Lecture Outlines Chapter 23 Environment: The Science behind the Stories 4th Edition

1. Lecture Outlines Chapter 23 Environment:The Science behind the Stories 4th Edition Withgott/Brennan

2. Notes HW • Write each slide title on the left side of the paper • Summarize provided information on the right side of the paper • If there are slides with Objectives or “this lecture will help you understand” you do NOT need to write these. • Define any words or answer any questions or fill in the blanks when something appears in red. • Sometimes it is a question linked to a website you should view • Sometime there are comments written in purple. You do not need to write these. They are just my personal commentary  • Be prepared to discuss the questions at the end.

3. This lecture will help you understand: • Mineral resources and their contributions to society • Mining methods • Social and environmental impacts of mining • Sustainable use of mineral resources

4. Central Case: Mining for … cell phones? • Cell phones and other high-tech products contain tantalum • Coltan = columbite + tantalum • The Democratic Republic of the Congo was at war • Since 1998, 5 million died and millions more fled • Soldiers controlled mining operations and forced farmers and others to work, while taking most of the ore • People entered national parks, killing wildlife and clearing rainforests • Profits from coltan sales financed the war • Most tantalum from the Congo goes to China

5. Minerals and mining • We extract raw minerals from beneath our planet’s surface • Rock and resources from the lithosphere contribute to our economies and lives • Rock? • Mineral? • It has a crystal structure, specific chemical composition, and distinct physical properties Minerals are nonrenewable, so we need to be aware of their finite and decreasing supplies

6. Minerals are everywhere in our products: List 5?

7. We obtain minerals by mining • We obtain minerals through the process of mining • Mining? • We mine minerals, fossil fuels, and groundwater • Because minerals occur in low concentrations, concentrated sources must be found before mining

8. We extract minerals from ores • Metal ? • Ore? • Economically valuable metals include copper, iron, lead, gold, aluminum Tantalite ore is mined, processed into tantalum, and used in electronic devices

9. We process metals after mining ore • Most minerals must be processed after mining • After mining the ore, rock is crushed and the metals are isolated by chemical or physical means • Alloy? • Steel is an alloy of iron and carbon • Smelting?

10. Processing minerals has costs • Processing minerals has environmental costs • Most methods are water- and energy-intensive • Chemical reactions and heating to extract metals from ores emit air pollution • Tailings? • Pollutes soil and water • They may contain heavy metals or acids (cyanide, sulfuric acid) • Water evaporates from tailings ponds, which may leach pollutants into the environment

11. We also mine nonmetallic minerals and fuels • Nonmetallic minerals include sand, gravel, phosphates, limestone, and gemstones • $7 billion/year of sand and gravel are mined in the U.S. • Phosphates provide fertilizer • “Blood diamonds” are mined and sold to fund, prolong, and intensify wars in Angola and other areas • Substances are mined for fuel • Uranium for nuclear power • Coal, petroleum, natural gas are not minerals (they are organic), but they are also extracted from the Earth

12. No need to write. Just look.

13. Mining methods and their impacts • People in developing nations suffer war and exploitation because of the developed world’s appetite for minerals • In 2009, raw materials from mining gave $57 billion to the U.S. economy • After processing, minerals contributed $454 billion • 28,000 Americans were directly employed for mining • Large amounts of material are removed during mining • Disturbing lots of land • Different mining methods are used to extract minerals • Economics determines which method to use

14. Strip mining removes surface soil and rock • Strip mining? • Overburden? • After extraction, each strip is refilled with the overburden • Used for coal, oil sands, sand, gravel • Destroys natural communities over large areas and triggers erosion • Acid drainage?

15. Strip mining destroys the environment Strip mining removes soil Discolored water is a sign of acid drainage

16. A mining method: subsurface mining • Accesses deep pockets of a mineral through tunnels and shafts • The deepest mines are 2.5 mi • Zinc, lead, nickel, tin, gold, diamonds, phosphate, salt, coal • The most dangerous form of mining • Dynamite blasts, collapsed tunnels • Toxic fumes and coal dust • Acid drainage, polluted groundwater • Sinkholes damage roads, homes, etc.

