1. Mining and Energy Resources
Ch 8, 12 and 13

2. Mineral Resources
Concentration of naturally occurring material in or on the earth’s crust.
can be extracted and processed into useful materials at an affordable cost
they are classified as nonrenewable resources because they take so long to produce

3. Formation of mineral Resources
Hydrothermal processes
divergent boundaries allow
magma to superheat seawater
dissolving metals from rock
and magma
Sedimentary sorting
minerals settle out in streams on the basis of density (Gold panning)
Evaporative mineral deposits
as water evaporates it leaves
behind minerals (salt, borax, sodium carbonate)

4. Reserves
Reserves- the known quantity of a resource that can be economically recovered. 4

5. Types of Mining
Surface mining- removing minerals that are close to Earth’s surface.
Strip mining- removing strips of soil and rock to expose ore.
Open pit mining- the creation of a large pit or hole in the ground that is visible from the surface.
Mountain top removal- removing the entire top of a mountain with explosives.
Placer mining- looking for metals and stones in river sediments. 5

6. Types of Mining
Subsurface mining- mining for resources that are 100 m below Earth’s surface. 6

7. Surface Mining Restoration Difficult and usually incomplete
Most surface mining is in arid/semiarid regions
Damage to these biomes is almost always permanent

8. Environmental Effects of Mining
Land Surface:
scarring and disruption
fires in coal mines
land subsidence causing houses to tilt, cracked sewer lines, broken gas mains and disrupted groundwater systems
erosion of spoil heaps and tailings by water and wind
air and water pollution

9. Environmental Effects of Mining
Rainwater seeping through a mine or mine waste can carry sulfuric acid to nearby streams
Smelting—used to separate metals from other elements in the ore mineral
Emit enormous quantities of air pollutants
SO2, soot, tiny particles of arsenic, cadmium, lead and other heavy metals
Other mining wastes: radioactive uranium compounds, compounds of lead, mercury, arsenic and cadmium

10. Mining the oceans
Most minerals in seawater occur at very low concentrations – not economically practical to recover them.
Only minerals that can be profitably extracted are magnesium, bromine and sodium chloride
Continental Shelf – sand, gravel, phosphates, sulfur, tin, copper, iron, tungsten, silver, titanium, platinum, and diamonds.

11. Mining The Oceans
Deep ocean floor – future site for sources of manganese and other metals; uncertainty who owns the mineral rights in international waters.
Hot volcanic springs – sources of sulfide deposits of gold, silver, zinc and copper
Environmental effects of deep-sea mining are unclear and debatable

12. Economics of Mining
Economic Depletion - Occurs when it costs more to find and extract the deposit than it is worth
Depletion time—time it takes to use up a certain proportion (80%) of the reserves of a mineral at a given rate of use
Then our choice becomes recycling, reusing, wasting less, using less, finding a substitute or doing without

13. U.S. Energy Use United States is the world’s largest energy user
History of energy use in U.S.
Coal
Oil
Oil overtook coal in 1950
Hydroelectric power overtook wood in 1968
Nuclear overtook wood and hydro in 1973

14. Net Energy
Net Energy—total amount of energy available from an energy resource minus the energy needed to find, extract, process, and get that energy to consumers
Net energy ratio—ratio of useful energy produced to the useful energy used to produce it
Oil has a high net energy ratio because much of it comes from large accessible deposits in the Middle East
Nuclear energy has a low net energy ratio due to the costs associated with power generation

15. Nonrenewable Energy
Nonrenewable energy resources- fossil fuels (coal, oil, natural gas) and nuclear fuels.

16. Energy Use
Commercial energy sources- those that are bought and sold, such as coal, oil and natural gas.
Subsistence energy sources- those gathered by individuals for their own use such as wood, charcoal and animal waste.

17. Process of Energy Use

18. Overall Fuel Efficiency of U.S. Automobiles

19. Electricity Generation

20. Electricity Generation
The burning fuel from coal transfers energy to water, which becomes steam.
The kinetic energy contained within the steam is transferred to the blades of a turbine, a large device that resembles a fan.
As the energy in the steam turns the turbine, the shaft in the center of the turbine turns the generator.
This mechanical motion generates energy.

21. Energy Efficiency
Most coal burning power plants are about 35% efficient.

22. Coal
Coal- a solid fuel formed primarily from the remains of trees, ferns, and other plant materials that were preserved million years ago.
Four types of coal ranked from lesser to greater age, exposure to pressure, and energy content.
These four types are: lignite, sub-bituminous, bituminous, and anthracite.
The largest coal reserves are in the United States, Russia, China, and India.

