MINERALS
General Classification of
Nonrenewable Mineral Resources

The U.S. Geological Survey classifies mineral resources
into four major categories:
 Identified:
known location, quantity, and quality or existence
known based on direct evidence and measurements.
 Undiscovered: potential supplies that are assumed to exist.
 Reserves: identified resources that can be extracted
profitably.
 Other: undiscovered or identified resources not classified as
reserves
General Classification of
Nonrenewable Mineral Resources

Examples are fossil
fuels (coal, oil),
metallic minerals
(copper, iron), and
nonmetallic minerals
(sand, gravel).
Figure 15-7
GEOLOGIC PROCESSES


Deposits of nonrenewable mineral resources in the
earth’s crust vary in their abundance and
distribution.
A very slow chemical cycle recycles three types of
rock found in the earth’s crust:
 Sedimentary
rock (sandstone, limestone).
 Metamorphic rock (slate, marble, quartzite).
 Igneous rock (granite, pumice, basalt).
Erosion
Transportation
Weathering
Deposition
Igneous rock
Granite,
pumice,
basalt
Sedimentary
rock
Sandstone,
limestone
Heat, pressure
Cooling
Heat, pressure,
stress
Magma
(molten rock)
Melting
Metamorphic rock
Slate, marble,
gneiss, quartzite
Fig. 15-8, p. 343
ENVIRONMENTAL EFFECTS OF USING
MINERAL RESOURCES


Minerals are removed through a variety of methods that
vary widely in their costs, safety factors, and levels of
environmental harm.
A variety of methods are used based on mineral depth.
 Surface
mining: shallow deposits are removed.
 Subsurface mining: deep deposits are removed.
Mining Regulations

The General Mining Act of 1872 is a United States
federal law that authorizes and governs prospecting
and mining for economic minerals, such as gold,
platinum, and silver, on federal public lands. This law,
approved on May 10, 1872, codified the informal
system of acquiring and protecting mining claims on
public land, formed by prospectors in California and
Nevada from the late 1840s through the 1860s, such
as during the California Gold Rush.
Open-pit Mining


Machines dig holes
and remove ores,
sand, gravel, and
stone.
Toxic groundwater
can accumulate at
the bottom.
Figure 15-11
Area Strip Mining


Earth movers strips
away overburden,
and giant shovels
removes mineral
deposit.
Often leaves highly
erodible hills of
rubble called spoil
banks.
Figure 15-12
Contour Strip Mining


Used on hilly or
mountainous terrain.
Unless the land is
restored, a wall of
dirt is left in front of
a highly erodible
bank called a
highwall.
Figure 15-13
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 15-14
Environmental Impacts of Mining






Acid Mine Drainage
Erosion and Sedimentation
Cyanide & Other Toxic Releases
Dust Emissions
Habitat Modification
Surface and Groundwater Contamination
Coal mining affects the environment

Strip mining causes severe soil erosion and chemical runoff
 Acid drainage = sulfide minerals on exposed rock surfaces
react with oxygen and rainwater to produce sulfuric acid
 Mountaintop removal causes enormous damage
Coal mining harms human health



Subsurface mining is harmful to human health
 Mine shaft collapses
 Inhalation of coal dust can lead to fatal black lung disease
Costs to repair damages of mining are very high
 These costs are not included in the market prices of fossil
fuels, which are kept inexpensive by government subsidies
Mining companies must restore landscapes, but the impacts are
still severe
 Looser of restrictions in 2002 allowed companies to dump
rock and soil into valleys, regardless of the consequences
Now what do we do with it?

Once the ore is mined and hauled to the surface, it
must be processed
 Tailings
are what is left behind once the valuable
portion of the ore is removed.
 Gangue is the commercially worthless minerals
associated with a valuable find.
Mining Impacts

Metal ores are smelted
or treated with
(potentially toxic)
chemicals to extract the
desired metal.
Figure 15-15
Gold Processing

Gold is treated with a Cyanide compound which
produces a Gold-Cyanide complex which is soluble
 Problem:
Hydrogen Cyanide gas is toxic
Hyperaccumulation

