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Anthracite, also known as hard coal, and black coal, is a hard, compact variety of
coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when ...
that has a submetallic luster. It has the highest
carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon ma ...
content, the fewest impurities, and the highest
energy density In physics, energy density is the amount of energy stored in a given system or region of space per unit volume. It is sometimes confused with energy per unit mass which is properly called specific energy or . Often only the ''useful'' or extrac ...
of all types of coal and is the highest
ranking A ranking is a relationship between a set of items such that, for any two items, the first is either "ranked higher than", "ranked lower than" or "ranked equal to" the second. In mathematics, this is known as a weak order or total preorder of o ...
of coals. Anthracite is the most
metamorphosed Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, causi ...
type of coal (but still represents low-grade metamorphism), in which the carbon content is between 86% and 97%. The term is applied to those varieties of coal which do not give off tarry or other
hydrocarbon In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons are examples of group 14 hydrides. Hydrocarbons are generally colourless and hydrophobic, and their odors are usually weak or ...
vapours when heated below their point of
ignition Ignition may refer to: Science and technology * Firelighting, the human act of creating a fire for warmth, cooking and other uses * Combustion, an exothermic chemical reaction between a fuel and an oxidant * Fusion ignition, the point at which a ...
. Anthracite ignites with difficulty and burns with a short, blue, and smokeless flame. Anthracite is categorized into standard grade, which is used mainly in power generation, high grade (HG) and ultra high grade (UHG), the principal uses of which are in the
metallurgy Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys. Metallurgy encompasses both the sc ...
sector. Anthracite accounts for about 1% of global coal reserves, and is mined in only a few countries around the world. The
Coal Region The Coal Region is a region of Northeastern Pennsylvania. It is known for being home to the largest known deposits of anthracite coal in the world with an estimated reserve of seven billion short tons. The region is typically defined as compris ...
of northeastern
Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
in the United States has the largest known deposits of anthracite coal in the world with an estimated reserve of seven billion short tons.
China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slig ...
accounts for the majority of global production; other producers are
Russia Russia (, , ), or the Russian Federation, is a transcontinental country spanning Eastern Europe and Northern Asia. It is the largest country in the world, with its internationally recognised territory covering , and encompassing one-ei ...
,
Ukraine Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inva ...
,
North Korea North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korean Peninsula and shares borders with China and Russia to the north, at the Yalu (Amnok) and T ...
,
South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...
,
Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making ...
,
the UK The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
,
Australia Australia, officially the Commonwealth of Australia, is a sovereign country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by ...
,
Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...
, and the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
. Total production in 2020 was 615 million tons.


Names

Anthracite derives from the
Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...
''anthrakítēs'' (), literally "coal-like". Other terms which refer to anthracite are black coal, hard coal, stone coal, dark coal, coffee coal, blind coal (in Scotland), Kilkenny coal (in Ireland), crow coal or craw coal, and black diamond. "Blue Coal" is the term for a once-popular and trademarked brand of anthracite, mined by the Glen Alden Coal Company in Pennsylvania, and sprayed with a blue dye at the mine before shipping to its northeastern U.S. markets to distinguish it from its competitors. Culm has different meanings in
British British may refer to: Peoples, culture, and language * British people, nationals or natives of the United Kingdom, British Overseas Territories, and Crown Dependencies. ** Britishness, the British identity and common culture * British English, ...
and
American English American English, sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. English is the most widely spoken language in the United States and in most circumstances ...
. In British English, "culm" is the imperfect anthracite of north
Devon Devon ( , historically known as Devonshire , ) is a ceremonial and non-metropolitan county in South West England. The most populous settlement in Devon is the city of Plymouth, followed by Devon's county town, the city of Exeter. Devo ...
and
Cornwall Cornwall (; kw, Kernow ) is a Historic counties of England, historic county and Ceremonial counties of England, ceremonial county in South West England. It is recognised as one of the Celtic nations, and is the homeland of the Cornish people ...
, which was used as a
pigment A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compou ...
. The term is also used to refer to some Carboniferous
rock strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as e ...
found in both Britain and in the
Rhenish The Rhineland (german: Rheinland; french: Rhénanie; nl, Rijnland; ksh, Rhingland; Latinised name: ''Rhenania'') is a loosely defined area of Western Germany along the Rhine, chiefly its middle section. Term Historically, the Rhinelands ...
hill countries (the
Culm Measures The Culm Measures are a thick sequence of geological strata originating during the Carboniferous Period that occur in south-west England, principally in Devon and Cornwall, now known as the Culm Supergroup. Its estimated thickness varies between ...
). Lastly, it may refer to coal exported from Britain during the 19th century. In American English, "culm" refers to the waste or slack from anthracite mining, mostly dust and small pieces not suitable for use in home furnaces.


