Coal is classified into different types based on its carbon content, energy content, and the stage of its formation process. The classification also depends on how much moisture, volatile matter, and fixed carbon it contains (Coal 101, 2025).
Coal is classified into four main types:
- Anthracite: It is the hardest and highest quality coal as it has a carbon content of over 90% and burns slowly without smoke. It is used in the production of steel, where it helps in the reduction of iron ore to produce steel.
- Bituminous: Has a carbon content between 45% and 86%. Bituminous coal is commonly used in coal-fired power plants to generate electricity. Its relatively high energy content makes it a cost-effective fuel (Coal 101, 2025).
- Sub – Bituminous Coal: This coal contains 35% to 45% carbon and has a higher moisture content compared to bituminous coal. Its energy content is lower than bituminous coal and it is softer and burns with a lower heat output. It is also used in industries that require moderate heat, such as brick kilns and paper mills. (Coal 101, 2025).
- Lignite: Also known as brown coal. Has a soft texture, often crumbly and high moisture content with lower energy density than other types of coal. Lignite can be used for gasification, which produces synthetic natural gas for various applications (Coal 101, 2025).
Coal plays a significant role in electricity generation in thermal power plants. Coal is used in the production of steel, particularly in the form of coke. It is also used as a source of heat and energy for domestic purposes.
Coal remains one of the most important natural resources in the world. The four types of coal – anthracite, bituminous, sub-bituminous, and lignite – have distinct properties that make them suitable for a variety of uses. From generating electricity to producing steel, coal plays a key role in modern industries and economies (Coal 101, 2025).
Have you worked with any specific type of coal? What was it used for?
References:
Coal 101: The 4 Coal Types and Their Uses 2025 – oftrb.com. (2025, January 24). https://www.oftrb.com/archives/30203
