Download Chapter 15: Geologic Resources: Nonrenewable Mineral and

Chapter 15: Geologic Resources: Nonrenewable Mineral and Energy Resources
15.1 Nature and Formation of Mineral Resources
What Are Mineral Resources?
How Do Ores Form From Magma?
How Do Ores and Other Minerals Form From Sedimentary and Weathering Processes?







A mineral resource is a concentration of naturally occurring material in or on the earth’s crust that can be extracted ands
processed into useful materials at an affordable cost.
Nonrenewable resource is a fossil fuel energy resource that take a long time to produce.
o i.e.- metallic mineral resources (iron, copper, aluminum)
o non-metallic mineral resources (clay, salt, sand, phosphates, & soil)
o Energy resources (coal, oil, natural gas, uranium)
Ore is rock containing enough of one or more metallic minerals to mine profitably. They form as a result of several internal
and external geologic processes.
Plate tectonics
o Shapes the earth’s crust as the earth’s plates collide, retreat, and slide across one another at the boundaries
between them
o Determines where the earth’s richest mineral deposits form
This happens when movements of the earth’s palates allow magma (molten rock) to flow up into the earth’s crust at
divergent and convergent palate boundaries.
As it cools it crystallizes into various layers of mineral containing igneous
As sediments settle they can form or deposit by sedimentary sorting and precipitation
o i.e.-many streams carry a mixture of salt, sand, gravel, and occasional small grains of gold
o when the stream current slows down these minerals settle out on the basis of their density
o heavier minerals (gold) fall first in this sedimentary sorting process
o over time fairly rich deposits of settled gold particles called placer deposits concentrate near bedrock or coarse
gravel in streams
15.2 Finding and Removing Nonrenewable Mineral Resources
How Are Buried Mineral Deposits Found?
Methods that mining companies use to find mineral deposits found?
 using aerial photos and satellite images to reveal protruding rock formations associated with certain minerals.
 using planes equipped with radiation-measuring and a magnetometer.
 using a gravimeter to measure differences in gravity b/c the density of an ore deposit usually differs from that of the
surrounding rock.
 drilling a deep well and extracting core samples.
 putting sensors in existing wells.
 making seismic surveys on land and sea.
 performing chemical analysis of water and plants to detect deposits of underground minerals.
Mining techniques to remove deposits:
 Shallow deposits are removed by surface miningMechanized equipment strips away the overburden of soil and rock and discards it as water material called spoils.
Methods of surface mining:
 Open-pit mining, in which machines dig holes and remove ores, sand, gravel.
 Dredging, in which chain buckets and draglines scrape up underwater mineral deposits.
 Area strip mining, used where the terrain is fairly flat. Earthmover strips away overburden, and a power shovel digs a cut to
remove mineral deposit. After mineral is removed, the trench is filled with overburden and a new cut is made.
 Contour strip mining, used on hilly or mountainous terrain. A power shovel cuts a series of terraces in the side of a hill.
 Mountaintop removal. This method uses explosives, massive shovels, and draglines to remove the top of a mountain and
expose seams of coal underneath.
Negatives to surface mining – very expensive, and not done in many countries.
Surface Mining Control and Reclamation Act of 1977 requires mining companies to restore most surface-mined land so it can be
used for the same purpose as it was before. It also levies a tax on mining companies to restore land that was disturbed by surface
mining.
Subsurface Mining
 Deep deposits are removed by subsurface mining.
 Used to remove coal and various metal ores that are too deep to be extracted by surface mining.
 Subsurface mining disturbs less than 1/10 as much land as surface mining and produces less waste material. Hazards
include collapse of roofs, explosions of dust and gas, and lung diseases caused by dust.
15.3 Environmental Effects of Extracting, Processing, and Using Mineral Resources
What Are the Environmental Impacts of Using Mineral Resources?
Are There Environmental Limits to Resource Extraction and Use?
Effects of mining on the environment:
 Scarring and disruption of the land surface.