Properties

Anthracite is similar in appearance to the
mineraloid A mineraloid is a naturally occurring mineral-like substance that does not demonstrate crystallinity. Mineraloids possess chemical compositions that vary beyond the generally accepted ranges for specific minerals. For example, obsidian is an a ...
jet and is sometimes used as a jet imitation. Anthracite differs from ordinary
bituminous coal Bituminous coal, or black coal, is a type of coal containing a tar-like substance called bitumen or asphalt. Its coloration can be black or sometimes dark brown; often there are well-defined bands of bright and dull material within the seams. It ...
by its greater hardness (2.75–3 on the
Mohs scale The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by ...
), its higher
relative density Relative density, or specific gravity, is the ratio of the density (mass of a unit volume) of a substance to the density of a given reference material. Specific gravity for liquids is nearly always measured with respect to water at its densest ...
of 1.3–1.4, and luster, which is often semi-metallic with a mildly green reflection. It contains a high percentage of fixed carbon and a low percentage of volatile matter. It is also free from included soft or fibrous notches and does not soil the fingers when rubbed. Anthracitization is the transformation of bituminous coal into anthracite. The moisture content of fresh-mined anthracite generally is less than 15 percent. The heat content of anthracite ranges from 26 to 33 MJ/kg (22 to 28 million Btu/
short ton The short ton (symbol tn) is a measurement unit equal to . It is commonly used in the United States, where it is known simply as a ton, although the term is ambiguous, the single word being variously used for short, long, and metric ton. The var ...
) on a moist, mineral-matter-free basis. The heat content of anthracite coal consumed in the United States averages 29 MJ/kg (25 million Btu/ton), on the as-received basis (i.e., containing both inherent moisture and mineral matter). Since the 1980s, anthracite refuse or mine waste has been used for coal power generation in a form of
recycling Recycling is the process of converting waste materials into new materials and objects. The Energy recycling, recovery of energy from waste materials is often included in this concept. The recyclability of a material depends on its ability t ...
. The practice known as reclamation is being applied to culm piles antedating laws requiring mine owners to restore lands to their approximate original condition. Chemically, anthracite may be considered as a transition stage between ordinary bituminous coal and
graphite Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on la ...
, produced by the more or less complete elimination of the volatile constituents of the former, and it is found most abundantly in areas that have been subjected to considerable stresses and pressures, such as the flanks of great mountain ranges. Anthracite is associated with strongly deformed
sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...
s that were subjected to higher pressures and temperatures (but short of metamorphic conditions) just as bituminous coal is generally associated with less deformed or flat-lying sedimentary rocks. For example, the compressed layers of anthracite that are deep mined in the folded Ridge and Valley Province of the
Appalachian Mountains The Appalachian Mountains, often called the Appalachians, (french: Appalaches), are a system of mountains in eastern to northeastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. The ...
of the
Coal Region The Coal Region is a region of Northeastern Pennsylvania. It is known for being home to the largest known deposits of anthracite coal in the world with an estimated reserve of seven billion short tons. The region is typically defined as compris ...
of East-central
Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
are extensions of the same layers of bituminous coal that are mined on the generally flat lying and undeformed sedimentary rocks further west on the
Allegheny Plateau The Allegheny Plateau , in the United States, is a large dissected plateau area of the Appalachian Mountains in western and central New York (state), New York, northern and western Pennsylvania, northern and western West Virginia, and eastern Oh ...
of
Kentucky Kentucky ( , ), officially the Commonwealth of Kentucky, is a state in the Southeastern region of the United States and one of the states of the Upper South. It borders Illinois, Indiana, and Ohio to the north; West Virginia and Virginia ...
and
West Virginia West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the ...
, Eastern Ohio, and Western Pennsylvania. In the same way the anthracite region of
South Wales South Wales ( cy, De Cymru) is a loosely defined region of Wales bordered by England to the east and mid Wales to the north. Generally considered to include the historic counties of Glamorgan and Monmouthshire, south Wales extends westwards ...
is confined to the contorted portion west of
Swansea Swansea (; cy, Abertawe ) is a coastal city and the second-largest city of Wales Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the C ...
and
Llanelli Llanelli ("St Elli's Parish"; ) is a market town and the largest community in Carmarthenshire and the preserved county of Dyfed, Wales. It is located on the Loughor estuary north-west of Swansea and south-east of the county town, Carma ...
, the central and eastern portions producing
steam coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...
,
coking coal Metallurgical coal or coking coal is a grade of coal that can be used to produce good-quality coke. Coke is an essential fuel and reactant in the blast furnace process for primary steelmaking. The demand for metallurgical coal is highly coupled ...
and domestic house coals. Structurally, anthracite shows some alteration by the development of secondary divisional planes and fissures so that the original stratification lines are not always easily seen. The thermal conductivity is also higher; a lump of anthracite feels perceptibly colder when held in the warm hand than a similar lump of bituminous coal at the same temperature. Anthracite has a history of use in
blast furnace A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. ''Blast'' refers to the combustion air being "forced" or supplied above atmospheri ...
s for iron smelting; however, it lacked the pore space of metallurgical coke, which eventually replaced anthracite.


