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Lecture 8

Lecture 8. Energy and Minerals. Mineral. A mineral is any naturally occurring inorganic substance or element found in the Earth’s crust The word rock refers to solid mineral deposits

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Lecture 8

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  1. Lecture 8 Energy and Minerals

  2. Mineral • A mineral is any naturally occurring inorganic substance or element found in the Earth’s crust • The word rock refers to solid mineral deposits • An ore is rock that contains a large proportion of a particular mineral, making it profitable for mining or extraction.

  3. Formation of Rocks Rocks are classified based on their method of formation: • Igneous rocks are formed due to intense heat and are associated with volcanic activity • Sedimentary rocks are formed by settling and fusing of sediments • Metamorphic rocks are formed by transformation due to pressure, heat and water.

  4. Types of minerals • Metals are minerals e.g. iron, aluminium and copper, which are malleable, lustrous and good conductors of heat and electricity. • Non-metallic minerals lack these characteristics e.g. sand, stone, salt and phosphates.

  5. Uses of Minerals • many can be extracted & converted into useful materials For example: - aluminium is used to make cars & airplanes - steel is an essential building material - copper is used for electrical & communication wiring - sulfur is used to make plastics & refine oil

  6. Mineral • Mineral resources are deposits of minerals in such quantities and of a particular grade that there are reasonable prospects for economic extraction. • Mineral reserves are mineral deposits that are profitable to extract • A country’s mineral reserves is only a part of its total mineral resources

  7. Jamaica’s Bauxite Resources Total Reserves estimated at 2 billion tons

  8. Mining - the various processes whereby minerals are extracted The 2 main types of mining are: • Sub-surface Mining • Surface Mining

  9. Mining • Sub-surface Mining - extraction of a metal ore or fuel resource from a deep underground deposit • Surface Mining - removal of soilbeforeextracting a mineral deposit found fairly close to the earth’s surface

  10. Mining Overburden - layer of soil and rock overlying mineral deposit - removed during surface mining

  11. Types of Surface Mining • Open-pit mining • Dredging • Strip mining

  12. Types of Surface Mining Open-pit Mining - machines dig holes and remove ores, e.g., iron, copper, bauxite

  13. Types of Surface Mining • Dredging - chain buckets and draglines scrape up underwater mineral deposits

  14. Types of Surface Mining • Strip Mining - surface mining in which bulldozers, power shovels, or stripping wheels remove the overburden in strips - used mostly for removing coal and some phosphate rock

  15. Types of Sub-surface Mining • Shaft Mine • Slope Mine

  16. Types of Sub-surface Mining • Shaft Mine - a direct vertical shaft to the vein of the ore - the ore is broken up underground, then hoisted through the shaft through the surface in buckets

  17. Types of Sub-surface Mining • Slope Mine - has a slanting passage that makes it possible to haul the broken oreout of the mine in cars

  18. Environmental Implications of Bauxite Mining in Jamaica Extraction    - Mining involves deforestation Removal of top soil - Noise pollution - Dust pollution

  19. Environmental Implications of Bauxite Mining in Jamaica Cont’d Deforestation - Habitat destruction - Soil erosion - Sedimentation of rivers - Smothering of aquatic habitats

  20. Bauxite Mining in Jamaica Cont’d • Legislation • - Mining Act of 1947. • Top soil should be removed before mining and restored as part of the reclamation process • Soil less capable of retaining water. Only tree crops and pasture feasible

  21. Processing Bauxite This involves smelting – melting the ore at high temperatures to help separate impurities from the molten metal. If air pollution control devices are not installed, many dangerous gases are emitted during smelting.

  22. Environmental Implications of Bauxite Mining in Jamaica Cont’d Processing - Processing and disposal of minerals pollute the air, soil and water. - Rio Cobre polluted to the point where fish kills observed - Air pollution implicated in roof damage, fence damage

  23. Environmental Implications of Bauxite Mining in Jamaica Cont’d Bauxite and Alumina dust - Causes respiratory problems - Affects coral reefs due to spillage at ports - Defaces property

  24. Environmental Implications of Bauxite Mining in Jamaica Cont’d Solutions - Construct marshes or ponds downstream from mines. - When a mine is abandoned, the land can be reclaimed, or restored to semi-natural conditions - New disposal method for red mud - Install pollution control devices to smelters

