1. Geologic Resources
Chapter 15

2. General Mining Law 1872 Encouraged mineral exploration
Help develop the West – selling land
Mining provides – jobs, resources, stimulation of economy
Environmentalist want – lease not ownership, pay royalty, clean up

3. Resources Metallic – nickel, iron, gold, aluminum
Nonmetallic – salt, gypsum, clay, soil
Energy – coal, oil, natural gas, uranium
Ore – rock containing a metallic mineral
Reserve – known deposit of mineral that can be extracted for a profit

4. Resources in the ocean
Black smokers – hydrothermal vents that deposit minerals in tall chimneylike stacks
Manganese nodules – found on the ocean floor, they contain 30-40% manganese and other important minerals

5. Black smoker White smoker Sulfide deposit Magma Tube worms White crab
White clam
Fig. 14.3, p. 322

6. Removing mineral resources
Shallow deposits are removed through surface mining
Open-pit mining
Dredging
Area strip mining
Contour strip mining
Deep deposits through subsurface mining

7. Contour Strip Mining
Fig. 14.4d, p. 324

8. Area Strip Mining
Fig. 14.4c, p. 324

9. Dredging
Fig. 14.4b, p. 324

10. Open Pit Mine
Fig. 14.4a, p. 324

11. Room-and-pillar
Fig. 14.5b, p. 325

12. Underground Coal Mine
Fig. 14.5a, p. 325

13. Longwall Mining of Coal
Fig. 14.5c, p. 325

14. Mining Overburden is removed to expose mineral, disposed of as spoil
Surface mining accounts for about 90% of non fuel mining and 60% of coal
Surface Mining Control and Reclamation Act 1977 – companies had to restore most of the surface to pre-mining conditions

15. Environmental effects of mining
Scarring and disruption of land surface
Collapse and subsiding of land
Wind and water caused toxin-laced mining wastes
Acid mine drainage
Sulfuric acid from rain water combination
Run-off to streams
Destroys aquatic life
Toxic chemical emission into air

16. Percolation to groundwater Leaching of toxic metals
Subsurface
Mine Opening
Surface Mine
Runoff of
sediment
Acid drainage from
reaction of mineral
or ore with water
Spoil banks
Percolation to groundwater
Leaching of toxic metals
and other compounds
from mine spoil
Leaching may carry
acids into soil and
ground
water supplies
Fig. 14.7, p. 326

17. Environmental Effects
Steps
Environmental Effects
Disturbed land; mining accidents;
health hazards; mine waste dumping;
oil spills and blowouts; noise;
ugliness; heat
Mining
exploration, extraction
Processing
Solid wastes; radioactive material;
air, water, and soil pollution;
noise; safety and health
hazards; ugliness; heat
transportation, purification,
manufacturing
Use
Noise; ugliness
thermal water pollution;
pollution of air, water, and soil;
solid and radioactive wastes;
safety and health hazards; heat
transportation or transmission
to individual user,
eventual use, and discarding
Fig. 14.6, p. 326

18. After mining Ore contains desired metal and waste called gangue
Removed gangue is piled into heaps called tailings
Smelting is then used to separate the metal minerals

19. Smelting Smelters create a large quantity of air pollution
They also produce liquid and solid hazardous waste that must be disposed
Companies are trying to reduce pollution, lower costs, and decrease liability

20. How much is there?
Depletion time is the time it takes to use up 80% of the reserve (profitable)
Reserve to production ratio – how long will the known reserves last at current rates of production

21. Recycle; increase reserves by improved mining
Mine, use, throw away;
no new discoveries;
rising prices
Recycle; increase reserves
by improved mining
technology, higher prices,
and new discoveries B
Production
Recycle, reuse, reduce
consumption; increase
reserves by improved
mining technology,
higher prices, and
new discoveries C
Present
Depletion
time A
Depletion
time B
Depletion
time C
Fig. 14.9, p. 329
Time

22. The big three US, Germany, and Russia Only 8% of the population
Use 75% of the most common metals
US uses 25% of the fossil fuels (cars)

23. Fig , p. 329

24. Ocean mining Will the ocean supply us with enough minerals?
They are there, but too expensive currently

25. Energy resources
99% of energy used to heat the earth and all the buildings comes from the sun
The sun also creates renewable energy resources – wind, flowing water, biomass

