Mining

1
Mining
2
Mining

• Minerals are naturally occurring substances found
  in rocks, soils, or sediments.
• Minerals deposits that can be mined profitably
  are called ores.
• They can be either metallic or non-metallic

3
Minerals can be classified into 4 categories.

• 1. Metallic minerals
• Associated with intrusive igneous rock
• These deposits can consist of valuable metals
  such as nickel, copper , zinc , lead, and gold
• Metallic minerals must be broken apart and
  chemically processed to extract the useful metal
  from the mineral.
• At one time magma containing dispersed minerals
  was forced up towards the earths surface through
  fissures.

4

• Super heated brines dissolved metallic elements,
  which flowed into some of these cracks. As they
  cooled they solidified and formed veins.

5
Veins of gold
6

• Fuel minerals
• - Found in sedimentary rock
• - formed from the remains of living organisms
  that were transformed over time by heat and
  pressure into coal, oil, or natural gas.

7

• Industrial minerals (gypsum, potash, rock salt)
• - found mainly in sedimentary rock.
• - formed in shallow seas in regions with hot dry
  climates.
• - as water evaporated, it became more and more
  salty
• - eventually the salt began ti build up in
  layers
• - in some cases the seas dried up .

8
(No Transcript)
9

• Structural minerals
• - associated with all types of rocks
• - are the products of river, wind, and glacial
  deposition
• - include sand, gravel, and clay
• - used mostly as construction materials

10
Finding a deposit
11

• The old fashioned way of finding a mine was your
  prospector with a pick and shovel, a gold pan,
  and a lot of luck.

12

• Today, technologies used include, but are not
  limited to, exploration geology, geophysics,
  geochemistry, and satellite imagery.

13
Geology

• Geology is the study of the planet Earththe
  materials of which our planet is made, the
  processes that act on these materials, and the
  products formed.
• Geologists use ground-mapping techniques to
  identify features seen on satellite images and
  aerial maps of large tracts of the continent.

14
Satellite Imagery

• Ground-based surveys are expensive, and one can
  often experience difficulty in mapping
  large-scale structures. However, large geological
  structures are often readily visible on satellite
  imagery.

15
Geophysics

• Geophysical exploration involves searching for
  favorable mineral deposits using the physical
  properties of rocks.
• Geophysical investigations ground-penetrating
  radar studies or the use of seismic waves to show
  contrasting rock types.
• The selected rock units of interest might then be
  mapped and sampled.

16
Geochemistry

• Geochemists can determine the composition of what
  lies below the Earth's surface by sampling soil.
  Soil at the surface can carry a chemical
  signature of what lies below, because of the
  movement of chemicals through the rise and fall
  of the water table.

17

• Positive geochemical results from surface
  sampling are followed by a drilling program.
  Because of the great expense, drilling is only
  carried out when the area is very likely to
  contain substantial mineral deposits.
• Drilling produces either rock fragments, or
  'cores' of rock for sampling to determine whether
  the mineral deposit contains worthwhile
  concentrations of ore minerals.

18
(No Transcript)
19
(No Transcript)
20
Types of Mines 1. Open pit

• Used when ore bodies lie near the surface
• Large hole exposes the ore body
• Waste rock (overburden) is removed
• 2nd cheapest method, but has the largest
  environmental impact. Why?

21
2. Strip Mining

• The cheapest and safest method, but can have a
  significant impact environmentally on the
  surface. Why?
• The ore is close to the surface of the land (30m)
  but has one or more layers of rock and dirt on
  top of it.  To mine the ore, these layers have to
  be taken off.
• This mining is done in long, narrow strips.  When
  the ore is done in one strip, the miners begin to
  create another strip next to it.  The waste,
  dirt, and rock that they take off of the top of
  the next strip is put on top of the last one.

22
(No Transcript)
23
3. Underground Mining

• Very expensive and the most dangerous of the
  three methods, but has the least impact
  environmentally on the earths surface. Why?
• Underground mining is done when the rocks,
  minerals, or gemstones are too far underground to
  get out with surface mining.
• Entry into underground mines is by vertical
  shafts, or by a sloping tunnel.

24

• To extract the ore, the components required to
  build large pieces of machinery are taken down
  the shaft and assembled in the area where the
  miners are working.
• All underground mines are ventilated
• http//www.uraniumsa.org/processing/underground.ht
  m

25
Minerals Maps

• See map page 191 of text
• Distribution of Major Deposits
• Value of Cumulative Production
• http//gsc.nrcan.gc.ca/mindep/maps/images/c01_cana
  da_all_e.jpg
• http//gsc.nrcan.gc.ca/mindep/maps/images/c03_cana
  da_gres_e.jpg
• http//gsc.nrcan.gc.ca/mindep/synth_dep/index_e.ph
  p

26
(No Transcript)
27
Links

• Sustainable practices
• Copper Molybdenum Mining in Canada