Mining - Mining
 Overview
 Steps Mining Descriptions...

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Unformatted text preview: Mining
 Overview
 Steps Mining Descriptions Removing mineral resource from the ground. Can involve under-ground mines, drilling, room-andpillar mining, long-wall mining, open pit, dredging, contour strip mining, and mountaintop mining Env ironmental Issues Mine wastes – acids and toxins Displacement of native species Reclamation of land and recycling Processing Removing ore from gangue. Involves transportation, processing, purification, smelting, and manufacturing Involves distribution to end user Pollution (air, water, soil, and noise) Human health concerns, risks, and hazards Use Extraction
 •  Before
mining
begins,
economic
decisions
are
 made
regarding
profitability
of
the
site
 –  Current
&
Projected
Price
 –  Amount
of
ore
at
site
 –  Concentration
of
Ore
 –  Koz
says
“hi”
 –  Type
of
Mining
Required
 –  Cost
of
Transportation
to
Ore
Processing
 –  Cost
of
Reclamation
 Site
Development
 •  Sampling
takes
place
to
determine
quantity
 and
quality
of
minerals
 •  Roads
and
equipment
are
brought
in
 Methods
of
Extraction
 •  Surface
mining
–
earth
moving
equipment
 employed
 •  Pros:
 –  Safe
and
Cost‐Effective
 •  Cons:
 –  Topsoil
and
vegetation
removed
 –  Dust
and
waste
causes
air
quality
issues
 –  Deep
pits
draw
out
groundwater
which
effects
fish
 and
wetlands
through
erosion
and
sedimentation
 Methods
of
Extraction
 •  Underground
Mining
–
large
 shafts
are
dug
into
the
Earth
 •  Pros:
 –  Less
surface
destruction
and
waste
 rock
 •  Cons:
 –  Unsafe
 –  Acid
mine
drainage
containing
 pyrites
and
other
sulfides
are
 produced
which
affect
air
and
water
 quality
 Methods
of
Extraction
 •  In‐situ
Leaching:
small
holes
are
drilled
into
a
site
and
 water
based
chemical
solvents
flush
out
desired
 minerals
 •  Pros:
 –  Waste
rock
is
minimal
 –  Safer
procedures
used
by
miners
 –  Less
expensive
since
rock
is
not
broken
up
 –  Shorter
times
to
production,
less
surface
destruction,
and
 less
remediation
 –  Fluids
injected
into
Earth
are
toxic
and
enter
groundwater
 •  Cons:
 Processing
 •  Intensive
chemical
processing
during
smelting
 – Heating
beyond
melting
point
in
presence
of
 reducing
agents
like
coke
or
oxidizing
agents
such
 as
air
 Processing
 •  Cyanide
heap
leaching
 –  Gold
ore
is
heaped
into
a
large
pile
 –  Cyanide
solution
is
sprayed
on
top
of
 pile
 –  Gold
leaches
out
of
the
ore
and
 collects
on
the
bottom
as
cyanide
 percolates
through
 –  Liquid
cyanide
waste
are
kept
in
tailing
 ponds,
which
eventually
leak
and
enter
 groundwater
 Global
Reserves
 •  Two
billion
tons
of
minerals
are
extracted
and
 used
each
year
in
the
U.S.
–
about
10
tons
per
 each
American
 •  U.S.
imports
more
than
50%
of
needed
 minerals
 •  As
lower
grade
ore
is
mined,
more
processing
 and
pollution
result
 Oil
 •  45‐70%
of
global
crude
oil
reserve
 depleted
 •  Estimated
50‐yr
supply
left
with
 Middle
East
owning
½
of
what ’s
left
 •  U.S.
owns
3%
of
world’s
oil
reserve
 but
uses
30%
of
oil
extracted
each
 year
 Oil
 •  2/3
of
oil
in
U.S.
is
used
for
transportation
 •  ¼
used
in
industry
(plastics,
medicines,
 cosmetics)
 •  Oil
imports
52%
in
1996,
to
projected
70%
in
 2010
 Coal
 •  Single
largest
source
of
fuel
used
to
produce
 electricity
 •  China
is
world’s
largest
producer
 •  Global
coal
reserves
are
estimated
to
last
 about
300
years
at
current
extraction
levels
 Natural
Gas
 •  Most
natural
gas
reserves
are
located
in
 Middle
East
(34%
of
world
total)
 •  Europe,
Russia
Federation,
and
former
 countries
of
U.S.S.R.
own
42%
of
total
world
 reserves
 •  The
U.S.
possesses
3%
of
the
world’s
total
 natural
gas
reserves
 Natural
Gas
 •  Given
U.S.
production
levels,
there
is
enough
 natural
gas
in
the
U.S.
to
meet
approximately
 75
years
of
domestic
production
 – Does
not
account
for
increased
levels
from
the
 potential
opening
up
of
access
to
Arctic
National
 Wildlife
Refuge
 Relevant
Laws
 •  General
Mining
Law
(1872)
 – Free
access
to
individuals
and
corporations
to
 prospect
for
minerals
in
public
domain
lands
and
 allows
them
to
stake
claim
 •  Surface
Mining
Control
and
Reclamation
Act
 (1977)
 – Established
a
program
for
regulating
surface
 control
coal
mining
and
reclamation
activities
 ...
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