minerals and mining

Minerals and Mining Minerals • Concentration of naturally occurring elements in/on Earth • Formed over millions of yrs  non-renewable resource What We Mine?!? • Metallic minerals: Iron, Copper, Aluminum • Non-metallic minerals: salt, clay, sand • Energy minerals: coal, oil, uranium Crushed Iron Sodium Chloride Crystal “Dur”rty Coal Ore • Rock that has metallic mineral • Usable stuff is the mineral • Non-usable is called gangue  landfill Gold Gangue Smelt ers • Used to remove mineral from gangue in an ore  major polluters (Runescape!) Bauxite Most Important Aluminum Ore Oxygen: The Most Abundant Element in the Earth’s Crust Finding Mineral Deposits • Use aerial photos and satellite images to see rock formations Finding Mineral Deposits • Use planes w/ Geiger meter (uranium) or magnetometer (iron) Geiger Meter… Only $460! Magnetometer… Only $700! Case Study Gold: Cyanide Heap Leaching • Cyanide sprayed on low grade gold ore in a giant heap (pile) • Gold flows down w/ cyanide and is collected at bottom of heap Heap Case Study Gold: Cyanide Heap Leaching • Toxic to birds and mammals • Leach ponds can overflow  H2O pollution • Leaky liners? Leach Liner Subsurface Mining • Used to remove minerals deep in Earth’s surface • Less env Impact Types of Subsurface Mining • Room and Pillar • Machines are used to cut out minerals and are placed on a shuttle car Scraper Types of Subsurface Mining • Longwall Coal Mining • Moveable steel props support cave while machinery cut off coal onto a conveyor belt Environmenta l Damage • Collapse/subsidence of land from subsurface mines • Causes houses to tilt, sewer lines crack, gas mains break Environmenta l Damage • Wind/water carry away [by erosion] toxic mining waste • Goes in food webs and watersheds Environmenta l Damage Habitat Loss!! My Home!!! Environmenta l Damage • Transportation of minerals  global warming, lung probs Environmenta l Damage Acid mine drainage • Bacteria eat FeS in spoil  create H2SO4  runs off into streams Surface Mining Reclamation and Control Act • Mining ops must reclaim area after land has been used and abused • Must put aside $$$ to reclaim before mining op’s begin • States oversee Act • Land put back, trees grow, no toxic runoff! [...]... Drilling a deep well and extracting ore samples Exploration Drilling Surface Mining • Minerals must be shallowly deposited • Removed rock and soil is called overburden or spoil Types of Surface Mining Open Pit Mining • Dig hole and remove ores • Fe, Cu, and Sand Types of Surface Mining Dredging (Sand) • Draglines scrape up underwater mineral deposits Types of Surface Mining Area Strip Mining • Cut new... Subsurface Mining • Used to remove minerals deep in Earth’s surface • Less env Impact Types of Subsurface Mining • Room and Pillar • Machines are used to cut out minerals and are placed on a shuttle car Scraper Types of Subsurface Mining • Longwall Coal Mining • Moveable steel props support cave while machinery cut off coal onto a conveyor belt Environmenta l Damage • Collapse/subsidence of land from... erosion] toxic mining waste • Goes in food webs and watersheds Environmenta l Damage Habitat Loss!! My Home!!! Environmenta l Damage • Transportation of minerals  global warming, lung probs Environmenta l Damage Acid mine drainage • Bacteria eat FeS in spoil  create H2SO4  runs off into streams Surface Mining Reclamation and Control Act • Mining ops must reclaim area after land has been used and abused... taken out Types of Surface Mining Mountaintop Removal • Use TNT, huge shovels, and large machines to remove top of a mtn and expose coal underneath Case Study Gold: Cyanide Heap Leaching • Cyanide sprayed on low grade gold ore in a giant heap (pile) • Gold flows down w/ cyanide and is collected at bottom of heap Heap Case Study Gold: Cyanide Heap Leaching • Toxic to birds and mammals • Leach ponds... H2SO4  runs off into streams Surface Mining Reclamation and Control Act • Mining ops must reclaim area after land has been used and abused • Must put aside $$$ to reclaim before mining op’s begin • States oversee Act • Land put back, trees grow, no toxic runoff!