Types of Coal

Introduction

Coal, like oil, consists of a wide variety of components, and those components are present in a wide variety of concentrations within various coal deposits. In order to simplify descriptions of coal in its multiple forms, four main categories of coal have been commonly used:


  • Anthracite - contains 86-97% carbon
  • Bituminous - contains 45-86% carbon
  • Subbituminous - contains 35-45% carbon
  • Lignite - contains 25-35% carbon

Anthracite

Anthracite coal contains 86% - 97% carbon and has the highest heating value of all forms of coal. Only 1% of the coal mined in the U.S. in 2016 was anthracite. All of it came from mines in northeastern Pennsylvania.

Bituminous Coal

Bituminous coal contains 45% - 86% carbon. It is the most common coal found in the U.S. and ranks just under anthracite in its heating value. It is used to generate electricity and to produce steel.

Subbituminous Coal

Subbituminous coal contains 35% - 45% carbon and ranks just under bituminous coal in its heating value.

Lignite

Lignite contains 25% - 35% carbon. It has the lowest heating value of all the various types of coal.