 Collapse of land above underground mines which causes houses to tilt.
 Wind or water caused erosion of toxic mining wastes.
 Acid mine drainage
 Emission of toxic chemicals into the atmosphere.
 Exposure of wildlife to toxic mining wastes.
Life cycle of a metal resource:
 Ore extracted from the earth’s crust consists: ore mineral and waste material called gangue.
 After gangue has been removed, smelting is used to separate the metal from the other elements in the ore mineral.
 Smelters can cause water pollution, air pollution, and produce hazardous wastes.
 After pure metal has been produced by smelting, it is converted to desired products, which are then used and discarded or
recycled requires a lot of energy.
Are there environmental limits to resource extraction and use?
Environmentalists think the greatest danger of our consumption of non-renewable resources is the environmental damage caused
by their extraction, processing, and conversion to products.
15.4 Supplies of Mineral Resources
Will There Be Enough Mineral Resources
How Does Economics Affect Mineral Resource Supplies
Should More Mining Be Allowed on Public Lands in the United States?
Can We Get Enough Minerals by Mining Lower-Grade Ores
Can We Get Enough Minerals by Mining the Oceans?
Can We Find Substitutes for Scarce Nonrenewable Mineral Resources?
The Materials Revolution
Will There Be Enough Mineral Resources?
 They can become economically depleted (costs more to find, extract, transport and process them than it’s worth) but they
can never completely run out
 After economic depletion, there are five choices:
o Recycle or reuse
o Waste less
o Use less
o Find a substitute
o Do without
 Depletion time – time it takes to use up a certain proportion of the reserves of a mineral at a given rate of use
 Reserve-to-production ratio – the number of years that proven reserves of a particular nonrenewable mineral will last at
current annual production rates
How Does Economics Affect Mineral Resource Supplies?
 Geologic processes – determine the quantity and location of a mineral resource in the earth’s crust
 Economics – determines what part of the known supply is extracted and used
 Resource is cheap when supply exceeds demand, price rises when a resource becomes scarce
o Encourages exploration for new deposits
o Stimulates development of better mining technology
o Makes it profitable to mine lower-grade ores
o Encourages a search for substitutes
o Promotes conversation
 Two other economic problems which hinder the development of new supplies of mineral resources:
o Mineral scarcity doesn’t raise the market price of products a lot because the cost of mineral resources is only a
small part of the final cost of goods
o Exploring for new mineral resources takes a lot of increasingly scarce investment capital and is a risky thing to do
financially
Should More Mining Be Allowed on Public Lands in the United States?
 Have stepped up efforts to have Congress open up new lands for mineral development, sell off mineral-rich public lands to
private interests, or turn their management over to state and local governments
 Conservation biologists and environmentalists strongly oppose these efforts
Can We Get Enough Minerals by Mining Lower-Grade Ores?
 Develop new earth-moving equipment, improved techniques for removing impurities from ores, and other technological
advances in mineral extraction and processing
 Mining of lower-grade ores can be limited by increased cost of mining and processing larger volumes of ore, availability of
fresh water needed to mine and process some minerals, and the environmental impact of the increased land disruption,
waste material, and pollution produced during mining and processing
Can We Get Enough Minerals by Mining the Oceans?
 Ocean mineral resources are found in seawater, sediments and deposits, hydrothermal ore deposits, and manganese-rich
nodules on the ocean floor
 Too expensive to extract certain materials from the deep-ocean floor even though some of them have important minerals
 High costs prevent development of resource-rich mineral beds in international waters
 Dumping back unwanted material in the ocean would stir up ocean sediments, destroy seafloor organisms, and have
potentially harmful effects on poorly understood ocean food webs and marine biodiversity
Can We Find Substitutes for Scarce Nonrenewable Mineral Resources? The Materials Revolution
 Even if supplies of key minerals become expensive or scarce, human ingenuity will find substitutes
 Materials revolution – silicon and new materials are being developed and used as replacements for metals
 Ceramics are harder, stronger, lighter, longer lasting than many metals
 Plastics have high strength and cost less, don’t need painting, can be molded to any shape
15.5 Evaluating Energy Resources
What Types of Energy Do We Use?