26. The rest The last 1% comes from fuel resources
Fossil fuels make up the vast majority
Petroleum, coal, and natural gas
A small portion also comes from nuclear sources

27. Oil and Natural Gas Coal Geothermal Energy Contour strip mining
Hot water
storage
Floating oil drilling
platform
Oil storage
Geothermal
power plant
Oil drilling
platform
on legs
Pipeline
Area strip
mining
Oil well
Pipeline
Mined coal
Drilling
tower
Gas well
Valves
Pump
Water
penetrates
down
through
the
rock
Underground
coal mine
Water is heated
and brought up
as dry steam or
wet steam
Impervious rock
Natural gas
Coal seam
Oil
Hot rock
Water
Water
Magma
Fig , p. 332

28. Shifts in energy usage worldwide
During the 20th century
Coal use dropped from 55 to 22%
Oil increased from 2 to 30%
Natural gas rose from 1 to 23%
Nuclear rose from 0 to 6%
Renewable (wood and water ) dropped from 42 to 19%

29. Way to go US The U.S. is the world’s largest energy consumer
We use 25% of the world’s energy (even though we only have 4.5% of the total population)
India with 17% of the population only uses 3% of the world’s commercial energy
91% of the U.S.’s energy in nonrenewable

30. Energy
Net energy refers to the amount of useful energy minus the energy needed to find, extract, process, concentrate, and transport to the users
Nuclear energy has a low net energy ratio because it is expensive to extract and process uranium, convert it into a fuel, build and operate the plant, and dismantle and deal with radioactive plants and waste

31. Oil, Oil everywhere and not a drop to drink
Extracted as crude oil or petroleum, a thick liquid consisting of hydrocarbons, and some sulfur, oxygen and nitrogen impurities
Produced from decayed plant and animal material over millions of years

32. Oil continued
Normally crude oil is not found in underground pools, but is spread out in the pores and cracks within rock deep beneath the ground
Primary recovery – drill a hole and pump out the light weight crude that fills the hole

33. Oil continued
Secondary recovery – pumping water into the well to force oil out of the pores
The oil and water mixture is separated after pumping
Only about 35% of the oil is removed by primary and secondary recovery

34. Oil continued
Tertiary recovery – either a heated gas or a liquid detergent is pumped into the well to help remove more oil
Tertiary is expensive

35. Oil continued
At the refinery oil is converted into petrochemicals and used as a resource to create industrial organic chemicals, pesticides, plastics, synthetic fibers, paints, medicines and more.
OPEC – organization of petroleum exporting countries control 67% of the worlds oil and maintain control over pricing

36. Gases Gasoline Aviation fuel Heating oil Heated crude oil Diesel oil
Naphtha
Grease
and wax
Furnace
Fig , p. 337
Asphalt

37. Advantages Disadvantages
Ample supply for
42–93 years
Need to find
substitute within
50 years
Low cost (with
huge subsidies)
Artificially low
price encourages
waste and
discourages
search for
alternatives
High net
energy yield
Easily transported
within and
between countries
Air pollution
when burned
Low land use
Releases CO2
when burned
Moderate water
pollution
Fig , p. 340

38. Oil continued
Oil shale is a fine grained sedimentary rock containing solid combustible organic material called kerogen
Shale oil is made from heating oil shale
Tar sand contains bitumen another combustible organic material
Both are more expensive than crude recovery

39. Advantages Disadvantages
Moderate existing
supplies
High costs
Low net energy
yield
Large potential
supplies
Large amount of
water needed to
process
Severe land
disruption from
surface mining
Water pollution
from mining
residues
Air pollution
when burned
CO2 emissions
when burned
Fig , p. 342

40. Natural Gas
Mostly CH4 methane with some ethane, propane and butane and small amounts of hydrogen sulfide (toxic)
LPG (liquefied petroleum gas) the propane and butane are removed from natural gas and stored under pressure

41. How long will it last?
Natural gas should last about 125 years worldwide
About 75 years in the US
Overall about years with rising prices, better technology, and more discoveries

42. Advantages Disadvantages
Ample supplies
(125 years)
Releases CO2
when burned
High net energy
yield
Methane
(a greenhouse
gas) can leak
from pipelines
Low cost (with
huge subsidies)
Shipped across
ocean as highly
explosive LNG
Less air pollution
than other
fossil fuels
Sometimes
burned off and
wasted at wells
because of low
price
Lower CO2
emissions than
other fossil fuels
Moderate environ-
mental impact
Easily transported
by pipeline
Low land use
Good fuel for
fuel cells and
gas turbines
Fig , p. 342

43. The future of power plants
There is currently being developed a combined cycle natural gas electric power plant with 60% efficiency
This is much better than 32-40% efficiency of others (coal, oil, nuke)
What other reasons make it better?

