Anthracite Coal is the highest rank and purest form of coal, representing the final stage of coal metamorphism. It is formed when bituminous coal is subjected to extreme heat and pressure over geological time, resulting in exceptionally high fixed carbon content, very low volatile matter, and superior fuel efficiency.
Anthracite is distinguished by its hardness, high density, semi-metallic glossy appearance, and clean-burning characteristics. Among all coal types, it produces the least smoke, lowest emissions, and highest energy per unit weight, making it ideal for industrial heating, metallurgy, water filtration, and premium domestic fuel applications.
Coal Rank Position
Coal progression sequence:
Lignite – Lowest rank
Sub-Bituminous Coal
Bituminous Coal
Anthracite Coal – Highest rank
Anthracite represents the most carbonized and energy-dense form of coal, offering superior combustion behavior with minimal impurities.
Key Characteristics of Anthracite Coal
Extremely High Carbon Content
Fixed carbon content ranges from 86% to 97%, delivering very high calorific value,
long steady burning duration, and lower fuel consumption per unit of heat.
Very Low Volatile Matter
Typically between 3% and 14%, resulting in smokeless combustion, reduced air
pollution, and no visible flame after ignition. Anthracite burns primarily as a
glowing ember with a short blue flame.
Low Moisture & Sulfur Content
Moisture content ranges from 2% to 5%, while sulfur content is typically between
0.2% and 0.7%. This minimizes corrosion, reduces SO₂ emissions, and improves
compliance with environmental regulations.
Hard, Dense & Durable Structure
With a Mohs hardness of approximately 2.75–3, anthracite is mechanically strong,
resistant to crushing, and experiences minimal breakage during handling.
High Calorific Value
Typically 6,500 – 7,500 kcal/kg, delivering consistent heat output, lower ash
residue, and high thermal efficiency.
Clean & Environmentally Preferable Fuel
Produces very low smoke, soot, and particulate emissions with minimal clinker
formation, making it suitable for eco-sensitive and urban applications.
Typical Mechanical, Physical & Chemical Properties
Proximate & Ultimate Properties
Fixed Carbon: 86 – 97%
Volatile Matter: 3 – 14%
Moisture: 2 – 5%
Ash Content: 8 – 12%
Sulfur: 0.2 – 0.7%
Calorific Value: 6,500 – 7,500 kcal/kg
Physical Properties
Appearance: Shiny black, semi-metallic
Bulk Density: 800 – 900 kg/m³
Porosity: Low
Grindability (HGI): Low (hard to grind)
Ignition Temperature: Higher than bituminous coal
Combustion Behavior
Anthracite requires a higher ignition temperature and strong draft or forced air systems. Once ignited, it burns slowly with intense radiant heat, minimal flame, and virtually no smoke.
Grades & Sizing of Anthracite Coal
Lump Anthracite
Size: 20–80 mm / 50–100 mm
Used in industrial furnaces, boilers, foundries, and heating systems.
Granular / Grain Anthracite
Size: 0.6–2 mm / 2–4 mm
Widely used in water filtration and wastewater treatment due to high surface area
and durability.
Briquetted Anthracite
Compacted for uniform burning, suitable for domestic heating and low-smoke
industrial applications.
Anthracite Fines / Powder
Size: 0–6 mm
Used in metallurgy, sintering, carbon raisers, and injection carbon applications.
Applications of Anthracite Coal
Industrial Applications
Metallurgical furnaces, steel and iron production, cement and lime kilns,
industrial boilers, and specialized power generation.
Water Filtration Industry
Granular anthracite is used in municipal water treatment, drinking water
filtration, wastewater treatment, and desalination pre-treatment, often layered
with sand and gravel in multimedia filters.
Commercial & Domestic Heating
Used in home heating systems, industrial stoves, fireplaces, and steam boilers,
offering long burn time, minimal ash, and clean indoor use.
Metallurgical & Chemical Uses
Carbon raiser in steelmaking, reducing agent, pig iron production, and chemical
synthesis processes.
Agriculture & Specialty Uses
Soil carbon enrichment, odor control media, and carbon filtration systems.
Advantages of Anthracite Coal
Highest carbon content among coal types, cleanest burning solid fossil fuel, low sulfur and ash, high energy efficiency, long storage life, and minimal maintenance requirements.
Limitations & Considerations
Higher cost compared to bituminous coal, harder ignition, limited global reserves, and requirement for properly designed combustion systems.
Anthracite vs Other Coal Types
Compared to bituminous and sub-bituminous coal, anthracite offers the highest carbon content, lowest smoke, and highest calorific value, but at a higher cost and with stricter combustion requirements.
Anthracite Coal is a premium solid fuel delivering maximum heat output, minimum emissions, and superior durability. Its clean combustion, mechanical strength, and chemical stability make it indispensable for industrial heating, metallurgy, water filtration, and eco-friendly domestic use where performance and cleanliness are critical.