We can make some minerals in the earth’s crust into useful products, but extracting and using these resources can disturb the land, erode soils,
produce large amounts of solid waste, and pollute the air, water, and soil.
How are minerals used?
Mineral UseSilver Photography, chemistry,
electronic products, jewelry, coins
Titanium Jet engines, powder for white paint pigment, paper, rubber
Limestone ConstructionHalite Diet (salt), sodium
hydroxide, ceramic glazesGraphite Dry lubricant, brake linings,
pencils
Mineral
• Element/compound of elements naturally occurring in the crust
• EX. Steel = Iron & Carbon Bronze = Tin & Copper Copper Sulfur
Where are minerals found?
• Rocks – combinations of minerals• Ore/ore body – concentrated
mineral chunk that can be mined for profit
Classification of Minerals
• Mineral resources include: –Metallic–Non-metallic– Energy Resources
Non-renewable
Classification
Metallic• Iron, Copper,
Aluminum– Malleable– Lustrous– conductors
Nonmetallic• Sand• Stone• Phosphates• Salts
How do minerals form? Name Description
Magma Concentration As magma cools, separates into layers based on differences in densities (iron on bottom, silicates on top)]
Fe, Cu, Ni, Cr
Hydrothermal Processes - Ore deposits - Black smokers
Heated groundwater seeps through cracks/fissures dissolving minerals in rocks which get transported with water
Au, Ag, Pb, Zn
How do minerals form?
Magma
Black smoker
Sulfidedeposit
White crab
Tube worms
Whitesmoker
Hydrothermal ore also occur when upwelling magma solidifies into black smokers
Especially rich in Cu, Pb, Zn, Ag, Au
How do minerals form? Name Description
Sedimentation Weathering breaks down parent rock into particles which are transported by water and deposited into beds
Fe, MN, P, S, Cu
Evaporation Dissolved material accumulates in inland lakes/seas with no/small outlets – evaporation occurs leaving behind mineral deposits.
NaCl, borax, gypsum salts
How are minerals discovered and extracted?
1. Prospecting2. Mining/Extractions3. Smelting/Processing
Prospecting Tools
• Satellite Imagery• Aerial Sensors (magnetometers)• Gravity Difference (gravimeter)• Core Sampling• Seismic Surveys• Chemical analysis of water &
plants
2. Mining Extracting
Surface• Less $• Open Pit• Strip Mining• Safer for miners• Environmental
Damage
Subsurface• More $$$• Shaft• Slope• Hazardous for
miners• Less Environmental
Damage
Surface Mining
• Mechanized equipment strips overburden of soil & rock
• Discards it as waste called spoils• In US: – 90% of nonfuel mineral & rock
resources– 60% of coal by weight
Surface Mining Types *
Area Strip Mining
Subsurface Mining
Used to remove coal and various metal ores that are too deep to be extracted by surface mining
Subsurface Mining
• Shaft• Slope–Disturbs less
land– Produces less
waste–More
dangerous–More expensive
3. Smelting/Processing *
Heat to extract pure ore from impurities
Surface mining
Metal ore Separation of ore from gangue
Smelting Melting metal
Conversion to product
Discarding of product
Recycling
Life Cycle of a Metal Resource
Environmental Implications
Decisions to mine depend on: - Financial risk- Potential profit- Risk of environmental damage- Economic viability of mineralNOT A SIMPLE ISSUE!
Natural Capital Degradation
Extracting, Processing, and Using Nonrenewable Mineral and Energy
ResourcesSteps Environmental Effects
Mining Disturbed land; mining accidents; health hazards; mine waste dumping; oil spills and blowouts; noise; ugliness; heat
Exploration, extraction
Processing Solid wastes; radioactive material; air, water, and soil pollution; noise; safety and health hazards; ugliness; heat
Transportation, purification, manufacturing
Use Noise; ugliness; thermal water pollution; pollution of air, water, and soil; solid and radioactive wastes; safety and health hazards; heat
Transportation or transmission to individual user, eventual use, and discarding
• Land damage of surface and vegetation
• Water use threatens supplies of groundwater
• Water quality damage: heavy metals are leached resulting in acid mine drainage
• Gangue: worthless material that surrounds, or is mixed with minerals in an ore deposit.
Environmental Effects of Mining/Extraction
Environmental Effects of Mining/Extraction
• Tailings: mine waste from impurities in ore can be toxic
• Air pollution from smelting plants
• Energy requirements of equipment, processing, refining, labor intensive, etc.
• Subsidence or collapse
Environmental Effects of Using a Mineral Resource
a) Disruption of land surface 500,000 mines
b) Subsidencec) Erosion of solid mining wasted) Acid mine drainage
H2SO4
e) Air pollution Mining produces more toxic emissions than
any other industry
f) Storage and leakage of liquid mining waste
Legislation
• Surface Mining Control and Reclamation Act of 1977– Requires mining companies to
restore most surface-mined land so it can be used for the same purpose as it was before it was mined
– Levied a tax on mining companies to restore land that was disturbed by surface mining before the law was passed.
Legislation
• General Mining Act of 1872– allowed individuals/corporations to
stake claims to mine metals on federal lands at $2.50 to $5 per acre
– cheap land for developing the western US by patenting
– law contains no provision for env. protection or reclamation of topsoil/vegetation/habitat
Fun Facts
EX. In 1995 ASARCA (US company) paid $1,745 for land that produced $2.9 billion worth of minerals (Cu/Ag)
EX. 1993 Manville Corp. paid $10,000 for land in Montana that contains about $32 billion of palladium and platinum
Of the ~1200 Superfund sites (the nations worst toxic waste sites) about 52 are mines.