Culm (waste Coal)
   HOME

TheInfoList



OR:

Coal refuse, also known as coal waste, rock, slag, coal tailings, waste material, rock bank, culm, boney, or gob (garbage of bituminous), is the material left over from
coal mining Coal mining is the process of resource extraction, extracting coal from the ground or from a mine. Coal is valued for its Energy value of coal, energy content and since the 1880s has been widely used to Electricity generation, generate electr ...
, usually as tailings piles or
spoil tip A spoil tip (also called a boney pile, culm bank, gob pile, waste tip or bing) is a pile built of accumulated ''spoil'' – waste material removed during mining. Spoil tips are not formed of slag, but in some areas, such as England and Wales, ...
s. For every tonne of
hard coal Anthracite, also known as hard coal and black coal, is a hard, compact variety of coal that has a submetallic lustre. It has the highest carbon content, the fewest impurities, and the highest energy density of all types of coal and is the highe ...
generated by mining, of waste material remains, which includes some lost
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 Chemical element, elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal i ...
that is partially economically recoverable. Coal refuse is distinct from the byproducts of burning coal, such as
fly ash Coal combustion products (CCPs), also called coal combustion wastes (CCWs) or coal combustion residuals (CCRs), are byproducts of burning coal. They are categorized in four groups, each based on physical and chemical forms derived from coal combust ...
. Piles of coal refuse can have significant negative environmental consequences, including the leaching of
iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...
,
manganese Manganese is a chemical element; it has Symbol (chemistry), symbol Mn and atomic number 25. It is a hard, brittle, silvery metal, often found in minerals in combination with iron. Manganese was first isolated in the 1770s. It is a transition m ...
, and
aluminum Aluminium (or aluminum in North American English) is a chemical element; it has chemical symbol, symbol Al and atomic number 13. It has a density lower than that of other common metals, about one-third that of steel. Aluminium has ...
residues into waterways and
acid mine drainage Acid mine drainage, acid and metalliferous drainage (AMD), or acid rock drainage (ARD) is the outflow of acidic water from metal mines and coal mines. Acid rock drainage occurs naturally within some environments as part of the rock weatherin ...
. The runoff can create both surface and groundwater contamination. The piles also create a fire hazard, with the potential to spontaneously ignite. Because most coal refuse harbors
toxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subst ...
components, it is not easily reclaimed by replanting with plants like beach grasses. Gob (garbage of bituminous) has about four times as much toxic mercury and more
sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...
than typical coal. Culm is the term for waste
anthracite Anthracite, also known as hard coal and black coal, is a hard, compact variety of coal that has a lustre (mineralogy)#Submetallic lustre, submetallic lustre. It has the highest carbon content, the fewest impurities, and the highest energy densit ...
coal.


Disposal

The first step to reclaiming land occupied by coal refuse piles is to remove the refuse matter.


As fuel

Where economically viable, some coal miners try to reprocess these wastes. This may include complex reprocessing in more industrialized economies, such as
fluidized bed combustion Fluidized bed combustion (FBC) is a combustion technology used to burn solid fuels. In its most basic form, fuel particles are suspended in a hot, bubbling fluidity bed of ash and other particulate materials (sand, limestone etc.) through whic ...
in power plants. In less industrialized systems, manual sorting may be employed. For example, in the Jharia coalfield in eastern
India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...
, a large cohort of "coal cycle wallahs" manually sort mine tailings with their families, and then transport the salvaged coal on bicycles more than to market. The burning of waste coal typically produces more environmental toxins than higher energy coals. Modern
fluidized bed A fluidized bed is a physical phenomenon that occurs when a solid particulate substance (usually present in a holding vessel) is under the right conditions so that it behaves like a fluid. The usual way to achieve a fluidized bed is to pump press ...
combustion with limestone for acid gas control can lower toxin emissions to acceptable levels, concentrating the toxicity into waste ash. For every 100 tons of coal waste burned, 85 tons of waste ash (more toxic versions of
fly ash Coal combustion products (CCPs), also called coal combustion wastes (CCWs) or coal combustion residuals (CCRs), are byproducts of burning coal. They are categorized in four groups, each based on physical and chemical forms derived from coal combust ...
and
bottom ash Bottom ash is part of the non- combustible residue of combustion in a power plant, boiler, furnace, or incinerator. In an industrial context, it has traditionally referred to coal combustion and comprises traces of combustibles embedded in for ...
) are created. However, this ash is more stable than the waste and may simply be re-compacted into the mine site with less risk of leaching. It can also be used to neutralize acidic mine discharge.


