Mining & Non Renewable Resources

Transcription

1 Mining & Non Renewable Resources

2 Mineral Resources Can be extracted from the Earth s crust & processed into raw materials and products Two Types: 1.Metallics Aluminum Gold 2.Non metallics Sand Limestone

3 Removing Mineral Deposits Surface mining Subsurface mining

4 Surface Mining Removal of shallow mineral deposits by removing materials overlying a deposit to expose resource Types: Open pit Strip mining Contour strip mining Mountaintop removal Type used depends: Resource Local topography

5 Open Pit Machines dig large holes to remove metal ores as well as sand, gravel, & limestone

6 Strip Mining Useful & economic way to remove mineral deposits that lie in horizontal Overburden from one layer is used to fill the void from resource removal Next cut is made parallel to the previous

7 Contour Strip Mining Huge power shovels and bulldozers cut a series of terraces into the side of a hill Usually coal Mountains/hills Left with highly erodible bank

8 Mountain Top Removal Explosives, earth movers, & large power shovels are used to remove the top of a mountain and expose seams of coal Appalachian Mountains

9 Mountain Top Removal

10 Subsurface Mining Underground mineral resources are removed through tunnels and shafts Less waste

11 Mining: Harmful Environmental Effects Scarring and disruption of land No topsoil, chemical weathering, erosion Mountain top removal Loss of rivers & streams Air pollution Groundwater contamination Arsenic & Mercury Biodiversity loss Clearing forest Pollution

12 Mining: Harmful Environmental Effects Subsurface mining Subsidence Acid mine drainage Rainwater seeping through mine picks up sulfuric acid Major pollutant of water and air Large amounts of solid waste ¾ of US solid waste

13 Life Cycle of a Metal Resource

14 Smelting Harmful Effects of Removing Ores Using heat or chemicals to remove mineral from its ore Air & Water Pollution Liquid & Solid hazardous waste Cyanide salts used to extract gold

15 Non Renewable Energy

16 Energy Use: World & US

17 1 st Law of Thermodynamics When energy is converted from one form to another in a physical or chemical change, no energy is created or destroyed

18 2 nd Law of Thermodynamics Whenever energy is changed from one form to another, we end up with lower-quality or less usable energy than we started with

19 Net Energy Total amount of useful energy available from a resource minus the energy needed to make the energy available to consumers Net Energy Ratio Ratio of energy produced to energy used to produce it Ex: Producing corn into ethanol that gives you 10 units of energy but it took 9 units of energy to produce it 10/9 = 1.1 units Higher ratio = higher energy output Below 1 = energy loss

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21 Energy Waste 84% of all commercial energy used in the U.S. is wasted 43% after accounting for second law of thermodynamics Energy Efficient Buildings Energy Efficient Cars

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23 Petroleum 1/3 of commercial energy 40% US Rapid increase since 1950

24 Oil Reserves

25 Proven oil reserves Oil Reserves Identified deposits that can be extracted profitably with current technology Unproven reserves Probable reserves: 50% chance of recovery Possible reserves: 10-40% chance of recovery Proven and unproven reserves will be 80% depleted sometime between 2050 and 2100

26 Issues with US Future Oil Potential reserves are not proven reserves Must use net energy yield to evaluate potential of any oil deposit Must take into account high global use of oil

27 Arctic Oil

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29 Coal Solid fossil fuel Organism remains exposed to heat & pressure for billion years 42% of world s electricity 46% in US

30 Coal World s most abundant fossil fuel US has most with 28%

31 Environmental Effects of Coal Coal is the dirtiest fossil fuel Land degradation Mining Air pollutants Sulfur dioxide Soot Carbon dioxide Trace radioactive materials

32 Coal Ash Highly toxic chemicals left from burning & emissions Most buried or put in ponds 2008 Kingston, TN spill Equivalent of 300 football fields Destroyed 40 homes & buildings Tainted waterways & soil Cleaned up April 2015

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34 Natural Gas Mixture of gas 50-90% methane Found mostly in Russia & Iran Benefits: ½ CO2 1 / 3 NOx Less SOx Methane:70x more powerful greenhouse gas

35 Fracking Technique to fracture rocks using pressurized chemically treated water (sometimes sand) to allow natural gas & petroleum to flow more freely First success

36 Fracking Environmental Impacts Constructions of drilling equipment Chemical Waste Groundwater contamination Flowback water management Water demands Air pollution Methane & VOCs Earthquakes

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38 Nuclear Power

39 Nuclear Energy Uranium ½ life million years Must store after use # of Half Lives Elapsed Percentage Remaining

40 Nuclear Fuel Cycle Mine Uranium Process Uranium Use in reactor Safely store waste Decommission reactor

41 TVA Nuclear Facilities Brown s Ferry Watt s Bar Sequoyah Red Hydroelectric Yellow Coal Burning Purple - Nuclear

42 U.S. Nuclear Facilities

43 World Nuclear Facilities

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45 Decline in Nuclear Power Cost Disposal Good where fossil fuels are limited 75% France s energy needs

46 Three Mile Island 1979 Pennsylvania Low amount of radioactive release No detectable health effects Aftermath brought important changes in safety measures

47 Chernobyl 1986 Ukraine Explosions caused a reactor roof to blow Partial meltdown & burn for 10 days Effects Estimated 32,000 deaths (premature) 62,000 square mile contamination $400 billion

48 Fukushima 2011-Japan Tsunami caused meltdown of 3 out of 6 reactors

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