What Types of Energy Does the World Depend On, and How Might This Change?
What Types of Energy Does the US Depend On, and How Might That Change?
How Can We Decide Which Energy Resources To Use?
What is Net Energy? The Only Energy That Really Counts.
What types of energy do we use?
 Solar
 Wind
 Hydropower
 Biomass
 Commercial Energy (fossil fuels)
What type of energy does the world depend on? How might this change?
 Nonrenewable energy (fossil fuels-coal, oil, natural gas)
 We are depleting it at a fast rate-so we’ll have to find alternative sources of energy.
What types of energy does the US depend on, and how might this change?
 84% from fossil fuels
 8% from nuclear power
 The US could enter a solar-hydrogen energy age because cleaner and less climate-disrupting forms of energy are needed.
 By 2100: it is projected that oil and coal use will fall dramatically, we will no longer be using nuclear energy, and will instead
use natural gas and hydrogen-solar
How do we decide which energy resources to use? Based on:
 Availability
 Net energy yield (efficiency)
 Cost to develop
 Amount of government research to spur or hinder development
 Effect on national and global economic and military security
 Vulnerability to terrorism
 Impact on the environment
What is net energy? The only energy that really counts.
 Net energy-the total amount of energy available from an energy resource minus the energy (1) used, (2) automatically or
unnecessarily wasted.
o Analogy: Income after tax
 Expressed as the ratio of useful energy produced to the useful energy used to produce it.
o The higher the ratio, the greater the net energy.
o For example, if you have 10 energy units and 2 are used to refine and transport it, the net energy is 8.
15.6 Oil
What is Crude Oil, and How Is It Extracted and Processed?
Who Has the World’s Oil Supplies?
Case Study: Oil Use in the United States
How Long Will Oil Supplies Last, and What Are the Pros and Cons of Oil?
How Useful Are Heavy Oils from Oil Shale and Tar Sands?
Crude Oil- (also known as petroleum)
 is a thick liquid consisting of hundreds of combustible hydrocarbons along with small amounts of sulfur, oxygen, and
nitrogen impurities.
 It’s produced by the decomposition of dead organic matter from plants and animals.
 Deposits of crude oil and natural gas are often trapped together under a dome, deep within the earth’s crust on land or
under the sea floor. A well can be drilled then it is possible to pump out the crude oil that is drawn by gravity out of the
rock pores and into the bottom of the well.
 On average only 35% of the oil is extracted.
 Drilling for oil causes moderate damage to the earth’s land. Oil drilling always involves some oil spills on land and aquatic
systems.
Who has world’s oil supplies?
 11 countries make up the Organization of Petroleum Export Countries.
 They have 67% of world’s crude oil reserves.
Case Study: Oil use in the US
 In 2001 25% of US domestic oil came from off shore drilling, 17% from Alaska’s North Slope. 93% of all US off shore drilling
takes place in the Gulf of Mexico.
 US has only 3% of the world’s oil.
 US uses about 26% of crude oil extracted world wide each year. US oil extraction has declined since 1985.
 In 2001, US imported 55% of the oil it used due to declining domestic oil reserves, higher production costs and increased
use. By 2010 US could be importing an estimated 61% or more of foreign oil.
How long will oil last?
 Since oil is nonrenewable, world oil supplies are expected to decline.
 It is projected to shift to natural gas and hydrogen by 2100.
Pros of oil:
 Long lasting
 can be used for multiple purposes,
 low cost with huge subsidies,
 high net energy yield,
 easily transported,
 low land use,
 well developed technology,
 efficient distribution,
 moderate existing supplies,
 large potential supplies.
Cons of oil
 Nonrenewable,
 artificially low price encourages waste and discourages search for alternatives,
 air pollution when burned,
 releases CO2 when burned,
 moderate water pollution.
