Transcript Document
Mineral Resources Mr. Clark BHS Mineral Resources Types of mineral resources Finding and extracting mineral resources Mineral Resources Metallic Non-metallic Energy resources Ores Categories of Mineral Resources Identified Resources Undiscovered Resources Reserves Other Locating Mineral Resources Satellite and air imagery Radiation detectors Magnetometers Gravity differences Seismic surveys Chemical analyses Extracting Mineral Resources: Surface Mining Open-pit mining Dredging Area strip mining Contour strip mining Extracting Mineral Resources: Underground Mining Underground mining or subsurface mining Room-and-pillar mining Longwall mining Surface Mining Control and Reclamation Act Surface Mining Control and Reclamation Act was established 1977 Mine lands must be restored to premining conditions Taxes on mining companies to restore pre-1977 sites Limited success Environmental Effects of Mining Mineral Resources Disruption of land surface Subsidence Erosion of solid mining waste Acid mine drainage (AMD) Air pollution Storage and leakage of liquid mining waste Environmental Effects of Mining Mineral Resources Fig. 16-14 p. 344 Environmental Impacts of Mining Mineral Resources Surface mining Subsurface mining Overburden Room and pillar Spoil Longwall Open-pit Dredging Strip mining Refer to Figs. 15-4 and 15-5, p. 341 and 342 Processing Mineral Resources Ore mineral Gangue Tailings Smelting Smelting Separation of ore from gangue Melting metal Metal ore Conversion to product Recycling Discarding of product Surface mining Scattered in environment Supplies of Mineral Resources Economic depletion Depletion time Foreign sources Environmental concerns Economics New technologies Mining the ocean Finding substitutes Open Pit Mine Dredging Area Strip Mining Contour Strip Mining Ventilation shaft Main shaft Lift cage Shaft Coal seams Pumps Underground Coal Mine Room-and-pillar Longwall Mining of Coal Transition from Peat to Lignite to Bituminous to Anthracite U. S. Coal Deposits Yellow = Anthracite Blue = Sub Bituminous Orange = Bituminous Green = Low Volatile Bituminous Purple = Lignite Major Coal fields in USA Canadian Coal Deposits Strip Mining for Coal Open Pit and Spoil Bank Strip Mine and Reclaimed Land Coal Drag Line World’s Largest Open Pit Copper Mine- Bingham Mine, Utah Open Pit Gold Mine - Nevada Bingham Canyon Mine and Tailings, Utah Bingham Canyon Open Pit Copper Mine Shovel and Truck Trucks at Crusher Shovel and Truck Ore Being Delivered to Crusher for Transport to Smelter 5 Miles Away Tailings Piles – Bingham Mine Mine Tailings Underground Coal Mine Sterling Hill Zinc Mine, Franklin, New Jersey Knox Mine Before Disaster Room and Pillar Mine Sink Hole – Cargill, Kansas Sink Hole Cross Section of Sink Hole Smelting At 500 C 3Fe2O3 +CO -> 2Fe3O4 + CO2 Fe2O3 +CO -> 2FeO + CO2 At 850 C Fe3O4 +CO -> 3FeO + CO2 At 1000 C FeO +CO -> Fe + CO2 At 1300 C CO2 + C -> 2CO At 1900 C C+ O2 -> CO2 FeO +C -> Fe + CO Blast Furnace Charcoal Blast Furnace Slag Being Dumped Slag the Next day Gold and Silver Mine Tailings Central City, Colorado Clayton Silver Mine, Idaho Acid Mine Drainage – Eastern Pennsylvania Acid Mine Drainage in Colorado Acid Mine Drainage Chemistry Chemical reactions that represent the chemistry of pyrite weathering to form Acid Mine Drainage (AMD). An overall summary reaction is as follows: 4 FeS2 + 15 O2 + 14 H2O 4 Fe(OH)3 + 8 H2SO4 Pyrite + Oxygen + Water "Yellowboy" + Sulfuric Acid Acid Mine Drainage Chemistry Weathering of pyrite includes the oxidation of pyrite by oxygen. Sulfur is oxidized to sulfate and ferrous iron is released. This reaction generates two moles of acidity for each mole of pyrite oxidized. 2 FeS2 + 7 O2 + 2 H2O 2 Fe2+ + 4 SO42- + 4 H+ Pyrite + Oxygen + Water Ferrous Iron + Sulfate + Acidity Acid Mine Drainage Chemistry The conversion of ferrous iron to ferric iron consumes one mole of acidity. Certain bacteria increase the rate of oxidation from ferrous to ferric iron. 4 Fe2+ + O2 + 4 H+ 4 Fe3+ + 2 H2O Ferrous Iron + Oxygen + Acidity Ferric Iron + Water Centralia Fires Rt. 61 into Centralia, Pa. Centralia Fires Still Burning Underground Copper Basin, Tennessee Copper Basin, Tennessee Copper Basin, Tennessee Copper Mine Abandoned Mine Entrance - Alaska Before Reclamation After