Underground mining involves extracting rocks, minerals, or gemstones located too deep below ground for surface mining. There are several types of underground mining including borehole mining, drift mining, hard rock mining, shaft mining, and slope mining. Borehole mining uses drilled holes to break up material with water and pump it to the surface. Drift mining extracts material from horizontal tunnels dug into mountainsides. Hard rock mining uses vertical shafts and horizontal tunnels. Shaft mining uses vertical shafts to transport workers, equipment, and extracted material. Slope mines have slanted shafts to access deep, flat deposits. Common underground mining machinery includes dump trucks, shuttle cars, continuous miners, and longwall equipment.

1. Underground mining
Olga Shubkina
Siberian Federal University
e-mail: oshubkina@gmail.com
Twitter: @OlgaShubkina

2. Underground mining is done when the rocks, minerals,
or gemstones are too far underground to get out with surface
mining.
Some kinds of underground mining are:
 Borehole Mining
 Drift Mining
 Hard Rock Mining
 Shaft Mining
 Slope Mining

3. Borehole Mining
It can be used in open pit mining which is a kind of surface mining.
With borehole mining:
 a hole is drilled deep enough into the ground to reach whatever is going to be
mined;
 a long, tube-like tool is dropped into the hole;
 this tube has places for water to be forced down the tube and places where the
water can be pushed back up the tube;
 the water is forced down this tube;
 the stream of water breaks up the dirt and rock when it hits it;
 the water combines with the dirt, rock, and minerals to make a combination
called a slurry;
 the slurry is pumped back up to the surface where it is put into a storage tank;
 the water is drained and the ore is taken out of it;
 from that time on, the ore is treated depending on what it will be used for.

4. Borehole Mining technologies

5. Drift Mining
This kind of mining is done when the rock or mineral is on the side of a mountain.
This makes it an easy, cheaper way to mine.
Whenever possible, the opening to the mine will be dug a little lower than the rock
or mineral vein. This makes it easier to get the materials out because gravity helps
move them downhill. The tunnels that are dug are horizontal and are called drifts.
Drift mining was really dangerous in the early days. Many tunnels caved in
trapping and killing miners.
Ore was often mined this way. Ore is rock with minerals inside of it.

6. Drift Mining

7. Hard Rock Mining
Hard rock mining is a kind of underground mining. With this kind, an opening is
made that is called an adit.
Tunnels into the ground are dug, blasted with dynamite, or drilled out. These
tunnels are called shafts. Shafts are dug straight down vertically into the
ground. Each shaft has a purpose. One shaft might be for miners to use to go in
and out of the mine. One shaft might be just for mine machinery. Another shaft is
used for air or ventilation.
The tunnels in a hard rock mine are divided into rooms with rock pillars.
Hard rock mining is one of the most dangerous kinds of mining:
 it can be very deep underground;
 some mines like coal ones have deadly gases in them.

8. Hard Rock Mining

9. Shaft mining
The shaft mine has a vertical manshaft, a tunnel where the men travel up and
down in an elevator. Equipment is taken into the mine using this shaft,
too. Short tunnels to the ore are dug from that manshaft. When the ore is
dynamited and broken into chunks, it is taken to the top and loaded into trucks
through a second shaft. There is usually an airshaft that gives the mine
ventilation.

10. Slope mines
With slope mining, the coal or mineral bed is located very deep and parallel to the
ground. It is called a slope mine because the shafts are slanted.
This kind of mining is done when there would be problems drilling shafts straight
down.

11. To take out the minerals out of the mine, the miners make
underground rooms to work in. The mining company
chooses the best way to get the minerals out. Most
mining is done using continuous mining that uses
a continuous mining machine to cut coal from the
walls. This means there is less blasting and drilling and
puts less miners down in the mines. It is safer than the
old kind of mining.

12. Two of the ways that they mine underground are:
 Room and pillar mining: there are intersecting 'rooms' with pillars of coal that
hold up the roof. These pillars are mined when the mine, or a part of it, are
closing. They are careful when they do this because the roof caves in as they
leave.
 Longwall mining: usually a machine called a continuous miner slices layers of
coal or minerals from the walls.

13. Rocks, minerals, and gemstones that are mined
using the underground mining method:
Alexandrite Amethyst Biotite Calcite Chalcopyrite Magnetite Muscovite Nickel
Copper Diamond Gold Emerald Galena/Lead Graphite Gypsum Halite/Salt
Hematite Olivine/Peridot Platinum Pyrite Ruby Silver Sphalerite Sulfur Turquoise
Uraninite Zinc

14. Machinery used for underground mining:
 Dump trucks
 Shuttle car
 Continuous miner
 Longwall mining equipment
 Getman Underground Mining Equipment