How useful are heavy oils from oil shale and tar sands?
 Estimated global supplies of shale oil are about 240 times that of conventional oil.
 Most deposits are of low grade and take more energy and money to extract than crude oil.
 As conventional oil prices rise, it may become economically feasible to exploit reserves of oil shale.
 Tar sand deposits though difficult to extract could supply all of Canada’s projected oil means for about 33 years but they
would last the world only about 2 years.
15.7 Natural Gas
What is Natural Gas
Who Has the World’s Natural Gas Supplies?
How Long Will Natural Gas Supplies Last?
What is the Future of Natural Gas?
Natural gas: a mixture of:
 50-90% methane,
 smaller amounts of heavier gaseous hydrocarbons,
 small amounts of highly toxic hydrogen sulfide.
Who has the world’s natural gas supply:
 Russia and Kazakhstan—42%,
 other countries that have large gas reserves include: Iran, Qatar, Saudi Arabia, etc.
How Long Will Natural Gas Supplies Last?
 At the current consumption rate and known reserves, and undiscovered reserves, natural gas is expected to last the world
125 years.
What is the Future of Natural Gas?
 Experts project an increase in the global use of gas because of its availability, low costs and lower pollution.
 It’s better than oil, coal and nuclear energy so they see natural gas as the best transition to improve energy efficiency.
15.8 Coal
What Is Coal, and How Is It Extracted and Processed?
How Is Coal Used, and Where Are The Largest Supplies?
How Long Will Coal Supplies Last?
What Are the Pros and Cons of Converting Soil Coal in Gaseous and Liquid Fuels?
What is Coal?
 Solid, combustible mixture of organic compounds with 30-98% carbon by weight, mixed with various amounts of water and
small amounts of sulfur and nitrogen compounds.
 It forms in several stages as the remains of plants are subjected to heat and pressure over millions of years.
How is Coal Extracted?
 area strip mining
o Type of surface mining used where the terrain is flat.
o An earthmover strips away the overburden, and a power shovel digs a cut to remove the mineral deposit.
o After removal of the mineral, the trench is filled with overburden, and a new cut is made parallel to the previous
one. T
o he process is repeated over the entire site.

contour strip mining
o Form of surface mining used on hilly or mountainous terrain.
o A power shovel cuts a series of terraces into the side of a hill.
o An earthmover removes the overburden, and a power shovel extracts the coal, with the overburden from each
new terrace dumped onto the one below.
How is Coal Processed?
 Broken up, crushed, washed to remove impurities, dried, shipped to users- mostly power plants and industrial plants
How is Coal Used?
 Commercial energy,
 Electricity,
 Steel
Where are the Largest Suppliers of Coal?
 United States,
 Russia,
 China,
 India;
 half of world consumption in US and China
How long will Coal Supplies Last?
 Identified (known) world reserves should last about 225 years at current rate
 Unidentified (unknown) coal reserves should last about 900 years at current rate
 Total coal reserves should last about 1,125 years at current rate
What is the Future of Coal?
 Advantages:
o Ample supplies,
o high Energy,
o low Cost,
o well-developed Technology,
o pollution can be reduced by
1) fluidized-bed combustion and
2) coal gasification (see below)

Disadvantages:
o very high Environmental impact,
o high Land use,
o threat to Human health,
o
o
high CO2 emissions when burned,
releases Radioactive particles and mercury into the air
In 2001, the Bush Administration:
 rejected participation in Kyoto treaty to reduce global CO2 emissions
 proposed $2 billion program into researching cleaner coal technologies
 supported exemption of older plants from latest Clean Air Act standards for another decade
 allowed coal plants to qualify for renewable energy subsidies just for mixing biomass w/burned coal
 asked Congress to reduce gov’t research and development for energy efficiency
Converting Solid Coal into Gaseous and Liquid Fuels
 synthetic natural gas (SNG):
Gaseous fuel containing mostly methane produced from solid coal.
 coal gasification: Conversion of solid coal to synthetic natural gas (SNG).
 coal liquefaction: Conversion of solid coal to a liquid hydrocarbon fuel such as synthetic gasoline or methanol.
