1. Mining and Mineral Resources
Chapter 16
Ms. Cuthrell
Ecology
2nd Period

2. What are Mineral Resources?
Concentration of naturally occurring material in or on the earth’s crust that can be extracted and processed into useful materials
Classified as nonrenewable resources because they take so long to produce
We know how to find and extract 100+ nonrenewable minerals from the earth’s crust

3. We can extract… Metallic mineral resources (iron, copper, aluminum)
Nonmetallic mineral resources (salt, clay, sand, phosphates, soil)
Energy resources (coal, oil, natural gas, uranium)

4. Ore
Rock containing enough of 1+ metallic minerals to be mined for profit
We convert 40 metals extracted from ores into everyday items that are either 1) used and thrown away OR 2) reused or recycled

5. Categories of nonrenewable mineral resources
US Geological Survey divides nonrenewable mineral resource into categories:
Identified resources: deposits of nonrenewable mineral resource with a known location and quantity
Undiscovered resources: potential supplies assumed to exist in theory
Reserves: identified resources from which resource can be extracted for profit
Other resources: identified and discovered but not classified as reserves

6. How do ores form from magma?
Ores form as a result of internal and external geologic processes
Plate tectonics shape the earth’s crust and determine where the richest mineral deposits are found

7. As magma cools, it crystallizes into mineral-containing igneous rocks
Ore deposits form through
hydrothermal processes
Upwelling magma solidifies into black smokers
Shoots out mineral-rich hot water on the seafloor
Minerals accumulate as hot and cold water contact
Form ore deposits rich in copper, lead, zinc, silver, and gold

8. Finding nonrenewable resources
Aerial photos and satellite images
Planes that detect deposits of radioactive metals
Gravimeter to measure differences in density (ore differs from surrounding rock)
Drilling deep well and extracting core samples
Seismic surveys by explosions and analyzing shock waves
Chemical analysis of water and plants (absorb minerals)

9. Mining techniques (once resources have been found)
Surface mining: equipment strips outer layer of soil and rock; in US, used to extract 90% nonfuel resources and 60% coal
Open-pit mining: machines dig holes and remove ores
Dredging: chains scrape underwater mineral deposits
Area strip mining: parallel strips made in flat land; power shovels used
Contour strip mining: terraces cut into side of hill; power shovels used
Mountaintop removal: explosives used to remove top of mountain and expose coal underneath

10. Open Pit mining

11. Dredging

12. Area Strip Mining

13. Contour Strip Mining

14. Surface Mining Control and Reclamation Act of 1977
Requires mining companies to restore surface-mined land so that it is usable again
Although surface-mined land can be restored, it is expensive and not done in many countries

15. Subsurface mining
Used to remove coal and other metal ores that are too deep to be extracted by surface mining
Blast tunnels to get to deposit, use machinery to transport ore to the surface
Disturbs 1/10 as much land as surface mining, produces less waste
More dangerous and expensive

16. Environmental Effects of Extracting Mineral Resources

17. Percolation to groundwater
Subsurface
Mine Opening
Runoff of
sediment
Surface Mine
Percolation to groundwater
Spoil banks
Acid drainage from
reaction of mineral
or ore with water
Leaching of toxic metals
and other compounds
from mine spoil
Leaching may carry
acids into soil and
groundwater supplies
Acid mine drainage-pollution and degradation
by acid runoff and toxic chemicals from mining
-can kill fish and other aquatic life

18. Processes involved in extraction
Smelting: used to separate metal from other elements in the ore
Enormous amount of pollution which damages surrounding vegetation and soil
Smelters also produce liquid and hazardous waste that must be disposed of safely

19. Smelting
Separation
of ore from
machine
Melting
metal
Conversion
to product
Metal ore
Recycling
Surface
mining
Discarding
of product
Scattered in environment

20. Are there environmental limits?
Resource experts believe that the greatest danger from increasing consumption of nonrenewable resources is environmental damage caused by extraction and processing.
More accessible and high-grade ores are exploited first
It takes more $ to exploit the deeper ores, causing more environmental effects

21. Will there be enough mineral resources?
Future of nonrenewable minerals depends on: actual supply and rate at which supply is used
Economic depletion: cost more to find, extract, transport and process than it’s worth
Depletion time: time it takes to use up a certain proportion of nonrenewable minerals.

22. Supplies of mineral resources
Reserve-to-production ratio: number of years that reserves of a nonrewnewable minerals will last
Materials revolution: new materials (ceramics and plastics) are being developed as replacements for metals
Substitutes cannot be found for many mineral resources