Other uses

There have been some attempts to use non-flammable coal waste in
concrete Concrete is a composite material composed of aggregate bound together with a fluid cement that cures to a solid over time. It is the second-most-used substance (after water), the most–widely used building material, and the most-manufactur ...
production, similar to the use of
fly ash Coal combustion products (CCPs), also called coal combustion wastes (CCWs) or coal combustion residuals (CCRs), are byproducts of burning coal. They are categorized in four groups, each based on physical and chemical forms derived from coal combust ...
. The waste ash from burning coal waste was approved as a source of fly ash by the West Virginia Department of Highways in 2019.


By geography


United States

In the United States, most waste coal piles accumulated from 1900 to 1970 when processing techniques were less sophisticated. The US has a longstanding inspection program of these refuse piles. In
Pennsylvania Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...
alone, there are over 770 such piles identified. There are at least 18 coal waste burning plants in the United States, mostly in Pennsylvania. The Grant Town Power Project in
West Virginia West Virginia is a mountainous U.S. state, state in the Southern United States, Southern and Mid-Atlantic (United States), Mid-Atlantic regions of the United States.The United States Census Bureau, Census Bureau and the Association of American ...
burns 530,000 tons of coal refuse annually, allowing the reclamation of 30 acres of land annually. Still, there's criticism regarding the plant's negative profitability and its
greenhouse gas Greenhouse gases (GHGs) are the gases in the atmosphere that raise the surface temperature of planets such as the Earth. Unlike other gases, greenhouse gases absorb the radiations that a planet emits, resulting in the greenhouse effect. T ...
emissions from burning coal. The plant has controversially proposed pivoting to
cryptocurrency mining GPU mining is the use of Graphics Processing Units (GPUs) to "mine" proof-of-work cryptocurrencies, such as Bitcoin. Miners receive rewards for performing computationally intensive work, such as calculating hashes, that amend and verify transactio ...
for funding. Wider replacement of
cement A cement is a binder, a chemical substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel ( aggregate) together. Cement mi ...
by its
fly ash Coal combustion products (CCPs), also called coal combustion wastes (CCWs) or coal combustion residuals (CCRs), are byproducts of burning coal. They are categorized in four groups, each based on physical and chemical forms derived from coal combust ...
should bring down its
carbon footprint A carbon footprint (or greenhouse gas footprint) is a calculated value or index that makes it possible to compare the total amount of greenhouse gases that an activity, product, company or country Greenhouse gas emissions, adds to the atmospher ...
.


Etymology

The word about coal waste is of uncertain origin but goes back over 200 years, long before a
false etymology A false etymology (fake etymology or pseudo-etymology) is a false theory about the origin or derivation of a specific word or phrase. When a false etymology becomes a popular belief in a cultural/linguistic community, it is a folk etymology (or po ...
as a
backronym A backronym is an acronym formed from an already existing word by expanding its letters into the words of a phrase. Backronyms may be invented with either serious or humorous intent, or they may be a type of false etymology or folk etymology. The ...
for "garbage of
bituminous Bitumen ( , ) is an immensely viscous constituent of petroleum. Depending on its exact composition, it can be a sticky, black liquid or an apparently solid mass that behaves as a liquid over very large time scales. In American English, the m ...
" was humorously invented to "explain" it.


Disasters

In the 1966
Aberfan disaster The Aberfan disaster () was the catastrophic collapse of a colliery spoil tip on 21 October 1966. The tip had been created on a mountain slope above the Welsh village of Aberfan, near Merthyr Tydfil, and overlaid a natural spring. Heavy rai ...
in Wales, a colliery
spoil tip A spoil tip (also called a boney pile, culm bank, gob pile, waste tip or bing) is a pile built of accumulated ''spoil'' – waste material removed during mining. Spoil tips are not formed of slag, but in some areas, such as England and Wales, ...
collapsed, engulfing a school and killing 116 children and 28 adults. Other accidents involving coal waste include the Martin County coal slurry spill (US, 2000), the
Kingston Fossil Plant coal fly ash slurry spill The Kingston Fossil Plant Spill was an environmental disaster, environmental and industrial disaster that occurred on December 22, 2008, when a Levee, dike ruptured at a coal ash ash pond, pond at the Tennessee Valley Authority's Kingston Fossi ...
(US, 2008), and the Obed Mountain coal mine spill (Canada, 2013).


References

{{Use dmy dates, date=December 2020 Coal mining Mining waste