Transcript Chapter 14 notes - Aurora City School

LIVING IN THE ENVIRONMENT, 18e
G. TYLER MILLER • SCOTT E. SPOOLMAN
14
Nonrenewable Mineral
Resources
©©Cengage
CengageLearning
Learning2015
2015
Core Case Study: The Crucial Importance
of Rare-Earth Metals
• Crucial to the technologies that support
today’s lifestyles and economies
– Used to make LCDs, LED light bulbs, fiber
optic cables, cell phones, and digital cameras
• Without affordable supplies of rare earth
elements, we could not develop cleaner
technologies
© Cengage Learning 2015
Catalytic converter
• Cerium
• Lanthanum
Battery
• Lanthanum
• Cerium
LCD screen
• Europium
• Yttrium
• Cerium
Electric motors
and generator
• Dysprosium
• Neodymium
• Praseodymium
• Terbium
Fig. 14-2, p. 350
14-1 What Are the Earth’s Major
Geological Processes/Mineral Resources?
• Dynamic processes within the earth and
on its surface produce the mineral
resources on which we depend
• Mineral resources are nonrenewable
– Produced and renewed over millions of years
mostly by the earth’s rock cycle
© Cengage Learning 2015
The Earth Is a Dynamic Planet
• Geology
– Study of dynamic processes taking place on
earth’s surface and in earth’s interior
Three major concentric zones of the earth
1. Core
2. Mantle
3. Crust
© Cengage Learning 2015
- 1. Core:
• innermost zone; extremely hot and has a solid inner
layer surrounded by molten rock, or hot liquid rock,
and semisolid material
– 2. Mantle
• Made mostly of solid rock that can be soft and
pliable at very high temperatures.
• including the asthenosphere (volume of hot, partly
melted rock that flows)
© Cengage Learning 2015
– Tremendous heat within the core and mantle
generates convection cells or currents that
move large volumes of rock and heat in loops
within the mantle like gigantic conveyor belts.
– 3. Crust
• Outermost and thinnest zone of solid material.
• Consists of continental crust and oceanic crust(
71% of crust)
• Crust and outermost part of the mantle make the
lithosphere
© Cengage Learning 2015
Spreading center
Oceanic crust
Oceanic crust
Continental
crust
Continental
crust
Cold dense
Material cools as
material falls back
it reaches the
through mantle
outer mantle
Mantle
convection cell
Two plates move towards
each other. One is
subducted back into the
mantle on a falling
convection current.
Hot
material
rising
through
the
mantle
Asthenosphere
Mantle
Hot outer
core
Inner
core
Fig. 14-3, p. 351
What Are Minerals and Rocks?
• Mineral
– Naturally occurring compound that exists as a
crystalline solid; Mercury, gold
• Mineral resource
– Concentration that we can extract and
process into raw materials; Salt, quartz
• Rock
– Solid combination of one or more minerals;
limestone (calcium carbonate), granite (mica,
feldspar, and quartz)
© Cengage Learning 2015
Types of rock
• 1.Sedimentary rock
– Made of sediments
• Dead plant and animal remains
• Tiny particles of weathered and eroded rocks
• Dolomite and limestone
© Cengage Learning 2015
Types of rock
• 2.Igneous rock
– Intense heat and pressure when magma wells
up from earth’s mantle and then cools and
hardens
– Granite and lava rock
• 3.Metamorphic rock
– Existing rock subjected to high temperatures,
pressures, fluids, or a combination
– Slate and marble
© Cengage Learning 2015
Earth’s Rocks Are Recycled Very Slowly
• Rock cycle
– Rocks are recycled over millions of years
– 3 Processes: Erosion, melting, and
metamorphism
– Produce sedimentary, igneous, and
metamorphic rocks respectively
– Rocks are broken down, melted, fused
together, cooled, and recrystallized
– Slowest of earth’s cycle processes
© Cengage Learning 2015
• 100 different minerals from the earth’s
crust:
– Metallic minerals
• Aluminum, gold
– Nonmetallic minerals
• Sand and limestone
© Cengage Learning 2015
We Depend on a Variety of Nonrenewable
Mineral Resources
• Ore
– Contains profitable concentration of a mineral
through mining and processing
– High-grade ore
– Low-grade ore
• Metallic mineral resources
– Aluminum for automobiles
– Iron for steel
– Copper for conducting electricity
© Cengage Learning 2015
We Depend on a Variety of Nonrenewable
Mineral Resources (cont’d.)
