Black Silicon Carbide (B-SiC)
Abrasives, Refractory & Metallurgical Grades
FerrumX manufactures and supplies black silicon carbide in lumps, grains, macrogrits, microgrits and fine powders. Combining high hardness, thermal stability and wear resistance, our black SiC is widely used in abrasive tools, blasting and surface treatment, refractory formulations, metallurgy and selected ceramic applications. Multiple purity levels, particle-size standards and packing options are available to support different production processes and long-term industrial supply.
Black Silicon Carbide is a synthetic material produced from silica sand (SiO₂) and petroleum coke (C) in an Acheson furnace at temperatures above 2,500°C. The high-temperature reaction forms hard, crystalline SiC grains with a metallic lustre and excellent mechanical strength.
With a Mohs hardness of 9.2, Black SiC is one of the hardest industrial materials available, offering outstanding thermal conductivity, chemical stability, and wear resistance even under extreme conditions.
After furnace synthesis, the crude SiC blocks are crushed, refined, and classified into a full range of grit sizes, from macro grains for grinding wheels to micro powders for polishing and metallurgical use.
Black Silicon Carbide is widely used in the abrasives, refractory, and metallurgical industries — for grinding non-ferrous metals, cutting hard stones, lining high-temperature furnaces, and as a deoxidising or carburising additive in steelmaking.
FerrumX produces Black SiC with a consistent particle-size distribution, controlled purity, and stable performance, ensuring reliable results for industrial, refractory, and metallurgical applications.
Black Silicon Carbide Production
Black Silicon Carbide (SiC) is produced through the high-temperature reaction of silica (SiO₂) and carbon materials such as petroleum coke or anthracite in an Acheson-type resistance furnace. Under temperatures exceeding 2,500 °C, carbon reduces silica to form SiC crystals through the reaction:
SiO₂ + 3C → SiC + 2CO↑
During the process, the furnace core reaches its maximum temperature, at which large SiC crystals form, while the surrounding zones produce fine, friable material suitable for abrasive applications. After natural cooling, the solid block is crushed, magnetically separated, and precisely classified into different particle sizes.
At FerrumX, each batch of black silicon carbide is refined through strict temperature control, optimized raw-material blending, and energy-efficient furnace operation, ensuring uniform grain structure, high purity, and stable performance.
The production base is located in a region with abundant quartz and coke resources, low-cost electricity, and favorable industrial infrastructure, enabling continuous, cost-effective, and environmentally responsible SiC production.
Product Range
Types of Black Silicon Carbide Grade for Sale
B-SiC 99#
High-purity grade for precision abrasives & advanced ceramics
B-SiC 98#
High-purity abrasive & refractory grade
B-SiC 97#
General-purpose abrasive for bonded & coated abrasives
B-SiC 95#
Refractory & bonded abrasive grade
B-SiC 90#
Most popular refractory & metallurgical grade
B-SiC 85#
Metallurgical deoxidizer & energy booster
Technical Data
Chemical Composition & Grit Size Standards
Complete chemical specifications and FEPA/JIS grit size data for FerrumX black silicon carbide.
Chemical Composition — Processing Grades
| Grade | SiC (%) | F.C. (%) | Fe₂O₃ (%) | H₂O (%) | Primary Application |
|---|---|---|---|---|---|
| 99# | ≥99.00 | ≤0.10 | ≤0.10 | ≤0.10 | Precision abrasives, wire-saw, advanced ceramics |
| 98# | ≥98.00 | ≤0.25 | ≤0.30 | ≤0.30 | Bonded abrasives, refractory castables |
| 97# | ≥97.00 | ≤0.30 | ≤0.40 | ≤0.30 | Coated abrasives, sandblasting media |
| 95# | ≥95.00 | ≤1.00 | ≤1.00 | ≤0.30 | Refractory bricks, taphole clay |
| 90# | ≥90.00 | ≤2.20 | ≤2.30 | ≤0.50 | Refractory monolithics, metallurgical additive |
| 85# | ≥85.00 | ≤3.00 | ≤3.00 | ≤1.00 | Steelmaking deoxidizer, BOF energy booster |
