MINING : The process of obtaining mineral resources from the Earth

1. MINING: The process of obtaining mineral resources from the Earth

2. Do Now • What are examples of resources we extract from the earth? • How do we get those resources out of the earth so we can use them?

3. What do we mine? • Coal!!! • Salt • Sulfur • Granite • Marble • Sand • Gravel • Gold • Copper • Iron • Diamonds • Gemstones, other minerals

4. Why do we mine? • Energy- coal, oil, natural gas, uranium • Technology- metals for electronics • Infrastructure- rocks, gravel, metals • Agriculture- minerals for fertilizers • Luxury- diamonds, gold, sapphires, rubies, etc.

5. Mining Methods Surface Mining Sub-Surface Cut small “shafts” into earth and excavate from within • Digging down from the surface

6. Surface Mining: Open Pit Mining • Used when minerals are close to the surface • Mined from top downward in layers • Ore pulled out via trucks • Gold and Copper can be mined this way The El Chino mine located near Silver City, New Mexico is an open-pit copper mine.

7. Surface Mining: Strip Mining • A long strip of soil and rock is removed and the mineral seam is exposed • This layer of removed soil is called the overburden • Used for mining coal. • Overburden layer can be replaced once the mineral has been taken out of the ground

8. Surface Mining: Quarrying • Rocks such as marble and granite can be mined this way • Construction Materials such as sand, gravel and stone can also be mined this way An abandoned construction aggregatequarry near Adelaide, South Australia

9. Surface Mining: Solar Evaporation • Salty Sea water is placed into very shallow artificial ponds. • The salt water slowly evaporates and salt crystals form • 30% of our Salt comes from this process • Most common in dry climates…why??? A salt pan worker in a salt evaporation pond in Tamil Nadu, India

10. Subsurface Mining: Room-and-Pillar Mining • “Rooms” are cut into seams of coal • Pillars of ore are left standing to support the ceiling • When all possible ore is extracted from the rooms, the pillars are then removed and the land above collapses

11. Subsurface Mining: Longwall Mining • A machine (a shearer) cuts and scrapes coal from the wall of a coal seam • The coal drops onto a conveyor belt • The ceiling next to the machine is held up by roof supports and as the machine advances into the coal seam the roof collapses

12. Subsurface Mining: Solution Mining • Hot water is injected into the mineral deposit through a well • The mineral water mixture is then pumped to the surface

13. Mining Regulations & Mine Reclamation

14. Environmental Impacts of Mining What are some environmental impacts associated with mining? Be ready to explain your answers or provide examples.

15. Environmental Impacts of Mining • Air and noise pollution • Water pollution • Displacement of wildlife • Erosion and sedimentation • Soil degradation • Subsidence Because the environmental impacts are so great, mining is one of the most heavily regulated industries in the US!

16. Air and Noise Pollution • Dust is produced by removing, loading, hauling, and dumping soil and overburden (stuff on top of ore) • Dust is also produced from ore blasting • Noise is created by equipment and blasting

17. Air and Noise Pollution Regulation • Most surface mines are NOT located near urban populations • Regulations in US forbid mining operations to allow dust or noise to exit the area being mined

18. Water Contamination • Water that seeps into mines or through piles of rock can pick up or dissolve toxic substances • Containments can then wash into streams where they can harm or kill aquatic life Think! What do you think happens when water is contaminated with a mineral like sulfur? What regulations do you think exist to combat water contamination?

19. Water Contamination & Regulation • Minerals that contain a lot of sulfur and react with oxygen and water to produce dilute sulfuric acid • Contaminated water from this process is called Acid Mine Drainage (AMD) • Regulations in the US require companies to dispose of acid-producing rock in landfill or in ways that prevent water contamination

20. Displacement of wildlife • Removing soil from a surface mine site strips away all plant life. • Without plants, animals will leave the area. • Dredging disturbs river bottoms and destroys aquatic plant life. (Example: gold and silver) Think! What do you think happens when soil is returned to a surface mine site?

21. Displacement of wildlife When the soil is returned to the site different plants and animals may establish themselves, creating a new ecosystem. Think!- Would this be primary or secondary succession?

22. Erosion and Sedimentation • Excess rock from mines is dumped into large piles called dumps. • Running water erodes unprotected dumps and may harm water quality and aquatic life

23. Soil Degradation • Soil at a mine is removed from the uppermost layer downward. • Soil must be stored in layers with the upper layers stored above lower layers. Think! What do you think happens if the soil is not removed and stored properly?

24. Soil Degradation • Soil must be removed and stored properly or it can be depleted of nutrients when it is reclaimed. • Deeper soil layers may also contain sulfur. Think! • What might happens to sulfur compounds in the soil? • How might this affect plant growth?

25. Subsidence • The sinking of regions of ground with little or no horizontal movement. • Caused when pillars in a mine collapse or the mine roof or floor fails • Think! • What are some hazards that may result from subsidence?

26. Subsidence • Buildings, houses, roads, bridges, underground pipelines and utilities may be damaged - Explosions, fires • Loss of wildlife or human life

27. Underground Mine Fires • Fires in underground coal seams are one of the most serious environmental consequences of coal mining • Lightning, forest fires and burning trash can cause coal-seam fires. • Centralia, PA. – still burning since 1962 Think! • What are some of the problems with underground mine fires?

28. Underground Mine Fires • These fires are hard to put out and often left to burn out (which may take decades). • They release smoke and gasses that can cause respiratory problems.

30. Mining Regulations • Mining is the most heavily regulated industry in the US. • Mines on land in the US are regulated by federal and state laws. • States must issue permits for mining, run inspections, and address noncompliance. Think! • What federal regulations exist to control negative impacts mining has on the environment?

31. Mining Regulations • The Clean Water Act &The Safe Drinking Water Act • The Comprehensive Response Compensation and Liability Act • regulates the release of hazardous substances into air, soil, & water • The Endangered Species Act • protects threatened & endangered species and their habitats

32. Reclamation • Reclaiming the land or returning it to its original or better condition after mining. • Billions of dollars are spent to clean up abandoned mines. • The Surface Mining control and Reclamation Act of 1977 (SMCRA) • Set standards to minimize the effects of coal mining on environment • Established funds used to reclaim land and water resources adversely affected by mining

33. Mine Reclamation Before After

34. Before After

35. After Before

36. Lessening impact: The 3 R’s of Mining • Reduce the amount of waste you produce (use less stuff) • Reuse materials in the waste stream as much as possible • Maximize Recycling opportunities

37. Mining Video Clips • https://www.youtube.com/watch?v=4WbaONJEbRE - Surface Mining: Open pit Mining • https://www.youtube.com/watch?v=-4_tDoTvQ6A -Underground Mining