• Nonmetallic mineral resources
– Sand, gravel, and limestone
• Reserves
– Estimated supply of a mineral resource
© Cengage Learning 2015
Erosion
Transportation
Weathering
Deposition
Igneous rock
Granite,
pumice,
basalt
Sedimentary rock
Sandstone,
limestone
Heat, pressure
Cooling
Heat, pressure,
stress
Magma
(molten rock)
Melting
Metamorphic rock
Slate, marble,
gneiss, quartzite
© Cengage Learning 2015
Fig. 14-5, p. 353
How Long Might Supplies of
Nonrenewable Mineral Resources Last?
• Nonrenewable mineral resources exist in
finite amounts
– Can become economically depleted when it
costs more than it is worth to find, extract, and
process the remaining deposits
• There are several ways to extend supplies
of mineral resources
– But each of these is limited by economic and
environmental factors
© Cengage Learning 2015
Supplies of Nonrenewable Mineral
Resources Can Be Economically Depleted
• Reserves
– Identified deposits from which we can extract
the mineral profitably
• Depletion time
– Time to use a certain portion of reserves,
usually 80%
© Cengage Learning 2015
Nonrenewable Mineral Resources Can Be
Economically Depleted (cont’d.)
• When a resource becomes economically
depleted:
– Recycle or reuse existing supplies
– Waste less
– Use less
– Find a substitute
– Do without
© Cengage Learning 2015
A
Mine, use, throw away;
no new discoveries;
rising prices
Recycle; increase reserves
by improved mining
technology, higher prices,
and new discoveries
Production
B
Recycle, reuse,
reduce consumption;
increase reserves by
improved mining
technology, higher
prices, and new
discoveries
C
Present
© Cengage Learning 2015
Depletion
time A
Depletion Depletion
time B
time C
Time
Stepped Art
Fig. 14-6, p. 360
Global and U.S. Rare-Earth Supplies
• Rare-earth elements aren’t really rare, but
they are hard to find in concentrations high
enough to extract and process at an
affordable price.
• 50% of reserves are in China, where they
produce 97% of the world’s rare-earth
metals and oxides
• 13% reserves are in US, but they produce
none
© Cengage Learning 2015
Market Prices Affect Supplies of
Nonrenewable Minerals
• An increase in price of a scarce mineral
recourse can often lead to increased
supplies and can encourage more efficient
use.
• However, subsidies and tax breaks to
mining companies are keeping mineral
prices artificially low
© Cengage Learning 2015
Can We Expand Reserves by Mining
Lower-Grade Ores?
• Factors that limit the mining of lower-grade
ores
– Increased cost of mining and processing
larger volumes of ore
– Availability of freshwater
– Environmental impact
• To improve mining technology and lessen
E.I:
– Using microorganisms – biomining (slow
process)
© Cengage Learning 2015
Can We Get More Minerals from the
Ocean?
• May be less E.I. than on land
• Mineral resources dissolved in the ocean
– Low concentrations and so take a great deal of
money and energy; just magnesium, bromine,
and sodium chloride
• Deposits of minerals in sediments along the
shallow continental shelf and near
shorelines
– Great source of sand, gravel, phosphates,
copper, iron, and more!
© Cengage Learning 2015
• Hydrothermal ore deposits
– Copper, lead, zinc, silver, gold
– Hot water vents in the ocean floor
• Metals from the ocean floor
– Manganese nodules
© Cengage Learning 2015
Can We Get More Minerals from the
Ocean? (cont’d.)
• Hydrothermal ore deposits
• What is the effect of mining on aquatic
life?
© Cengage Learning 2015
Black
smoker
White
smoker
Sulfide
deposits
Magma
White
crab
White clam
Tube worms
Fig. 14-8, p. 356
14-3 What Are The Environmental Effects
From Using Nonrenewable Minerals?