Hyperaccumulator plants accumulate inordinate
amounts of one or more Trace Elements (TE)s in their
above ground biomass.
 Hyperaccumulators
species may accumulate one or
more of a range of TEs that currently includes nickel,
manganese, zinc, cadmium, thallium, copper, cobalt and
arsenic.
 Hyperaccumulation may have applications in mining in
the future.
Natural Capital Degradation
Extracting, Processing, and Using Nonrenewable Mineral and Energy Resources
Steps
Environmental effects
Mining
Disturbed land; mining
accidents; health hazards,
mine waste dumping, oil
spills and blowouts; noise;
ugliness; heat
Exploration,
extraction
Processing
Use
Solid wastes; radioactive
material; air, water, and
soil pollution; noise;
safety and health
hazards; ugliness; heat
Transportation or
transmission to
individual user,
eventual use, and
discarding
Noise; ugliness; thermal
water pollution; pollution
of air, water, and soil;
solid and radioactive
wastes; safety and health
hazards; heat
Transportation,
purification,
manufacturing
Fig. 15-10, p. 344
Mining Waste



Subsidence is a phenomenon where the surface
collapses directly above a subsurface mine.
Spoils are the unwanted rock and other waste left
over after mining either on the surface or
subsurface
Tailings are the materials left over after the
process of separating the valuable fraction from the
worthless fraction of an ore.
What to do with the waste

Incorporate the mine waste into
 Concrete
for buildings
 Backfill for roads
 Extraction of other minerals
ENVIRONMENTAL EFFECTS OF USING
MINERAL RESOURCES

The extraction, processing, and use of mineral resources
has a large environmental impact.
Figure 15-9
SUPPLIES OF MINERAL RESOURCES


The future supply of a resource depends on its
affordable supply and how rapidly that supply is used.
A rising price for a scarce mineral resource can increase
supplies and encourage more efficient use.
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 15-16
SUPPLIES OF MINERAL RESOURCES


New technologies can increase the mining of low-grade
ores at affordable prices, but harmful environmental
effects can limit this approach.
Most minerals in seawater and on the deep ocean floor
cost too much to extract, and there are squabbles over
who owns them.
Getting More Minerals from the
Ocean

Hydrothermal deposits
form when mineral-rich
superheated water
shoots out of vents in
solidified magma on
the ocean floor.
Figure 15-17
USING MINERAL RESOURCES MORE
SUSTAINABLY


Scientists and engineers are developing new types
of materials as substitutes for many metals.
Recycling valuable and scarce metals saves money
and has a lower environmental impact then mining
and extracting them from their ores.
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.
Fig. 15-18, p. 351
Controls

Surface Mining Control and Reclamation Act of
1977: regulates active coal mines and reclaims
abandoned mines
 Standards
of Performance.
 Permitting.
 Bonding.
 Inspection and Enforcement.
 Land Restrictions.
SMCRA

SMCRA and its implementing regulations set
environmental standards that mines must
follow while operating, and achieve when
reclaiming mined land.
Requirements
SMCRA requires
that companies obtain permits before conducting surface mining. Permit
applications must describe what the premining environmental conditions and land use are,
what the proposed mining and reclamation will be, how the mine will meet the SMCRA
performance standards, and how the land will be used after reclamation is complete. This
information is intended to help the government determine whether to allow the mine and set
requirements in the permit that will protect the environment.
Bonding.
SMCRA requires that mining companies post a bond sufficient to cover the cost
of reclaiming the site. This is meant to ensure that the mining site will be reclaimed even if
the company goes out of business or fails to clean up the land for some other reason. The
bond is not released until the mining site has been fully reclaimed and the government has
(after five years in the East and ten years in the West) found the that the reclamation was
successful.
Inspection
and Enforcement. SMCRA gives government regulators the authority to
inspect mining operations, and to punish companies that violate SMCRA or an equivalent
state statute. Inspectors can issue "notices of violation," which require operators to correct
problems within a certain amount of time; levy fines; or order that mining cease.
Land
Restrictions. SMCRA prohibits surface mining altogether on certain lands, such as
in National Parks and wilderness areas. It also allows citizens to challenge proposed surface
mining operations on the ground that they will cause too much environmental harm.
Case Study:
The Ecoindustrial Revolution


Growing signs point to an ecoindustrial revolution
taking place over the next 50 years.
The goal is to redesign industrial manufacturing
processes to mimic how nature deals with wastes.
 Industries
can interact in complex resource exchange
webs in which wastes from manufacturer become raw
materials for another.
Case Study:
The Ecoindustrial Revolution
Figure 15-19