23. Coal

24. Advantages and Disadvantages of Coal
Energy-dense
Contains impurities
Plentiful
Release impurities into air when burned
Easy to exploit by surface mining
Trace metals like mercury, lead, and arsenic are found in coal
Technological demands are small
Combustion leads to increased levels of sulfur dioxide and other air pollutants into the atmosphere.
Economic costs are low
Ash is left behind
Easy to handle and transport
Carbon is released into the atmosphere which contributes to climate change
Needs little refining

25. Petroleum
Petroleum- a mixture of hydrocarbons, water, and sulfur that occurs in underground deposits.
Oil and gasoline make this ideal for mobile combustion, such as vehicles.
Formed from the remains of ocean-dwelling phytoplankton that died million years ago.
Countries with the most petroleum are Saudi Arabia, Russia, the United States, Iran, China, Canada, and Mexico.

26. Petroleum

27. Advantages and Disadvantages of Petroleum
Convenient to transport and use
Releases carbon dioxide into atmosphere
Relatively energy-dense
Possibility of leaks when extracted and transported
Cleaner-burning than coal
Releases sulfur, mercury, lead, and arsenic into the atmosphere when burned

28. Natural Gas
Natural gas- exists as a component of petroleum in the ground as well as in gaseous deposits separate from petroleum.
Contains 80 to 95 percent methane and 5 to 20 percent ethane, propane, and butane.

29. Advantages and Disadvantages Natural Gas
Contains fewer impurities and therefore emits almost no sulfur dioxide or particulates
When unburned, methane escapes into the atmosphere
Emits only 60% as much carbon dioxide as coal
Exploration of natural gas has the potential of contaminating groundwater

30. Other Fossil Fuels
Oil sands- slow-flowing, viscous deposits of bitumen mixed with sand, water, and clay.
Bitumen (tar or pitch)- a degraded type of petroleum that forms when a petroleum migrates close to the surface, where bacteria metabolize some of the light hydrocarbons and others evaporate.

32. The Hubbert Curve
Hubbert curve- a graph that shows the point at which world oil production would reach a maximum and the point at which we would run out of oil.

33. The Future of Fossil Fuel Use
If current global use continues, we will run out of conventional oil in less than 40 years.
Coal supplies will last for at least 200 years, and probably much longer.

34. Nuclear Energy
Fission- a nuclear reaction in which a neutron strikes a relatively large atomic nucleus, which then splits into two or more parts.

35. Nuclear Reactors

36. Nuclear Reactors
Fuel rods- the cylindrical tubes that house the nuclear fuel used in a nuclear power plant.
Nuclear power plants work by using heat from nuclear fission to heat water. This water produces the steam to turn the turbine, which turns a generator.
Control rods- cylindrical devices that can be inserted between the fuel rods to absorb excess neutrons, thus slowing or stopping the fission reaction.

37. Advantages and Disadvantages of Nuclear Energy
No air pollution is produced
Possibility of accidents
Countries can limit their need for imported oil
Disposal of the radioactive waste

38. Radioactive Waste
Radioactive waste- once the nuclear fuel can not produce enough heat to be used in a power plant but it continues to emit radioactivity.
This waste must be stored in special, highly secure locations because of the danger to living organisms.

39. Radioactive Waste
High-level radioactive waste- the form used in fuel rods.
Low-level radioactive waste- the protective clothing, tools, rags, and other items used in routine plant maintenance.

40. Chernobyl, Ukraine 1986 http://www.youtube.com/watch?v=BfKm0XXfiis
Explosion in a nuclear power plant
Sent highly radioactive debris throughout northern Europe
32,000 deaths and 62,000 miles contaminated, over 500,000 people exposed to dangerous levels of radiation

41. Fusion
Nuclear fusion- the reaction that powers the Sun and other stars. This occurs when lighter nuclei are forced together to produce heavier nuclei and heat is released.
Fusion is a promising, unlimited source of energy in the future, but so far scientists have had difficulty cotaining the heat that is produced.

42. What is renewable energy?
Renewable energy can be rapidly regenerated, and some can never be depleted, no matter how much of them we use.

44. How can we use less energy?
Energy conservation- finding ways to use less energy. For example, lowering your thermostat during the winter or driving fewer miles.
Energy efficiency- getting the same result from using a smaller amount of energy.

46. Benefits of Conservation and Efficiency
Many energy companies have an extra backup source of energy available to meet the peak demand, the greatest quantity of energy used at any one time.
Variable price structure- utility customers can pay less to use energy when demand is lowest and more during peak demand.

