This makes it expensive and dangerous to mine, store, and transport. It is susceptible to accidential combustion and has very high carbon emission s when burned.
Most lignite coal is used in power stations very close to where it was mined. Lignite is mainly combusted and used to generate electricity. In the U. Sub-Bituminous Coal Sub-bituminous coal is about million years old. Like lignite, sub-bituminous coal is mainly used as fuel for generating electricity. Most sub-bituminous coal in the U. Outside the U. Bituminous Coal Bituminous coal is formed under more heat and pressure, and is million to million years old.
It is named after the sticky, tar-like substance called bitumen that is also found in petroleum. Bituminous coal is divided into three major types: smithing coal, cannel coal, and coking coal.
Smithing coal has very low ash content, and is ideal for forges, where metals are heated and shaped. Cannel coal was extensively used as a source of coal oil in the 19th century. Coal oil is made by heating cannel coal with a controlled amount of oxygen, a process called pyrolysis. Coal oil was used primarily as fuel for streetlights and other illumination. The widespread use of kerosene reduced the use of coal oil in the 20th century.
Coking coal is used in large-scale industrial processes. The coal is coke d, a process of heating the rock in the absense of oxygen. This reduces the moisture content and makes it a more stable product. The steel industry relies on coking coal. Bituminous coal accounts for almost half of all the coal that is used for energy in the United States. It is mainly mined in Kentucky, Pennsylvania, and West Virginia. Anthracite Anthracite is the highest rank of coal.
It is harder, more dense, and more lustrous than other types of coal. Almost all the water and carbon dioxide have been expelled, and it does not contain the soft or fibrous sections found in bituminous coal or lignite. Because anthracite is a high-quality coal, it burns cleanly, with very little soot. It is more expensive than other coals, and is rarely used in power plants.
Instead, anthracite is mainly used in stoves and furnaces. Anthracite is also used in water- filtration systems. It has tinier pores than sand, so more harmful particles are trapped. This makes water safer for drinking, sanitation , and industry. Anthracite can typically be found in geographical areas that have undergone particularly stressful geologic activity.
For example, the coal reserves on the Allegheny Plateau in Kentucky and West Virginia stretch to the base of the Appalachian Mountains. Here, the process of orogeny , or mountain formation, contributed to temperatures and pressures high enough to create anthracite. China dominates the mining of anthracite, accounting for almost three-quarters of anthracite coal production. Graphite Graphite is an allotrope of carbon, meaning it is a substance made up only of carbon atoms. Diamond is another allotrope of carbon.
Graphite is the final stage of the carbonization process. Graphite conducts electricity well, and is commonly used in lithium ion batteries. It can be used in products such as fire-resistant doors, and missile parts such as nose cones.
Coal Mining Coal can be extracted from the earth either by surface mining or underground mining. Once coal has been extracted, it can be used directly for heating and industrial processes or to fuel power plants for electricity. Surface Mining If coal is less than 61 meters feet underground, it can be extracted through surface mining. In surface mining, workers simply remove any overlying sediment, vegetation, and rock, called overburden. Economically, surface mining is a cheaper option for extracting coal than underground mining.
About two and a half times as much coal can be extracted per worker, per hour, than is possible with underground mining. The environmental impacts of surface mining are dramatic.
The landscape is literally torn apart, destroying habitats and entire ecosystem s. Surface mining can also cause landslide s and subsidence when the ground begins to sink or cave in. Toxic substances leach ing into the air, aquifer s, and water table s may endanger the health of local residents.
In the United States, the Surface Mining Control and Reclamation Act of regulates the process of coal mining, and is an effort to limit the harmful effects on the environment. The act provides funds to help fix these problems and clean up abandoned mining sites.
The three main types of surface coal mining are strip mining, open-pit mining, and mountaintop removal MTR mining. Surface Mining: Strip Mining Strip mining is used where coal seams are located very near the surface and can be removed in massive layers, or strips.
Overburden is usually removed with explosives and towed away with some of the largest vehicles ever made. Dump trucks used at strip mines often weigh more than tons and have more than 3, horsepower. Strip mining can be used in both flat and hilly landscapes. Strip mining in a mountainous area is called contour mining. Contour mining follows the ridges, or contours, around a hill. A pit, sometimes called a borrow, is dug in an area.
This pit becomes the open-pit mine , sometimes called a quarry. Open-pit mines can expand to huge dimensions, until the coal deposit has been mined or the cost of transporting the overburden is greater than the investment in the mine. Open-pit mining is usually restricted to flat landscapes. After the mine has been exhausted, the pit is sometimes converted into a landfill.
After the summit is cleared of vegetation, explosives are used to expose the coal seam. After the coal is extracted, the summit is sculpted with overburden from the next mountaintop to be mined. By law, valuable topsoil is supposed to be saved and replaced after mining is done. Barren land can be replanted with trees and other vegetation.
Mountaintop removal began in the s as a cheap alternative to underground mining. It is now used for extracting coal mainly in the Appalachian Mountains of the U. MTR is probaby the most controversial coal mining technique. The environmental consequences are radical and severe.
