Geologically immature coal
This article examines the nature, distribution, extraction, economic role and industrial importance of geologically immature coal, commonly referred to as lignite or brown coal. Often overlooked in global energy debates…
Aged lignite
This article examines aged lignite — commonly known as lignite or brown coal — from geological, technical, economic and environmental perspectives. It explains what distinguishes aged lignite from fresh coal,…
Tutupan Coal Mine – Indonesia
The Tutupan coal mine is one of Indonesia’s most significant coal-producing sites, forming a central part of the country’s export-oriented mining industry. Located in the resource-rich region of Kalimantan, Tutupan…
Dull coal
This article examines the topic of dull coal — a descriptive classification of coal distinguished by its matte appearance, particular physical and chemical characteristics, and specific industrial uses. Dull coal…
Jembayan Coal Mine – Indonesia
This article provides a comprehensive overview of the Jembayan Coal Mine in Indonesia, covering its location, geological and technical characteristics, economic and statistical context, and broader significance to the Indonesian…
Super-low-volatile coal
Super-low-volatile coal is a specialized, high-rank form of coal valued primarily for its high fixed carbon content, low volatile matter, and strong performance in metallurgical and high-temperature industrial applications. This…
Low-BTU coal
This article examines the characteristics, occurrences, extraction, economic roles and industrial importance of low-calorific-value coal—commonly referred to as low-BTU coal. It presents geological and geographical contexts, outlines the technological and…
High-rank coal
High-rank coal occupies a distinctive place among fossil fuels. Often associated with superior energy density, lower volatile content and a higher fixed carbon fraction, this class of coal plays specific…
F-grade coal
This article explores the characteristics, occurrence, production, economic role and industrial significance of what is commonly referred to as F-grade coal — a practical label used in some markets and…
E-grade coal
This article explores E-grade coal — a commercial classification commonly used to describe lower-rank thermal coals with specific physical and chemical characteristics. It covers where such coals are found and…
