Characteristics of Low-Rank Coals Important in Their Utilization

摘要

Following a brief description on the occurrence of low-rank coals in the United States, the characteristics of low-rank coals are discussed in detail. The principal means of classifying low-rank coals is by heating value. Lignite is defined as a coal with a heating value less than 8300 Btu/lb. The range for subbituminous coal is 8300 to 11,500 Btu/lb. Low-rank coals can be characterized as having high moisture, high oxygen, low sulfur with an alkaline ash. High moisture, high oxygen, and alkaline ash can have strong impacts on the utilization or conversion technologies. Each of these properties are discussed in detail. 7 tables. (ERA citation 08:003980)