Rock Mechanics
Rock Mechanics
Here's a series of lectures Rock Mechanics
or
الخميس، 10 يوليو 2014
What Is Underground Mining?
Underground mining is a technique used to access ores and valuable minerals in the ground by digging into the ground to extract them. This is in contrast with techniques like open pit mining, in which the surface layers of ground are scooped away to access deposits, or mountaintop removal, in which the top of a mountain is simply shaved off to access the ore inside. When people think of mining, they often visualize underground mining, and many people think of coal mines in particular, although numerous products can be mined underground, with some of the deepest mines in the world being used to access deposits of gold.
Companies opt to use underground mining when deposits of ore are so buried that surface mining
is not an option. This requires a lot of logistics to be safe, even
with the highly mechanized nature of modern underground mining.
Especially with soft ores, much of the work is done by machine, not
people, but it's still important to avoid subsidence above the mine,
collapses in the mine, explosions, and an assortment of other health and
safety risks.
What Is Surface Mining?
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Surface mining is a method of mining used to extract minerals and metals
which are near the surface of the Earth. There are three basic types of surface
mining: open pit mining, strip mining, and quarry
mining. These methods are much more economical than underground mining, yet they
can have a more significant impact on the surrounding environment unless
efforts are taken to reclaim the land.
Open pit mining involves excavation which looks like a terrace. Cuts are
made into the ground, and the area at that depth is worked around the
circumference of the mine. Once the minerals and waste have been removed from
the ledge, called a bench, the excavation moves down a level and work begins
again. This type of surface mining, also known as hard rock mining, is
typically employed to extract metal ores, like copper, gold, iron, and
aluminum, and other minerals.
Strip mining is a form of
surface mining that is primarily used for coal excavation. The rock and dirt covering the ore is removed one strip at a
time. Once the ore has been taken from the first strip, a second strip is cut
next to it, and the waste from the second strip is used to back fill the first.
This goes on until the ore is exhausted, and then the waste from the first
strip is used to fill in the last
