Surface Mining

Strip Mining is used when coal is near the surface or when the overburden is unstable. As the mining progresses the overburden is placed in the previous mine coal. Contour Mining is a type of sttrip or surface mining followa the contour of a hill or mountain leaving terraces in the mountainside. Mountaintop Removel tops of hills are removed to access horizontal coal seams. Overburden is pushed to areas between high elevations. Following reclamation, the original contour is not restored. This is the most controversial mining method.




Shrip Mining
advantages -Filling the adjacent empty pits with the overburden is systemic to the process and therefore insures the genesis of mined-land land reclamation.
disadvantages- Pollution.

Contour Mining
advantages-disadvantages-




Mountaintop Removel
advantages-safer for the miners to surface mine and that using coal is a clean source of energy.
disadvantages-severely detrimental to the environment and the communities that surround the mining sites.


nformation
http://www.eoearth.org/article/Strip_mining
http://wiki.answers.com/Q/What_are_the_disadvantages_of_strip_mining
http://iml.jou.ufl.edu/projects/spring07/Bartlett/effects.html



pictures
http://visual.merriam-webster.com/energy/geothermal-fossil-energy/coal-mine/strip-mine.php
http://energyinvestingnews.com/273-north-american-gem-inc-blue-gem-coal-in-kentucky.html
http://www.mountainroadshow.com/gallery/index.html

underground mining

The drift mining is possible where the coal seam intersects the surface. It enters the seam in a horizontal direction following the coal. Shaft mining is a common method accessing a coal seam in which elevators provide access to mines. The room and pillar mining is nearly half the coal is left behind to support the mine roof. The pillars can squeeze and put pressure on adjacent pillars leading to roof collapse. Continuous mining machines can be used with drift or room and pillar mines. One miner can operate a contintuous miner to a rotating steel drum with tungsten carbide teeth to mine 5 tons of coal per minute. Longwall mining or retreat mining is highly efficient. The huge mining machines support the roof with hydraulics as it removes coal. When the coal is remover the machine retreats allowing the roof to fall behind it. Longwall mines extract much more of the coal than room and pillar mines.




advantages-well-drained, required less machinery and less initial effort. Its easy way to mine, its a cheap way to mine.
disadvantages-its not the safest way to mine as the tunnels may collase killing and trapping miners.
   Shaft Mining
advantages-that mining can be done as deep as possible and that it reduces the rock bursts or mines from falling off the ground.
disadvantages-it cost too much.


 Room and Pillar Mining
advantages-this cycle maximizes face utilization.
disadvantages-there is no face-to-face shift handover.

 

   Continuous Mining
advantages-flexibility and its adaptability to various mining conditions.
disadvantages-complexities, its inability to clean up adequately while advancing the face and its slow mining rate, a function of its small area of face attack.


advantages-safety of the miners enhanced by being under the hydraulic roof supports when they are extracting coal.
disadvantages-surface subsidence, which may considerably alter the landscape above the mine which can damage natural or man-made structures or features

information
http://www.coalcampmemories.com/miningmethods.html
http://rachealjane.wix.com/racheal-jane
http://www.ask.com/answers/304896681/advantages-and-disadvantages-of-adit-and-shaft-mining
http://www.saimm.co.za/Conferences/Pt2010/231-238_Pickering.pdf
 http://www.illawarracoal.com/technology.htm
http://www.sourcewatch.org/index.php?title=Longwall_mining

picture
http://elpmm.blogspot.com/
http://library.thinkquest.org/05aug/00461/shaft.htm
http://kids.britannica.com/comptons/art-1519/Room-and-pillar-mining-of-a-horizontal-ore-body
http://www.coalleader.com/continuous_mining.htm
http://www.umwa.org/?q=content/longwall-mining

Excel Aerosols Chart

coal formation

It forms from the remainings of swamp plant from 300-400 million. Which dead plants became burried in the swamp. Peat slowing decaying plant matter found in bogs, moors, and mustegs. When acidic and anacrobic conditions prevent complete decay. Heat value of peat is very low- compared to coal. Lignite sometimes called "brown coal". Its found in Alaska and some Western States. Low carbon concentration (30%) and low heat value (< 10,000 BTU/lb). Used in electric power generation. Bituminous Coal is most common form of coal. The carbon value is highly variable (45-85%) and heat value ranges from 10,000-15,000 BTU/lb. Anthracite Coal result from the metamorphosis of bituminous coal. The highest carbon content (85-95%) and heat value (15,000 BTU/lb). Low smoke and high heat values make anthracite popular for human heating in the northeastern U.S. Coke primarily used as a heat source in the steel industry. Water, tar, and other volatiles are driven off to leave high carbon fuel. The by-products of coking are collected for energy production.

