12–18% reduction | Baseline | SiC |
Applications Across Industries
SiC refractory materials serve steelmaking, ceramics, non-ferrous metals, energy, and chemical industries — from blast furnace hearths to aluminium reduction cells.
Vitrified Bond (Ceramic)
Glass-like ceramic bond sintered at 1100–1300°C. High rigidity, excellent form-holding, and superior dressability. Porous structure allows coolant penetration and chip clearance.
MET 98
MET 95
MET 90
Ceramic Industry
Kiln furniture — setter plates, saggars, beams, posts, pusher plates, muffle boards. SiC beams support kiln cars up to 1600°C.
MET 99
MET 98
Aluminum & Non-Ferrous
Reduction cell sidewalls, casting moulds, crucibles, zinc distillation kettles. Non-wetting to molten aluminium and cryolite.
MET 98
MET 97.5
Waste Incineration
Combustion zone hot faces, waste-to-energy boiler linings. Repels high-sulfur gas infiltration and molten slag scoring.
MET 98
MET 95
Energy & Chemical
Heat exchanger tubes, reactor linings, gas cleaning systems, desulfurisation nozzles, burner linings, pyrolysis furnace components.
MET 99
Copper & Foundry
Ladle linings, tundish nozzles, stopper rods, crucibles, ceramic filters. Resistant to copper oxide corrosion.
MET 95
MET 90
Cement & Lime
Rotary kiln linings, preheater cyclones, cooler walls. SiC’s thermal conductivity improves heat transfer and fuel efficiency.
MET 95
MET 90
Glass & Silicate
Furnace regenerators, refractory plates, foam glass production. High thermal shock resistance prevents cracking during cycling
MET 98
MET 97.5
Petrochemical
High-temperature reactor linings, thermal insulation partitions, catalytic cracker components. Chemical inertness under severe conditions.
MET 99
Production & Quality Process
From raw material grading to diamond-machined finished products — six controlled phases ensuring consistent quality across large industrial batches.
1
Raw Material Grading
Premium crystalline black or green SiC aggregates sourced from our own Acheson furnaces, sorted through automated sieving into precise particle sizes to optimise packing density.
2
Compulsory Blending
Dry and wet mixing within intensive paddle mixers to coat every SiC aggregate uniformly with chosen chemical binders and sintering additives.
3
High-Tonnage Forming
Compacting under computer-controlled hydraulic friction presses reaching up to 1,000 tons of force, ensuring high bulk density and low initial porosity.
4
Forced Dehydration
Curing inside automated tunnel dryers at 110°C to eliminate structural moisture, preventing cracking during final firing.
5
High-Temperature Firing
Sintering inside digital gas kilns at 1350–1550°C under precise nitriding or oxidising gas flows, depending on the bonding type required.
6
Diamond Machining & Inspection
Precision grinding of critical joints to ±1 mm tolerance, paired with ultrasonic internal flaw checks and ICP spectroscopy verification.
Market Insights
The global silicon carbide refractories market is projected to grow from $1.5B (2024) to $3.2B by 2033, at a CAGR of 9.2% — driven by steel industry modernisation, EAF transition, and green energy initiatives.
$3.2B
Projected SiC refractories market by 2033 (CAGR 9.2%)
2–3×
Fuel efficiency improvement in SiC-lined furnaces
12–18%
Fuel efficiency improvement in SiC-lined furnaces
50%+
China’s share of global SiC refractory consumption
Steel Industry Modernisation
EAF transition and blast furnace campaign life extension drive demand for nitride-bonded SiC bricks in lower stack and hearth applications.
Green Energy & Decarbonisation
SiC’s high thermal conductivity reduces fuel consumption by 12–18%, supporting corporate carbon footprint targets under the EU Green Deal and US EPA regulations.
Waste-to-Energy Expansion
Growing waste incineration capacity globally creates demand for oxide-bonded SiC bricks resistant to high-sulfur gases and corrosive slags.