Macro Grits: F8–F220 (FEPA Standard)
| Grit No. | Particle Size (μm) | Min SiC (%) | Max F.C. (%) | Max Fe₂O₃ (%) | Bulk Density (g/cm³) |
|---|---|---|---|---|---|
| F8 | ~2000 | 99.0 | 0.40 | 0.40 | 1.42–1.50 |
| F12 | ~1400 | 99.0 | 0.40 | 0.40 | 1.41–1.49 |
| F24 | ~600 | 99.0 | 0.40 | 0.40 | 1.45–1.53 |
| F46 | ~300 | 99.0 | 0.40 | 0.40 | 1.47–1.55 |
| F80 | ~150 | 99.0 | 0.40 | 0.40 | 1.44–1.52 |
| F120 | ~90 | 99.0 | 0.40 | 0.40 | 1.40–1.48 |
| F220 | ~45 | 99.0 | 0.40 | 0.40 | 1.36–1.44 |
Micro Grits: F230–F1500 (FEPA Standard)
| Grit No. | Particle Size (μm) | Min SiC (%) | Max F.C. (%) | Max Fe₂O₃ (%) | Loose Pack Density (g/cm³) |
|---|---|---|---|---|---|
| F230 | 28–32 | 98.6 | 0.40 | 0.08 | 1.27 ± 0.05 |
| F320 | 16–20 | 98.6 | 0.40 | 0.08 | 1.17 ± 0.08 |
| F500 | 5–8 | 99.6 | 0.20 | 0.08 | 0.95 ± 0.08 |
| F800 | 2–3 | 99.6 | 0.20 | 0.08 | 0.81 ± 0.08 |
| F1200 | 0.7–1.5 | 99.4 | 0.20 | 0.08 | — |
| F1500 | 0.5–1.0 | 99.4 | 0.20 | 0.08 | — |
Physical & Thermal Properties
Properties of Black Silicon Carbide
Black SiC combines extreme hardness, chemical inertness, and excellent thermal conductivity — making it one of the most versatile industrial materials for abrasive, refractory, and metallurgical applications.
| Property | Value | Industrial Significance |
|---|---|---|
| Crystal Structure | α-SiC, hexagonal (monocrystalline) | Blocky, sharp-edged grain shape provides efficient cutting and self-sharpening behavior |
| Mohs Hardness | 9.2 | Second only to diamond and B₄C; enables grinding of hard non-ferrous metals and ceramics |
| Knoop Hardness (100g) | 2,480 kg/mm² | High micro-hardness ensures consistent abrasive performance under load |
| Density | 3.20–3.22 g/cm³ | High density allows particles to penetrate workpiece surface effectively |
| Bulk Density (macro grits) | 1.35–1.55 g/cm³ | Optimized packing density for bonded abrasive formulations |
| Thermal Conductivity | 50–100 W/m·K | Superior heat dissipation prevents thermal damage during grinding and in refractory linings |
| Coefficient of Thermal Expansion | 4.0–4.5 × 10⁻⁶ /K | Low CTE provides excellent thermal shock resistance in refractory applications |
| Max Service Temperature (Air) | 1,900 °C | Stable at steelmaking and foundry temperatures; does not decompose prematurely |
| Max Service Temperature (Inert) | 2,400 °C | Extremely stable in reducing atmospheres — suitable for furnace linings and crucibles |
| Decomposition Point | ~2,250 °C | High decomposition temperature ensures structural integrity under extreme heat |
| Chemical Inertness | Resistant to acids & alkalis | Does not react with most molten metals, slags, or process chemicals |
| Particle Shape | Blocky, sharp-edged, semi-friable | Sharp edges provide aggressive cutting; semi-friability enables self-sharpening during grinding |
Applications
Applications of Black Silicon Carbide
Black SiC serves as a critical raw material across eight major industries — from bonded abrasives and refractory monolithics to steelmaking deoxidation and advanced ceramics.
Bonded & Coated Abrasives
Grinding wheels, cutting discs, sandpaper, and blasting media for non-ferrous metals, stone, glass, and ceramics. Black SiC’s blocky, semi-friable crystals provide aggressive cutting with self-sharpening behavior.
Hardness: Mohs 9.2, Knoop 2480
Better toughness than green SiC for heavy grinding
Thermal conductivity: 50–100 W/m·K
Recommended: B-SiC 97–99 · F12–F220 → SiC Abrasives →
Refractory Materials
Tap hole clay, iron runner castables, ramming masses, and kiln furniture. SiC refractories last 2–3× longer than alumina-silicate alternatives and reduce energy consumption by 12–18%.
Stable to 1,900°C in air, 2,400°C inert
Low CTE: 4.0–4.5 × 10⁻⁶ /K
Resistant to thermal shock and slag
Recommended: B-SiC 90–98 · 0–5mm → SiC for Refractories →
Steelmaking Deoxidation
Combined Si/C deoxidizer and exothermic agent for induction furnaces, ladle furnaces, and BOF converters. Lower aluminum than FeSi, reducing Al₂O₃ inclusions.