Waterways are cut off or contaminated by valley fill. Habitats are destroyed. Toxic byproduct s of the mining and explosive processes can drain into local waterways and pollute the air.
Miners travel by elevator down a mine shaft to reach the depths of the mine, and operate heavy machinery that extracts the coal and moves it above ground. The immediate environmental impact of underground mining appears less dramatic than surface mining. There is little overburden, but underground mining operations leave significant tailings.
Tailings are the often-toxic residue left over from the process of separating coal from gangue , or economically unimportant minerals. Toxic coal tailings can pollute local water supplies. To miners, the dangers of underground mining are serious.
Underground explosions, suffocation from lack of oxygen, or exposure to toxic gases are very real threats. To prevent the buildup of gases, methane must be constantly ventilated out of underground mines to keep miners safe. There are three major types of underground coal mining: longwall mining, room-and-pillar mining, and retreat mining.
Underground Mining: Longwall Mining During longwall mining , miners slice off enormous panels of coal that are about 1 meter 3 feet thick, kilometers The panels are moved by conveyor belt back to the surface.
The roof of the mine is maintained by hydraulic supports known as chock s. As the mine advances, the chocks also advance. The area behind the chocks collapses. Longwall mining is one of the oldest methods of mining coal. Before the widespread use of conveyor belts, ponies would descend to the deep, narrow channels and haul the coal back to the surface.
Today, almost a third of American coal mines use longwall mining. Columns pillars of coal support the ceiling and overburden. The rooms are about 9 meters 30 feet wide, and the support pillars can be 30 meters feet wide.
There are two types of room-and-pillar mining: conventional and continuous. In conventional mining, explosives and cutting tools are used.
In continuous mining, a sophisticated machine called a continuous miner extracts the coal. In developing countries, room-and-pillar coal mines use the conventional method.
Underground Mining: Retreat Mining Retreat mining is a variation of room-and-pillar. When all available coal has been extracted from a room, miners abandon the room, carefully destroy the pillars, and let the ceiling cave in. Remains of the giant pillars supply even more coal. Retreat mining may be the most dangerous method of mining. Miners have to dig hundreds of feet into the ground and breathe in fine particles that can cause health problems in the eyes, nose, throat, and can even cause serious lung disease.
Unearthing the coal can also release dangerous gasses into the air that can harm the coal miners and cause explosions. Miners also run the risk of being trapped in the mines. There are even underground fires that burn for decades, releasing more fumes and gasses into the atmosphere. Furthermore, as is evidenced by the dangers of miners on the front lines of coal collection, coal is not a clean energy source.
Burning coal releases hazardous emissions such as carbon dioxide, mercury, sulfur, and other toxic chemicals into the air. The consequences are widespread health issues and damage to the global environment causing and worsening climate change.
Some of the other common fossil fuels still used today are petroleum oil , natural gas, and uranium used for nuclear power plants.
Like coal, these resources are fairly easy to harvest and distribute, which is why they are still in use.
But like coal, they have some serious drawbacks. Petroleum goes through a refining process then is used for gasoline and other everyday products. The burning of oil, gasoline, and natural gas releases damaging carbon dioxide into the atmosphere causing devastating environmental consequences. The bottom line with all of these is that even if there was a way to safely collect them and somehow burn them cleanly with no health or environmental concerns, they are still non-renewable and will eventually run out.
Some of the most well-known sources of renewable energy are wind, hydro, geothermal, biomass, and of course solar power. These options are gaining attention and traction because they provide energy with little to no impact on the environment. Solar power is leading the way in renewable energy because it is easy to deploy on a large scale and is increasingly more affordable for individual homeowners and business owners.
Also, it can actually help people save on their energy bills over time. We love helping people problem solve and get that energy bill under control. To get a free quote, call By clicking this button, you consent to receive calls about our products and services at the number you provided above. Emergency Management. Survey Manual.
The four ranks are:. The precursor to coal is peat. Peat is a soft, organic material consisting of partly decayed plant and mineral matter. When peat is placed under high pressure and heat, it undergoes physical and chemical changes coalification to become coal. The U. In , coal-fired power plants provided This is anthracite, the highest rank of coal. 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 matter.
Anthracite is not as commonly mined as other ranks of coal. It played a significant role in Pennsylvania coal during the Industrial Revolution in the United. This sample is of bituminous coal, a middle rank coal between subbituminous and anthracite formed by additional pressure and heat on lignite. Usually has a high Btu value and may be referred to as "soft coal. Cannel coal is a type of bituminous coal that is also sometimes referred to as a type of oil shale.
It's name likely came from the word " candle. Read more about our coal research here:. Clinker coal is the result of a seam of coal catching fire and burning so hot that it baked surrounding rock layers into brick-like formations.
Read more about our. This sample is of peacock coal. Peacock coal is not a specific class of coal, but rather the name for an effect in which oxidizing materials in the coal create a dazzling array of colors on the surface of the coal.
Usually it is short-lived, as the material fully oxidizes away shortly after exposed to air. A sample of lignite, the lowest rank of coal. It is primarily mined for burning in steam-generation power plants. Lignite is low rank, or relatively unaltered soft, or "brown" coal, and is characterized by a brownish color and appearance that often resembles wood.
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