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Chapter 15
1.Stone Age 6,000 BC to 2,000 BC2.Bronze Age 2,500BC or 1,000AD to iron age3. Iron Age - most by 1,000BC
Stone = differently shaped rocksBronze = Copper and TinSteel = iron and carbon
What age are we in now?
Mining law 18721. Promoted development & settlement of western
public lands
1. File claims to hard rock minerals at $2.50-5.00 an acre / keep all profits / no royalties to…
1. Supersedes all other uses of the land or designations
1. Legacy of law - superfund sites / acid drainage / 40% all headwaters contaminated in west
1. Colorado has about 23,000 abandoned hard-rock mine sites - more than 500,000 nation wide
Open Pit Mining
Heap Leaching
Cyanide for Gold
Acid Mine Drainage
Sulfides exposed to air & water = sulfuric acid1.Somerset, PA will construct five ponds using Shore Guard vinyl sheet piling.2.The first two settling ponds the iron mixes with oxygen. 3.The next two ponds contain limestone to remove the acid.4.Pond five will capture any remaining metals.5.Then it will flow through a wetland before entering Indian creek.
PyriteIron Sulfate
Acid Mine Drainage = Perpetual Pollution
Heap leachingCyanideSulfuric Acid
Hg – Gold Amalgamation
Ducktown Tennessee Burra Burra Mine
1960’s
300 Acres left unforested as a reminder – view on Google EarthPicher Oklahoma & Chat Piles: https://www.youtube.com/watch?v=3ls3NdTKSHs
Copper Basin (Ducktown, TN) Reclamation
Problem: 1. Mine Operated 1899-19592. Acid Precipitation3. 50 square miles turned to waste4. Dams lost 25% storage capacity
Solution:1. 1930’s remediation failed - kudzu2. 16 Million Acid tolerant pine and grass seeds broadcast3. Added lime and fertilizer4. Cost $500.00 per acre (32K acres)5. Erosion went from 200 tons to 8 annually6. Target completion date 2000
Smelting
Coke:Hydrocarbon heated to remove volatiles to get pure carbon.
Phytoremediation - Thlaspi1. Absorbs Zinc & Cadmium2. Has an ability to concentrate heavy metals in plant parts
Advantages Disadvantages
Works on a variety of organic and inorganics
May take several years to remediate
Easy to implement Restricted to shallow sites
Low Cost Dependent on Climate
Environmentally friendly
Possible impacts on food chain
Pleasing to the eye Harvest can be classified as hazardous waste
Reduces waste to landfill
Human consumption of food a concern
Summitville ColoradoHistory:1.1870 Gold Discovered2.250 Claims3.By 1959 18K lbs gold4.1984 heap leached pyritic ore with cycanide on 73 acre pad5.Activated Carbon used to extract minerals from leachate6.By 1991 200K lbs gold & 640K silver removed from 500acres of ore7.1992 Company declares bankruptcy8.30 Million Paid in Settlement9.17 Mile stretch of river all life10. 210 million clean up
Why are minerals located here?
Mineral Formation
1. Magmatic concentration - as magma cools it separates with silicates rising and iron, nickel, & copper sinking - layered by density
2. Hydrothermal processes - dissolved minerals mix with salts to form a metal-bearing complex - gold, silver, copper, lead & zinc
3. Sedimentation - dissolved minerals are deposited manganese, copper, sulfur & phosphorus - warm meets cold
4. Evaporation - lakes without outlets salt, borax, potassium, gypsum
Metallic and Non-Metallic Minerals
Source / Transport / Trapping
Salt Flats
HydrothermalMineral Deposits
KaolinChattahoochee, Ocmulgee, Oconee and Savannah Rivers where inland shipping was stopped by falls or rapids at the Fall Line.
Uses: paper, food additive, toothpaste, cosmetics…
Geo
log
y
Ore Vs Product
Hydraulic Mining
Hard Rock Mining
Stone MT. in Bloom
Diamorphia Smallii
Confederate Daisy
The LawSurface Mining Control & Reclamation Act of 1997Only covers coal
SMCRA created two programs: 1. Regulation of active coal mines2. Reclamation of abandoned mines funded by
tax on current mines
Reserve Vs Resource
Reserves:1. Have been located and quantified2. Can be extracted with current technology3. Can be extracted profitably
Resource:1. Not yet quantified but located 2. Future technology may make accessible
• To Deep or under ocean3. Not profitable under current technology
• Low Grade• Contaminated• Drilled out as a reserve source
Cost Benefit Analysis
Weigh the cost and benefit of mining…Montana
Future Trends
1. Deep Oceans - international waters2. Antarctica - should we - will we3. Biomining4. Undiscovered Deposits
International Sources - Stockpiling
The United States has discovered nearly $1 trillion in untapped mineral deposits in Afghanistan, including huge veins of iron, copper, cobalt, gold and lithium.
Will We Run Out?
1. New Discoveries2. Replacement Materials - plastics3. Changing global economy4. Technology Changes5. Conservation