Predict what affects aerosols may have on climate change.

Two different ways direct radiative forcing the scattering of solar radiation and the absorption/emission of terrestrial radiation. Indirect radiative forcing, mainly by effects of aerosols on cloud properties. Greenhouse gases effect on the global radiative balance and surface temperatures. The effect of aerosols on clouds is highly speculative. If more aerosol, the smaller the cloud droplets tend to be, and clouds with more but smaller drops have a higher albedo.

Aerosols

Aerosols or particulates are fine particles in the air and can either be solid or a liquid aerosol. They are formed from a wide variety of natural and anthropocentric sources like biomass burning, incomplete combustion like black carbon, soil dust and sea salts. These are not good for the climate and can cause changes like an extreme precipitation change. We use aerosols around the house every day that are not harmful, but other aerosols can really affect our lives. If there are more aerosols on the clouds and are reflecting the suns heat it can lead to world global cooling.

At ground level, ozone is an air pollutant that damages human health, vegetation, many common materials, and is a key ingredient of smog. Ozone is the gas present in the atmosphere which has capacity to protect the living beings on the earth from the ultraviolet rays from the sun that are harmful. Ozone has the same chemical structure (O3) whether it occurs miles above the earth or at ground level. At ground level, "bad" ozone is formed when certain compounds react in the presence of direct sunlight. Ozone may aggravate chronic lung diseases such as emphysema and bronchitis and reduce the immune system's ability to fight off bacterial infections in the respiratory system

Summary- Atmosphere Power Point

Solar energy as radiation is nearly 150 million kilometers separate the sun and earth and it drives earth’s weather. Earth’s atmosphere is 99% atmospheric gases, including water vapor, extend only 30 kilometers (km) above earth’s surface. Atmosphere gases include nitrogen, oxygen, argon, water vapor, and carbon dioxide are invisible. Variable and increasing gases; nitrogen and oxygen concentrations experience little change but carbon dioxide methane and oxides of nitrogen are greenhouse gases experiencing increasing in concentrations C02 have raised more than 18%. Atmospheric Greenhouse affects the warming of the atmosphere by absorbing and emitting infrared radiation and allowing shortwave infrared radiation to pass through. The main gases responsible for the greenhouse effect are water vapor and carbon dioxide. Aerosols are human and natural activities displace tiny soil salt and ash particles as suspended aerosols. Pollution are sulfur and nitrogen oxides, and hydrocarbons are emitted as pollution. Lapse rate is the rate at which air temperature decreases with height. In average lapse rate in the lower atmosphere is about 6.5 degrees (*) per 1 km or 3.6 *f per 1000ft. Urban heat island effect occurs when a metropolitan area is warmer than the surrounding rural areas. UHI effect is caused primarily by modification of land surfaces in developments that use materials that retain heat. The cloud triangle: Clouds can be defined by: Their shape & form: The cloud base altitude: If they are precipitating. Air pressure: Warm air-expanding or rising: Air-leaves behind L pressure: Cold air-sinking air=leaves an H pressure. Wind movement uneven heat of the earth’s surface causes some areas to be warmer than others.  Warm always follows cold to share its warmth- when this happens in the atmosphere, wind happens. Pressure, wind and weather, the winds are horizontal flows of air; winds blow from areas of high pressure to areas of low pressure. Pressure describes the tendency of the air to rise or to sink at any given place or time. Humidity measure of the amount of water vapor stuck between molecules in the air and the airs ability to hold water depends on the air temperature. Relative humidity amount of water vapor (%) compared to the amount the air can hold and 100%= air is saturated.