Roger Weller, geology instructor
The hard, dark sedimentary rock called coal is very important to the United States. It has powered the nation for many years and to this day it produces about half of the nation’s electrical and heating supply. Coal is also one of the most abundant resources the United States has.
Coal is a nonrenewable resource. It is a sedimentary rock made mostly from carbons and hydrocarbons. Coal is formed when plant remains are covered and become under pressure. The plant remains also have to be in contact with moisture and not in contact with air.
The amount of coal the United States has is called the Demonstrated Reserve Base or DRB. The DRB consists of about 484 billion short tons (2000 lbs) of coal. But out of all this, only about 263 billion short tons are recoverable. This is because of land right, and environmental issues. This amount of coal will power and heat the United States for about 250 years if we keep using coal at the same rate that we are now. Most of the recoverable coal is found in the Appalachian mountain region, Midwest United States, and central United States.
All this coal in the United States makes up about 28% of the recoverable coal in the whole world; this is the largest amount of coal that is found in one country. The country with the second largest amount of retrievable coal is Russia. All of Russia’s coal equals about 19% of the world’s recoverable coal. In total, the world has about 930 billion short tons of retrievable coal. This is enough coal to power and heat the planet for about 132 years at its current rate of coal usage.
The coal in the DRB and in the world is not all the same. There are actually four different types of coal: Lignite, Subbituminous, Bituminous, and Anthracite. Each of these types of coal is based on a ranking system. This ranking system is based on the coal’s heating value, its carbon and volatile matter, and its caking properties.
The type of coal that has the lowest rank is called Lignite. Lignite is a soft brownish-black coal with high-moisture content. It makes up about 9% of the DRB. The uses of Lignite are fewer compared to the other coals, but it can still be used to produce electricity. It is not used in heating. Lignite is most commonly found in the Midwestern United States.
comes right after Lignite in terms of rank. It is a dull-black coal and makes up
about 37% of the DRB. Electricity is Subbituminous’ main use, but it is also
used a little in heating. It is found mostly in the Midwest or Mid United
Next is the most commonly used coal, Bituminous. Bituminous makes up about 53% of the DRB. Again it is mostly used for electricity, but it is also used for heating. It is a hard dark coal found mostly in the Mid United States or in the Appalachian mountain region.
The highest ranking
coal is Anthracite. Although it is the highest ranking type of coal, it is also
rarer then all the other types. It makes up only about 1% of the DRB. Anthracite
is mostly found in the Appalachian region near Pennsylvania. It is dark and
hard like Bituminous, but it can also be a bit shiny. It is used for both
heating and electricity.
With all this coal in
the DRB, how do we get it all? We mine it. There are actually two types of coal
mining: surface mining and underground mining.
Surface mining is the type of mining used to get coal at 200ft or less. It is the most common form of mining in the United States and is actually a very good way to mine. In surface mining the miners will remove the dirt and rock to get to the coal. After they are done mining the coal, they fill in the quarry with dirt, rock, and soil. When that is done, the newly filled quarry is used for farms, commercial, or industrial use.
Underground mining is the opposite of surface mining. It is the mining of coal more then 200ft below the surface. In underground mining, the miners cut the coal out of the ground and move it to the surface by elevators or by some other means. This way of mining is not used very much in the United States.
In conclusion, the United States has been blessed with massive amounts of coal. In fact, it has more coal then any country in the entire world. The four types of coal; Lignite, Subbituminous, Bituminous, and Anthracite; have heated and powered the United States for many years and they will probably keep on heating and powering it for many years to come.