47. Sustainable Design
Improving the efficiency of the buildings we live and work in.

48. Passive Solar Energy
Using passive solar energy can lower your electricity bill without the need for pumps or other mechanical devices.
Building the house with windows along a south-facing wall which allows the Sun’s rays to warm the house would be an example.

49. Biomass is energy from the Sun
The Sun is the ultimate source of almost all types of energy

50. Modern Carbon vs. Fossil Carbon
Many people are confused how burning biomass such as wood is better then burning coal.
The carbon found in biomass was in the atmosphere as carbon dioxide, taken in by the tree, and by burning it we put it back into the atmosphere
Burning coal is carbon that has been buried for millions of years and was out of circulation until we began to use it. This results in a rapid increase in the concentration of carbon dioxide in the atmosphere.

51. Biomass
Wood, Charcoal and Manure- used to heat homes throughout the world.
Ethanol and Biodiesel (biofuels)- used as substitutes for gasoline and diesel fuel.

52. The kinetic energy of water can generate electricity
Hydroelectricity- electricity generated by the kinetic energy of moving water. This is the second most common form of renewable energy in the world.

54. Types of hydroelectric power systems
Run-of-the-river systems- water is held behind a dam and runs through a channel before returning to the river.
Water impoundment- water is stored behind a dam and the gates of the dam are opened and closed controlling the flow of water.
Tidal systems- the movement of water is driven by the gravitational pull of the Moon.

55. The Sun’s energy can be captured directly
Active solar energy- capturing the energy of sunlight with the use of a pump or photovoltaic cell and generating electricity.

56. Earth’s internal heat produces geothermal energy
Geothermal energy- using the heat from natural radioactive decay of elements deep within Earth as well as heat coming from Earth.

58. Wind energy is the most rapidly growing source of electricity
Wind energy- using a wind turbine to convert kinetic energy into electrical energy.

59. Hydrogen fuel cells have many potential applications
Fuel cell- a device that operates like a common battery where electricity is generated by a reaction between two chemicals.

62. What is energy efficiency?
Energy efficiency – Percentage of total energy input to a machine or equipment that is consumed in useful work and not wasted as useless heat.
Life cycle cost - the initial cost plus lifetime operating costs
The 3 least energy efficient using devices
incandescent light bulbs
vehicles w/ internal combustion engines
nuclear power plants producing electricity for space heating

63. Why is it important to reduce energy waste?
make nonrenewable fossil fuels last longer
gives us time to phase in renewable energy resources
decreases dependence on oil imports
lessens need for military intervention in the oil-rich and politically unstable Middle East
Reduces local and global environmental damage
Is the cheapest and quickest way to slow projected global warming
The reason there is not more emphasis on improving energy efficiency is low-cost underpriced fossil fuels!
A second cause is huge government subsidies

64. Cogeneration
Cogeneration- using a fuel to generate electricity and to produce heat.
Example- If steam is used for industrial purposes or to heat buildings it is diverted to turn a turbine first.
This improves the efficiency to as high as 90%.

65. How can we save energy in transportation?
Increase the fuel efficiency of motor vehicles
There is little interest in fuel-efficient vehicles when gasoline is so cheap
Electric cars
pollution to recharge batteries is produced elsewhere
Electric cars are not very efficient
Shift to more energy efficient ways to move people and freight

66. Vehicles Electric car- Hybrid car- (gasoline/electric)
Almost no pollution
Limited range between charges
Hybrid car- (gasoline/electric)
Increase mileage
Reduce emissions
Increase efficiency
5 important parts-
engine-smaller in size reduces emissions and increase efficiency
Fuel tank- energy storage device
Advanced electronics- electric motor acts as a generator, draw energy from batteries to accelerate
Generator- similar to electric motor and produces electrical power
Batteries- energy storage device for the electric motor

67. How can we save energy in buildings?
Use the most energy-efficient ways to heat houses: passive solar heating and high-efficiency natural gas furnaces
electric resistance heating is the most wasteful
Heat pumps work in warm climates
For existing homes add insulation, plug leaks and install energy saving windows
Use the most energy-efficient ways to heat water (using electricity is the least efficient)
Use the most energy-efficient appliances and lights
Rebates or tax credits for building energy-efficient buildings
Direct use of solar energy for heat and electricity

68. Sustainable Energy Strategy
Improve energy efficiency
Use natural gas as we make transition to decentralized, local renewable sources
What can the government do?
increase fuel efficiency standards for motor vehicles
establish energy-efficiency standards for buildings and appliances
increase government sponsored R&D to improve energy efficiency