History of mining and use

In southwest
Wales Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in ...
, anthracite has been burned as a domestic fuel since at least medieval times, when it was mined near
Saundersfoot Saundersfoot ( cy, Llanusyllt; Old Welsh: ''Llanussyllt'') is a large village and community (and former electoral ward) in Pembrokeshire, Wales. It is near Tenby, both being holiday destinations. Saundersfoot lies in the Pembrokeshire Coast Natio ...
. More recently, large-scale mining of anthracite took place right across the western part of the
South Wales Coalfield The South Wales Coalfield ( cy, Maes glo De Cymru) extends across Pembrokeshire, Carmarthenshire, Swansea, Neath Port Talbot, Bridgend, Rhondda Cynon Taf, Merthyr Tydfil, Caerphilly, Blaenau Gwent and Torfaen. It is rich in coal deposits, espe ...
until the late 20th century. Mining continues but now on a smaller scale. In the United States, anthracite coal history began in 1790 in
Pottsville, Pennsylvania Pottsville is the county seat of Schuylkill County, Pennsylvania, United States. The population was 13,346 at the 2020 census, and is the principal city of the Pottsville, PA Micropolitan Statistical Area. The city lies along the west bank of t ...
, with the discovery of coal made by the hunter Necho Allen in what is now known as the
Coal Region The Coal Region is a region of Northeastern Pennsylvania. It is known for being home to the largest known deposits of anthracite coal in the world with an estimated reserve of seven billion short tons. The region is typically defined as compris ...
. Legend has it that Allen fell asleep at the base of Broad Mountain and woke to the sight of a large fire because his campfire had ignited an outcrop of anthracite coal. By 1795, an anthracite-fired
iron furnace A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. ''Blast'' refers to the combustion air being "forced" or supplied above atmospheric ...
had been built on the
Schuylkill River The Schuylkill River ( , ) is a river running northwest to southeast in eastern Pennsylvania. The river was improved by navigations into the Schuylkill Canal, and several of its tributaries drain major parts of Pennsylvania's Coal Region. It f ...
. Anthracite was first experimentally burned as a residential heating fuel in the US on 11 February 1808, by Judge
Jesse Fell Jesse Fell was an early political leader in Wilkes-Barre, Pennsylvania. He was one of the first Pennsylvanians to successfully burn anthracite on an open air grate. Anthracite differs from wood in that it needs a draft from the bottom, and Judge ...
in
Wilkes-Barre, Pennsylvania Wilkes-Barre ( or ) is a city in the U.S. state of Pennsylvania and the county seat of Luzerne County. Located at the center of the Wyoming Valley in Northeastern Pennsylvania, it had a population of 44,328 in the 2020 census. It is the s ...
, on an open grate in a fireplace. Anthracite differs from wood in that it needs a draft from the bottom, and Judge Fell proved with his grate design that it was a viable heating fuel. In spring 1808, John and Abijah Smith shipped the first commercially mined load of anthracite down the
Susquehanna River The Susquehanna River (; Lenape: Siskëwahane) is a major river located in the Mid-Atlantic region of the United States, overlapping between the lower Northeast and the Upland South. At long, it is the longest river on the East Coast of the ...
from Plymouth, Pennsylvania, marking the birth of commercial anthracite mining in the United States. From that first mine, production rose to an all-time high of over 100 million tons in 1917. Anthracite usage was inhibited by the difficulty of igniting it. This was a particular concern in smelting iron using a
blast furnace A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. ''Blast'' refers to the combustion air being "forced" or supplied above atmospheri ...
. With the invention of
hot blast Hot blast refers to the preheating of air blown into a blast furnace or other metallurgical process. As this considerably reduced the fuel consumed, hot blast was one of the most important technologies developed during the Industrial Revolution. ...
