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Chapter 27
Minerals and the
Environment
What is a Mineral?
• A substance formed by geological
processes
• Nonrenewable
• Availability determines standard of
living
• (Rock – aggregate of one or more
minerals)
How Mineral Deposits Are
Formed
• Ore Deposits – formed when metals
are concentrated in unusually high
amounts by geological processes
• Mineral resources are usually extracted
from ore deposits
• Plate Boundaries – metals are
precipitated and carried to the surface
– Hg
How Mineral Deposits Are
Formed
• Igneous Process – magma cools and
then crystallizes
– Diamonds
• Sedimentary Process – wind, water,
and glaciers; sorting process
– Sand and gravel
• Steam process sort heavy metals
– Gold
How Mineral Deposits Are
Formed
• Evaporation – minerals fall out as a
precipitate
– Salts
• Biological – can form minerals
• Weathering – concentrate minerals
in the soil
Resources and Reserves
• Minerals are classified as:
– Mineral Resources
• Elements, chemical compounds, minerals or
rocks that can be extracted to obtain a
usable commodity
– Mineral Reserves
• The portion of the resource that is identified
and from which usable materials can be
legally and economically extracted at the
time of evaluation
Availability of Mineral
Resources
• When the availability of a mineral becomes
limited, there are 4 possible solutions:
1. Find more sources
2. Recycle and reuse what has already been
obtained
3. Reduce consumption
4. Find a substitute
Impacts of Mineral Development
• Environmental Impacts
– Mining procedures
• Surface vs. Deep-mining
– Waste
• Pollution
Impacts of Mineral Development
• Social Impacts
– Increased demand for housing and
services in mining areas
– Economic stress of mining shutdown
Minimizing Environmental
Impact of Mineral Development
• Environmental regulations at the federal,
state and local levels
• On-site and off-site treatment of waste
• Practicing the 3 R’s of waste management
Minerals and Sustainability
• R-to-C Ratio
– A measure of the time available for
finding the solutions to depletion of
nonrenewable resources
– R = known reserves
– C = rate of consumption
• High Fluctuation