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MINING CH. 15
2 main mining techniques
Surface Mountain top removal
Depends on location of resource and topography
Open pit vs strip mining
Subsurface Dangerous (miners in WV and Chile trapped
in mine), more expensive
Open-pit Mining Machines dig
holes and remove ores, sand, gravel, and stone.
Toxic groundwater can accumulate at the bottom.
Figure 15-Figure 15-1111
Strip mining
Fig. 15-13, p. 346
Contour strip mining
Overburden Highwall Coal seam Overburd
en Pit Benc
hCoal seam
Spoil banks
Mountaintop Removal Machinery
removes the tops of mountains to expose coal.
The resulting waste rock and dirt are dumped into the streams and valleys below.
Figure 15-Figure 15-1414
Mining Impacts
Metal ores are smelted or treated with chemicals to extract the desired metal like arsenic, mercury, and cyanide which can contaminate groundwater.
Disrupts land, increases erosion
Pollution: solid wastes, acid drainage (sulfuric acid)
Figure 15-Figure 15-1515
SUPPLIES OF MINERAL RESOURCES
Depletion curves for a renewable resource using three sets of assumptions. Dashed vertical
lines represent times when 80% depletion occurs.
Figure 15-Figure 15-1616
Why are goods made from mined products so cheap? Should they cost more to account for
environment recovery efforts? Should mining be sent overseas due to
strict regulations in US?
Fig. 15-18, p. 351
Solutions
Sustainable Use of Nonrenewable Minerals
• Do not waste mineral resources.• Recycle and reuse 60–80% of mineral resources.• Include the harmful environmental costs of mining and processing minerals in the prices of items (full-cost pricing).
• Reduce subsidies for mining mineral resources.• Increase subsidies for recycling, reuse, and finding less environmentally harmful substitutes.
• Redesign manufacturing processes to use less mineral resources and to produce less pollution and waste.
• Have the mineral-based wastes of one manufacturing process become the raw materials for other processes.
• Sell services instead of things.• Slow population growth.
