Coal blending

Coal blending is the process of mixing coals after coal has been mined to achieve quality attributes that are desirable for the coal’s intended application (e.g. steam generation, coking). The quality attributes that are most important in blending will differ from one mine site to another and also depend on how the coal seams vary in quality and their final intended use. In thermal coals, quality attributes of interest often include ash, volatile matter, total Sulfur, and gross calorific value. For coking coals, additional attributes are sometimes considered including crucible swelling number, fluidity, and RoMax.