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

Smelters

• Used to remove mineral from gangue in an ore major polluters (Runescape!).

BauxiteMost 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!

Finding Mineral Deposits

• 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

Dredging (Sand)• Draglines scrape up underwater mineral

deposits

Types of Surface Mining

Area Strip Mining

• Cut new strips away; spoil placed on side, mineral 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.

Types of Surface Mining

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

• Longwall Coal Mining

• Moveable steel props support cave while machinery cut off coal onto a conveyor belt.

Types of Subsurface Mining

• Collapse/subsidence of land from subsurface mines.

• Causes houses to tilt, sewer lines crack, gas mains break.

Environmental Damage

• Wind/water carry away [by erosion] toxic mining waste.

• Goes in food webs and watersheds.

Environmental Damage

Habitat Loss!!

Environmental Damage

My Home!!!

• Transportation of minerals global warming, lung probs.

Environmental Damage

Acid mine drainage• Bacteria eat FeS in spoil create

H2SO4 runs off into streams

Environmental Damage

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!