• Extracting minerals from the earth’s crust
and converting them into useful products
can:
– Disturb the land
– Erode soils
– Produce large amounts of solid waste
– Pollute the air, water, and soil
© Cengage Learning 2015
Mineral Use Creates Environmental
Impacts
• Metal product life cycle
– Includes mining, processing, manufacturing,
and disposal
• Environmental impacts
– Determined by an ore’s grade
• Percentage of metal content
• Higher-grade ores are exploited first because
lower-grade take more money, energy, and
resources and lead to more pollution, waste, and
disruption
© Cengage Learning 2015
Mining
Metal
ore
Separation
of ore from
waste
material
Smelting
Melting
metal
Conversion to
product
Discarding of
product
Recycling
© Cengage Learning 2015
Fig. 14-9, p. 357
Removing Mineral Deposits Has Harmful
Environmental Effects
• Surface mining
– Removes shallow deposits
– vegetation, soil, and rock overlying a mineral
deposit are cleared away
– Overburden (soil and rock) are deposited into
spoils (waste material)
– Used to extract about 90% of nonfuel mineral
resources and 60% of coal in US.
© Cengage Learning 2015
• Open-pit mining
– Machines are used to dig very large holes and
remove metal ores containing copper, gold, or
other metals
• Strip mining
– Any form of mining involving the extraction of
mineral deposits that lie in large horizontal
beds close to the earth’s surface
– Removes mineral deposits or an energy
source such as coal
© Cengage Learning 2015
• Contour strip mining
– used mostly to mine coal and various mineral
resources on hilly or mountainous terrain.
• Mountaintop removal
– Top of a mountain is removed to expose
seams of coal, which are then extracted
© Cengage Learning 2015
© Cengage Learning 2015
Fig. 14-10, p. 358
© Cengage Learning 2015
Fig. 14-11, p. 358
Undisturbed land
Overburden
Pit
Bench
Spoil banks
Fig. 14-13, p. 359
Removing Mineral Deposits Has Harmful
Environmental Effects (cont’d.)
• Subsurface mining
– Deep deposits; underground mineral
resources are removed through tunnels and
shafts
– Potential problems
• Miners often get lung disease
• Subsidence
• Acid mine drainage (when rainwater seeps through
a mine and carries sulfuric acid to nearby streams
and groundwater)
© Cengage Learning 2015
Fig. 14-15, p. 360
Case Study: The Real Cost of Gold
• At about 90% of the world’s gold mines
– Mineral extracted with cyanide salts
– Cyanide is extremely toxic
• Mining companies declare bankruptcy
– Allows them to avoid environmental
remediation
© Cengage Learning 2015
Removing Metals from Ores Has Harmful
Environmental Effects
• Ore extracted by mining has two
components:
– 1. Ore mineral, containing the desired metal
– 2. Waste material, or tailings that are left in
piles or put into tailings ponds
– After waste is removed, smelting using heat or
chemicals is used to extract metals mineral
ores. Can cause:
• Air pollution
• Water pollution
© Cengage Learning 2015
14-4 How Can We Use Mineral Resources
More Sustainability?
• We can:
– Try to find substitutes for scarce resources
– Reduce resource waste
– Recycle and reuse minerals
© Cengage Learning 2015
We Can Find Substitutes for Some Scarce
Mineral Resources
• Materials revolution
– Silicon replacing some metals for common
uses
• New technologies:
– Substitute scarce minerals through
nanotechnology ceramics, and highstrength plastics
• Substitution doesn’t always work
– Platinum – industrial catalyst with no substitue
© Cengage Learning 2015
We Can Use Mineral Resources More
Sustainably
• Recycling and reuse
– Lower environmental impact than mining and
processing metals from ores
– To ensure adequate supplies of rare-earth
elements in the short-term and long-term, use
alternatives like extracting from e-waste
– Substitutes for rare-earth elements (using
lithium-ion batteries)
© Cengage Learning 2015
Solutions: Sustainable Use of
Nonrenewable Minerals
© Cengage Learning 2015
Fig. 14-17, p. 364
14-5 What Are the Earth’s Major Geologic
Hazards?
• Dynamic processes move matter within
the earth and on its surface and can cause
volcanic eruptions, earthquakes, tsunamis,
erosion, and landslides
© Cengage Learning 2015
The Earth Beneath Your Feet Is Moving
• The earth’s crust is broken into tectonic
plates
– “Float” on the asthenosphere very slowly
• Much geological activity takes place at the
plate boundaries as they separate, collide,
or grind causing mountains to form,
earthquakes to shake parts of the crust,
and volcanoes to erupt.