Si recovery: 80–85%, C recovery: >90%
Exothermic: ΔH = −901.76 kJ/mol
10–20% cost savings vs ferrosilicon
Recommended: B-SiC 85–90 · 0–10mm → Metallurgical SiC →
Surface Treatment & Blasting
Sandblasting, shot peening, and surface texturing of metals, stainless steel, and glass. Angular grain shape provides aggressive cleaning and uniform surface profiling.
Recyclable: 6–10 passes before replacement
Lower dust generation than garnet
Uniform etching profile
Recommended: B-SiC 98–99 · F230–F1200 → SiC Powder →
Wire-Saw & PV Wafer Cutting
Standard photovoltaic wafer slicing — a cost-optimized alternative to green SiC for commercial solar manufacturing. Each GW of PV capacity requires ~1,000–1,200 t of SiC micro powder.
Standard choice for commercial PV
Cost: 60–70% of green SiC pricing
Adequate purity for standard silicon wafers
Recommended: B-SiC 99 · F400–F600
Structural & Wear Ceramics
Wear-resistant components, structural ceramics, kiln supports, and ceramic armor. SiC’s high thermal conductivity and mechanical strength enhance ceramic performance in demanding environments.
Flexural strength: 300–500 MPa
Wear resistance: 5–10× alumina
Ready-To-Press (RTP) granules available
Recommended: B-SiC 98–99 · custom shapes
Key Advantages
Why Choose FerrumX Black Silicon Carbide
Factory
FerrumX is a direct factory manufacturer.
FerrumX produces black silicon carbide through the high-temperature Acheson process. From raw material preparation and furnace production to precision processing and final testing, every stage is carefully controlled to deliver consistent purity, particle size and performance.
STEP 01
Raw Material Preparation
Quartz sand (SiO₂ ≥98%) + petroleum coke (fixed C ≥98%) + wood chips (porosity) + NaCl (impurity removal). Carbon is kept 3–5% above the stoichiometric requirement to ensure complete SiO₂ conversion.
Key ratio: SiO₂:C ≈ 1:2.2 (molar excess)
STEP 02
Furnace Charging
Graphite furnace core (conductor) positioned centrally. Mixed raw materials are filled in layers around the core. An insulation layer of coke powder and quartz sand is packed on the outside to retain heat and reduce energy losses.
Furnace dimensions: ~15m long, ~3m diameter
STEP 03
Electrolytic Smelting
5,000–10,000 A current applied through a graphite core. Temperature rises: SiO₂+C reaction begins at ~1,400°C; SiC crystal formation completes at 2,000–2,500°C. Duration: 24–40 hours depending on furnace size.
Energy consumption: 6,000–7,000 kWh/t
STEP 04
Cooling
Furnace allowed to cool naturally for 7–14 days. Rapid cooling would cause thermal stress fractures in the SiC crystal mass, degrading product quality and yield.
No forced cooling — patience preserves crystal integrity
STEP 05
Grading
Core zone: ≥97% SiC (Grade I, 6H crystal). Middle zone: Grade II (15R+4H, more impurities). Outer zone: unreacted mixture recovered and recycled into the next furnace cycle — zero waste.
This zoning creates the 6-grade product spectrum
STEP 06
Processing
Crushing → screening → acid washing → magnetic separation → hydraulic classification → laser PSD analysis. Five deep-processing lines ensure each grade meets its target purity, grit size, and bulk density specifications.
Final QC: ICP analysis + laser PSD + bulk density
FerrumX Black Silicon Carbide Supply Advantages
Located in a region with abundant quartz and coke resources, low-cost electricity, and favorable industrial infrastructure, FerrumX delivers cost-effective, environmentally responsible SiC production at scale.
Abundant Raw Materials
Located near high-purity quartz sand and petroleum coke sources — ensuring consistent raw material quality and a stable supply chain.
Low-Cost Energy
Access to low-cost hydroelectric and coal-fired power enables energy-intensive Acheson furnace operation at a competitive cost structure.
Full Production Chain
From raw material blending to Acheson synthesis, crushing, classification, and packaging — all under one roof for quality control.
Dual ISO Certification
ISO 9001 (Quality) and ISO 45001 (Health & Safety) — ensuring consistent product quality and responsible manufacturing practices.
FEPA/JIS/ANSI Compliance
All products are graded per international standards — FEPA F-series, JIS #240–#3000, and ANSI 6×10–80×180 mesh grades.
Advanced QC Lab
ICP spectrometry, laser particle-size analysis, and bulk density testing — every batch is traceable with full COA documentation.
