1. Mining and Mineral Resources
Environmental Science Class Notes
03/21/17

2. Mineral Consumption per Person (U.S.)

3. What Is a Mineral? A mineral is a: Can be made up of
naturally occurring
inorganic solid
characteristic chemical composition
orderly internal structure
characteristic set of physical properties.
Can be made up of
Atoms of a single element
Compounds (atoms of 2 or more elements chemically bonded

4. Ore Minerals Ore Mineral- has economic value
Gangue Mineral- has no economic value
Ore and Gangue minerals are extracted together.
Ore is separated from gangue
In order to be profitable, the price of the ore must be higher than the costs to extract and

5. Metallic Minerals Ore minerals are either metallic or nonmetallic.
Metals have the following characteristics:
can conduct electricity
have shiny surfaces
are opaque

6. Nonmetallic Minerals Nonmetals have the following characteristics:
tend to be good insulators
may have shiny or dull surfaces
may allow light to pass through

7. Mineral Resources and Their Uses
Uses for nonmetals:
Building materials
Gemstones
Uses for metals:
Metals are easy to mold
Metals conduct electricity
Two or more metals combine to form alloys

8. Mineral Exploration Geologists go out into the field and find deposits
Deposit is sampled to find quality and size of deposit
Cost analysis to determine if mining will be profitable

9. Subsurface mining
soil and rocks are removed to reach underlying coal or minerals.
50 m or more beneath Earth’s surface.
Room-and-pillar mining
common method of subsurface mining.
used to extract salt and coal.
Pillars of ore are left to support the roof of the mine

10. Longwall Mining
more efficient method of removing coal from a subsurface seam.
A machine called a shearer moves back and forth along the face of a coal seam.
As coal is sheared from the long wall, it falls onto a conveyor and is transported out of the mine.

11. Solution Mining Used for deposits of soluble mineral ores
potash
salt
sulfur
Ore is injected with hot water
Compressed air is then pumped into the dissolved ore
Air bubbles lift it to the surface.

12. Surface Mining
Soil and rocks are removed to reach underlying coal or minerals.
Used for deposits close to Earth’s surface
Ores are mined downward, layer by layer.
Explosive are used to break up the ore

13. Quarrying A type of open-pit surface mining
Used to mine for near-surface minerals
Building stone
Crushed rock
Sand
Gravel
Clay
Gypsum
Talc
Produces aggregates

14. Solar Evaporation Produces 30% of the world’s salt
Useful in places with high temps and low rainfall
Salt water is pumped into a shallow pond
Water evaporates off, leaving salt behind

15. The Environmental Impacts of Mining
All mining poses a significant threat to the environment
Mining companies now have to prevent or fix those problems
Environmental Impacts:
Air and Noise Pollution
Water Contamination
Displacement of Wildlife
Erosion and Sedimentation
Soil Degradation
Subsidence
Fires

16. Air and Noise Pollution
Surface mines produce lots of noise from equipment and blasting
Dust is generated in mining process
Regulations prevent mines from releasing dust or noise into larger environment

17. Water Contamination
Water that seeps through mine sites can pick up or dissolve toxic substances.
These contaminants can wash into streams, where they can harm or kill aquatic life.
Regulations require companies to dispose of toxic products away from water sources.

18. Displacement of Wildlife
Creation of mine = destruction of habitat
Dredging rivers destroys river bottom ecosystems
Can be helped by planning to replant the habitat after mining is finished

19. Erosion and Sedimentation
Excess rock from mines is sometimes dumped into large piles called dumps.
Running water erodes unprotected dumps and transports sediments into nearby streams.

20. Soil Degradation
Soil at a mine site is removed from the uppermost layer downward.
Storing soil layers can mix them up
Layers should be put back in the order they originally were to prevent degradation

21. Subsidence
Sinking of regions of the ground with little or no horizontal movement.
Occurs when pillars that have been left standing in mines collapse or the mine roof or floor fails.
We don’t know where all old mines are- we might build on top of a precarious mine

22. Underground Mine Fires
Underground coal seams can catch on fire
Lightning
Forest fires
Human-created fires
Very difficult to put out- can take decades
Smoke and gases can be released to the surface

23. Mining Regulation and Reclamation
Mines on land in the United States are regulated by federal and state laws.
Mining companies must comply with:
the Clean Water Act and the Safe Drinking Water Act.
the Endangered Species Act

24. Reclamation
the process of returning land to its original condition after mining is completed.
The Surface Mining Control and Reclamation Act of 1977
created a program for the regulation of surface coal mining on public and private land.
established a fund that is used to reclaim land and water resources

25. State Regulation of Mining
Mining companies must obtain permits from state environmental agencies before mining a site.
State agencies inspect mines for safety
State agencies can impose fines or shut down mines