44. Coal
Solid fuel of combustible carbon, most formed million years ago
Peat – 1st, low heat content
Lignite – 2nd, low heat and low sulfur
Bituminous Coal – 3rd, high heat and abundant supply, high sulfur
Anthracite – 4th, high heat, low sulfur, limited supply

45. Increasing heat and carbon content Increasing moisture content
Peat
(not a coal)
Lignite
(brown coal)
Bituminous Coal
(soft coal)
Anthracite
(hard coal)
Heat
Heat
Heat
Pressure
Pressure
Pressure
Partially decayed
plant matter in swamps
and bogs; low heat
content
Low heat content;
low sulfur content;
limited supplies in
most areas
Extensively used
as a fuel because
of its high heat content
and large supplies;
normally has a
high sulfur content
Highly desirable fuel
because of its high
heat content and
low sulfur content;
supplies are limited
in most areas
Fig , p. 344

46. Coal for energy
Coal provides about 22% of the commercial energy in the world
It is used to create 62% of the worlds electricity
75% of the worlds steel
China is the largest user followed by US
US creates 52% of energy with coal

47. Advantages Disadvantages
Ample supplies
(225–900 years)
Very high
environmental
impact
High net energy
yield
Severe land
disturbance, air
pollution, and
water pollution
Low cost (with
huge subsidies)
High land use
(including mining)
Severe threat to
human health
High CO2
emissions
when burned
Releases
radioactive
particles and
mercury into air
Fig , p. 344

48. The cost of coal Land disturbance
Air pollution (especially sulfur dioxide)
Co2 emissions
Water pollution
Electricity production (coal) is the second largest producer of toxic emissions
The most deadly emission is mercury

49. Wonderful coal
60,000 babies annually are born with brain damage due to mercury exposure, typically from pregnant mothers eating mercury in fish
Coal also releases more radioactive particles into the atmosphere than nuclear power plants
Also, acid rain and methane release

50. Coal in the US
Air pollutants kill thousands (estimates are from 60,000 – 200,000)
Cause at least 50,000 cases of respiratory disease
Cost several billion dollars in property damage

51. The good news
Fluidized bed combustion is reducing the amount of pollution
Hot air is blown under a mix of crushed limestone and coal while it is burnt
This removes most sulfur dioxide, reduces Nox and burns the coal more efficiently and cheaply

52. Flue gases Coal Limestone Steam Fluidized bed Water Air nozzles Air
Calcium sulfate
and ash
Fig , p. 345

53. Coal gasification
Solid coal can be converted into synthetic natural gas (SNG)
It can also be made into synfuels (liquids) through coal liquefaction
Neither is expected to play a major role in our future energy needs

54. Raw coal Remove dust, tar, water, sulfur Recover sulfur Air or oxygen
Steam
Raw gases
Clean
Methane gas 2C
Coal + O2
2CO
Pulverizer
Recycle unreacted
carbon (char) CO +
3H2
CH4 +
H2O
Methane
(natural gas)
Slag removal
Pulverized coal
Fig , p. 345

55. Advantages Disadvantages
Large potential
supply
Low to moderate
net energy yield
Higher cost than
coal
Vehicle fuel
High
environmental
impact
Increased surface
mining of coal
High water use
Higher CO2
emissions than
coal
Fig , p. 346

56. Nuclear Energy
Uranium 235 and plutonium 239 are split (nucleus) to release energy
The reaction rate is controlled
The energy heats water and turns it to steam
Steam spins turbines connected to generators which create electricity