in 1828, which used waste heat to preheat combustion air, anthracite became a preferred fuel, accounting for 45% of US pig iron production within 15 years. Anthracite for iron smelting was later displaced by coke. From the late 19th century until the 1950s, anthracite was the most popular fuel for heating homes and other buildings in the northern US, until it was supplanted by oil-burning systems and more recently natural gas systems. Many large public buildings, such as schools, were heated with anthracite-burning furnaces through the 1980s. During the
American Civil War The American Civil War (April 12, 1861 – May 26, 1865; also known by Names of the American Civil War, other names) was a civil war in the United States. It was fought between the Union (American Civil War), Union ("the North") and t ...
, Confederate
blockade runners A blockade runner is a merchant vessel used for evading a naval blockade of a port or strait. It is usually light and fast, using stealth and speed rather than confronting the blockaders in order to break the blockade. Blockade runners usuall ...
used anthracite as a smokeless fuel for their boilers to avoid giving away their position to the blockaders. The invention of the
Wootten firebox The Wootten firebox is a type of firebox used on steam locomotives. The firebox was very wide to allow combustion of anthracite waste, known as " culm". Its size necessitated unusual placement of the crew, examples being camelback locomotives. T ...
enabled
locomotives A locomotive or engine is a rail transport vehicle that provides the motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, motor coach, railcar or power car; the ...
to directly burn anthracite efficiently, particularly waste culm. In the early 20th century US, the
Delaware, Lackawanna & Western Railroad The Delaware, Lackawanna and Western Railroad (also known as the DL&W or Lackawanna Railroad) was a U.S. Class 1 railroad that connected Buffalo, New York, and Hoboken, New Jersey (and by ferry with New York City), a distance of . Incorporated in ...
started using only the more expensive anthracite coal in its passenger locomotives, dubbed themselves "The Road of Anthracite," and advertised widely that travelers on their line could make railway journeys without getting their clothing stained with soot. The advertisements featured a white-clad woman named
Phoebe Snow Phoebe Snow (born Phoebe Ann Laub; July 17, 1950 – April 26, 2011) was an American roots music singer-songwriter and guitarist, known for her hit 1974 and 1975 songs " San Francisco Bay Blues", " Poetry Man", "Harpo's Blues", and her credited ...
and poems containing lines like "My gown stays white / From morn till night / Upon the road of Anthracite". Similarly, the
Great Western Railway The Great Western Railway (GWR) was a British railway company that linked London with the southwest, west and West Midlands of England and most of Wales. It was founded in 1833, received its enabling Act of Parliament on 31 August 1835 and ran ...
in the UK was able to use its access to anthracite (it dominated the anthracite region) to earn a reputation for efficiency and cleanliness unmatched by other UK companies. Internal combustion motors driven by the so-called "mixed", "poor", "semi-water" or " Dowson gas" produced by the
gasification Gasification is a process that converts biomass- or fossil fuel-based carbonaceous materials into gases, including as the largest fractions: nitrogen (N2), carbon monoxide (CO), hydrogen (H2), and carbon dioxide (). This is achieved by reacting ...
of anthracite with air (and a small proportion of steam) were at one time the most economical method of obtaining power, requiring only , or less. Large quantities of anthracite for power purposes were formerly exported from South Wales to France, Switzerland and parts of Germany. , widespread commercial anthracite mining in
Wales Wales ( cy, Cymru ) is a country that is part of the United Kingdom. It is bordered by England to the east, the Irish Sea to the north and west, the Celtic Sea to the south west and the Bristol Channel to the south. It had a population in ...
has now ceased, although a few large open cast sites remain, along with some relatively small
drift mining Drift mining is either the mining of an ore deposit by underground methods, or the working of coal seams accessed by adits driven into the surface outcrop of the coal bed. A drift mine is an underground mine in which the entry or access is abov ...
operations.


