Surface Mining Blog

 

The three methods of surface mining

1) Strip mining.


Strip mining is used when the coal is near the surface or when the overburden was unstable. As mining progresses, the overburden is placed in the previous mine cavity. The advantages of this method are that the cost of mining is lower, and it is safer than underground mining because miners aren't exposed to the toxic air and possible collapsing tunnels. The disadvantages could include the destruction of the natural ecosystem and pollutants being exposed to the atmosphere. After fragile ecosystems are disturbed, it can take many years to regain equilibrium, which could result in the loss of plant and animal life.

2) Contour Mining






Contour mining is a type of of strip or surface mining that follows the contour of a hill or mountain leaving terraces in the mountainside. Contour mining uses small earth-moving equipment such as power shovels, backhoes and bulldozers — similar to equipment used for most other kinds of construction. Contour mining is therefore a favorite technique of small operators in Appalachia, because it is easy to move in and out of the mining business as market conditions change. The bad thing about contour mining is that  contour operators often have too much spoil after mining is finished. When overburden is removed it breaks up and loses some of the compaction that occurred over the thousands of years that it laid undisturbed. The volume of the material can increase up to 25%. The pits left after extracting the relatively thin coal seams of the East are often not large enough to hold this added volume. As a result, most contour miners must dispose of their excess spoil in another disposal area. This means that additional land beyond that required for mining has to be disturbed in order to fix the results of what the mining caused.


3) Mountaintop Removal

Mountain top removal is when the tops of mountains are removed to access horizontal coal seams. Overburden is pushed to areas between high elevations. After reclamation, the original contour is not restored. This is the most controversial mining method because the companies dump the rock they blast into neighbouring streams or valleys. The streams are completely blocked by the fill and the streams that remain are polluted by the dumping, and it could centuries before they return to biological health. The advantages are that it is too much more efficent and safer than underground mining.

Do aerosols affect climate change through the Urban Heat Island Effect and greenhouse gases?

 Aerosols do affect the urban heat island affect. This is because of the albedo of the darker surfaces typically found on the buildings in bigger cities. This could easily be fixed by changing the colors of the roofs of buildings to lighter surfaces- for example, white. Lighter colors reflect heat back into the atmosphere where as darker colors absorb the light and reemit it back into the atmosphere. This is a prime example of long wave infrared radiation. This is also why other countries that have warmer climates usually have all white or tan buildings- it keeps the surrounding area cooler.

When aerosols aren’t absorbed, they can be stuck in the atmosphere for a long time. The Aerosol Optical Thickness that is shown in the graphs we put together show this- and this is all completely based off of temperature.

Now that we’ve discussed the urban heat island effect, it’s time to show that aerosols also affect greenhouse gases. This is because the heat that is later emitted then becomes trapped. This obviously leads to a higher temperature. According to the data we collected by going outside and taking surface temperatures, the warmer the temperature- the warmer the asphalt on the ground. It warms asphalt and concrete more so than grass.

So, overall, aerosols do undoubtedly affect the urban heat island effect and greenhouse gases. This can be proved by the data our class collected first hand. Our data is completely reliable seeing as it was collected over the course of many weeks, and on many different surfaces: the student parking lot, the bus loop, the practice football field, the student parking lot, and the softball in-field. We collected the temperatures daily, then in the end, put them all into excel and produced a graph that shows temperature, AOT, and percent transmission.

 

 

 

Coal Camp Blog

The Abney Coal Camp

 



This coal camp is located in western Raleigh County and eastern Wyoming County in southern West Virginia. The community began with 50 houses, but has evolved into a bigger city with many more residents. In 2010, the population was 1,308. The demographics of the residents are that they are 98% white, and 2% other. Before this coal camp was called "Abney," it was reffered to as "Phillips." The town was named after William Phillips, the Pemberton Coal and Coke Company's president. The name was changed to Abney by the post office years later. This is all located in The Winding Gulf Coalfield. In 1921, the coal camp was constructred in Raleigh County on a ledge over the Piney River. Camp Phillips was supposed to be "one of the most attractive coal operations in the coal fields." This quote came from an article written on November 11, 1921, in the Raleigh Register. This article also stated that this coal camp would be supplied with 50 bungalows that would contain the "pursest water, piped from a mountain spring in a three-inch galvanized pipe." This would provide excellent protection against fire. Today, the town is still being lived in, and a one-room school house that once took up an entire field is now a lot for multiple trailer homes, and the once Abney company store is a private residence.

 

Original Company Store

Company Store Today

 

 

 

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Underground Coal Mining Blog Post

There are five methods of underground mining. These methods include drift mining, shaft mining, room & pillar mining, continuous mining, and longwall mining. 

1) Drift Mining

Drift mining is possible where the coal seam intersects the surface- the mine then enters the seam in a horizontal direction following the coal. This type of mining is done when mineral or rock is on the side of a hill. It is a much cheaper, more efficient method compared to most others. But, it can also be very dangerous. Many tunnels can cave in- collapsing and killing miners.

2) Shaft Mining

Next we have shaft mining. Shaft mining is a pretty common method. This mining method accesses a coal seam in which elevators provide access to mines. In WV, it is not rare to see a shaft coal mine deeper than 1000 feet below the surface. Shaft mines are much faster and conventional than most regular mines. While that's one advantage, another can be that there is safer breathing: due to the moving air that vents the gases that are naturally underground. The one negative thing about this way of mining could be that often times tunnels are deepended and the mine is made larger until there isn't any ore left, or the cost of removal is too high.



3) Room & pillar mining

The third method is room & pillar mining. In this method, nearly half of the coal is left behind to support the roof of the mine. Pillars can “squeeze” which puts pressure on pillars, which can ultimately lead to roof collapse. Roof falls are a constant danger, which is a disadvantage. An advantage of this type of mining could be that it can be alot faster than other types.

4) Continuous mining

The fourth method is called continuous mining. The machines for continuous mining can be used with drift or room & pillar mines. A miner can operate this machine to a rotating steel drum with tungsten carbide teeth to mine 5 tons of coal per minute. (WV Coal Project) This method/ machine has been in use since the 1940s. These machines are paired with conveyor systems to transport the coal from the mine as it is mined. The biggest advantage to this would definitely be how time efficient it is. It can make as much as five tons of coal a minute- which is more than a mine without technology in the 1920s could produce in an entire day. 45% of coal production comes from continous mining. A disadvantage, once again, can be that there is not much roof support, which could cause a roof to collapse.


5) Longwall mining

Last but not least, we have longwall mining. This method is “highly efficient.” Huge mining machines support the roof with hydraulics as it removes coal. Once the coal is removed, the machine retreats allowing the roof to fall behind it. Longwall mines extract much more of the coal than room & pillar mines, which is why it’s known to be highly efficient. This accounts for about 50% of the underground production of coal. Longwall systems have their own "hydraulic" roof supports. As the mining equipment moves forward, the overlying rock that no longer has the support of coal falls behind the equipment. This makes for a very safe work enviroment. After about 75% of the coal is removed, the roof collapses in a safe, controlled manner. While this all sounds great, the collapse afterwards can really damage rivers, which is a disadvantage.

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