Mineral Resources

2. Mineral Resources • Energy Resources-coal, oil, natural gas, uranium, geothermal energy • Metallic mineral resources-iron, copper, aluminum, gold, silver • Nonmetallic mineral resources-salt, gypsum, clay, sand, phosphates, water, soil

3. Metallic Mineral Resources • Vocabulary: • Ore—A metal-yielding material that can be economically extracted . • Economically Depleted—when cost of finding, extracting, transporting and processing remaining deposits exceed the returns. • Techniques used to find mineral resources * Aerial photos * Satellite images * Effect on the Earth’s magnetic and gravitational fields

4. Types of Mining Minerals • Subsurface mining—removal of deep deposits of minerals • Surface mining—used to retrieve shallow mineral deposits * Overburden—soil and rock which lies over shallow mineral deposits. Must be removed. * Spoil—waste material Open-pit mining—dig a large hole to remove ores Dredging—scrape up mineral deposits underwater using chain buckets and draglines

5. Types of Mining Minerals • Strip mining—overburden is removed in strips. • 2 types: • Area Strip mining—terrain is flat, overburden is stripped away and mineral deposit is removed by power shovels then trench is filled with overburden; Spoil banks are left forming a wavy series of hills • Contour Strip mining—terrain is hilly. Terraces are cut into the side of the hill; overburden is removed and mineral is extracted. Overburden from each terrace dumped into the one below.

6. Types of Mining Minerals • Mountaintop Removal—mountain tops are completely removed. Debris is dumped into the valleys.

7. Environmental Effects of Mining • Requires a huge amount of energy • Scarring and disruption of land • Fires in coal mines • Land subsidence • Erosion of spoil heaps by water and wind • Air and water pollution • Rainwater carries toxins to nearby streams • Other mine waste—radioactive uranium compounds, lead, mercury, arsenic (gold mines) and cadmium

8. Mining Legislation • Surface Mining Control and Reclamation Act—Requires mining companies to restore most surface mined land so it can be used for the same purpose as it was before it was mined.

9. Energy Resources:Renewable and Nonrenewable

10. Renewable vs. Non-renewable Non-renewable resource Exists in finite supply Is used faster than it can replenish Ex: oil, coal, nuclear fuels Renewable or perpetual Replenishes very rapidly Inexhaustible supply Ex: solar, wind, hydropower

11. Non-Renewable Energy Sources Conventional Petroleum Natural Gas Coal Nuclear Unconventional (examples) Oil Shale Natural gas hydrates in marine sediment

12. Renewable Energy Sources Solar photovoltaic Passive solar air and water heating Wind Hydropower Biomass Ocean energy Geothermal Waste to Energy

13. Evaluating Energy Resources US Energy Resources: • Renewable energy: 8% • Non-renewable energy: 92% Considerations for Resources • Future availability • Net energy yield • Cost • Environmental effects

14. Petroleum (Oil): 39% of US Energy Fig. 17-8 p. 356 • US uses 26% of oil • extracted worldwide; • we have 2.9% of world’s oil reserves • Depletion of our reserves • means more oil imported • World oil reserves 80% • depleted in 42-93 years • Oil is a finite resource!

15. Oil: 39% of US Energy Fig. 17-8 p. 356 • Pros of Oil: • High net energy • Easily transported • Strong infrastructure • Cons of Oil: • Requires subsidies • Air pollution • Global warming • Limited supplies

16. Peak Production of Petroleum in US

17. Arctic National Wildlife Refuge: Is this the answer? • Would meet US needs for 7-24 months • 1 mpg increase for new cars = ANWR

18. Natural Gas: 23% of US Energy • Mostly methane + other gases • LNG-versatile and high net energy • Cleaner burning than oil or coal • But, US has only 3% of world supply

19. Coal: 23% of US Energy Fig. 17-20 p. 364

20. Coal: 23% of US Energy Produces 62% of world’s electricity and 52% of US electricity Most abundant fossil fuel and could easily last at least 200 years US has 25% of world’s reserves, Russia = 16%, China = 12% High net energy yield, but…

21. Coal: 23% of US Energy Accounts for 36% CO2 released Severely degrades land causing land, air and water pollution Severe human health threat Air pollution and acid rain

