Coal that has a gross calorific value less than 24 MJ/kg (determined in conformance with ISO 1928), and vitrinite mean random reflectance less than 0.6% (determined in conformance with ISO 7404-5). Gross calorific value is recalculated to a moist, ash free basis using bed moisture (determined according to ISO 1015 or ISO 5068). Includes all low-rank coals, including sub-bitiminous coal. A consolidated, dull, soft brown to black coal having many readily discernible plant fragments set in a finer grained organic matrix. Tends to crack and fall apart on drying. Operationally sub-bituminous and bitiminous coal are qualitatively distinguished based on brown streak for sub-bitiminous coal and black streak for bituminous coal.
Economic Commission for Europe, Committee on Sustainable Energy- United Nations (ECE-UN), 1998, International Classification of in-Seam Coals: Energy 19, 41 pp.
See Also: brown coal, metalignite, ortholignite, sub-bituminous coal
Parents: Coal (62)
[Description taken from GeoSciML SimpleLithology201012.rdf]
Category: Analysed material
The different kinds of sample material collected in the field have been classified hierarchically. Examples: “till”, “soil”, “vegetation”. Taken from the “Sample_Types_SHARED” database table.
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