Coal Mining

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					                     Coal Mining
   The goal of coal mining is to
    economically remove coal from
    the ground. Coal is valued for its
    energy content, and since the
    1880s is widely used to generate
    electricity. Steel and cement
    industries use coal as a fuel for
    extraction of iron from iron ore
    and for cement production. In the
    United States, United Kingdom,
    and South Africa, a coal mine and
    its structures are a "colliery". In
    Australia, "colliery" generally
    refers to an underground coal
    mine   .
History of Coal Mining

   The oldest continuously worked deep-mine in the
    United Kingdom is Tower Colliery in South Wales
    valleys in the heart of the South Wales coalfield. This
    colliery was developed in 1805, and its miners bought it
    out at the end of the 20th century, to prevent it from
    being closed. Tower Colliery was finally closed on 25
    January 2008, although production continues at the
    Aberpergwym drift mine nearby.
   Coal was mined in America in the early 1700s, and
    commercial mining started around 1730 in Midlothian,
    Virginia.
   Coal-cutting machines were invented in the 1880s.
    Before the invention, coal was mined from underground
    with a pick and shovel. By 1912 surface mining was
    conducted with steam shovels designed for coal
    mining.
Surface Mining
   Surface mining (also
    commonly called strip        Surface coal mining in Wyoming in the United
    mining, though this is       States.
    actually only one
    possible form of surface
    mining), is a type of
    mining in which soil
    and rock overlying the
    mineral deposit (the
    overburden) are
    removed. It is the
    opposite of
    underground mining, in
    which the overlying
    rock is left in place, and
    the mineral removed
    through shafts or
    tunnels.
Underground mining (soft rock)
   Most coal seams are too deep underground for opencast
    mining and require underground mining, which method
    currently accounts for about 60% of world coal production. In
    deep mining, the room and pillar or bord and pillar method
    progresses along the seam, while pillars and timber are left
    standing to support the mine roof. Once room and pillar mines
    have been developed to a stopping point (limited by geology,
    ventilation, or economics), a supplementary version of room
    and pillar mining, termed second mining or retreat mining, is
    commonly started. Miners remove the coal in the pillars,
    thereby recovering as much coal from the coal seam as
    possible. A work area involved in pillar extraction is called a
    pillar section. Modern pillar sections use remote-controlled
    equipment, including large hydraulic mobile roof-supports,
    which can prevent cave-ins until the miners and their
    equipment have left a work area. The mobile roof supports are
    similar to a large dining-room table, but with hydraulic jacks
    for legs. After the large pillars of coal have been mined away,
    the mobile roof support's legs shorten and it is withdrawn to a
    safe area. The mine roof typically collapses once the mobile
    roof supports leave an area.
five principal methods of underground
mining
   Longwall mining- is a form of underground coal
    mining where a long wall of coal is mined in a
    single slice
   Continuous mining-(also called bord and pillar) is
    a mining system in which the mined material is
    extracted across a horizontal plane while leaving
    "pillars" of untouched material to support the
    overburden leaving open areas or "rooms"
    underground.
   Blast mining-is the controlled use of explosives to
    excavate or remove rock
   Retreat mining-is a term used to reference the
    final phase of an underground mining technique
    known as room and pillar mining. This involves
    excavating a room or chamber while leaving
    behind pillars of material for support.
Other Methods of Coal Mining

   Area mining
   Contour mining
   Mountaintop removal mining
   Room and pillar mining
 Coal mining can result in a number of adverse effects on the environment.
  Surface mining of coal completely eliminates existing vegetation, destroys
 the genetic soil profile, displaces or destroys wildlife and habitat, degrades
     air quality, alters current land uses, and to some extent permanently
  changes the general topography of the area mined, This often results in a
    scarred landscape with no scenic value. Rehabilitation or reclamation
       mitigates some of these concerns and is required by Federal Law,
    specifically the Surface Mining Control and Reclamation Act of 1977.
     Mine tailing dumps produce acid mine drainage which can seep into
waterways and aquifers, with consequences on ecological and human health.
   If underground mine tunnels collapse, this can cause subsidence of land
 surfaces. During actual mining operations, methane, a known greenhouse
     gas, may be released into the air. And by the movement, storage, and
    redistribution of soil, the community of microorganisms and nutrient
                        cycling processes can be disrupted.
Ecology of Mining
   Coal mining can result in a number of adverse
    effects on the environment. Surface mining of
    coal completely eliminates existing vegetation,
    destroys the genetic soil profile, displaces or
    destroys wildlife and habitat, degrades air quality,
    alters current land uses, and to some extent
    permanently changes the general topography of
    the area mined, This often results in a scarred
    landscape with no scenic value. Rehabilitation or
    reclamation mitigates some of these concerns and
    is required by Federal Law, specifically the
    Surface Mining Control and Reclamation Act of
    1977.
Problem of air and water pollutions in
Mining areas

   Air and water are universal resources of
    multifuncional character. Air is a resource
    intensively used primarily by industry,
    transport and public utilities. As a result
    the quality of air with respect to human
    health undergoes deterioration in large
    part of industrial areas. The situation is
    similar in the case of water sources.

Air Pollution
   Worldwide air pollution - contamination of the air
    by noxious gases and minute particles of solid
    and liquid matter (particulates) in concentrations
    that endanger health - is responsible for large
    numbers of deaths and cases of respiratory
    disease.
    According to their chemical characteristics,
    concentration in the air mass and meteorological
    conditions, air pollutant substances may have a
    major or minor impact on air quality. The
    occurrence of strong winds and rain, for instance,
    may have a good impact on the pollutants
    dispersion, and the presence of sunlight can have
    a negative effect on air quality.
Water pollution in mining areas
   In industrial areas available natural
    resources of water are very poor due to
    anthropogenic contamination. It is an
    effect of both wastewater discharge to the
    environment and improper disposal of
    pollutants, waste, operational failures,
    spills to the environment. For instance, in
    the Katowice Agglomeration most of
    river’s water don’t fall within any purity
    classes. Because of contamination, only a
    small portion of surface waters can be
    used for economic purposes.
   We should LESSEN the usage of coal
    mining for it can cause devastating
    damage on our landforms. If Coal Mining
    could not be lessened, at least pick out a
    spot were there are no “beautiful”
    landforms that could be damaged. As
    stated in Surface Mining Control and
    Reclamation Act of 1977 (SMCRA) which
    means it has to be approved by the
    federal government before mining begins.

				
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posted:10/5/2011
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