22. Mining Waste Impacts on Surface and Groundwater Miller, 13th edition, Fig. 15-7 p. 344

24. Nuclear: 8% of US Energy Significant fuel supply Low CO2 output Moderate land disruption and pollution but… • Expensive--subsidies needed • Catastrophic accidents possible • No solution to nuclear waste disposal • Subject to terrorist attack

25. 235 92 U n 92 36 Kr 235 92 n U n 235 92 U n 141 56 Ba 92 36 Kr n 92 36 Kr n n n n 235 92 n U 141 56 Ba 92 36 Kr n 141 56 Ba 235 92 U n 235 92 U n 141 56 Ba 235 92 U

26. Nuclear: 8% of US Energy Miller, 13th edition Fig. 15-36 p. 367

28. Nuclear Fusion

31. Fusion-Disadvantages • Need around 100 millon degrees for duterium and tritium to fuse • With our current technology, we use more energy than we can produce.

32. Oil Shale • Fine grained rock containing a solid , waxy mixture of hydrocarbons called kerogen • Extracted from rock by crushing and heating. • Global supplies are potentially 200 times larger than conventional oil.

33. Oil Shale-Disadvantages: • Lower net energy yield • Requires large amounts of water • Contaminates water supplies with toxic metals • Too expensive

34. Tar Sands • Mixture of clay, sand, water, and bitumen (gooey black high-sulfur oil) • Removed by surface mining using pressurized steam • World’s largest supply in northern Alberta, Canada

35. Tar Sands-Disadvantages • Low net energy yield • Requires large quanties of water • Creates huge waste dispposal ponds

36. Natural Gas Hydrates • Methane Hydrates found in a solid form under great pressure in deep ocean sediments • Cannot be retreived efficiently with current technology

37. Renewable Energy sources

38. Solar Energy • Solar energy consists of harnessing radiant energy from the sun. • Active solar heats water or air inside a home-requires electricity to circulate • Passive solar-the structure is built to maximize solar capture • Photovoltaic cells generate electricity

39. Solar Energy Pros Cons Inefficient where sunlight is limited Maintenance costs high Systems must be periodically replaced Current efficiency only 10%-25% • Limitless supply • Little environmental impact • Good for remote locations

40. Wind Energy • Wind turns giant turbine blades that produce electricity

41. Wind Energy Pros Cons Steady wind is required Needs backup systems Visual and noise pollution May interfere with flight patterns of birds • Can be built quickly • Maintenance is low • Moderate to high energy yeild • No air pollution • Land underneath can be used for agriculture

42. Hydropower: 10 % of US Energy • Dams built to trap water, which in turn is then released and channeled through turbines to generate electricity

43. Hydropower Pros Cons Displace many people Destroy wildlife habitats Sedimentation requires dredging Expensive to build Destroys wild rivers • Control flooding • Low operating cost • No pollution • Long life span • Moderate to high energy yield • Areas for water recreation

44. Biomass • Any carbon-based, biologically derived fuel source. • Plants suitabelefor biofuel include switch grass, corn, and sugarcane • Supplies about 15% of world’s energy

45. Biomass Pros Cons Requires adequate water and fertilizer Could cause massive deforestation Expensive to transport Not efficient • Renewable energy source • Can be sustainable • Does not distupt atmospheric CO2

46. Geothermal < 1% US Energy • Heat from underground rock or magma used to produce steam that drive turbines.

47. Geothermal Pros Cons Reservoir sites are scarce Can be depleted if not managed properly Noise, odor, land subsidence Can degrade ecosystem • Moderate energy yield • Limitless and reliable source if managed properly • Little air pollution • Competitive cost

48. Solutions: Energy Efficiency! 43% of energy in the US is wasted unnecessarily Incandescent bulb=5% efficient Fluorescent bulb=20% efficient Auto fleet standards = CAFE Standards (Corporate Average Fuel Economy) 12.9 mpg in 1974 27.9 mpg today 40 mpg CAFE standard would cut gas use by 50%

49. Efficiencies

50. Ways to Improve Energy Efficiency • Insulation • Eliminate air leaks • Air to air heat exchangers • Efficient appliances • Efficient electric motors • High-efficiency lighting • Increasing fuel economy