57. LWR light water reactors
All US reactors are of this type, so know it

58. Small amounts of Radioactive gases Uranium fuel input (reactor core)
Containment shell
Waste heat
Electrical power
Emergency core
Cooling system
Steam
Control
rods
Useful energy
25 to 30%
Turbine
Generator
Heat
exchanger
Hot coolant
Hot water output
Condenser
Pump
Pump
Coolant
Coolant
passage
Moderator
Cool water input
Black
Pump
Waste
heat
Pressure
vessel
Water
Shielding
Waste
heat
Water source
(river, lake, ocean)
Periodic removal
and storage of
radioactive wastes
and spent fuel assemblies
Periodic removal
and storage of
radioactive liquid wastes
Fig , p. 346

59. Nuclear is out of favor
The US has not ordered a new nuclear facility since 1978, and 120 ordered since 1973 were cancelled
Most countries are phasing out nuclear plants or are not continuing to expand their programs, except China who is trying to move away from dependence on coal

60. Why is nuclear not meeting expectations?
Multi-billion dollar cost of construction
Strict govt. safety regulations
High operating costs
More malfunctions than expected
Poor management
Public concern after Chernobyl, and Three Mile Island
Investor concern about economic feasibility

61. Advantages Disadvantages
Large fuel
supply
High cost (even
with large
subsidies)
Low
environmental
impact (without
accidents)
Low net
energy yield
High
environmental
impact (with major
accidents)
Emits 1/6 as
much CO2 as coal
Moderate land
disruption and
water pollution
(without
accidents)
Catastrophic
accidents can
happen
(Chernobyl)
Moderate land use
No acceptable
solution for
long-term storage
of radioactive
wastes and
decommissioning
worn-out plants
Low risk of
accidents
because of
multiple
safety systems
(except in 35
poorly designed
and run reactors
in former Soviet
Union and
Eastern Europe)
Spreads
knowledge and
technology for
building nuclear
weapons
Fig , p. 349

62. Coal Nuclear Ample supply Ample supply of uranium High net energy
yield
Low net energy
yield
Low air pollution
(mostly from fuel
reprocessing)
Very high air
pollution
High CO2
emissions
Low CO2
emissions
(mostly from fuel
reprocessing)
65,000 to 200,000
deaths per year
in U.S.
About 6,000
deaths per
year in U.S.
High land
disruption from
surface mining
Much lower land
disruption from
surface mining
High land use
Moderate land
use
Low cost (with
huge subsidies)
High cost (with
huge subsidies)
Fig , p. 349

63. Chernobyl
In the former Soviet Union, April 26, 1986 the reactor core went out of control and exploded sending a cloud of radioactive dust into the atmosphere
3,576 – 32,000 people died
400,000 forced to evacuate
62,000 square miles still contaminated
More than 500,000 people exposed to high level radiation
Cost the govt. $385 billion

64. Three Mile Island March 29, 1979 in Harrisburg, Penn.
Coolant failed and core melted
Radioactive material escaped into air
50,000 people evacuated
Luckily the radiation release was believed to be too low to cause death or cancer
Cleanup has cost $1.2 billion so far

65. What do we do with the waste?
Low level radioactive waste must be stored for years until it reaches a safe level (does not give off harmful ionizing radiation)
This was done by sealing the waste in steel drums and dumping it in the ocean
Today some countries (US) stores the waste at govt. run landfills, but no one wants to live anywhere near them

66. Waste container 2 meters wide 2–5 meters high Several steel drums
holding waste
Steel wall
Steel wall
Lead shielding
Fig a, p. 351

67. Up to 60 deep trenches dug into clay. As many as 20 flatbed trucks
deliver waste
containers daily.
Barrels are stacked
and surrounded
with sand. Covering
is mounded to aid
rain runoff.
Clay bottom
Fig b, p. 351

68. And the bad stuff?
High level radioactive waste must be stored for 10,000 to 240,000 years until it reaches a safe level
Currently most is stored at the reactor site, sealed in drums, in pools of water

69. Proposed methods of disposal
Bury deep underground – this is the leading strategy currently
Shoot it into space/Sun
Bury it deep in the Antarctic ice sheet
Dump it into descending subduction zones
Bury in deep mud deposits on ocean floor
Convert into less harmful isotopes (currently we do not have the technology)

70. Fig a, p. 352

71. Radioactive contamination
The EPA suggests that there are 45,000 sites in the US (20,000 belong to the DOE)
It is expected to cost over $230 billion over the next 75 years
More than 144 highly contaminated weapons construction sites will never be completely cleaned