More Related Content
What's hot
What's hot (20)
Viewers also liked
Viewers also liked (9)
Similar to Lecture 11
Similar to Lecture 11 (20)
More from RayF42
Recently uploaded
Recently uploaded (20)
Lecture 11
- 1. Mineral and Energy Resources The Blue Planet: Chapter 18
- 2. Outline • Nonrenewable Resources • Mineral Resources • Energy Resources
- 3. Nonrenewable Resources • Conserving nonrenewable resources and minimizing the impacts of their use involves closing the resource cycle • Waste is generated at every stage of the resource cycle • Recycling refers to the extraction of usable raw materials from waste products • Leakage in the resource cycle occurs at the post-consumer stage
- 5. Outline • Nonrenewable Resources • Mineral Resources • Energy Resources
- 6. Mineral Resources • Mineral resources are used to make clothes, build shelters, fertilize crops, provide transportation, distribute electric power, and communicate electronically • We have uses for almost all naturally occurring chemical elements and more than 200 different minerals are mined
- 8. Mineral Resources • Geochemically abundant elements – Make up more than 0.1% of Earth’s crust – Only 12 of the 92 naturally occurring elements • Geochemically scarce elements – Make up less than 0.1% of Earth’s crust
- 9. Mineral Resources • Metallic minerals are mined specifically for the metals that can be extracted by smelting – Sphalerite (zinc), galena (lead) • Nonmetallic minerals are mined for their chemical or physical properties they have, not the metals they contain – Clay, gravel, salt, gems
- 10. Mineral Resources • Mineral resources are mined from concentrations that formed under suitable conditions by geologic processes – Weathering, sedimentation, volcanism • Suitable conditions are rare, and may take millions of years to form a deposit • Intensive mining, depletion, declining production and dependence on imports can be applied on a local, regional or global scale to estimate the remaining lifetime of a mineral resource
- 11. Mineral Resources • Today the favorable geologic locations for mineral exploration have mostly been prospected, assessed, and mined
- 12. Mineral Resources • A geologic process or combination of processes must produce a localized enrichment of minerals for a mineral deposit to form 1. Hydrothermal solutions 2. Metamorphic or magmatic processes 3. Chemical sedimentary processes 4. Action of waves or currents 5. Weathering
- 15. Mineral Resources • Hydrothermal ore deposits – Hot, aqueous, metal-saturated fluids that react chemically with the crust rock – Most mineral deposits – Primary sources of metals – Veins – Stratabound mineral deposits
- 17. Mineral Resources • Metamorphic ore deposits – Alteration and recrystallization • Magmatic ore deposits – Fractional crystallization – Pegmatites – Kimberlite pipes
- 19. Mineral Resources • Sedimentary ore deposits – Concentration by sedimentation • Precipitation by seawater or lake water – Evaporation • Evaporite deposits – Biochemical reactions • Banded iron formations
- 20. Mineral Resources • Placer ore deposits – Heavy mineral grains concentrated by sifting or winnowing by flowing water
- 21. Mineral Resources • Residual ore deposits – Chemical weathering – Removes soluble materials first, leaving a concentrated layer of insoluble minerals behind – Dissolved materials carried by water may be deposited in one concentrated layer – Laterites
- 23. Mineral Resources • Mining – Set of processes whereby useful resources are withdrawn from the stock of nonrenewable resource • Extraction of mineral resources – Sequential land use is the concept of mining and then restoring the land to its former state for use by other purposes
- 24. Mineral Resources • Mining – Prospecting or exploration • An area is assessed for potential – Extraction – Milling • Ore is crushed and concentrated • Waste is discarded as tailings – Postoperational phase • Mine is closed, tailings are contained and monitored: minesite decomissioning
- 26. Mineral Resources • Impacts of mining – Geosphere • Open pit mines and strip mines are destructive to the land • Abandoned subsurface mines are susceptible to subsidence • Construction of mine roads, buildings and tailings piles impact wilderness
- 28. Mineral Resources • Impacts of mining – Atmosphere • Smelting and refining emit pollutants: – Particulates – NOx SOx - can cause acid precipitation – Vaporized metals – Volatile organic compounds • Blowing dust from tailings piles
- 29. Mineral Resources • Impacts of mining – Hydrosphere • Liquid waste (effluent) generated during milling • Acid mine drainage from water interacting with sulfide minerals in tailings
- 31. Mineral Resources • Impacts of mining – Biosphere and human health • Acid mine drainage on ecosystems • Black lung disease, cancer • Coal dust explosions • Mine collapse
- 32. Outline • Nonrenewable Resources • Mineral Resources • Energy Resources
- 33. Energy Resources • Includes food energy and sources of energy used to sustain the activities and structures of modern society – Fossil fuels – Alternative energy sources • Hydroelectic • Nuclear • New renewables
