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Coal and Its Classification


Coal is the product of vegetable matter that has beenvformed by
the action of decay, weathering, the effects of pressure, temperature and time millions of years ago.

Although coal is not a true mineral, its formation processes are
similar to those of sedimentary rocks.

According to the amount of carbon coals are classified into;
brown coals, bituminous coals and anthracite. Brown coals are in
their turn subdivided into lignite and common brown coal.

Although carbon is the most important element in coal, as
many as 72 elements have been found in some coal deposits, including
lithium, chromium, cobalt, copper, nickel, tungsten and others.

Lignite is intermediate in properties between peat and bitumi-
nous coal, containing when dry about 60 to 75 per cent of carbon
and a variable proportion of ash. Lignite is a low-rank brown-to-black
coal containing 30 to 40 per cent of moisture. Developing heat it
gives from 2,500 to 4,500 calories. It is easily inflammable but burns
with a smoky flame. Lignite is liable to spontaneous combustion. It
has been estimated that about 50 per cent of the world's total coal
reserves are lignitic.

Brown coal is harder than lignite, containing from 60 to 65 per
cent of carbon and developing greater heat than lignite (4,000-7,000
calories). It is very combustible and gives a brown powder. Bituminous
is the most abundant variety, varying from medium to high
rank. It is a soft, black, usually- banded coal. It gives a black powder
and contains 75 to 90 per cent of carbon. It weathers only slightly
and may be kept in open piles with little danger of spontaneous
combustion if properly stored. Medium-to-low volatile bituminous
coals may be of coking quality. Coal is used intensively in blast
furnaces for smelting iron ore. There are noncoking varieties of

As for the thickness, the beds of this kind of coal are not very
thick (1-1.5 metres). The great quantities of bituminous coal are
found in the Russian Federation.

Anthracite or "hard" coal has a brilliant lustre containing more
than 90 per cent of carbon and low percentage of volatile matter. It
is used primarily as a domestic fuel, although it can sometimes be
blended with bituminous grades of coal to produce a mixture with
improved coking qualities. The largest beds of anthracite are found
in Russia, the USA and Great Britain.





Task 16

Write an abstract of the text “ Coal and Its Classification” according to the plan:


1. The classification of coal.

2. The characteristic of lignite, brown coal, anthracite

3. The largest deposits of coals in the world





available доступный
to concentrate сосредоточиваться
decay распад
to refer to объяснять, ссылаться, относиться
to give off выделять, испускать
to divide делить
manufactured промышленного производства, искусственный
peat торф
plant растение
to include включать в себя
coke кокс
charcoal древесный уголь
commercial промышленный, коммерческий
steel industry сталелитейное производство
tendency тенденция, стремление
to increase возрастать, увеличиваться, усиливаться
raw material сырье
petrochemical нефтехимический
to design разрабатывать, конструировать, проектировать
coal conversion переработка угля
strip mining открытая разработка
to haul перевозить, транспортировать
to drive from происходить
crude oil сырая нефть
to furnish поставлять, снабжать
to refine очищать
pollutant загрязняющее вещество, примесь
distribution распределение, размещение
to promise обещать
extensive обширный, пространный
storage хранение, накопление
compartment отделение, камера
to pipe пускать по трубам
trial испытание, опыт
exhaust выхлопная труба, выхлоп
consequence последовательность
to spill (spilled, spilt) проливаться, разливаться
instantaneously мгновенно
dissipate рассеиваться
emergency авария
to be aware знать, сознавать
damage повреждать
liable подверженный, склонный
reduction восстановление
harmful вредный
eject выбрасывать, выпускать
coal deposit угольное месторождение
peat торф
bituminous битумный
low-rank низкосортный
inflammable легко воспломеняющийся
liable подверженный
lignite лигнит, бурый уголь
lignitic гумат(для обработки буровых скважин)
to weather подвергаться (атмосферным воздействиям)
pile отвал, отвал грунта
blast furnace доменная печь
coking коксование
lustre блеск
blended смешанный
grade сорт



Date: 2014-12-29; view: 4261

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