How Silicon Carbide Is Made: Manufacturing & Supplier Guide 2025

Silicon carbide (SiC) is one of the most important industrial materials for modern manufacturing. It is used in grinding wheels, blasting media, lapping powders, ceramic parts, kiln furniture, and even semiconductor wafers. However, many buyers only look at the final specifications or price and ignore the production process behind silicon carbide – which is actually the key to choosing a reliable supplier.

Table of Contents

1. Why the Silicon Carbide Manufacturing Process Matters
2. Step 1 – Raw Materials for Silicon Carbide
3. Step 2 – Acheson Furnace Production
4. Step 3 – Crushing, Magnetic Separation, and Cleaning
5. Step 4 – Particle Size Control: F Grits and Micro Powders
6. Step 5 – Quality Control Tests Every Buyer Should Request
7. Buyer Checklist: How to Evaluate a Silicon Carbide Supplier
8. Recommended Silicon Carbide Supplier for Global Buyers
9. FAQ: Common Questions from Silicon Carbide Buyers

1. Why the Silicon Carbide Manufacturing Process Matters

On paper, many suppliers can provide similar specifications: SiC 98% min, low Fe₂O₃, and standard FEPA or JIS grit sizes. But in real production, buyers often find big differences in grinding performance, cutting speed, wheel life, and surface finish. The reason is simple: not all silicon carbide is made in the same way.

The manufacturing process determines:

• Crystal structure (α/β SiC) and hardness
• Consistency of grain shape and sharpness
• Presence of free carbon, silica, or metallic impurities
• Bulk density and packing behavior in your formulation
• Stability between different batches and shipments

Therefore, serious buyers should understand how silicon carbide is produced and what to check in a supplier’s factory before confirming long-term cooperation.

2. Step 1 – Raw Materials for Silicon Carbide

Industrial silicon carbide is typically produced from two major raw materials:

• Silica sand (SiO₂) – high-purity quartz sand or silica stone with low impurities.
• Carbon source – usually petroleum coke or anthracite coal with controlled sulfur and ash content.

For Black SiC, standard industrial grades of silica and coke are used. For Green SiC, higher purity raw materials and stricter control are required to achieve low impurity and higher hardness.

A professional supplier should be able to explain:

• Where their silica and coke are sourced from
• How they control sulfur, ash, and metallic impurities
• How they store and pre-treat raw materials to keep moisture and contamination under control

3. Step 2 – Acheson Furnace Production

Most abrasive-grade silicon carbide is produced in a large resistance furnace called the Acheson furnace. The basic principle has not changed for decades, but small details in operation make a big difference in quality.

3.1 Furnace Structure

An Acheson furnace is built with refractory bricks and lined with carbon materials. It is filled with a mixture of silica sand and carbon around a central graphite core. When electric current passes through the core, resistance heating raises the temperature to more than 2,000 °C.

3.2 Chemical Reaction

The main reaction can be simplified as:

SiO₂ + 3C → SiC + 2CO↑

At these high temperatures, silica reacts with carbon, forming a solid SiC crystal layer near the core. Closer to the outer area, partially reacted material and by-products are formed.

3.3 Firing Time and Energy Control

Depending on furnace size, a single heat can run for several days. Good suppliers control:

• Heating rate and maximum temperature
• Holding time at high temperature
• Cooling curve to reduce cracking

Improper firing can cause under-reacted zones, excess free carbon, or weak, porous crystal structures that directly affect abrasive performance.

4. Step 3 – Crushing, Magnetic Separation, and Cleaning

After cooling, the SiC “furnace block” is removed and separated into different zones. The highest quality material comes from the dense, fully reacted zone close to the core.

4.1 Primary Crushing

The furnace block is crushed into smaller pieces using jaw crushers and impact crushers. At this stage, pieces are still quite large (several centimeters).

4.2 Magnetic Separation

Metal contamination from furnace lining, electrodes, or crushing equipment is a common problem. Professional silicon carbide suppliers use multiple stages of magnetic separation to remove iron and other metals. This is critical for applications like lapping, polishing, and high-precision grinding wheels.

4.3 Washing and Drying

For higher grade products, the crushed SiC is washed to remove dust, loosely attached fines, and soluble impurities. After washing, the material is dried in rotary or chamber dryers.

5. Step 4 – Particle Size Control: F Grits and Micro Powders

One of the most important steps in silicon carbide production is accurate particle size classification. Abrasive users rely on consistent grit sizes to achieve stable grinding and polishing results.