Why Choose FerrumX for SiC Refractory Materials?
From raw material sourcing to diamond-machined finished products — FerrumX provides vertically integrated SiC supply for the most demanding refractory applications.
Abundant Raw Materials
Plant located in a major quartz sand and petroleum coke producing region, ensuring stable supply and controllable costs.
Customised PSD
From coarse splits to sub-micron fines, with cubic or sharp-edged grain shapes and controlled bulk density.
120,000 t/yr Capacity
Two 40,000 KVA Acheson furnaces plus five deep-processing lines for consistent, scalable supply.
Low Magnetic Iron
Advanced magnetic separation achieves MI ≤100 ppm for high-end kiln furniture and aluminium cell applications.
RTP Granules
Ready-to-press granules with SSA 10–15 m²/g, including sintering additives and temporary binders.
R&D Co-Development
Dedicated laboratory for developing customer-specific SiC grades and formulations for demanding applications.
ISO 9001 & 45001
Dual-certified quality management and occupational health & safety systems for every shipment.
Global Export
Supplying 50+ countries with consistent quality, COA documentation, and reliable international logistics.
FAQ
Frequently Asked Questions About Silicon Carbide
Direct answers to common questions about silicon carbide for refractory applications.
FerrumX supplies five SiC refractory grades: MET 99 (SiC ≥99%, MI ≤100 ppm), MET 98 (SiC ≥98%, MI 100–350 ppm), MET 97.5 (SiC ≥97.5%, MI per customer spec), MET 95 (SiC ≥95%), and MET 90 (SiC ≥90%). All grades are available in standard splits, blends, and fines, with customised particle size distributions.
Silicon carbide maintains structural integrity up to 1500°C in oxidising (air) atmospheres and up to 2400°C in inert atmospheres. The passive oxidation layer (SiO₂) that forms on the SiC surface at 800–1200°C provides a protective barrier, extending service life in many furnace environments.
FerrumX offers standard splits (0.1–5 mm, 6×10–80×180 mesh), standard blends (0–1 mm, 6F–80F), and standard fines (0–0.06 mm, 100F–1200F, sub-4 μm). Grains can be produced in cubic or sharp-edged forms with controlled bulk density. RTP (ready-to-press) granules with SSA of 10–15 m²/g are also available.
Low magnetic iron content is critical because iron impurities cause localised thermal expansion mismatch, catalyse premature SiC oxidation, and create weak points in refractory structures. High-end applications such as kiln furniture, aluminium reduction cells, and blast furnace linings require MI ≤100 ppm to ensure maximum service life and structural integrity.
SiC is used in kiln furniture (setter plates, saggars, beams), blast furnace bricks and monolithics, tap hole clay, trough and runner materials, aluminium reduction cell sidewalls, torpedo ladle linings, incinerator hot faces, heat exchanger tubes, desulfurisation nozzles, burner linings, crucibles, and ceramic filters.
SiC refractories offer 5–10× higher thermal conductivity (50–100 W/m·K vs 5–10 W/m·K), significantly better thermal shock resistance (ΔT 350–500°C), superior abrasion resistance, and chemical inertness against acidic slags. The trade-off is higher material cost, offset by 2–3× longer campaign life and 12–18% fuel efficiency improvement.
Common bonding types include clay-bonded (cost-effective, ≤1300°C), oxide-bonded (SiO₂ film protection, good oxidation resistance), nitride-bonded (Si₃N₄ matrix, non-wetting to molten metals, for blast furnaces and aluminium cells), oxynitride-bonded (Si₂ON₂, balanced performance), SIALON-bonded (high strength), and recrystallised R-SiC (bond-free, >2200°C sintered, up to 1600°C service).
Yes. FerrumX offers customised PSD, grain shape (cubic or sharp-edged), bulk density, and ready-to-press (RTP) granules with specific surface areas of 10–15 m²/g. We also provide sintering additives and temporary binders. Our R&D team works closely with customers to co-develop tailored solutions for demanding refractory applications.