 Pros: large Potential supply, vehicle Fuel, moderate Cost, lower air Pollution when burned than coal
Cons:






low to moderate Energy,
higher Cost than coal,
high Environmental impact,
increased Surface mining of coal,
higher Water use,
higher CO2 emissions
15.9 Nuclear Energy
How Does a Nuclear Fission Reactor Work?
What Happened to Nuclear Power
What Are the Pros and Cons of Nuclear Power?
How Safe Are Nuclear Power Plants and Other Nuclear Facilities?
What Do We Do With Low-Level Radioactive Waste?
What Should We Do with High-Level Radioactive Waste?
How Widespread Are Contaminated Radioactive Sites?
What Can We Do with Worn-Out Nuclear Plants
What is the Connection Between Nuclear Reactors and the Spread of Nuclear Weapons?
What is the Threat From “Dirty” Radioactive Bombs?
Can Nuclear Power Reduce Dependence on Oil?
Can We Afford Nuclear Power?
Can We Develop New and Safer Types of Nuclear Reactors?
Is Breeder Nuclear Fission a Feasible Alternative?
Is Nuclear Fusion a Feasible Alternative?
What Should Be the Future of Nuclear Power in the United States?
How Does a Nuclear Fission Reactor Work?
 In a nuclear fission chain reaction, neutrons split the nuclei of atoms and release energy, mostly as high temperature heat.
 In a reactor, the rate of fission is controlled and the generated is used to produce high-pressure steam, which in turn, spins
turbines which produce electricity.
 light/water reactors- produce nuclear generated electricity using oxygen, carbon and hydrogen.
 Different parts of the reactor:
o Coreo Uranium oxide fuel
o Control rods
o moderator
o coolant
 Nuclear power plants are only one part of the fuel cycle: we must look at entire cycle, not just nuclear plant to evaluate
safety and economics.
What Happened to Nuclear Power:
 The Atomic Energy Commission, in the 1950s promised that nuclear power would generate cheaper electricity then coal
and other alternatives.
 The government then proceeded to pay for about one fourth of the first commercial reactors.
 Price/Anderson Act: protects US nuclear industry from liability in case of accidents because insurance companies refuse to
ensure nuclear power.
 Goals have not been met: In 2001 in 32 countries nuclear reactors were producing 6% of the world’s commercial energy
and 16% of its electricity.
 Since 1989 electricity production growth has leveled off and developed countries are losing interest in nuclear power.
 this is because of multibillion $ construction cost overruns, stricter government safety regulations, higher costs, and more
malfunctions, poor management, public concerns, and investor concerns about economic feasibility.
What are the pros and cons of Nuclear power:
 Advantages: Large fuel supply, low environmental impact, emits less CO2 , moderate land disruption and pollution and low
risk of accidents.
 Disadvantages: High costs, low net energy yield, high environmental impact, catastrophic accidents, spreads knowledge for
building nuclear weapons.
How safe are nuclear power plants and facilities:
 Risk in US and other developed countries is low. NRC (Nuclear Regulatory Commission) : 15-45 % chance of a complete core
meltdown of a US reactor during the next 20 yrs.
 2001 destruction of World Trade Center, proved that a plane loaded with fuel could break open a reactors containment
shell and set off a reactor melt down.
 According to NRC data nuclear plant guards are incapable of repelling serious terrorist attacks, 21 reactors are with in 5
miles of an airport.
 Wide spread public distrust in NRC.
What do we do with low level radioactive waste:
 Low level radioactive wastes give of small amounts of ionizing radiations and must be stored for 100-500 yrs until decaying
to safe levels.
What should we do with high level radioactive waste:
 High level radioactive wastes large amounts of ionizing radiation for short time and small amounts for a long time. Must be
stored for at least 10,000 years
 Most are spent fuel rods from commercial nuclear power plants, and an assortment of wastes from plants that produce
chemicals for nuclear weapons.