5.1 Macro Grits (F12–F220)

Macro grits are produced using vibrating screens, air classifiers, and sometimes water classifiers. Common standards include:

• FEPA F Grits – F12 to F220
• ANSI – 16 to 220
• JIS – 16 to 220

For each grit, the supplier must maintain a strict particle size distribution (PSD) according to FEPA or customer requirements. A good SiC supplier performs regular sieve analysis and records results for every batch.

5.2 Micro Powders (F230–F1200, JIS 600–8000)

Micro powders are produced using ball mills, jet mills, and precision air classification. These ultra-fine powders are used in lapping, polishing, and advanced ceramics. For these grades, minor deviations in PSD or contamination can cause serious problems in the customer’s process.

Buyers should ask suppliers how they control:

• D₁₀ / D₅₀ / D₉₀ of micro powder
• Oversize and undersize particles
• Agglomeration and flowability

6. Step 5 – Quality Control Tests Every Buyer Should Request

Reliable silicon carbide suppliers operate a dedicated laboratory. Typical tests include:

• Chemical composition – SiC %, free C, SiO₂, Fe₂O₃, Al₂O₃, and other oxides
• Bulk density / tapped density – affects wheel structure and refractory design
• Magnetic content – to ensure minimal metallic contamination
• PSD analysis – laser particle size or sieve test for each batch
• Visual inspection – color, crystal shape, and impurity observation

When discussing a new order, international buyers should always ask for a COA (Certificate of Analysis) and, if possible, independent SGS or third-party testing for critical applications.

7. Buyer Checklist: How to Evaluate a Silicon Carbide Supplier

Understanding the manufacturing process is useful, but buyers still need a practical checklist. Below is a summary you can use when screening suppliers by email or during a factory visit.

7.1 Technical & Production Capability

• Do they operate their own Acheson furnaces, or are they a trader only?
• Can they produce both Black SiC and Green SiC?
• Which grit ranges are available – only F12–F220, or also micro powders like F600, F800, F1000, F1200?
• Can they meet FEPA, JIS, or ANSI standards according to your market?

7.2 Quality Management

• Do they have an in-house laboratory?
• Can they send COA with every shipment?
• How often do they check PSD and magnetic content?
• Can they provide samples from at least two different batches?

7.3 Export Experience

• Which countries have they already shipped silicon carbide to?
• Are they familiar with documentation for Europe, the US, Japan, Korea, and the Middle East?
• Can they handle different trade terms like FOB, CIF, and DDP?

7.4 Logistics and Packaging

• Standard packaging options – 25 kg bags, 1,000 kg jumbo bags, pallets, shrink wrap
• Estimated lead time for 1 FCL (20–25 tons)
• Nearest loading ports and available shipping lines

For buyers who do not have time to deeply audit multiple factories, it is often more efficient to work with a specialized silicon carbide supplier that already integrates production, grading, and export service.

8. Recommended Silicon Carbide Supplier for Global Buyers

If you are looking for a partner that can supply both Black and Green silicon carbide across different grit sizes, you can refer to the dedicated supplier page below:

Silicon Carbide Suppliers – CanAbrasive

This page provides a full overview of available grades, grit ranges, applications, packaging, and shipment options. By combining the manufacturing knowledge from this article with the detailed specifications on the supplier page, buyers can make a confident and informed decision.

9. FAQ: Common Questions from Silicon Carbide Buyers

Q1. What is the difference between Black and Green silicon carbide?

Black SiC is produced from quartz sand and coke. It has slightly lower purity but excellent toughness and is widely used in grinding wheels, cutting discs, and blasting media. Green SiC is made from higher purity raw materials and has higher hardness and brittleness, making it suitable for precision grinding, lapping, and polishing of hard materials like glass and ceramics.

Q2. How do I know whether a supplier is a real manufacturer?

Ask for furnace photos, production flow charts, and testing reports with batch numbers. Real manufacturers can clearly explain their furnace capacity, annual output, and key equipment such as crushers, classifiers, and magnetic separators. Traders often cannot provide detailed production information.

Q3. Can different batches from the same supplier perform differently?

Yes. Even with the same nominal specification, inconsistency in raw materials, firing conditions, or screening can lead to differences in performance. That is why buyers should request stable QC data over time and monitor wheel performance, cutting speed, or polishing results with each batch.

Q4. What is a reasonable lead time for SiC shipments?

For standard F12–F220 grits, many suppliers can ship within 7–15 days after receiving deposit. For micro powders or special grades, 15–25 days is more common, especially during peak seasons.

Q5. How should silicon carbide be stored?

SiC should be stored in a dry, ventilated warehouse, away from moisture and contamination. Opened bags should be sealed again to prevent dust mixing and to keep particle size distribution stable.