- 34. Energy Resources • Earth’s energy comes from three sources – Solar radiation – Geothermal energy – Tidal energy • Circulates through the pathways and reservoirs of Earth’s energy cycle • All energy for human use is derived from the circulating energy in this cycle
- 35. Energy Resources
- 36. Energy Resources
- 37. Energy Resources
- 38. Energy Resources • Fossil fuels - hydrocarbons – Coal – Oil – Natural gas – Peat • The main source of commercial energy worldwide today • Consist of altered organic matter from the remains of plants or animals, trapped in sediment or sedimentary rock
- 39. Energy Resources • Coal – Solid fossil fuel derived from terrestrial organic matter – Peat forms in water-saturated places such as swamps and bogs – Coal forms from peat over millions of years in a process called coalification • Lignite, subbituminous, and bituminous coal
- 40. Energy Resources
- 41. Energy Resources
- 42. Energy Resources
- 43. Energy Resources • Oil and Natural Gas - petroleum – Naturally occurring gaseous, liquid, and semi-solid substances that formed in a marine environment – During burial and conversion to rock, organic compounds are chemically transformed into petroleum: maturation – Without a trap, petroleum would migrate away, escaping, and not be mine-able
- 44. Energy Resources
- 45. Energy Resources
- 46. Energy Resources
- 47. Energy Resources
- 48. Energy Resources
- 49. Energy Resources • Unconventional hydrocarbons – Tar sands: deposits of dense, thick, asphalt-like oil called tar – Oil shale: a wax-like compound called kerogen in fine-grained sedimentary rocks – Gas hydrates: deposits of frozen methane in permafrost and seafloor sediments
- 50. Energy Resources
- 51. Energy Resources • Alternative energies to fossil fuels – Solar, hydrogen, and biomass – Wind and wave – Hydroelectic, tidal, and geothermal – Nuclear
- 52. Energy Resources • Solar energy and hydrogen – Can be used to supply heat • Passive or active solar heating – Can be converted into electricity through • Solar thermal electric generation • Photovoltaic cells – Can be used to split water into hydrogen and oxygen: electrolysis • Generates hydrogen for fuel cells
- 53. Energy Resources
- 54. Energy Resources • Biomass energy – Derived from Earth’s plant life • Fuel wood – 1 billion + people use this for cooking and heat • Peat • Animal dung – Converted into methane produces biogas • Agricultural waste – Methane gas can be collected from landfills – Can be converted into the liquid fuels ethanol and methanol
- 55. Energy Resources
- 56. Energy Resources • Wind energy – An indirect expression of solar energy – Will soon be cost-competitive with coal- burning power plants – However existing power grids will not be able to bring electricity from production sites to where it will be used
- 57. Energy Resources
- 58. Energy Resources • Wave energy – Also an indirect expression of solar energy – Small-scale power stations produce electricity using a hollow, tubelike chamber containing a turbine – Waves push air into the chamber, spinning the turbine, generating electricity
- 59. Energy Resources • Hydroelectric energy – Generated from the energy of a stream of water flowing downhill – The only form of water-derived energy that currently fulfills a significant portion of the world’s energy needs – Unfortunately, to generate hydroelectric power, it is necessary to build a dam
- 60. Energy Resources • Tidal energy – Also water and gravity based energy – A dam is constructed across the mouth of a narrow bay, water flows in during high tide and out during low tide – When water is released at low tide, it drives a turbine, producing electricity
- 61. Energy Resources
- 62. Energy Resources • Geothermal energy – Hot rocks can be used to heat water – Volcanically produced steam can turn a turbine to generate electricity – Hydrothermal reservoirs, 200˚C or hotter, are most easily and efficiently exploited – Ground source heat pumps use small temperature differences between the ground surface and the shallow subsurface
- 63. Energy Resources • Nuclear energy – Comes from the heat energy produced during the induced transformation of a chemical element into other chemical elements – Can be generated two ways • Fission: splitting heavy atoms into lighter atoms • Fusion: joining together of two small atoms to create a single larger atom - like the Sun - but not available with our current technology
- 64. Energy Resources
- 65. Energy Resources • Nuclear energy – Uranium-235 is primarily used as fuel in nuclear fission reactors • Packed into fuel rods – Current nuclear reactor technologies are designed to eliminate meltdowns – Considered clean energy because there are no harmful atmospheric emissions • However, highly radioactive nuclear waste must be isolated from the bio- and hydrosphere
- 66. Energy Resources
- 67. Energy Resources • We need to find sources of energy for the future that will meet society’s needs in a way that is socially, environmentally, and economically acceptable • Fossil fuels cause environmental impacts at every stage from extraction, refining, transport, and usage
- 68. Energy Resources
- 69. Energy Resources • Increasing concerns about fossil fuel use will inevitably lead to greater interest in alternative sources of energy • In the meantime, fossil fuel prices are encouraging interest in energy efficiency
- 70. Energy Resources