 Proposed Methods and their drawbacks: Bury deep under ground, but this is scientifically unsound. Shoot it into space or
the sun, but this is expensive and this could disperse the wastes over earth’s surface. Bury under the Antarctic ice sheet,
could be destabilized by heat from the wastes and retrieving them could be difficult. Dump it into descending subduction
zones in the deep ocean but they might be spewed out by volcanic activity or could contaminate the ocean. Bury it in thick
deposits of mud on ocean floor, but his could corrode and release radioactive content.
 Change it to harmless or less harmful, isotopes: not possible, but even if it was the cost would be really high.
How Widespread Are Contaminated Radioactive Sites?
 Many sites contaminated with radioactive materials. Cleanup will be costly: some places where nuclear weapons are
produced may never be able to be cleaned up.
 Very little contamination in comparison to post Cold War Soviet Union:
o area contaminated by nuclear accidents
o nuclear power plants with unsafe set up
o waste dump sites
o radioactive waste processing plants
o contaminated nuclear test-sites
o nuclear wastes/ old nuclear powered submarines dumped into coastal waters
 1957, Mayak: plutonium production facility let out to much radiation. Because of this: no one can live with in 1000 square
miles of the site and even standing on the shores of nearby Lake Karachay is deadly (former dumping site.)
What Can We Do with Worn-Out Nuclear Plants?
 Unless the worn out nuclear plant’s life can be extended by expensive renovation, it must be decommissioned or retired.
This can be done by dismantling it and storing its large volume of highly radioactive materials in high level nuclear waste
storage facilities which currently do not exist, putting up a physical barrier and setting up full-time security for 30-100 years
before the plant is dismantled, or enclosing the entire plant in a tomb that must last for several thousand years.
What is the connection between nuclear reactors and the spread of nuclear weapons?
 The info and fuel needed to build nuclear weapons have come mostly from the research and commercial nuclear reactors
that the US and 14 other countries have been giving away and selling in the international marketplace for decades.
The threat from “dirty” radioactive bombs is:
 that a “dirty” bomb consists of an explosive, such as dynamite, mixed with some form of radioactive material that is not
difficult or expensive to obtain.
Nuclear power can and cannot reduce dependence on oil.
 Analysts point out that use of nuclear power has little effect on US oil use because:
o oil produces only about 2-3% of the electricity in the US and
o the major use for oil is in transportation which would not be affected by increasing nuclear power production.
Can we afford Nuclear power?
 Nuclear power IS expensive but in recent years the operating cost of many US nuclear power plants has dropped mostly
because of less down time.
 Environmentalists and economists point out that the cost must be based on the entire nuclear fuel cycle not merely the
operating cost of individual plants.
Can we develop new and safer types of nuclear reactors?
 The US nuclear industry hopes to persuade the federal government and utility companies to build hundreds of smaller,
second generation plants using standardized designs which they claim are safer and can be built more quickly.
Is Breeder Nuclear Fission a Feasible Alternative?
 Breeder nuclear fission generates more nuclear fuel than they consume by converting nonfissionable uranium-238 into
fissionable plutonium-239.
 The world’s known uranium reserves would last at least several thousand years, but if the safety system fails, the reactor
could lose some of its liquid sodium coolant, which ignites when exposed to air and reacts explosively if it comes into
contact with water, causing a runaway fission chain reaction and perhaps a powerful nuclear explosion.
Is Nuclear Fusion a Feasible Alternative?
 Proponents contend that with greatly increased federal funding, a commercial nuclear fusion power plant might be built by
2030. However, many energy experts do not expect nuclear fusion to be a significant energy source until 2100.
What Should Be the Future of Nuclear Power in the US?
 Some analysts call for 1) phasing out all of most government subsidies and tax breaks for nuclear power and 2) using such
funds to subsidize and accelerate the development of promising newer energy technologies