© Cengage Learning 2015
Juan
De Fuca
plate
North American plate
Eurasian plate
Philippine
plate
Caribbean
plate
Arabian
plate
Cocos Plate
African plate
Pacific plate
Nazca plate
South
American
plate
Pacific
plate
Indian-Australian
plate
Antarctic plate
Scotia plate
© Cengage Learning 2015
Fig. 14-18, p. 366
Volcanoes Release Molten Rock from the
Earth’s Interior
• Volcano
– Magma rising through the lithosphere reaches
the earth’s surface through a crack called a
fissure and forms lava and builds into a cone
– Form along boundaries of tectonic plates
– Eruption – release of lava, hot ash, and
gases into the environment
• Can be very destructive: loss of life, obliterating
ecosystems and human communities
• Can be very beneficial: formation of majestic
mountains and lakes
© Cengage Learning 2015
Extinct volcanoes
Eruption cloud
Ash flow
Ash
Acid rain
Lava flow
Mud flow
Landslide
Central vent
Magma
conduit
Magma
reservoir
Fig. 14-20, p. 367
Fig. 14-20, p. 367
Earthquakes Are Geological Rock-and-Roll
Events
• Earthquake
– Breakage and shifting of rocks
• Occurs at a fault (fracture in the earth’s crust)
– Moving through the rock in all directions are
seismic waves
• Vibrations in the crust from the energy accumulated
from the fault formation
– Focus – origin of earthquake
– Magnitude – severity of earthquake
– Amplitude – size of the seismic waves
© Cengage Learning 2015
Earthquakes Are Geological Rock-and-Roll
Events (cont’d.)
• Richter scale
– Insignificant: <4.0
– Minor: 4.0–4.9
– Damaging: 5.0–5.9
– Destructive: 6.0–6.9
– Major: 7.0–7.9
– Great: >8.0
• Largest recorded: 9.5 in Chile, 1960
© Cengage Learning 2015
Fig. 14-19, p. 366
Liquefaction of recent
sediments causes buildings
to sink
Landslides may
occur on hilly
ground
Two adjoining plates
move laterally along the
fault line
Earth movements
cause flooding in
low-lying areas
Shock waves
Focus
Epicenter
© Cengage Learning 2015
Fig. 14-21, p. 367
© Cengage Learning 2015
Fig. 14-21b, p. 367
Earthquakes on the Ocean Floor Can
Cause Huge Waves Called Tsunamis
• Tsunami (aka Tidal Waves)
– Series of huge waves generated when ocean
floor suddenly rises or drops
– Usually caused by certain types of faults in
the ocean floor moving up or down as a result
of an underwater earthquake.
– Travels several hundred miles per hour
• December 2004 – Indian Ocean tsunami
– Magnitude 9.15 and 31-meter waves at shore
© Cengage Learning 2015
Earthquakes on the Ocean Floor Can
Cause Huge Waves Called Tsunamis
• 2011 – Japan tsunami
– Damaged nuclear reactors
• Detection of tsunamis
– Buoys in open ocean
© Cengage Learning 2015
Earthquake in seafloor swiftly
pushes water upwards, and starts a
series of waves
Waves move rapidly in
deep ocean reaching
speeds of up to 890
kilometers per hour.
As the waves near land they
slow to about 45 kilometers per hour
but are squeezed upwards and
increased in height.
Waves head inland
causing damage in
their path.
Undersea thrust fault
Fig. 14-22a, p. 368
Upward wave
Earthquake
Fig. 14-22b, p. 368
Three Big Ideas
• Dynamic forces that move matter within
the earth:
– Recycle the earth’s rocks
– Form deposits of mineral resources
– Cause volcanic eruptions, earthquakes, and
tsunamis
© Cengage Learning 2015
Three Big Ideas (cont’d.)
• The available supply of a mineral resource
depends on:
– How much of it is in the earth’s crust
– How fast we use it
– The mining technology used to obtain it
– Market prices
– Harmful environmental effects of removing
and using it
© Cengage Learning 2015
Three Big Ideas (cont’d.)
• We can use mineral resources more
sustainably by:
– Trying to find substitutes for scarce resources
– Reducing resource waste
– Reusing and recycling nonrenewable minerals
© Cengage Learning 2015
Tying It All Together: Rare-Earth Metals
and Sustainability
• Rare-earth elements are important for a
variety of modern technologies
• New technological developments can help
extend mineral supplies
– Nanotechnology
– Biomining
– Graphene
© Cengage Learning 2015