Anthracite today

Anthracite generally costs two to three times as much as regular coal. In June 2008, the wholesale cost of anthracite was US$150/
short ton The short ton (symbol tn) is a measurement unit equal to . It is commonly used in the United States, where it is known simply as a ton, although the term is ambiguous, the single word being variously used for short, long, and metric ton. The var ...
. The principal use of anthracite today is for a domestic fuel in either hand-fired stoves or automatic stoker furnaces. It delivers high energy per its weight and burns cleanly with little soot, making it ideal for this purpose. Its high value makes it prohibitively expensive for power plant use. Other uses include the fine particles used as filter media, and as an ingredient in
charcoal Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, ...
briquettes A briquette (; also spelled briquet) is a compressed block of coal dust or other combustible biomass material (e.g. charcoal, sawdust, wood chips, peat, or paper) used for fuel and kindling to start a fire. The term derives from the French wor ...
. Anthracite was an authorised fuel in terms of the United Kingdom's Clean Air Act 1993, meaning that it could be used within a designated Smoke Control Area such as the central London boroughs.


Mining

China today mines by far the largest share of global anthracite production, accounting for more than three-quarters of global output. Most Chinese production is of standard-grade anthracite, which is used in power generation. Increased demand in China has made that country into a net importer of the fuel, mostly from Vietnam, another major producer of anthracite for power generation, although increasing domestic consumption in Vietnam means that exports may be scaled back.Petmin Annual Report 2011
Current U.S. anthracite production averages around five million tons per year. Of that, about 1.8 million tons were mined in the state of Pennsylvania. Mining of anthracite coal continues to this day in eastern Pennsylvania, and contributes up to 1% to the gross state product. More than 2,000 people were employed in the mining of anthracite coal in 1995. Most of the mining as of that date involved reclaiming coal from slag heaps (waste piles from past coal mining) at nearby closed mines. Some underground anthracite coal is also being mined. Countries producing HG and UHG anthracite include Russia and South Africa. HG and UHG anthracite are used as a coke or coal substitute in various
metallurgical coal Metallurgical coal or coking coal is a grade of coal that can be used to produce good-quality coke. Coke is an essential fuel and reactant in the blast furnace process for primary steelmaking. The demand for metallurgical coal is highly coupled ...
applications (
sintering Clinker nodules produced by sintering Sintering or frittage is the process of compacting and forming a solid mass of material by pressure or heat without melting it to the point of liquefaction. Sintering happens as part of a manufacturing ...
, PCI, direct BF charge,
pelletizing Pelletizing is the process of compressing or molding a material into the shape of a pellet. A wide range of different materials are pelletized including chemicals, iron ore, animal compound feed, plastics, waste materials, and more. The proces ...
). It plays an important role in cost reduction in the steel making process and is also used in production of
ferroalloy Ferroalloy refers to various alloys of iron with a high proportion of one or more other elements such as manganese (Mn), aluminium (Al), or silicon (Si). They are used in the production of steels and alloys. The alloys impart distinctive qualitie ...
s, silicomanganese,
calcium carbide Calcium carbide, also known as calcium acetylide, is a chemical compound with the chemical formula of Ca C2. Its main use industrially is in the production of acetylene and calcium cyanamide. The pure material is colorless, while pieces of te ...
and
silicon carbide Silicon carbide (SiC), also known as carborundum (), is a hard chemical compound containing silicon and carbon. A semiconductor, it occurs in nature as the extremely rare mineral moissanite, but has been mass-produced as a powder and crystal s ...
. South Africa exports lower-quality, higher-ash anthracite to Brazil to be used in steel-making.