  25. Bauxite Mining in Jamaica Cont’d • Legislation • - NRCA Air Quality Regulations 2002. • Companies apply for permit to emit air pollutants • Yearly reports to NEPA

  26. Fossil Fuel • Product of partial or completedecomposition of plants and animals that occur as crude oil, coal, natural gas, or heavy oils • Formed as a result of exposure to heat and pressure in the earth’s crust over millions of years • non-renewable, exhaustible resource

  27. Fossil Fuel LNG (Liquid Natural Gas) • Natural gas is 90% methane • LNG is easier to store and transport • Landfills are a renewable source • Environmentally friendly (Less sulphur and nitrogen compounds and ash)

  28. Nuclear Energy - energy released when atomic nuclei undergo a nuclear reaction, such as nuclear fission or nuclear fusion

  29. Nuclear Energy cont’d Nuclear Fission - nuclear change in which the nuclei of atoms are split apart - releases a large amount of energy

  30. Nuclear Energy cont’d Nuclear Fusion - nuclear change in which two nuclei are forced together - releases a large amount of energy

  31. Nuclear Power & the Caribbean • as small nuclear plants become more efficient and more cost-effective, this source of power could be considered an option for larger Caribbean countries • construction was halted on Cuba’s nuclear plant • nuclear power could economically give optimal value to Jamaican bauxite

  32. Alternate Energy Sources Renewable energy sources are sources of energy that are replenished by natural processes so that they can be used indefinitely. They include: Direct Solar Energy, Wind Energy, Hydropower, Ocean Thermal Energy, Geothermal Energy and Tidal Energy.

  33. Geothermal Energy • heat contained in underground rocks and fluids • heat transferred from the earth’s underground concentrations of dry steam, wet steam, or hot water trapped in rock • wells can be drilled to extract the steam or water • ~ 20 countries using geothermal energy

  34. Geothermal Energy & Caribbean States • utilised for power production in Guadeloupe • many Caribbean islands, e.g., St Lucia, Dominica, Montserrat, have potential • 35 hot springs identified in Jamaica • investment risks for geothermal exploration in developing countries is considered high

  35. Alternate Energy Sources • Renewable energy sources account for only 4% of energy mix. • Projected to reach 12% by 2020 • Wigton wind farm commissioned in May 2004 • 23 wind turbines of 20.7 MW capacity avg 7 MW

  36. Solar Energy • considered a renewable resource • direct radiant energy from the sun and a number of indirect forms of energy produced by the direct input

  37. Solar Energy & Caribbean States • ~ 3,500 solar water heaters installed in Jamaica (2002) • ~ 34,000 solar water heaters installed in Barbados (2002) • economic incentives should be provided to increase solar power use • all water heaters should be solar

  38. Energy Conservation Energy conservation is moderating or eliminating wasteful or unnecessary energy-consuming activities. Energy efficiency is using technology to accomplish a particular task with less energy.

  39. Energy Conservation

  40. Energy Conservation To calculate energy use for appliances use the following equation: Wattage Hrs Used per Day = Daily KWh consumption              1000(1 kilowatt (kW) = 1,000 Watts)

  41. National Energy Policy • The application of new technologies such as a cycle gas turbine. • Renewable energy production of electricity supplies should be increased from about 5% to 15 % by 2012. • Expansion of higher cost energy efficiency measures, such as solar water heaters and photovoltaic solutions. • The provision of increased tax incentives so as to ensure higher investments in energy efficiency.

  42. National Energy Policy Cont’d • NHT has the authority to introduce loans to improve solar water heater and photovoltaic systems • Tourism as one of the pillars of the economy. • The formulation of higher environmental standards by Petrojam. • The new coal plant is to incorporate clean coal technologies.

  43. Waste Management Solid Waste - Any unwanted or discardedmaterial that is not a liquid or a gas - It is estimated that approximately 1 billion tonnes of waste is generated across the island annually. - 70% collected - Half is generated in the Riverton wasteshed.

  44. Types of Solid Waste • Municipal Solid Waste - solid materials discarded by homes and businessesin or nearurban areas • Non-municipal Waste - includes waste from mining, agriculture, industry

  45. There are 4 ways to get rid of solid wastes: • dump • bury • burn • recycle

  46. Open Dumps • unsanitary • malodorous • methane gas released as wastes decompose • fire pollutes air with acrid smoke • hazardous wastes leach into groundwater

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