Culm coal
Culm coal is a term with several regional meanings, but it generally refers to **fine**, **waste** or low-grade coal material associated with mining and processing. This article reviews the nature…
Buckwheat coal
Can you clarify what you mean by “Buckwheat coal”? Is this a specific local or trade name (e.g., a regional variety, a nickname for a particular coal grade, or coal…
Rice coal
Rice coal is a term increasingly used to describe solid fuels derived from the agricultural residue of rice production — primarily rice husk — that have been carbonized, compressed or…
Pea coal
Pea coal is a widely recognized commercial grade of coal valued for its convenient size and versatile uses, especially in household heating and small industrial applications. This article examines what…
Nut coal
Nut coal is a widely recognized commercial grade of coal, principally defined by its particle size and practical applications rather than by a single chemical composition. It occupies a middle…
Stoker coal
Stoker coal occupies a special niche in the broad category of fossil fuels: it is not a distinct geologic rank but a practical product specification designed for a particular combustion…
Explosive-grade coal dust
Explosive-grade coal dust is a hazardous but economically significant form of fossil fuel material. Finely divided coal particles suspended in air can form highly combustible clouds that, when ignited, produce…
Coal dust
The following article explores the subject of coal and coal dust from geological occurrence to industrial applications, economic significance, and health and environmental implications. Coal remains one of the world’s…
Reworked coal
This article examines the geological, economic and industrial aspects of reworked coal — an intriguing category of coal that has been transported, eroded, oxidized or otherwise altered after initial formation.…
Secondary coal
This article explores the phenomenon commonly referred to as secondary coal, examining what the term means in different contexts, where such coal occurs, how it is recovered or mined, and…
