305708988-Surface-Mining equipment presentation

SURFACE MINING
I Made Bhismahayana
DBD 115
Lia Klarita
DBD 115
Widi Novianti
DBD 115 023

MINING METHODS
 There are mainly two method for extraction of
minerals which are as follows .
1. Underground Mining
2. Surface Mining

Factors influencing choice of mining
methods
 Depth of the deposit
 Shape of the deposit
 Thickness of the deposit
 Gradient of the deposit
 Availability of machineries
 Economic value of minerals
 Characteristics of roof and
floor
 Land contour

SURFACE MINING
 Surface mining is done by removing (stripping) surface
vegetation, dirt, and if necessary, layers of bedrock in order
to reach buried ore deposits (or) surface mining is the
process of extraction of minerals by removal of overburden .
 Overburden is the rock or waste material which is lying on
the mineral to be owned .
 Surface mining is also know as , Open pit, Open cast and
Strip Mining.
 Sump should be located at the bottom of the Mine .
 Height and width of the bench .
 Drilling and blasting .

METHOD OF SURFACE MINING INCLUDES
 Open-pit mining : Open pit mining is the process of mining a near
surface deposit by means of a surface pit excavated using one or more
horizontal benches. The term open pit mining is usually used for
metallic or non-metallic deposits and sparingly used for bedded
deposits like coal.
 Quarrying : similar to open pit mining, except that the desired product
is not metal in the rock, but the rock itself.
 Strip mining : Strip mining is a kind of surface mining. The ore is very
near to the surface of the land but has one or more layers of rock and
filth on top of it. To mine the ore, these layers have to be removed.
 Mountaintop removal : Commonly associated with coal mining, which
involves taking the top of a mountain off to reach ore deposits at depth.

The ores in an open pit mine are covered by overburden. Both the ores and
overburden are removed in benches ranging from height 9 m to 30 m. A thin deposit
may require one or few benches but a thick deposit needs more number of benches
and the pit in its production stage resembles like an inverted cone.

Materials typically extracted from open-pit
mines include:
 Bitumen
 Clay
 Coal
 Copper
 Coquina
 Diamonds
 Gravel and stone (stone refers to bedrock, while gravel is
unconsolidated material)
 Granite
 Gritstone
 Gypsum
 Limestone
 Marble
 Metal ores, such as copper, iron, gold, silver and molybdenum
 Uranium
 Phosphate

1. Most quarries have smaller and vertical benches.
Some of the quarries do not have any bench while
some even have a highwall up to 300m.
2. Quarries in level areas frequently have particular
engineering problems for drainage. The Coquina
Quarry is excavated to more than 60 feet (18 m) beneath
sea level. To lessen surface leakage, a moat lined with
clay was constructed round the complete quarry. Ground
water that leaks into the pit is pumped up into the moat.
3. Many quarries fill with water after desertion and
turn into lakes. Further quarries are made into
landfills.

Kinds of rock extracted from quarries
comprise:
 Cinder
 Chalk
 China Clay
 Clay
 Coal
 Coquina
 Construction aggregate (sand
and gravel)
 Globigerina Limestone (Malta)
 Granite
 Gritstone
 Gypsum
 Limestone
 Marble
 Ores
 Phosphate rock
 Sandstone
 Slate

STRIP MINING
Kind of minerals extracted from strip mining as similar as other
types of surface mining. but it is done on a different contour

The steps in strip mining are similar to open-
pit mining. The steps are:
 The trees and bushes are pushed down through bulldozers.
 This waste, along with the filth or sand under it, is taken to a close area and dumped.
 Lots of minute holes are drilled from the rock that is above the coal or mineral bed [vein]
 Explosives are put in the holes and blazed. This breaks up the rock which is taken to the
dumping area.
 When the coal or mineral is found, it may be broken up by the blazing. The size of the
chunks is important because the miners don't normally want it in minute pieces. They
usually want it in pieces that are capable to be moved with big machinery.
 This mining is done in elongated, narrow strips. When the ore is done in one strip, the
miners start to create another strip next to it. The waste, filth, and rock that they take off
of the top of the next strip is put on top of the last one. This is recurring until the last
strip is done and the waste from the primary strip is brought back to fill it.

The Bagger 288 is a bucket-wheel excavator used in strip mining.

MOUNTAIN TOP REMOVAL (MTR) or
MOUNTAIN TOP MINING (MTM)
The MTR process involves the removal of coal
seams by first fully removing the overburden laying
atop them, exposing the seams from above. This
method differs from more traditional underground
mining, where typically a narrow shaft is dug which
allows miners to collect seams using various
underground methods, while leaving the vast majority
of the overburden undisturbed. The overburden from
MTR is either placed back on the ridge, attempting to
reflect the approximate original contour of the
mountain, and/or it is moved into neighboring valleys.

US EPA diagram of mountaintop mining:
"Step 1. Layers of rock and dirt above the coal (called
overburden) are removed."
"Step 2. The upper seams of coal are removed with
spoils placed in an adjacent valley."
"Step 3. Draglines excavate lower layers of coal with
spoils placed in spoil piles."
"Step 4. Regrading begins as coal excavation continues."
"Step 5. Once coal removal is completed, final regrading
takes place and the area is revegetated."

ENVIRONMENTAL & HEALT IMPACT
 The Hobet mine in West
Virginia taken by
NASA LANDSAT in 1984
• The Hobet mine in West
Virginia taken by
NASA LANDSAT in 2009

"Some of the main problems associated with MTR include soil
depletion, sedimentation, low success rate of tree regrowth, lack of
successful revegetation, displacement of native wildlife, and burial of
streams.“
The ecological benefits after MTR are far below the level of the
original land.
As stated in the book, Bringing Down the Mountains:
Advocates of MTR claim that once the areas are reclaimed as mandated
by law, the area can provide flat land suitable for many uses in a region where
flat land is at a premium. They also maintain that the new growth on reclaimed
mountaintop mined areas is better suited to support populations of game
animals. While some of the land is able to be turned into grassland which game
animals can live in, the amount of grassland is minimal. The land does not
retake the form it had before the MTR.

Different Type of Machinery and
Transport System Used in Surface
Mines
 Drill Machine
 Shovel + Dumper
 Dragline
 Surface Miner
 Bucket Wheel Excavator
 In-pit Crusher + Spreader
 Belt Conveyors System
 Rail Transport System
 Tracks

Advantages of Surface Mining
 Like Underground Mining no minerals are blocked as shaft
pillars , supports , roadways etc.
 Roof control and ventilation is not required .
 Low cost as compared to Underground Mining .
 Low labor requirement than Underground Mining.
 Hazards and dangers are lesser than Underground Mining .
 Quality control is easy .
 Female labour can work in Surface Mining.
 High degree of mechanization is possible .
 High explosives can be used .

Limitation of Surface Mining
 This method can be uneconomic for extracting the
minerals at a depth of more than 300 m .
 There maybe huge environmental problems .
 Weather affects .
 Limited by striping ratio.
 Require a remote area for mine waste disposal .
 Degradation of surface land .

CONCLUSION
 About 85% of the world coal is obtained by open
cast mining method .
 By this method, more production can be obtained
than underground mining method.
 Greater simplicity in auxiliary operation and service
.

Mining is one of the environmentally
damaging job. But very important in industrial
needs and development of the country. If we
become indifferent from what we have done to the
earth, the money we earn from our land will be
useless. We kill ourself not only the earth

305708988-Surface-Mining equipment presentation

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