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…
Deep-cleaned coal
Deep-cleaned coal is an engineered product of coal preparation and upgrading processes designed to remove impurities and improve fuel properties. Over the past decades, advancements in coal washing, beneficiation and…
Metallurgical middlings
This article discusses the category known as metallurgical middlings — intermediate coal products generated in the preparation of metallurgical coal (also called coking coal). It explains what middlings are, where…
Thermal middlings
Thermal middlings are an often-overlooked but important fraction of coal that plays a practical role across mining, coal preparation and power-generation value chains. This article explains what thermal middlings are,…
Coal rejects
The phrase coal rejects refers to the material separated from mined coal during preparation and washing processes — the fraction considered unsuitable for direct sale or conventional combustion because of…
Coal middlings
This article examines the phenomenon commonly called coal middlings — the intermediate-sized, intermediate-quality fractions produced during coal mining and preparation. Coal middlings occupy a complex place between high-grade clean coal…
How Coal is Processed for Industrial Heating
Coal has been a cornerstone of industrial heating for centuries, providing a reliable and efficient source of energy. The process of transforming raw coal into a usable form for industrial…
