The document describes the process of mineral exploration and mining. There are several key steps: (1) prospecting to find mineral deposits, (2) exploration to determine if extraction is economically viable, (3) mining to extract the ore, (4) extraction to separate the minerals from waste rock, and (5) smelting and refining to purify the extracted minerals. Mining occurs either through subsurface techniques like room and pillar mining or longwall mining, or surface techniques including open pit mining and quarrying. The document also discusses how minerals are located and tested before mining begins.

1. Mining & Mineral Resources
Chapter 16, Section 2: Mineral Exploration &
Mining
Standards: SEV4a, b, e

2. What are the steps in harvesting
minerals?
 Prospecting- finding places
where ores occur
 Mine exploration &
development- learn whether
ore can be extracted
economically
 Mining- extract ore from
ground
 Extraction- separate ore
minerals from other mined rock
 Smelting & refining- extract
pure mineral from ore mineral
(get the good stuff out of waste
rock)
 Transportation- carry
mineral to market
 Marketing & sales- find
buyers & sell the mineral

3. How do we know where mineral
deposits are located?
 Airplanes can carry instruments that
detect
 Patterns of gravity
Images of the Saline Valley in California.
 Magnetism
Left picture- red indicates trees, white
 Radioactivity indicates snow
 Data is collected, satellite images are Middle picture- short wavelengths used
taken, and a geologic map is created. to identify types of rocks
Right picture- thermal infrared used to
 Rock samples are taken & analyzed for
identify types of rocks that contain
their content & grade valuable minerals. Red indicates quartz
 Test holes are drilled to create a 3D
estimate of the extent of the ore
 This will tell the driller if the amount
and grade of ore is high enough to
warrant the cost of opening a mine.
How Much Does a Mine Cost?

4. 3 Types of Mining
A. Subsurface mining
B. Surface mining
C. Placer mining

5. A. What is subsurface mining?
 Mining of ore deposits 50m
or more below Earth’s
surface. (This is as long as
an Olympic size pool)
 3 types of subsurface
mining:
1. Room & Pillar mining
2. Longwall mining
3. Solution mining

6. 1. Room & Pillar Mining
 Coal & Salt can be mined this
way
 “Rooms” are cut into a coal
seam. Coal seam is a long,
wide, layer of coal.
 The “walls” of the room act as
pillars to prevent collapse.
 After all rooms of coal
removed, the pillars are taken
down starting with farthest
away.

7. 2. Longwall mining
 A shearer machine moves
back and forth along the
coal seam.
 Sheared coal drops onto a
conveyor belt and exits the
mine
 Hydraulic roof supports
are used to prevent
collapse

8. 3. Solution Mining
 Potash, salt, sulfur are soluble
in water
 Hot water is injected into ore
 Ore is dissolved
 Removal of ore from water:
 Compressed air pumped into
dissolved ore and ore trapped
in air bubbles that rise to
surface… or…
 Water evaporates from
dissolved ore leaving ore
behind.

9. B. What is surface mining?
 Used when ore deposits are
located close to Earth’s
surface
 3 types
1. Open Pit Mining
2. Quarrying
3. Solar Evaporation

10. 1. Open Pit Mining
 Soil & rock (overburden) are
removed from top of ore deposit
 Use explosives or heavy machinery
 AKA- mountain top removal
 Loaders remove the exposed coal
 Pit is then refilled with overburden &
covered with soil.
 Some types of ore are taken to heap
leaching ponds where mineral is
removed from the ore rock.
 Gold miners used to use mercury to
extract gold but proved very
poisonous to animals & plants
 Now gold is extracted from ore rock
using cyanide. Cyanide is also very
poisonous.
Bottom picture: Open pit gold mine with
heap leaching cyanide ponds down below.

11. Machine used in open pit mining
Bucket Wheel Excavator- cost $184,400,000
Takes 5 people to operate it, moves 10 meters per minute, power lines have to be removed when
moving it.

12. 2. Quarrying
 Open pit mine that is used
to harvest
 Granite
 Marble Granite quarry in Elberton, GA
 Sand
 Gravel
 Crushed rock (aggregates) LaFarge
Granite
 Clay
Quarry in
 Gypsum Douglasville,
GA
 Talc

13. 3. Solar Evaporation
 Place sea water into
shallow ponds
 Water evaporates and
leaves crystallized salt
behind
 30% of world’s salt
produced this way
 Used largely in developing
countries
Salt evaporation ponds in San Francisco
Bay. The beautiful colors are a result of
harmless bacteria and brine shrimp
that live among the salt. The colors
vary depending on the “age” of the
pond.

14. C. What is placer mining?
 Rock with minerals weathers &
disintegrates
 Minerals carried by water in
streams
 As streams bend, the water slows,
minerals fall out of slower water
and accumulate as placer deposits
 Can also occur along coastline
where waves keep minerals from
moving out to sea.
 Use dredging to remove minerals
 Bucket system that scoops
sediment with minerals from
bottom of body of water.
 Minerals are separated from
sediment
Scoop placer deposits in bucket,
deposit on barge, barge takes to
refinery for separation.

15. How is mineral removed from ore?
 Smelting
 Crushed ore heated to high temps.
 Impurities are trapped by a
material called flux & create slag
that forms a layer on top of the
melted metal which is easily
removed (but toxic)
 Purified molten metal falls to the
bottom of the furnace and is
harvested.
 Heap Leaching
 Using chemicals to dissolve
mineral from ore
 Ex: cyanide used to remove gold
 Ex: sulfuric acid used to remove
copper
Copper can be extracted thru smelting (top)
OR thru heap leaching (bottom).