17. A mining method: open pit mining • Used with evenly distributed minerals • Terraced so men and machines can move about • Copper, iron, gold, diamonds, coal • Quarries? • Huge amounts of rock are removed to get small amounts of minerals • Habitat loss, aesthetic degradation, acid drainage • Abandoned pits fill with toxic water

18. One open pit mine One Utah mine is 2.5 mi across and 0.75 mi deep; almost half a million tons of ore and rock are removed each day

19. A mining method: placer mining • Using running water, miners sift through material in riverbeds • Coltan miners, California’s Gold Rush of 1849 • Used for gold, gems • Debris washed into streams makes them uninhabitable for wildlife • Disturbs stream banks, causes erosion • Harms riparian plant communities

20. A mining method: mountaintop removal • Entire mountaintops are blasted off • The waste is dumped into valleys • For coal in the Appalachian Mountains of the eastern U.S. • Economically efficient • “Valley filling” = dumping rock and debris into valleys • Degrades and destroys vast areas • Pollutes streams, deforests areas, erosion, mudslides, flash floods An area the size of Delaware has already been removed

21. Mountaintop removal is socially devastating • Mine blasting cracks foundations and walls • Floods and rock slides affect properties • Overloaded coal trucks speed down rural roads • Coal dust and contaminated water cause illness • High-efficiency mining reduces the need for workers

22. A mining method: solution mining • Solution mining (in-situ recovery) = resources in a deep deposit are dissolved in a liquid and siphoned out • Salts, lithium, boron, bromine, potash, copper, uranium • Less environmental impact than other methods • Less surface area is disturbed • Acids, heavy metals, uranium can accidentally leak

23. A mining method: undersea mining • We extract minerals (e.g., magnesium) from seawater • Minerals are dredged from the ocean floor • Sulfur, phosphate, calcium carbonate (for cement), silica (insulation and glass), copper, zinc, silver, gold • Manganese nodules = small, ball-shaped ores scattered across the ocean floor • Mining them is currently uneconomical • Hydrothermal vents may have gold, silver, zinc • Mining would destroy habitats and organisms and release toxic metals that could enter the food chain

24. Restoration of mined sites • Governments in developed countries require companies to reclaim (restore) surface-mined sites • Other nations (e.g., Congo) have no regulations at all • Reclamation ? • The U.S. 1977 Surface Mining Control and Reclamation Act mandates restoration • Companies must post bonds to ensure restoration

25. The General Mining Act of 1872 • Encourages metal and mineral mining on federal land • Any citizen or company can stake a claim on any public land open to mining for $5 per acre • The public gets no payment for any minerals found • Once a person owns the land, that land can be developed for any reason, having nothing to do with mining • Supporters say it encourages a domestic industry that is risky and provides essential products • Critics say it gives land basically free to private interests • Efforts to amend the act have failed in Congress

26. Minerals are nonrenewable and scarce • We must recover and recycle our limited supplies • Once known reserves are mined, minerals will be gone • For example, indium, used in LCD screens, might only last 32 more years • Gallium (for solar power) and platinum (fuel cells) are also scarce • Reserve estimates are uncertain • New discoveries, technologies, consumption patterns, and recycling affect mineral supplies • As minerals become scarcer, demand and price rise

27. Years remaining for selected minerals • Scarcity increases prices • Industries will spend more to reach further deposits

28. Factors affecting how long deposits last • Discovery of new reserves increases known reserves • Minerals worth $900 billion were discovered in Afghanistan in 2010 • New extraction technologies reach more minerals at less expense • Changing social and technological dynamics modify demand in unpredictable ways • Lithium batteries are replacing cadmium-nickel ones • Changing consumption patterns affect how fast we exploit reserves (e.g., a recession depresses demand) • Recycling extends the lifetimes of minerals