Sizing and grading

Anthracite is processed into different sizes by what is commonly referred to as a breaker. The large coal is raised from the mine and passed through breakers with toothed rolls to reduce the lumps to smaller pieces. The smaller pieces are separated into different sizes by a system of graduated sieves, placed in descending order. Sizing is necessary for different types of stoves and furnaces. Anthracite is classified into three grades, depending on its carbon content. Standard grade is used as a domestic fuel and in industrial power-generation. The rarer higher grades of anthracite are purer – i.e., they have a higher carbon content – and are used in steel-making and other segments of the metallurgical industries. Technical characteristics of the various grades of anthracite are as follows: Anthracite is divided by size mainly into applications that need lumps (typically larger than 10 mm) – various industrial processes where it replaces metallurgical coke, and domestic fuel – and those that need fines (less than 10 mm), such as sintering and pelletising. The common American classification by size is as follows: Lump, steamboat, egg and stove coals, the latter in two or three sizes, all three being above  in (38 mm) size on round-hole screens.


High grade

High grade (HG) and ultra high grade (UHG) anthracite are the highest grades of anthracite coal. They are the purest forms of coal, having the highest degree of coalification, the highest carbon count and energy content and the fewest impurities (moisture, ash and volatiles). High grade and ultra high grade anthracite are harder than standard grade anthracite, and have a higher relative density. An example of a chemical formula for high-grade anthracite would be C240H90O4NS, representing 94% carbon. UHG anthracite typically has a minimum carbon content of 95%. They also differ in usage from standard grade anthracite (used mainly for power generation), being employed mainly in metallurgy as a cost-efficient substitute for coke in processes such as
sintering Clinker nodules produced by sintering Sintering or frittage is the process of compacting and forming a solid mass of material by pressure or heat without melting it to the point of liquefaction. Sintering happens as part of a manufacturing ...
and pelletising, as well as pulverised coal injection (PCI) and direct injection into
blast furnace A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. ''Blast'' refers to the combustion air being "forced" or supplied above atmospheri ...
s. They can also be used in
water purification Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids, and gases from water. The goal is to produce water that is fit for specific purposes. Most water is purified and disinfected for hu ...
and domestically as a
smokeless fuel Smokeless fuel is a type of solid fuel which either does not emit visible smoke, or emits minimal amounts, during combustion. These types of fuel are becoming increasingly popular in areas which ban the use of coal and other fuels such as unseaso ...
. HG and UHG anthracite account for a small percentage of the total anthracite market. The major producing countries are Russia, Ukraine, Vietnam, South Africa and the US. The primary sizes used in the United States for domestic heating are Chestnut, Pea, Buckwheat and Rice, with Chestnut and Rice being the most popular. Chestnut and Pea are used in hand fired furnaces while the smaller Rice and Buckwheat are used in automatic stoker furnaces. Rice is currently the most sought-after size due to the ease of use and popularity of that type of furnace. In
South Wales South Wales ( cy, De Cymru) is a loosely defined region of Wales bordered by England to the east and mid Wales to the north. Generally considered to include the historic counties of Glamorgan and Monmouthshire, south Wales extends westwards ...
, a less elaborate classification is adopted, but great care is exercised in hand-picking and cleaning the coal from particles of pyrites in the higher qualities known as best malting coals, which are used for kiln-drying malt. Anthracite dust can be made into
briquettes A briquette (; also spelled briquet) is a compressed block of coal dust or other combustible biomass material (e.g. charcoal, sawdust, wood chips, peat, or paper) used for fuel and kindling to start a fire. The term derives from the French wor ...
and is sold in the United Kingdom under trade names such as Phurnacite, Ancit and Taybrite.


Semianthracite

On the opposite end from high-grade anthracite coal, semianthracite coal is defined as a coal which is intermediate between anthracite coal and bituminous coal, and particularly a coal which approaches anthracite in nonvolatile character.


