330 likes | 645 Views
CHAPTER 23 . MINERALS & MINING. MINERALS & MINING. A RESOURCE MINING METHODS ENVIRONMENTAL IMPACTS SUSTAINABILITY. BACK TO GEOLOGY, ROCK CYCLE, LITHOSPHERE. ROCK: “A solid aggregation of minerals.”
E N D
CHAPTER 23 MINERALS & MINING
MINERALS & MINING • A RESOURCE • MINING METHODS • ENVIRONMENTAL IMPACTS • SUSTAINABILITY
BACK TO GEOLOGY, ROCK CYCLE, LITHOSPHERE • ROCK: “A solid aggregation of minerals.” • MINERAL: “Naturally occurring solid chemical element or (inorganic) compound having well-defined crystalline structure, specific composition, and distinct physical properties.”
Eg., Tantalite • Tantalum, Oxygen, Iron, Manganese • Tantalum: electronics • Occurs in pegmatite(igneous rock), along with: feldspar, quartz, mica and occasionally gemstones.
METALS ARE MINED FROM “ORES” • ORES: METALS IN MINERAL FORM • Copper • Iron • Lead • Gold • Aluminum
ALUMINUM: NO Al, NO AIR TRAVEL, NO AIRLINES, NO AIR DEFENSE.....
MINING METHODS • STRIP MINING • SUBSURFACE MINING • OPEN PIT • MOUNTAINTOP REMOVAL
STRIP MINING • EFFICIENT FOR SHALLOW MINERALS • REMOVE UPPER LAYERS • COMMON FOR COAL • ENVIRONMENTALLY DISASTOROUS • Severe community disturbance! • Erosion! • Acid drainage: exposed sulfides + O2 + rainwater = H2SO4 • Acid promotes heavy metal leaching
SUBSURFACE MINING • TRADITIONAL • Zn, Pb, Ni, Sn, Au, Cu, U • Diamonds • MINERALS DEEP UNDERGROUND • DANGEROUS!
OPEN PIT • MINERALS SPREAD EVENLY • SOILS UNSUITABLE FOR TUNNELING • DIG GIGANTIC HOLE
One open pit mine One Utah mine is 2.5 mi across and 0.75 mi deep; almost half a million tons of ore and rock are removed each day
MOUNTAINTOP REMOVAL!! • COAL • APPALACHIAN MTNS • KENTUCKY, WEST VIRGINIA, PENNSYLVANIA
A mining method: mountaintop removal • Entire mountaintops are blasted off • The waste is dumped into valleys • For coal in the Appalachian Mountains of the eastern U.S. • Economically efficient • “Valley filling” = dumping rock and debris into valleys • Degrades and destroys vast areas • Pollutes streams, deforests areas, erosion, mudslides, flash floods An area the size of Delaware has already been removed
WHERE DOES ALL THAT ROCK AND SOIL GO? • VALLEY FILLING • 2,000 MILES OF STREAMS BURIED
MINING: OTHER ENVIRONMENTAL IMPACTS! • MINE “TAILINGS” • Leftover ore after metals extraction • Subject to “leaching” of residual heavy metals, extraction chemicals (cyanide/Hg to extract gold, sulfuric acid for copper) • Runoff to streams • Tailings Ponds: leaching to groundwater • WESTERN U.S.! • SMELTING: Air toxics pollution • WATER, ENERGY!
SMELTING • HEATING ORES BEYOND THEIR M.P. AND COMBINING WITH OTHER METALS/CHEMICALS • LEAD SMELTING!
RESTORATION OF MINING SITES • “RECLAMATION” • ONLY PARTIALLY EFFECTIVE
LAWS, REGULATIONS • THE GENERAL MINING ACT OF 1872 • ALLOWS ANY U.S. CITIZEN OR COMPANY TO STAKE A CLAIM ON ANY PLOT OF PUBLIC LAND OPEN TO MINING. • NO PAYMENTS TO PUBLIC REQUIRED.
‘SUSTAINABLE MINING’ • AN OXYMORON ?? • Oxymoron: a figure of speech by which a locution produces an incongruous, seemingly self-contradictory effect, as in “cruel kindness” • “CLEAN COAL”??
MINERALS ARE NON-RENEWABLE RESOURCES • SUSTAINABILITY HINGES ON RATE OF EXTRACTION • DISCOVERY OF NEW RESERVES • ENVIRONMENTAL IMPACTS?! • NEW EXTRACTION TECHNOLOGIES • ENVIRONMENTAL IMPACTS?! • RECYCLING
Years remaining for selected minerals • Scarcity increases prices • Industries will spend more to reach further deposits
DISCARDED CELL PHONES! • PAGE 661 • > $300 MILLION • MAJOR SOURCE OF TOXIC METALS FROM LANDFILLS