29. We can use minerals sustainably • Recycling addresses: • Finite supplies • Environmental damage • 35% of metals were recycled in 2008 from U.S. municipal solid waste • 7 million tons • Steel, iron, platinum, gold, nickel, germanium, tin, and chromium • Reduces greenhouse gases by 25 million metric tons

30. We can recycle rare metals from e-waste • Electronic waste (e-waste) from computers, printers, cell phones, etc. is rapidly rising • Recycling keeps hazardous wastes out of landfills while conserving mineral resources • 1.2 billion cell phones sold each year contain 200 chemicals and precious metals • Phones can be refurbished and resold or dismantled and their parts reused or recycled • Only 10% of cell phones are recycled • Recycling reduces demand for virgin ores and reduces pressure on ecosystems

31. Conclusion We depend on minerals and metals to make the products we use Mineral resources are mined by various methods Contributing to material wealth But causing extensive environmental damage (habitat loss, acid drainage, etc.) Restoration and regulations help minimize the environmental and social impacts of mining Maximize recycling and sustainable use of minerals

32. CH23-A • 1) Describe the following: mineral, metal, ore, alloy • 2) Describe and contrast how water is used in placer mining and solution mining. • 3) What is acid drainage and why can it be toxic to fish? • 4) Describe why reclamation efforts after mining often fail to effectively restore natural communities. Be sure to mention both soil and vegetation.

33. CH23-B • 5) Name three types of metal we currently recycle, and identify the products or materials that are recycled to recover these metals. • 6) Contrast strip mining, subsurface mining, open pit mining, and mountain top removal. • 7) Describe the General Mining Act of 1872. • 8) Describe the 1977 Surface Mining Control and Reclamation Act.

34. Which of the following best describes the process known as, “mountaintop removal”? • The use of trees planted at high elevations to eliminate CO2 from the atmosphere • The use of heavy equipment to move overburden downhill during the strip mining of coal • The placement of hazardous waste disposal sites at high elevations in mountainous regions • The shearing away of undersea mountain peaks to improve shipping lanes • The reduction of glacial ice resulting from increased global temperatures

35. Which of the following best describes the process known as, “mountaintop removal”? • The use of trees planted at high elevations to eliminate CO2 from the atmosphere • The use of heavy equipment to move overburden downhill during the strip mining of coal • The placement of hazardous waste disposal sites at high elevations in mountainous regions • The shearing away of undersea mountain peaks to improve shipping lanes • The reduction of glacial ice resulting from increased global temperatures

36. QUESTION: Review In mining operations, the material removed from the ground is almost always: • Smeltings • Tailings • Ore • Metals

37. QUESTION: Review In mining operations, the material removed from the ground is almost always: Smeltings Tailings Ore Metals

38. QUESTION: Review To strip-mine for coal, what must first be removed? • Acid drainage • Coal • Overburden • Ore

39. QUESTION: Review To strip-mine for coal, what must first be removed? Acid drainage Coal Overburden Ore

40. QUESTION: Review One negative impact of strip mining is: • Acid drainage • Lung diseases from breathing toxic fumes • Underground explosions • Mine collapses

41. QUESTION: Review One negative impact of strip mining is: Acid drainage Lung diseases from breathing toxic fumes Underground explosions Mine collapses

42. QUESTION: Review The best ways to use mineral resources sustainably are: • Finding new mines and recycling • Larger pit mines and recycling • Deeper mines and larger pit mines • Recycling and efficiency

43. QUESTION: Review The best ways to use mineral resources sustainably are: Finding new mines and recycling Larger pit mines and recycling Deeper mines and larger pit mines Recycling and efficiency

44. QUESTION: Interpreting Graphs and Data Based on the information in the figure, which mineral will run out first at the current rate of consumption? • Zinc • Lead • Cobalt • Nickel

45. QUESTION: Interpreting Graphs and Data Zinc Lead Cobalt Nickel Based on the information in the figure, which mineral will run out first at the current rate of consumption?