brown coal

brown coal

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      broad and variable group of low-rank coals (coal) characterized by their brownish coloration and high (greater than 50 percent) moisture content. These coals typically include lignite and some subbituminous coals (subbituminous coal). In Great Britain and other countries, the term brown coal is used to describe those low-rank coals (lignite and subbituminous coal) that generally have a brown colour. In Germany lignite, subbituminous coal, and some high-volatile bituminous coals are classified as brown coals (Braunkohle). In the United States and Canada, the term brown coal is not used.

      Brown coals actually vary in colour from yellow to black and have a dull to bright lustre. They may or may not have a stratified appearance. Stratified brown coals may contain layers of concentrated plant matter alternating with layers of more-coalified material. Many brown coals of lighter colour have a fibrous structure in which roots and other plant matter are still recognizable, indicating little coalification beyond peat. Brown coals can be distinguished from higher-ranked coals by observing their behaviour in dilute nitric acid or boiling potassium hydroxide solution. Brown coals react to produce a reddish solution, whereas higher-ranked coals do not react.

Otto C. Kopp

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Universalium. 2010.

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Look at other dictionaries:

  • Brown coal — Coal Coal (k[=o]l), n. [AS. col; akin to D. kool, OHG. chol, cholo, G. kohle, Icel. kol, pl., Sw. kol, Dan. kul; cf. Skr. jval to burn. Cf. {Kiln}, {Collier}.] 1. A thoroughly charred, and extinguished or still ignited, fragment from wood or… …   The Collaborative International Dictionary of English

  • Brown coal — Brown Brown (broun), a. [Compar. {Browner}; superl. {Brownest}.] [OE. brun, broun, AS. br?n; akin to D. bruin, OHG. br?n, Icel. br?nn, Sw. brun, Dan. bruun, G. braun, Lith. brunas, Skr. babhru. [root]93, 253. Cf. {Bruin}, {Beaver}, {Burnish},… …   The Collaborative International Dictionary of English

  • brown coal — n. LIGNITE …   English World dictionary

  • brown coal — noun intermediate between peat and bituminous coal • Syn: ↑lignite, ↑wood coal • Hypernyms: ↑coal, ↑humate • Hyponyms: ↑jet * * * noun …   Useful english dictionary

  • brown coal — Lignite Lig nite (l[i^]g n[imac]t), n. [L. lignum wood: cf. F. lignite.] (Min.) Mineral coal retaining the texture of the wood from which it was formed, and burning with an empyreumatic odor. It is of more recent origin than the anthracite and… …   The Collaborative International Dictionary of English

  • brown coal — rusvosios anglys statusas T sritis chemija apibrėžtis Rudos ir juodos spalvos, rudo brėžio uoliena, turinti iki 70% C. atitikmenys: angl. brown coal rus. бурый уголь …   Chemijos terminų aiškinamasis žodynas

  • brown coal — rusvosios anglys statusas T sritis ekologija ir aplinkotyra apibrėžtis Iš augalų liekanų susidariusi degioji uoliena, turinti 55–78 % grynos anglies. Slūgso tarp nuosėdinių uolienų, turi molio priemaišų, todėl yra gana peleningos. Kartais savaime …   Ekologijos terminų aiškinamasis žodynas

  • brown coal — /braʊn ˈkoʊl/ (say brown kohl) noun → lignite …  

  • brown coal — noun Date: 1821 lignite …   New Collegiate Dictionary

  • brown coal — lignite …   Eponyms, nicknames, and geographical games

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