Underground fires

Historically from time to time, underground seams of coal have caught fire, often from careless or unfortunate mining activities. The pocket of ignited coal is fed oxygen by vent paths that have not yet been discovered. These can smolder for years. Commonly, exhaust vents in populated areas are soon sensed and are sealed while vents in uninhabited areas remain undiscovered. Occasionally, vents are discovered via fumes sensed by passers-by, often in forested areas. Attempts to extinguish those remaining have at times been futile, and several such combustion areas exist today. The existence of an underground combustion site can sometimes be identified in the winter where fallen snow is seen to be melted by the warmth conducted from below. Proposals for harnessing this heat as geothermal energy have not been successful. A vein of anthracite that caught fire in Centralia, Pennsylvania, in 1962 has been burning ever since, turning the once-thriving borough into a
ghost town Ghost Town(s) or Ghosttown may refer to: * Ghost town, a town that has been abandoned Film and television * ''Ghost Town'' (1936 film), an American Western film by Harry L. Fraser * ''Ghost Town'' (1956 film), an American Western film by All ...
.


Major reserves

Among current producers, Russia, China and Ukraine have the largest estimated recoverable reserves of anthracite. Other countries with substantial reserves include Vietnam and North Korea. Geologically, the largest most concentrated anthracite deposit in the world is found in the Lackawanna Coal Mine in northeastern
Pennsylvania Pennsylvania (; ( Pennsylvania Dutch: )), officially the Commonwealth of Pennsylvania, is a state spanning the Mid-Atlantic, Northeastern, Appalachian, and Great Lakes regions of the United States. It borders Delaware to its southeast, ...
, United States in and around
Scranton Scranton is a city in the Commonwealth of Pennsylvania, United States, and the county seat of Lackawanna County. With a population of 76,328 as of the 2020 U.S. census, Scranton is the largest city in Northeastern Pennsylvania, the Wyoming V ...
, Pennsylvania. Locally called the
Coal Region The Coal Region is a region of Northeastern Pennsylvania. It is known for being home to the largest known deposits of anthracite coal in the world with an estimated reserve of seven billion short tons. The region is typically defined as compris ...
, the deposit contains of coal-bearing rock which originally held 22.8 billion short tons (20.68 billion tonnes) of anthracite. The geographic region is roughly 100 miles (161 km) in length and 30 miles (48 km) in width. Because of historical mining and development of the lands overlying the coal, it is estimated that 7 billion short tons (6.3 billion tonnes) of minable reserves remain. The United States also contains several smaller deposits of anthracite, such as those historically mined in
Crested Butte, Colorado Crested Butte is a home rule municipality located in Gunnison County, Colorado, United States. The town population was 1,639 at the 2020 United States Census. The former coal mining town is now called "the last great Colorado ski town". Creste ...
. The Groundhog Anthracite Deposit, located in
British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...
, Canada, is the largest previously undeveloped anthracite deposit in the world. It is owned by Australian publicly listed company, Atrum Coal and has 1.57 billion tonnes of high grade anthracite. Anthracites of newer Tertiary or Cretaceous age are found in the
Crowsnest Pass Crowsnest Pass (sometimes referred to as Crow's Nest Pass, french: link=no, col du Nid-de-Corbeau) is a low mountain pass across the Continental Divide of the Canadian Rockies on the Alberta– British Columbia border. Geography The pass is ...
part of the
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...
in Canada and at various places in the
Andes The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S ...
in Peru.


See also

* , named after a large supply of anthracite found there * , a softer coal * *


Explanatory notes


References

* Attribution: *


Further reading

* * – Useful overview of the industry in the 20th century; fair-minded with an operators perspective


Primary sources

* ''Report of the United states coal commission....'' (5 vol in 3; 1925) Official US government investigation
online vol 1-2
** Tryon, Frederick Gale, and Joseph Henry Willits, eds. ''What the Coal Commission Found: An Authoritative Summary by the Staff'' (1925). * General policies committee of anthracite operators. ''The anthracite coal strike of 1922: A statement of its causes and underlying purposes'' (1923); Official statement by the operators
online


External links




The Distribution of Pennsylvania Coals



"A Jewel In the Crown of Old King Coal Eckley Miners' Village" by Tony Wesolowsky, ''Pennsylvania Heritage Magazine'', Volume XXII, Number 1Winter 1996

The Eastern Pennsylvania Coalition for Abandoned Mine Reclamation

The Anthracite Heritage Museum.

Pennsylvania's Northern Coal Field
{{Authority control Coal Metamorphic rocks Organic minerals Coal mining