Custom PSD & RTP
Ready-to-press granules with integrated sintering additives and temporary binder systems for direct-pressing applications.
Global Export Network
50+ countries served with flexible packaging, multimodal logistics, and full customs documentation support.
FAQ
Frequently Asked Questions
Black SiC is the most widely produced SiC variant, accounting for approximately 70% of global SiC output. It is produced without NaCl catalyst, resulting in 85–99% SiC purity. Its key distinguishing features are: (1) higher toughness and lower friability than green SiC, making it better for heavy-duty grinding; (2) availability in 6 purity grades spanning metallurgical to precision applications; (3) lower energy consumption (6,000–7,000 kWh/tonne vs 8,000 for green SiC); and (4) approximately 60–70% of green SiC pricing, making it the cost-effective choice for bulk industrial use.
In steelmaking, black SiC (typically 85–90% grade) serves as a combined Si/C deoxidizer and exothermic agent. Silicon reacts with dissolved oxygen (Si + 2[O] → SiO₂, ΔH = −901.76 kJ/mol), releasing heat that raises molten steel temperature. Simultaneously, carbon reacts with oxygen ([C] + [O] → CO↑). Black SiC achieves silicon recovery of 80–85% and carbon recovery above 90%. Compared to ferrosilicon, SiC introduces less than 0.03% aluminum (vs 1–2% in FeSi), reducing Al₂O₃ inclusion formation. In BOF converters, the exothermic reaction also reduces lime consumption by 2–5 kg/tonne steel.
For refractory applications, grade selection depends on the specific product: (1) Tap hole clay and iron runner castables typically use B-SiC 90 (90% SiC, 0–5mm) for optimal cost-performance; (2) High-performance refractory bricks and specialty castables use B-SiC 95–97 for better oxidation resistance; (3) Kiln furniture and crucible applications use B-SiC 97–98 for maximum thermal stability. Lower grades (85–90%) are preferred for metallurgical refractories where SiC also serves as a deoxidizer. Higher grades (95–98%) are used when refractory longevity is the priority — SiC refractories last 2–3× longer than alumina-silicate alternatives.
Black SiC production consumes approximately 6,000–7,000 kWh per tonne, while green SiC requires about 8,000 kWh/tonne due to the higher purity raw materials and NaCl catalyst process. This 15–25% energy difference contributes to black SiC’s lower cost structure (60–70% of green SiC pricing). FerrumX’s location near hydroelectric and coal-fired power sources ensures competitive energy costs, enabling cost-effective production at scale.
Yes, black SiC (typically B-SiC 99, F400–F600) is used for standard photovoltaic wafer cutting where cost optimization is prioritized over maximum purity. Each gigawatt of PV capacity requires approximately 1,000–1,200 tonnes of SiC micro powder. For premium applications requiring minimal metallic contamination (e.g., semiconductor-grade wafers), green SiC is preferred. Black SiC is the standard choice for commercial solar PV manufacturing where the balance of cost and performance favors it.
FerrumX offers flexible packaging for bulk supply: 25kg paper bags on pallets (1-ton pallets), 1-ton FIBC jumbo bags, and custom bulk containers. Standard lead time is 3–4 weeks for FOB orders. We support FOB, CIF, and DAP delivery terms with full customs documentation. Our 120,000 t/yr capacity and five deep-processing lines ensure stable supply for both spot orders and long-term contracts. Multi-language documentation and certificates of analysis (COA) are provided with each shipment.
Black SiC (Mohs 9.2, Knoop 2480) is significantly harder than aluminum oxide (Mohs 9.0, Knoop 2100), providing faster material removal and longer tool life on hard, brittle workpiece materials. SiC is preferred for grinding non-ferrous metals (copper, aluminum, brass), stone, glass, ceramics, and carbides. Al₂O₃ is preferred for ferrous metals (steel, iron) because SiC can react with iron at high grinding temperatures. SiC also has higher thermal conductivity (50–100 W/m·K vs ~30 for Al₂O₃), reducing thermal damage to the workpiece.
FerrumX is ISO 9001 (Quality Management) and ISO 45001 (Occupational Health & Safety) certified. Every batch undergoes ICP chemical analysis for SiC%, F.C.%, and Fe₂O₃% content, laser particle-size analysis for PSD verification, and bulk density measurement. All products are traceable by batch number with certificates of analysis (COA) provided per shipment. Products are graded per FEPA F-series (F8–F1500), JIS (#240–#3000), and ANSI (6×10–80×180) standards.
