anthracite

anthracite
anthracitic /an'threuh sit"ik/, anthracitous /an"threuh suy'teuhs/, adj.
/an"threuh suyt'/, n.
a mineral coal containing little of the volatile hydrocarbons and burning almost without flame; hard coal. Also called anthracite coal.
[1810-15; prob. < F < L (Pliny) anthracitis kind of coal. See ANTHRAC-, -ITE1]

* * *

Coal containing more fixed carbon than any other form of coal and the lowest amount of volatile (quickly evaporating) material, giving it the greatest heat value.

The most valuable of the coals, it is also the least plentiful, making up less than 2% of all coal reserves in the U.S., with most of the known deposits occurring in the East. Anthracites are black and have a brilliant, almost metallic lustre. Hard and brittle, they can be polished and used for decorative purposes. They are difficult to ignite but burn with a pale-blue flame and require little attention to sustain combustion. In the past they were used for domestic heating, but today they have given way to other sources of energy (e.g., natural gas and electricity).

* * *

also called  hard coal  

      the most highly metamorphosed form of coal. It contains more fixed carbon (86 percent or greater on a dry, ash-free basis) than any other form of coal and the least amount of volatile matter (14 percent or less on a dry, ash-free basis), and it has calorific values near 35 megajoules per kilogram (approximately 15,000 British thermal units per pound), not much different from the calorific values for most bituminous coal. Anthracite is the least plentiful form of coal. It is found mostly in the eastern part of the United States and makes up less than 2 percent of all coal reserves in the country. Smaller amounts of anthracite occur in South Africa, Australia, western Canada, China, and other countries.

      Anthracites are black to steel gray in colour and have a brilliant, almost metallic lustre. They can be polished and used for decorative purposes. Hard and brittle, anthracites break with conchoidal fracture into sharp fragments. Unlike many bituminous coals, they are clean to the touch. Although anthracites are difficult to ignite, they burn with a pale blue flame and require little attention to sustain combustion. In the past they were used for domestic heating because they produce little dust upon handling, burn slowly, and emit relatively little smoke. Anthracite is rarely used for this purpose today because of its limited abundance and relatively high cost and the ready availability of other sources of energy (e.g., natural gas and electricity) for heating purposes. Although anthracites usually occur in geologically deformed areas, such as in the intensely folded sedimentary rocks of the anthracite region of Pennsylvania, U.S., their origin is due to higher than normal heating caused by the presence of nearby igneous (igneous rock) intrusions or high geothermal gradients. Both of these phenomena produce temperatures much higher than those reached at depth in most sedimentary basins. For instance, in Antarctica, large igneous sills intruded the coal measures and converted some of the existing bituminous coal to anthracite. Temperatures ranging from 170 to 250 °C (about 340 to 480 °F) are thought to be necessary for the formation of anthracite.

Otto C. Kopp
 

* * *


Universalium. 2010.

Игры ⚽ Поможем сделать НИР
Synonyms:

Look at other dictionaries:

  • Anthracite — (Greek Ανθρακίτης, literally a type of coal , from Anthrax [Άνθραξ] , coal) is a hard, compact variety of mineral coal that has a high lustre. It has the highest carbon count and contains the fewest impurities of all coals, despite its lower… …   Wikipedia

  • anthracite — [ ɑ̃trasit ] n. m. • 1803; a désigné depuis le XVIe diverses roches; du gr. anthrax, akos « charbon » ♦ Charbon (houille) d une variété très pure, donnant peu de cendres lors de sa combustion lente. Qui contient de l anthracite (anthraciteux,… …   Encyclopédie Universelle

  • Anthracite — An thra*cite, n. [L. anthracites a kind of bloodstone; fr. Gr. ? like coals, fr. ?, ?, coal or charcoal. Cf. {Anthrax}.] A hard, compact variety of mineral coal, of high luster, differing from bituminous coal in containing little or no bitumen,… …   The Collaborative International Dictionary of English

  • anthracite — (n.) non bituminous coal, 1812, earlier (c.1600) a type of ruby like gem described by Pliny, from L. anthracites bloodstone, semi precious gem, from Gk. anthrakites coal like, from anthrax (gen. anthrakos) live coal (see ANTHRAX (Cf. anthrax)).… …   Etymology dictionary

  • anthracite — ► NOUN ▪ hard coal that burns with little flame and smoke. ORIGIN Greek anthrakit s, from anthrax coal …   English terms dictionary

  • anthracite — [an′thrə sīt΄] n. [Gr anthrakitis, kind of coal < anthrax, coal] a shiny black, hard, metamorphic coal that contains a low percentage of volatile matter and burns with a smokeless flame: also called hard coal: see BITUMINOUS COAL anthracitic… …   English World dictionary

  • Anthracite — Pour les articles homonymes, voir Anthracite (homonymie). L anthracite (du grec anthrax, Άνθραξ, charbon) est une roche sédimentaire d origine organique. C est une variété de charbon grise, noirâtre et brillante extraite des mines. Il contient 92 …   Wikipédia en Français

  • Anthracite —   The highest rank of coal; used primarily for residential and commercial space heating. It is a hard, brittle, and black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile …   Energy terms

  • Anthracite — 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

  • anthracite — antracitas statusas T sritis Energetika apibrėžtis Juodos, dažniausiai pilko atspalvio, metalinio blizgesio degiosios iškasamosios akmens anglys. Tai labiausiai suanglėjusios akmens anglys. Naudojamosios masės sudėtis: (93–97) % anglies, (1–3) %… …   Aiškinamasis šiluminės ir branduolinės technikos terminų žodynas

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”